California

Polytechnic State University

TAGA2012–2013

Copyright © 2013 California Polytechnic State University, San Luis Obispo, Technical Association of Graphic Arts, Student Chapter

First Published in the United States of America by Cal Poly TAGA Student Chapter One Grand Avenue San Luis Obispo, CA 93407

Printed at California Polytechnic State University, San Luis Obispo

All rights reserved. All material in this book has been compiled with the knowledge and prior consent of those concerned, but is published without responsibility for errors or omissions. Nothing in this publication shall be reproduced without the expressed written consent of the authors and editors. Every effort has been made to insure that credits accurately comply with information supplied. We apologize for any inaccuracies that may have occurred.

Contents

President’s Message VSharon Hart

Effects of Optical Brightening Agents on Color Reproduction in Digital Printing 1Jaimie Garrison and Sandra Chaikovsky

Improving the Wettability of Inks and Substrates for Gravure Print 21Paige Cornelison

Design and Production Aspects of an Electroluminescent 37 Veronica Kopp

The True Value of Value-Added Services 59 Noemi Garcia

The Exploration of Gravure in Photovoltaic Process 81Rosie Bubb

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President’s Message

It is my honor to introduce to you, Cal Poly’s 2013 TAGA Research Journal. This year, our focus was to create a professionally designed and aesthetically pleasing technical journal with a few creative twists.

The first exciting aspect to our journal is our personalized college LED bookmark, which demonstrates the merging of print and electronic technology. Recently, our Graphic Communication Department has been researching and practicing with LED’s and other print-ed electronic technology. We wanted to represent this new development by creating our LED bookmark. Another creative aspect to the bookmark is the positioning of the LED’s. The first LED lights up in Portland, Oregon (the location of this year’s annual TAGA conference), while the second represents a particular college attending the conference. This provides an interactive personalized aspect to our journal.

Another part of our journal is the vellum paper. The vellum paper provides a unique separation for each student’s written technical paper. It also gives a textural element to the journal design. While the title of each technical paper was printed on vellum paper, the rest of the journal was printed on 100# McCoy Indigo Silk Text, which was generously donated by SAPPI Fine Paper.

I would like to thank all the companies who donated the materials necessary to produce our TAGA journal and also the Graphic Communication faculty and staff for providing their time and sup-port to the journal. With everyone’s support we were able to bring our creative ideas to a reality. Furthermore, I would like to thank all the TAGA members who helped produce this fantastic jour-nal. Everyone worked very hard, showing their passion and commitment to the print industry and the TAGA association. It was an enriching experience to work together as a team. Finally, I hope you

Effects of Optical Brightening Agents

on Color Reproduction

in Digital Printing

Jaimie Garrison & Sandra Chaikovsky

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Abstract

In this study the effects of optical brightening agents (OBAs) on color reproduction in digital toner-based printing are explored. Through the comparison of two distinct substrates with different levels of OBAs, notable differences in the reflectance of blue light in the visible light spectrum are ana-lyzed among light sources Illuminant A, D50, and D65. Fluorescence occurs in OBA paper under light with a UV component; between D65 and Illuminant A light sources there is a distinct differ-ence in fluorescing effect of the sample substrates. Color discrepancy as a result of OBAs is analyzed between D50 and Illuminant A light sources. For toner-based digital printing, greater difference in color occurs between light sources when there is a lower percent coverage of ink on the paper. Though most color discrepancy is notable, color-matching issues in the digital environment as a result of OBAs in paper may not be a chief concern unless a press is not calibrated or if substrates are drastically different in OBA levels.

Introduction

Optical brightening agents (OBAs), or fluorescent whitening agents (FWAs), are chemicals added to papers and plastics to increase the blue light reflectance, which in turn, increases the perceived whiteness of the material. “A ‘bluer’ white is perceived as ‘cleaner’, but a white mate-

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rial that has aged or become dirty appears to be yellow. As a result, OBAs are commonly added to white fabrics and other white materials enhance their appearance [2].

Spectrodensitometers traditionally use an incandescent illuminant to measure the differences in color of a printed product. As a result, no UV light reflectance occurs, and the effects of OBAs on perceived color remain unknown [8]. This creates a problem when using the mea-surement to match a defined color standard or when matching color across different substrates. Measurements taken using a standard spectrodensitometer may indicate a match between the printed piece’s color values and a defined standard or proof, but when viewed by the human eye under UV component lighting, they may not match.

In 2011, Konica Minolta (KM) introduced a spectrodensitometer that accurately evaluates color, including the effect of OBAs, because it illuminates the sample using an LED illuminant that replicates D50 lighting conditions. The D50 illuminant includes a UV light component, causes the OBAs to reflect light in the blue spectrum, and therefore the result is captured in the spectral reflectance curve. The FD-7 is capable of taking multiple measurements with dif-ferent illuminants and recording the different reflectance values in a table, which can be created graphically in Excel.

The purpose of this study is to compare the affects of OBAs on the perceived and numerical differences in paper brightness, and to highlight the need for more accurate color manage-ment across different substrates due to OBAs. Using the KM FD-7 for numerical analysis, this study examined the effect of OBAs on perceived brightness measured under ISO 13655 Measurement Condition M1 standards with a UV illuminant.

Literature Review

Optical Brightening Agents

Optical brightening agents (OBAs) are chemicals added to paper during the papermaking process to increase the brightness of paper. OBAs, also known as fluorescent whitening agents

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(FWAs) when used in textiles, increase an object’s reflectance of blue light under UV light, such as D65 lighting. Adding varying levels of OBAs to different papers may result in a prob-lem: while the perceived color in sunlight or D65 lighting reflects more blue with increased OBAs, white papers with different levels of OBAs will be perceived differently and will read

differently under a standard spectrodensitometer. “When the paper contains OBAs, the mea-surement of printed color is unpredictable, particularly in the highlight and mid-tones; and matching proof and press is problematic” [12].

OBAs in paper convert the invisible UV light (shown in Figure 2.1) into the blue range of visible light, increasing the perceived optical brightness of the paper. When measured under a UV light source, OBAs cause light that is absorbed in the 300 to 400 nanometer range to be reflected back as blue light at a wavelength of up to 460 nanometers [3]. Standard spec-trodensitometers are UV-cut, which results in different measurements when taken under UV and non-UV lighting conditions. Newer spectrodensitometers, such as the KM FD-7 offer measurement illuminants that mimic spectral illuminant standards, such as D50 and D65. They allow more accurate color measurements for different light sources, reducing metameric color matching frustrations. “Because the amount of OBA fluorescence is directly related to the amount of energy absorbed by the fluorescent molecule, a UV-enhanced spectrophotom-

Figure 2.1 – The Electromagnetic Spectrum [7]

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eter…must have a light source that emits the right amount of ultra-violet light—typical of normal daylight, which standard bodies have agreed to be CIE Illuminant D65” [2]. This new technology helps combat metamerism as well, keeping color in mind with the different light reflectance measurements.

Metamerism

Metamerism is the effect light has on the perception of color. For example, the lighting in the department store is different from the natural outdoor light. Metamerism is more likely to oc-cur in objects with OBAs because they reflect UV light.

When using two different light sources, one with a UV component and one without, illumi-nant metamerism is because of the increased blue light under one light source versus the other, especially when fluorescing occurs. New advances in color management technologies, such as X-Rite’s i1Profiler, help reduce the impact of metamerism for print and color matching. “i1Profiler also includes X-Rite’s groundbreaking Optical Brightener Correction technology (OBC)...[which] can effectively and precisely compensate for color shifts in the ICC output profiles typically caused by OBAs in papers and other printing substrates. This results in prints with an improved visual match and reduces undesirable colorcasts caused by the brighten-ing agents” [10]. Recent spectrodensitometer technologies help with color matching customer specifications and viewing conditions so that metamerism is addressed.

CIE Standard Illuminants

The International Commission of Illumination (CIE) has established different standard light-ing conditions, used to define and compare environments in which to make different mea-surements. CIE standard illuminant D50 of 5000 Kelvin is specified as the standard lighting environment for pressroom light booths [11]. Spectrodensitometers used to use Illuminant A, at 2856 Kelvin to make color measurements, until the effects of OBAs in paper were better understood. This is because, if one of two prints that match under Illuminant A had more

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OBAs in the paper, fluorescing would not be seen because the light source does not contain a UV component. Once the prints are viewed in any other environment with a light source con-taining UV, the substrate with more OBAs would fluoresce and appear bluer. Thus, Illuminant D50 is the preferred standard for measuring and viewing environments

Measurement Conditions

In 2009, the ISO developed standardized measurement conditions for printed material called the M series, which defined standard illuminants for different situations, “to minimize mea-surement variability, and to provide a way to communicate the illumination source used for measurement” [1]. M0 is the current industry standard and “the illuminant source that most closely matches standard Illuminant A” although it ignores the effects of OBAs [6].

However, the process of conversion to a matching color in D50 standard is where M0 can go wrong, which brings about the Source Independence Model of conversion that assumes if the source is placed in a different illuminant environment, the intensity of the viewing illuminant and the sample reflectivity at each wavelength can simply be multiplied to compute the spec-trum of the light emitted by the sample [4]. However, the principle behind the OBAs is that they absorb UV light and reflect it back in the blue range of the visible spectrum. This discrep-ancy creates “serious challenges for people trying to measure and manage color consistency in a variety of workflows,” [1]. Therefore, according to ISO 13655, “M0 is not recommended for use when measured sheets exhibit fluorescence” [1].

According to the ICC the, “ISO 13655 specifies how color measurements and calculations for use in Graphic Technology are to be conducted, and specifically calls for a D50 illuminant for accurate measurement” [5]. Though light booth standards in the pressroom matched D50, the illuminant in M0 reflectance measurement devices did not. Because of the issues with the M0 standard, the M1 standard was created, which, specifies that the light source must match D50, in order to reduce variation in measurement caused by fluorescence of the substrate [9]. This way, measurements on different substrates will have to match based on the light reflected from both visible and UV inci-

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dent light. Defining and controlling the UV component of the illumination source is the only way to effectively manage color on OBA-enhanced substrates. “When viewing paper containing fluores-cent whitening/brightening agents, the illumination must have a suitable form, must be continuous (energy balanced on all spectral lines), and must contain a sufficient amount of UV radiation to excite the fluorescent agent” in order to meet M1 specifications [11].

There are two other standards that are used less often, because they only apply to standardized communication of color for specific situations. The M2 standard excludes any UV filter or UV-cut. For an M2 standard illuminant, “spectral power distribution of the specimen illumination must be provided in the wavelength range from 420 nm to at least 700 nm and have no sub-stantial radiation power in the wavelength range below 400 nm,” the region in which UV light is transmitted [6]. M2 is useful when the potential effects of UV light on the substrate are to be purposefully ignored, because “to be able to measure the FWA in the paper, the instrument has to be able to trigger fluorescence, which it cannot do if it is fitted with a UV filter, or uses a light source that emits no UV (e.g. a white LED)” [3]. Another standard is M3, which includes a “linear polarizer in the influx and efflux portions of the optical path with tier principal axes of polarization in the orthogonal or ‘crossed’ orientation” [6].

Methodology Overview

The purpose of this study is to compare the effects of OBAs on the spectral reflec-tance of colors printed on two different sample substrates printed on the Konica Minolta C5000 digital toner press. Using the Konica Minolta FD-7, L*a*b* were measured and spectral reflectance values of paper and print samples when illuminated with light source D65, and light sources

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matching the standards M0 (A) and M1 (D50) were plotted. Targets measured on the samples provided reflectance results for CMYK and process color overprints, RBG, at different percent ink coverage ranging from 5% to 100%. The test sheet included G7 P2P targets, gray balance targets to check visual color balance, and one color logos to survey the effect on brand colors (Figure 3.1). Measurements were captured digitally using the FD-7 software for comparison numerically and graphically.

Paper Samples

Sample 1 was 100# Gloss Cover Futura Laser paper from New Page with 96 Brightness. Sample 2 was 80# Text Kelly Digital Coated Paper from Kelly Paper with 91 Brightness. The samples’ brightness levels were significantly different to emphasize the impact of different OBA levels.

Hypothesis

While both samples appear bright white, numerical and graphical analysis may reveal significant differences in UV reflectance between the samples. Sample 1 should have a higher difference in reflectance (ΔE2000 or ΔE00) between samples illuminated with UV and non-UV component light sources D50 and A than Sample 2. This reflectance difference under UV component light sources is impacted by the level of OBAs added to the substrates to augment brightness by increas-ing the fluorescence of the paper. The human eye starts to distinguish differences in perceived color at a ΔE00 of 1. Results in this study are isolated from factors such as, lack of press calibration and natural variation, which would increase the ΔE00.

According to ISO 13655 measurement standard, the qualification of each substrate as fluores-cent is determined by the ΔE00 between the Illuminant A and D65 L*a*b* values. This study proposes that a ΔE00 between light sources of greater than 0.5 reflectance is significant enough to assume the paper is fluorescing because of OBAs not natural variation in the measurement process. If this hypothesis proves true, this may confirm that Sample 1 fluoresces more than Sample 2 as result of OBAs.

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Because contract and press proofs are viewed under D50 viewing conditions, yet are often measured numerically under Illuminant A, the ΔE00 between Illuminants A and D50 were compared to prove the difference in fluorescing capability is significant enough to affect color perception for the print customer.

Methods

Both samples were printed on a Konica Minolta C5000 with multiple ink coverage test tar-gets, images, brand color logos, and G7 test targets. A GRACoL 2006 color profile was built using the EFI Fiery Color Profiler Suite by printing and measuring an ECI2000 target on each sample to obtain balanced grays. This allowed for the focus in any visual color shift to be directly related to the substrate instead of color cast issues.

Each sample was measured with the KM FD-7, which measures the reflectance of the paper using A, D50, and D65 light sources. The 25% and 100% coverage color patches for CMYK and the process color overprints RGB were measured and analyzed. The FD-7 device was used with the FD-7 DemoApp to capture spectral and L*a*b* data with the specified light sources. Results were graphically plotted and ΔE00s calculated in Excel.

Results

Delta-E 2000

ΔE00 (also ΔE2000) data were calculated using L*a*b* data. According to ISO 13655-2009 indicates the amount of OBAs in the substrate and is reflected in the ΔE00 between D65 and A, whether or not the substrate fluoresces.

LA aA bA LD65 aD65 bD65 ΔE00

Sample 1 Futura 95.96 1.21 -4.89 96.82 1.09 -9.27 3.4322Sample 2 Kelly 94.14 0.49 -3.4 94.49 0.76 -6.22 2.3452

Table 4.1 – Spectral Reflectance data and ΔE00 distribution between D65 and A for Samples (No Ink)

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Sample 1 has a greater ΔE00 value than Sample 2 by 1.1. Under the presumption that a ΔE00 greater than 0.5 proves fluorescing caused by OBAs, both substrates are fluorescing. Sample 1 is fluorescing more than Sample 2, which is a result of color discrepancy when viewed under different light sources as a result of OBAs in the paper.

Difference in color between D50 and Illuminant A light sources is relevant because of the discrepancy between the application of D50 and A.

Sample 1 Futura ΔE00 Sample 2 Futura ΔE00Black 25 1.6049 Black 25 0.845

Black 100 0 Black 100 0

Cyan 25 1.0108 Cyan 25 0.5207Cyan 100 0.3155 Cyan 100 0.1202

Magenta 25 1.2751 Magenta 25 0.6279Magenta 100 0.6618 Magenta 100 0.3087

Yellow 25 1.0671 Yellow 25 0.7859Yellow 100 0.2654 Yellow 100 0.0681

Red 25 0.8987 Red 25 0.553Red 100 0.3648 Red 100 0.1682

Green 25 1.0023 Green 25 0.5079Green 100 0.1385 Green 100 0.0409

Blue 25 1.142 Blue 25 0.496Blue 100 0.2323 Blue 100 0.071

Table 4. 2 – Spectral reflectance calculated as ΔE00 distribution between D65 and A for Samples 1 and 2 by color and

percent coverage (both 25% and 100%)

Table 4.2 shows ΔE00 data for both samples at different percent ink coverage for each process color or process color overprint. For Sample 1 and 2, each process color and process color

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overprint has a higher ΔE00 between Illuminant A and D50 in the 25% coverage area than the 100%. At 25% coverage for Sample 1 and 2 black had the highest ΔE00 value, while red had the lowest for Sample 1 and blue for Sample 2. At 100% coverage for Sample 1 and 2, magenta had the highest ΔE00 value and black had the lowest.

Sample 1 Futura Difference in ΔE00 Sample Difference in ΔE00Black 1.6049 Black 0.845Cyan 0.6953 Cyan 0.4005Magenta 0.6133 Magenta 0.3192Yellow 0.8017 Yellow 0.7178

Red 0.5339 Red 0.3848Green 0.8638 Green 0.467

Blue 0.9097 Blue 0.425

Table 4.3 – Difference in ΔE00 between 25 and 100 percent coverage between D65 and Illuminant A

Because black had the lowest ΔE00 at 100% coverage but the highest ΔE00 value at 25% coverage, this resulted in the large difference in ΔE00 for black in both samples (Figure 3). This means that as more ink was applied to the paper and percent coverage was increased, the amount of light reflected through the halftone screening was reduced and the impact of the OBAs decreased to a minimal level with the higher percent coverage.

Spectral Data

Spectral data is presented in graphical form to show the stratification of spectral reflectance for Illuminants A, D50, and D65 for each combination of substrate, color, and percent coverage.

Substrate

Spectral data of the three types of illuminants for both samples shows that the high-est reflectance in the visible spectrum of light occurs in the blue part of the spectrum

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under D65 lighting due to the addition of OBAs to the paper. The lowest reflectance occurs under Illuminant A. Comparing the two samples, Sample 1 has a higher bright-ness value, exhibits higher reflectance values in the blue part of the spectrum because of the higher amount of OBAs. This result impacts the measurement and appearance of process and process overprint colors under different light sources, particularly on a screen with low percentage of ink coverage.

Process Cyan

Figure 4.1 – Spectral Reflectance data of Sample 1 Substrate (No ink)

Figure 4.2 – Spectral Reflectance data of Sample 2 Substrate (No ink)

Figure 4.3 – Spectral Reflectance data of Sample 1 Substrate with cyan ink at 25% Coverage

Figure 4.4 – Spectral Reflectance data of Sample 2 Substrate with cyan ink at 25% Coverage

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Illuminant D65 had the highest reflectance in the blue part of the spectrum for both samples at 25% cyan coverage. The stratification in the blue part of the spectrum is most notable on Sample 1, which contains more OBAs than Sample 2. Outside of the blue part of the spec-trum, the difference in reflectance between light sources is minimal, supporting the idea that the OBAs are the source for the change in reflectance values.

Process Magenta

For both samples, the greatest change is in blue part of the spectrum for magenta ink at 25% coverage. The highest reflectance for magenta in Sample 1 occurs under the D65 light source, whereas in Sample 2 the peak in the reflectance curve occurs in the red part of the spectrum. The decrease in the green reflectance is because magenta absorbs green light.

Process Yellow

For yellow at 25% coverage on Sample 1, D65 reflects more in the blue part of the visible spectrum, however, when approaching the transition between the green and red part of the spectrum, D50 reflects more light than D65. This data may be skewed, because the other color’s graph did not behave this way, including the same ink on the other substrate. Also, the very low D50 reflectance at the beginning of the spectrum was not expected. Sample 2 shows

Figure 4.5 – Spectral Reflectance data of Sample 1 Substrate with magenta ink at 25% Coverage

Figure 4.6 – Spectral Reflectance data of Sample 2 Substrate with magenta ink at 25% Coverage

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Figure 4.7 – Spectral Reflectance data of Sample 1 Substrate with yellow ink at 25% Coverage

Figure 4.8 – Spectral Reflectance data of Sample 2 Substrate with yellow ink at 25%

less stratification in the spectrum than Sample 1, with D65 lighting providing the greatest dif-ference in reflectance values in the blue part of the spectrum, but the green to red portion of the spectrum still reflected the most, because yellow ink absorbs blue light.

Process Overprint Red

The reflectance values of both samples are relatively consistent, except in the blue portion of the spectrum. Sample 1 features greater stratification between reflectance values under the dif-ferent illuminants than Sample 2, however both have the highest reflectance values occuring under the D65 light source. The highest overall reflectance occurs in the red part, which is to be expected because this is what makes the color appear red.

Figure 4.9 – Spectral Reflectance data of Sample 1 Substrate with Process Overprint red at 25%

Figure 4.10 – Spectral Reflectance data of Sample 2 Substrate with Process Overprint red at 25%

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Process Overprint Blue

Comparing the two samples, Sample 1 exhibits greater stratification in the blue part of the spectrum than Sample 2 due to the greater presence of OBAs in Sample 1. Both samples’ great-est reflectance occurs in the blue part of the spectrum under the D65 light source.

Process Overprint Green

The greatest reflectance for both samples occurs in the green portion and the greatest stratifica-tion in reflectance values occurs in the blue portion. Under the D65 light source, both samples fluoresce and reflect more blue light. Overall the reflectance values are relatively stable.

Figure 4.11 – Spectral Reflectance data of Sample 1 Substrate with Process Overprint blue at 25%

Figure 4.12 – Spectral Reflectance data of Sample 2 Substrate with Process Overprint blue at 25%

Figure 4.13 – Spectral Reflectance data of Sample 1 Substrate with Process Overprint green at 25%

Figure 4.14 – Spectral Reflectance data of Sample 2 Substrate with Process Overprint green at 25%

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Conclusion

Brightness values affect reflectance because of the amount of OBAs in paper. Increasing the amount OBAs, increases the fluorescence, and therefore, the UV reflectance of the substrate. In this study, the sample images appeared similar under visual comparison due to G7 meth-odology used. However, the impact of increased OBAs still created a quantitative difference in the ΔE00 reflectance values between Illuminant A and D50.

The ΔE00 of 3.4322 between Illuminants A and D65 in Sample 1 and of 2.3452 in Sample 2 reveals that both substrates fluoresce according to ISO 13655, because both ΔE00 measurements are higher than .5. Sample 1 had a greater ΔE00 than Sample 2, meaning it fluoresces more and is a brighter paper. This is consistent with Sample 1’s higher brightness number and with support of ΔE00 findings, means it contains more OBAs than Sample 2. Comparing Figures 4.1 & 4.2 shows the substrate with more OBAs will have a greater variability in reflectance values between light sources, causing discrepancies when measured or viewed under different light sources. Because Sample 1 will appear brighter under UV component D50 lighting, colors may appear different between substrates under the same and different light sources. Because D50 and A light sources are commonly used in standard light booths and spectrodensitometer tools respectively, a ΔE00 differ-ence between these light sources is a of concern with color matching.

The 25% coverage areas for each color on both substrates had higher ΔE00 results than the 100% coverage areas. In fact, the substrate without ink had the highest ΔE00 for Sample 1 (0.9332) and the second highest ΔE00 for Sample 2 (1.4134). The greater the ink coverage on high OBA substrates, the less the spectral reflectance under different illuminants. This means that profile adjustments for accurate color reproduction cannot simply be made based on the ink color and substrate, but must also consider the coverage percentage.

It was initially assumed that the yellow ink would have greater ΔE00 between light sources because yellow is blue’s complimentary color. However, the data disproves this assumption. On

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Sample 1, the yellow 25% ΔE00 was 1.0671, higher than cyan, but lower than black, magenta, and the substrate itself. However, yellow had a higher difference between the 25% and 100% ΔE00 than cyan or magenta (0.8017), though lower than black, reinforcing the fact that the unprinted substrate fluoresces enough to influence the overall perceived color of the area. On Sample 2, the difference between yellow’s 25% and 100% ΔE00 was 0.7178, second highest after black. This is because the 100% black on both substrates reflects very little light leading to no ΔE00 between light sources.

Yellow was least affected by the fluorescence, but was most affected (except for black) com-pared to its solid area counterpart. Additionally, the ΔE00 values were determined from the L*a*b* values measured, not from spectral data specific to the blue region. Further study is needed to determine if specific colors are more influenced by OBAs substrates under different illuminants.

Red, green, and blue had lower ΔE00 measurements than CMYK. Among Sample 1 measure-ments, red 25% had the lowest ΔE00 at 0.8987, while blue 25% had the lowest for Sample 2, at 0.4960, because the layering multiple colors can muddy the effect of reflectance.

Overall, the majority of the ΔE00 measurements were under 1, with some slightly over, but none reaching 2. The highest ΔE00 for both substrates was black 25%, at 1.6049 for Sample 1 and 0.845 for Sample 2. Therefore, when measuring the effect on color may not vary drasti-cally when different light sources are used. However, when compounded with natural variation or other contributing factors to an increased ΔE00, this could create a problem when it comes to color matching specifications of a customer between press and proof.

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Works Cited[1] Cheydleur, R., & O’Connor, K. (2011). The M factor…what does it mean? X-Rite Incorporated. 1-3.

[2] Datacolor. (2012). UV calibration and whiteness FAQs. Datacolor. Retried from http://knowledgebase.data-color.com/admin/attachments/uv_calibration_and_whiteness_faqs15.pdf

[3] Gill, Graeme. (2011). Fluorescent Whitener Additive Compensation (FWA Compensation). Argyll CMS. Retried from http://www.argyllcms.com/doc/FWA.html

[4] Gill, G. W., & Melbourne, C.P.L. (2011). A practical approach to measuring and modeling paper fluorescence for improved colorimetric characterization of printing processes. 1.

[5] International Color Consortium. (2004). ICC recommendations for color measurement. ICC. Retried from www.color.org/ICC_white_paper3measurement.pdf

[6] International Organization for Standardization. (2009). Graphic technology — spectral measure-ment and colorimetric computation for graphic arts images. ISO. Retried from http://www.iso.org/iso/catalogue_detail?csnumber=39877

[7] Irvine, James. (2011). Topic 5 What are the uses and hazards of waves that form the Electromagnetic Spectrum?. Antonine Education Website. Retried from http://www.antonine-education.co.uk/physics_gcse/Unit_1/Topic_5/topic_5_what_are_the_uses_and_ha.htm

[8] Keif, M. (2012). Get out of the dark with optical brighteners? N/A. Word document.

[9] Konica Minolta. (2012). FD-7 / FD-5 Spectrodensitometers. Konica Minolta. Retried from http://www.koni-caminolta.com/instruments/products/color-measurement/spectrodensitometer/fd-7/index.html

[10] N/A. (2010). X-Rite introduces next generation color profiling. American Printer. Retried from http://search.proquest.com/docview/304730890/fulltext?source=fedsrch&accountid=10043

[11] Tappi. (2007). Light sources for evaluating papers including those containing fluorescent whitening agents. Tappi. Retried from ww.tappi.org/content/tag/sarg/t1212.pdf

[12] Wales, Trish. (2008). Making It White and Brighter. Graphic Arts Monthly, 80.7, 34.

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Improving the

Wettability of Inks and Substrates for

Gravure Print

Paige Cornelison

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Abstract

Gravure print is known for its abilities to perform well on a wide variety of substrates. But with such a great advantage comes a greater responsibility to account for possible issues – including wettability factors. This research paper examines what encompasses wettability and the various ways to maximize the benefits of surface energy and surface tension through tests and treat-ments for ink, substrates, and substrate coatings alike.

Introduction

What is the best way for a gravure plant to ensure that its substrate/ink wettability is at its absolute best? Research shows that there are two key steps to maintaining your best and most accurate wet-tability. The first is to have accurate test methods of both the ink and the substrate, so as to know exactly what you are working with before you even begin to print. The second is to use these test methods to be able to treat your substrates to an accurate level, so as to maximize the ability of your substrate and ink to cooperate together and produce a high-quality product. There are many meth-ods for both testing and treatment of substrates and inks; the goal of this paper is to use secondary research, which was built upon past classroom experience with this subject, in an analysis of each method to determine which ones are best for the gravure printing process.

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Understanding Wettability

AccuDyne describes wettability as “the ability of a substrate to anchor inks, coatings, or ad-hesives”. Within this definition are two key terms: surface energy and surface tension. Surface energy applies to the substrate. Surface tension strictly applies to the liquid, or in this case the ink. Surface tension is defined as “a measurement of surface energy… the property (due to molecular forces) by which all liquids through contraction of the surface tend to bring the contained volume onto a shape having the least surface area” [8]. This means that the higher the substrate’s surface energy is than the ink’s surface tension, the better its “wettability” will be. The more spreadable the ink is, the better. Three general rules for wettability are: 1) a substrate with high surface energy is easily wetted, 2) a liquid with low surface energy is good at wetting, and 3) wetting is ideal if the surface energy of the liquid is significantly less than the surface energy of the substrate [11].

It is relatively easy to visibly observe the difference between different inks with substantially different wettabilities. Inks with higher wettability appear much more spread out as opposed to those with lower wettabilities, which bead up on any given substrate. You can similarly tell the difference between two substrates’ wettabilities by observing the behavior of the same ink on each one. Wettability is measured in dynes per centimeter, or dyn/cm. You can use dynes to compare a substrates surface energy vs. ink’s surface tension. For example, some plastics need to be at 36 to 40 dynes/cm to have successful wettability; water based inks 40 to 44, coating applications 50 or more, and so on [10].

Figure 1. Differences in wettability

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This formula uses derivatives (the rate of change of a function), where y indicates the surface tension, W indicates surface energy, and A indicates surface area. This shows that tension and energy are directly proportional in relation to the surface energy of the substrate. “The work required to extend an interfacial area A by unit amount is termed interfacial energy W. It is proportional to the size of an additional unit and can be formulated as differential. The quotient Y is defined as inter-facial surface tension” [11]. (Interfacial means the two objects share a common boundary, or in this case where the ink is touching the paper). This formula is, in effect, used in all of the tests that are used to evaluate wettability.

How does wettability affect print quality? The straight answer is that the “wetter” the ink is and the more “wettable” a substrate is, the better outcome of quality your print job is going to have. This has to do with ink lay-down, sometimes referred to as ink “wet-out”. If an ink had no wetting (it was too thick) or it was “spreading” (too thin), or a substrate has too much (or not enough) absorption, it can lead to murky inks and blurred images. This is obviously far from ideal. It takes a perfect balance of ink and substrate to create the perfect images. Another important factor to consider in regards to wettability is that the amount of wettability needed is going to vary greatly between different inks and different substrates. For example, water has at least twice the amount of surface tension as most other liquids [11]. This means that water-based inks are going to require substrates with a much different surface energy level than that of solvent-based inks. In relation, the substrate is usually the only factor you can change – that is, treatment is only available to the substrate. Ink is not what is typically altered to reach the desired wettability levels, as it would most likely affect the image quality.

Methodology

There are several options as to the methodology for both testing and treatment of the wettability of both ink and substrates, and discovering how the derived numbers apply to the gravure print process.

Figure 2 Formula for surface tension (TEGO® 69)

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The contact angle method is used to determine the wettability factor between the ink and substrate. It is a widely used criterion and is well suited to evaluate how compatible the two are. As shown in Figure 4, each individual drop of liquid/ink is measured in relation to how it sits on the substrate. An angle is measured proportionately. In general, an ideal contact angle is less than 60 .̊ This signifies good surface wettability, and high surface energy. The contact angle is measured with a drop projection instrument that is attached to an angle-measuring device with a microscope and screen [1].

The contact angle method applies and expands upon the formula that was previously explained [11]. It incorporates what is called the Wenzel ratio, f, a cor-rection factor for the equation. This ratio compares the ideal surface conditions with its true surface conditions, helping a printer to understand how they need to adjust for the substrate at hand. The

article also explains that the higher the Wenzel ratio turns out to be, the greater the rough-ness of the substrate is. Also, the rougher the substrate is, the better the wettability. (This is an especially important consideration for gravure, because this process has a harder time

Figure 3. Wettability in terms of the contact angle of ink on a substrate

Figure 4. Wenzel ratio (TEGO® 72)

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printing well on rougher substrates, since it needs a very flat and even surface to transfer ink from it’s recessed cells.)

The next method for testing wettability was designed to examine only the substrate for it’s surface energy levels. The Dyne pen method is a very simple test method that consists of exactly what it sounds like; it is a pen used to find the dyne level of the substrate. There are generally a certain number of pens available that will give you positive results for a specific dyne level, usually ranging from about 30 to 60 dynes [8]. The pen is used to draw a few parallel lines across the substrate. If the solution drawn beads up within a couple of seconds, it is assumed that the surface energy is approximately the number of dynes as assigned to that specific pen. If not, you use the next dyne level and repeat the test, until you get the desired results [8].

This test method entails a few potential issues. First of all, it is not the most precise way to go about finding dyne levels. Every measurement will be rounded off to the nearest number. Also, the results are purely from the observations of the naked eye. It would be relatively easy to get different results, especially with different testers. The Sabreen Group’s Dyne Test demonstrated, “excessive solution will result in misreading”. Another problem is that the substrate cannot be at all contaminated before testing. Any particles of dirt, dust, or even fingerprints will invalidate results. The substrate must be perfectly pure as well. There is also the possibility of a chemical reaction occurring between the pen solu-tion and the substrate, which would also invalidate results. The solution is hazardous, and needs to be at room temperature with a specific and consistent humidity for it to work

Figure 5. Dyne pen test method

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accurately. In addition, it has about a 6-12 month shelf life, which is not very long if a printer uses a less broad variety of substrates and does not test them very often.

The du Noüy Ring Method is used to measure the surface tension of the coating that is ap-plied to a substrate. This method uses a ring made out of platinum-iridium, with handles, that is placed into a bucket of the liquid coating. As it is slowly withdrawn, a “lamella” is formed which “constitutes an increase in the surface area of the liquid”. They measure the surface tension of the liquid by determining the amount of force needed to pull the lamella up from the surface. It is done and calculated by a machine. It is important to note that this method only works with non-pigmented liquids; a pigment impairs the stability of a lamella so the surface tension values seem too low. Therefore, this test method would not work on inks themselves, only the coatings. One flaw that may be pre-sumed with this process is that it does not consider the substrate that is going to have the coating applied to it, and the specific substrate may have an influence on the wettability of the ink/coating combination. But, it does seem to derive results that can otherwise be relied upon when looking at which type of coating to choose for your desired print job.

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Treating Substrates for Improved Wettability

The most direct and effective way of improving wettability is to make a change to the substrate. This is done through what are called surface pretreatments, or simply treatments. There are three main types of surface treatments that each chemically alter the substrate, and each with a variety of differences that can be compared by a list of criterion.

The corona treatment uses oxidation to energize a substrate, or to raise its surface energy. The treatment is “a high frequency electric discharge towards a surface… the result from this is an improvement of the chemical connection (dyne/cm) between the molecules in the [substrate] and the applied media/liquid [ink]” [8]. This type of test is used on a variety of materials to im-prove wettability, and works just as effectively on paper and other substrates. Some problems it encounters, though, include the creation of an ozone gas that is often emitted, as well as some-times causing picking and blocking when it is printed on afterwards. It may also be considered a problem that the treatment affects the entire substrate as opposed to just the surface. It also cannot be used on any metallic-like material as well as other substrates like fluoropolymers or

Figure 7. Plastic material being treated with the corona method (tantec.com)

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polypropylenes [2]. The humidity can also have a negative effect on the treatment abilities.

The second treatment is a newer concept that is rapidly causing the fallout of the corona process. The plasma treatment forms a uniform layer of plasma bonded to the surface of the substrate, also via oxidation [9]. It is meant to reduce the contact angle of the liquid on the substrate. There are three sub-types of plasma treatments: cold gas, atmospheric, and grafting. Cold gas uses a vacuum to apply the treat-ment, atmospheric is the same without a vac-uum, and grafting plasma deposits a coating onto the substrate and changes the surface via polymerization. All three eliminate unstable molecules and clean the substrate surface (something corona treatments fail to do). The plasma has a long shelf life and works well on a very large gamut of substrates. It also works well with papers that are going to be run at high press speeds, something that the gravure process is very familiar to. There is usually no picking or blocking that occurs, and there are limited ozone emissions. It is also good at limiting pinholing, which is something else that gravure is used to experiencing. It is also a much faster process than corona. The one very limiting factor of this process is that it is far more costly than the corona treatment ever was, and ever will be. The plasma treatment seems to be the future of most substrate treatment types.

The third and final treatment for improving substrate wettability is called the flame treatment. It is very similar to the corona treatment in that it encourages oxidation of the substrate. The

Figure 8. Plasma treatment (smartgarmentpeople.com)

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main difference is that it uses an open flame as opposed to a corona discharge [9]. It has the lowest cost of all three treatments, and can lead to very high dyne levels in any substrate. It also has a high shelf life, is ozone free, and has no blocking/picking, or pinholing aftereffects. But flame treatments are not very popular because the process is very difficult to set up and control, and the open flame is simply not something most pressmen believe to be smart to have in a pressroom full of paper. In addition, whenever the flame treatment is used, it seems to be most effective on paperboard and thicker stocks, which are not generally the main substrates that gravure tends to make a lot of use of.

Results

It is very important to be able to conclusively decide what the best options are when you are choos-ing your consumables, and accuracy and ease of use are both essential to determining which test method is best suited for the needs of a printing plant. Testing is also an important avenue for be-ing able to closely treat your substrates to the best of your ability. After reviewing both the gravure process and the many different testing and treatment methods, it is feasible to come to a relative conclusion about which methods would be more successful in the gravure industry.

Test methods

When it comes to the dyne pen method, it is relatively obvious that the dyne pen is a much less complicated way of testing a substrate’s surface energy. It requires a very low amount of skill, as well as materials, to perform. But it ensues a wide range of variables that can easily influence the outcome of the test. When you are working with such a consistently high-quality process such as gravure, it is important to derive the most accurate results as possible, and be able to rely on more than just an “eye-ball” estimate of whether or not your substrate is at the level it is supposed to be. Additionally, this test does not determine the ink’s interaction with the sub-strate; it simply gives a general energy level of the substrate on it’s own. Overall, this method can be disproved based on its inability to achieve consistent, applicable, or reliable results.

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The du Noüy Ring Method sounds like a more fail-proof method to testing the coating of a substrate. But because this is the only thing it tests, it would be easy to receive results that are later influenced by other factors, such as the substrate itself and how that interacts with the ink. It may be argued that the coating serves as a barrier between the substrate and the ink and there would be no problems here. Yet, if you consider the fact that different substrates have different amounts of roughness that the coatings are contoured to it is easy to see how this test method can be disproved for guaranteeing the best outcome for the whole printing process.

The contact angle method is a relatively simple method to understand and test. It is also very scientifically and mathematically sound when it comes to comparing it’s results accurately and closely. It proves to be very useful specifically when it comes to testing both the substrate and ink for compatibility in a uniform and precise way. Although the price is moderately expensive since this method requires machine use, the precise accuracy along with it’s ability to measure both the ink and substrate together gives it good reason to be the best option for measuring wettability, perhaps for any print process.

Surface treatments

The flame treatment has some positive attributes that make it seem like it would be a reputable surface treatment method. But, because it has such a hazardous factor, not many people know how (or are willing to try) to use it. Especially for gravure, where the type of substrates that are used are not going to benefit greatly from the method that is primarily thick paperboard stocks, the flame treatment is a good solution in hindsight but does not quite fit the standard.

The corona treatment is a close second to the plasma treatment, but has too many factors that give it reason to fall short. It is true that it has a low cost, and that it is a method that people have been comfortable with for decades, but there are too many benefits from the plasma treat-ment to give corona another glimpse. Not to mention that gravure implements so many non-paper substrates that corona cannot accommodate for. It is true that there is a steep learning

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curve for the plasma treatment, but in a side-by-side comparison of the two, it is evident that plasma is overall the best investment a pressman can make in order to ensure higher quality press runs and quicker turnaround time to follow.

Conclusion

It is always essential for a printer to ensure the absolute highest quality in their products that they can achieve, and wettability is just as important as any other factor in the process. Although it seems there should be an obvious choice in both testing and treatment, it is true that the choice needs to be made specifically for the printing process at hand. Gravure’s process and substrates are going to be much different from that of flexography or lithography print-ing. For example, various substrates, such as foil, film, plastics, etc., are different from paper in surface energy, absorption and ink lay-down, and in turn there are different methods that need to be used to accommodate for them. It is also important to remember that these results are not at all absolute; there are always variables that every production plant needs to consider in order to pick the methods that cater to their needs and specifications, such as budgets and time factors. But it always starts with that simple concept of how a single drop of ink interacts with the surface of a sheet of paper.

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Works Cited[1] ASTM International. (2003). "Standard Test Method for Surface Wettability of Paper (Angle-of-Contact Method)." Shanghai Polymer Materials R&D Center. Retrieved from http://www.polymercenter.org/admin/up-file/20097101347550.pdf

[2] "Corona, Plasma, Flame ... How Do You Determine What's Right for You?" (2010). Pillar Technologies, Inc. Retrieved from http://www.pillartech.com/SurfaceTreatment/InTheNews/tabid/137/articleType/ArticleView/arti-cleId/35/Corona-Plasma-Flame-How-do-you-determine-whats-right-for-you.aspx

[3] Du Noüy ring. Digital image. Attension. Biolin Scientific. Web. 4 Mar. 2012. <http://www.attension.com/surface-tension>.

[4] Eisby, Frank. "Corona Treatment: Why Is It Necessary?" (n.d.). The Plastic's Network. WordPress. Retrieved from http://plasticsnetwork.files.wordpress.com/2007/12/corona-treatment.pdf

[5] Harris, James D., comp. "Chapter 16 - Gravure Nonpaper Substrates." Gravure: Process and Technology. Rochester, NY: Gravure Education Foundation, 2003. 479-518. Print.

[6] Nolan, Marc. "Flame Treatment - Corona's Poor Cousin?" Sherman Treaters. Pillar Technologies. Web. 1 Mar. 2012. <http://shermantreaters.co.uk/acrobat/flame.pdf>.

[7] Rong, Xioyang. Special Papers and Other Substrates. San Luis Obispo: Cal Poly State University, 2011. PPT.

[8] Sabreen, Scott. "Surface Wetting & Pretreatment Methods." (n.d.). Sabreen - Secondary Plastics Manufacturing. The Sabreen Group, Inc. Retrieved from http://www.sabreen.com/surface_wetting_pretreatment_methods.pdf

[9] Sanders, Elise M. "Plasma Substrate Treatment." (2009). GravurExchange. PLGA Global, Retrieved from http://www.gravurexchange.com/pdfs/GravurEzine-0904.pdf

[10] "Substrate Surface Energy Testing - Accu Dyne Test Procedure." (n.d.). ACCU DYNE TEST. Diversified Enterprises. Retrieved from http://www.accudynetest.com/qctest.html

[11] TEGO. (n.d.). "Substrate Wetting Additives." Technical Background. Evonik Industries. Retrieved from <http://www.tego.de/sites/dc/Downloadcenter/Evonik/Product/Tego/en/Technical-Background/substrate-wetting-additives.pdf>.

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DesigN and Production Aspects

of an Electroluminescent

Veronica Kopp

37

Abstract

The purpose of this study was to get a better understanding of the different ways printed circuits could be constructed and then implemented into creative, visual de-signs for printed electroluminescent displays. A variety of circuit design variables, such as area and length, were tested that will help create solutions for printed electronics.

This study tested different variables of circuit design, such as length of silver traces and the size of the image area, to help optimize ways to build a printed circuit. Then, findings were implemented into a segmented graphic display in order to analyze in-novative ways to utilize multiple displays in a small area. Results found that there are a variety of recommendations that can be considered when designing an electrolumi-nescent segment display. However, future testing can be done to develop wiring the power supply to the design.

Introduction

This research sought to answer two questions: First, how does the size of the image area, the length of silver trace lines, and the width of the silver trace lines affect the

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functionality in printed electroluminescent (EL) displays, and second, how can the different circuit design variables be implemented into a functional segmented design?

Literature Review

Screen printing is highly advantageous in the production of printed electronics due to its abil-ity to print on flexible films and its ability to create uniform ink films. However, the process must be monitored closely to ensure the functionality of the inks [16].

Printed electronics combines the use of functional insulators, semi-conductive, and conductive inks to produce flexible circuits, solar cells, and displays. In 2009 the printed electronics market was worth $2 billion, with an expected growth of $60 billion in the next ten years, according to IDTechEx [10]. EL displays can be used to create background displays, control panels, and consumer packaging.

EL displays can be made from organic or inorganic materials. EL displays consist of a layered structure with a front and rear conductive electrode with phosphor and dielectric layers in between [8]. The front conductive electrode is composed of a transparent film coated with Indium Tin Oxide (ITO), which acts as the substrate. Functional inks containing phosphor and dielectrics are printed onto the ITO to complete the printed circuit. The dielectric layer is an insulator layer that prevents arcing between conductive layers [16]. The inks in screen

printing must maintain certain viscosities and surface tensions to avoid problems, “such as drops that do not bond enough to conduct sufficiently, or an excessively rough surface that prevents the next functional layer from adhering” [18]. In order for the phosphor to emit light, either an alternative current (AC) or direct current (DC) can be applied. Lower voltages and frequencies are encouraged for longer life spans of the displays [8].

An understanding of circuits and electromagnetic waves are necessary for analyzing the perfor-mance of EL displays. When a power source is applied to the printed circuit, the silver ink is charged with a negative potential, while the rear electrode is charged with a positive potential.

39

In between the positive and negative charges is the dielectric, an insulating material, and when sandwiched between the rear electrode and the conductive silver ink, it creates a displacement current [10]. The displacement current comes from the electromagnetic field generated by the difference in potentials between the silver ink, and rear electrode. This current continuously moves through the phosphor in the circuit, causing it to emit light [10]. The intensity of the luminescence is determined by how much displacement current can travel through the silver trace to interact with the phosphor. This is determined by the resistance of the silver trace, which is affected by the resistivity of the ink, and the width of the silver ink [10].

Certain factors need to be created when designing segmented EL display. For example, silver trace lines should have enough room in between them so that an electrical charge won’t inter-fere with other parts of the segmented display. Also, the size and proximity of the common (front electrode) to the phosphor can help avoid short circuits. To control illuminating se-quences, circuits should be open at certain times when the phosphor should be off, and closed at other times, which is achieved with a series of relays.

Figure 2 —Example Build Sequence of an EL Display[16]

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Methodology

The purpose of this study was to determine if different variables of designing EL circuits have an impact on circuit performance.

Preliminary Testing

The preliminary test consisted of varying silver ink area sizes, the distance from the power sup-ply, the width of power lines, and isolating a common (Appendix A). The following procedure was used to conduct the preliminary testing:

1. Using Adobe Illustrator, construct a 7in x 10in test file. First, create a 50mm x 50mm square with a 1mm x 10mm power line and a 5mm x 5mm connector square. For the silver area test create a 10mm x 10mm square and a 100mm x100mm square, both with standard power lines. For the distance from the power source test, create a 1mm x 50mm square and a 1mm x 200mm square. For the width of the power line test, create a 0.5mm x 10mm square and a 2mm x 10mm square. All of the test squares share the same dielectric, phosphor, and are placed under one common. Finally, construct a standard test square with its own individual common. Output each layer as individual PDFs.

2. Next, prepare three 305tpi mesh count screens by degreasing and washing the phosphor screen. Coat the screen with a capillary film emulsion by RyoCap. Output the test files onto a transparency film and expose them onto the screens using a NuArc 3140 exposure unit with a 60 second vacuum and 60LTU.

3. Load the phosphor screen into the Automatic Screen Printer and apply the ink to the top of the screen. Print onto the ITO transparent film then run the film through the oven at 925 degrees for 60 seconds.

4. Repeat Steps 1-3 for the dielectric screen and the silver screen.

5. Test and record the functionality and conductivity of each segment.

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Implementing Results in a Segmented Display

After analyzing the procedure and resistances from the preliminary testing, a segmented circuit was designed to begin the preliminary findings. The test file combined nine individual dis-plays into one graphic design. The design was printed using 156 tpi screens and drying times between layers was increased (Appendix B). Requirements for the segmented display included being printed on a transparent ITO sheet and a concentric circle design.

Powering the Display

In order to control the sequence, the individual displays were illuminated and the printed ITO film was attached to relays on a breadboard, an Arduino Board, and a 5A power source. The control test started with a function generator that supplied 2V to the breadboard controlled by the relays. The Arduino Board, supplied by 12V through a USB connection to a computer, was wired to the relays. All the relays ground were linked together and sent back to the Arduino Board. The relays would allow the 2V to pass only when the Arduino Board sent the output to high, allowing the LEDs to be illuminated. The display was placed in a picture frame and code was written to control the lighting sequence. The design was evaluated on performance and measurements were collected using a multimeter.

Results and Discussion

Preliminary Testing

The test design was created to three different aspects: area, length and width. The area test was used to determine how the size of an image affects the ability to be illuminated. The length test was to test if the distance from the power source affects the performance of a display.

The width test was to find if the width of the silver trace line from the lead to the

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Width Test: 0.5mm x10mm

Width Test: 2 mm x10mm

Length Test: 200mm long

Length Test: 50mm long

Area Test: 100mm x100mm

Standard Test: 50x50 square10mm x 1mm lengthStandard with individual

common

Area Test: 10mm x 10mm

Silver Trace - Front Electrode

Transparent Coductor

Silver Trace -

Front Electrode

image has an affect on performance. Figure 3 includes labels of all test segments and blue areas represent the areas of the test that were functional.

When measured, the resistance decreased the further away the leads were from the common lead. In the length test, the phosphor in the silver traces would gradually illuminate more of the phosphor on the silver ink line the longer the leads of the power source were held on the test. Also, the traces illuminated two segments when sharing a common dielectric. Beneficial factors to include: drying time between printing layers, changing the screen mesh, and the issue of a common dielectric. Although the preliminary test did not produce the desired test results, valuable conclusions were drawn, which helped develope the graphics test.

Figure 3 — Preliminary Test Results

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implementing Results in a Segmented Display

A graphic design was developed to included multiple circuits. An ITO sheet acted as a front electrode in the stacking process, creating an electrical field wherever phosphor was layered. Due to the original design being concentric circles this left the issue of silver trace lines pass-ing through phosphor to supply power to inner circles. If a silver line crosses through an outer circle it would then light up both the inner and outer circles. A possible solution would be to create multiple dielectric layers, which would form a “bridge.”

Figure 4 — Issue with Concentric Circle Design

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To ensure a functional display some dis-plays were removed to create room for silver trace lines to pass through. Another solu-tion was to create arcs that would appear as circles when hidden behind another display or part of the non-electrical graphic shown in Figure 5. Changing a centrally located circle originally created room for the silver trace lines to supply power to circles farther away from the leads. This allowed for a way to hide the trace lines and a way to avoid coming into contact with unwanted phos-phor segments.

Integrating traditionally printed graph-ics with printed electronics played a key role in creating a segmented display without detracting from the graphic design. A separate graphics layer was placed on top of the printed circuits to hide the silver and dieletric layers in the design. On a strip of dielectric, silver trace lines travel up and down the film sheet connecting the leads to segments of the display that supply power toil-luminate the phosphor. In order to hide the dielectric and trace lines, a strip of black ink was incorporated into the de-

Arc Design

13mm Wide

13mm Wide

Area for traces

Figure 5 — Circuit Design Considerations; Green is the silver ink and yellow is the Dielectric ink

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sign (Figure 5). To keep the strip at minimum width, five traces stem from the top of the display and four stem from the bottom. Each line is 1mm wide and the top traces are 2mm apart and the bottom four traces are 3mm apart. The same design tactic was used to hide the dielectric and front electrode layers of the circuits. A black stroke was incorporated around the circles to hide the trace lines travel-ing to the individual segments.

Powering the Display

Another area of focus was developing a way to connect the wires from the power source to the ITO film. The major problem was that the wires had trouble staying attached and could not create the necessary connection needed for the display to light up. Tape was first used to adhere the 10 wires to the ITO (nine for each individual light and one for the common), but any movement of the film caused the wires to become dislodged or wouldn’t provide a solid connection. The next option was to solder the wires to the ITO film, however, this option was quickly dismissed because the melting temperature of the ITO is less than the tempera-ture required for the solder. Finally, the solution that worked was securing the wires to the ITO film with tape and then appling pressure to the wires by using a wooden stick. Also, the display was placed in a picture frame with the back of the frame adding pressure on the wires. The results

1

2

3

7

4

5

6

8

9

1 2 3 4 5

6 7 8 9

Figure 6 — Numbered Segment Display

46

proved to be sufficient, with the exception that Segment 3 didn’t light up. A possible cause couldbe that the wire was not securely attached before the pressure was secured to the ITO.

An additional decision on the construction of the graphic display was deciding how to power the display to illuminate all nine segments with equal brightness. Construction of the controls took place with nine relays connected in parallel between the power and the EL display. This was done through the use of a breadboard (Figure 7). Connections were made with wires soldered to the relays. These were linked to a common ground for the AC current, shown in black, and a common power source for 120V, shown in red. Also in red, is each of the wires connecting individual relays

to the 5V digital outputs in the Arduino Board. Wiring the displays in parallel proved to provide sufficient power to illuminate all nine displays using a 5A Backlight power source.

To illuminate the sections in the right order required control of the current using a passive matrix. The Arduino Board is provided a current from a 12V battery, which then sends out 5V signals to the relays. Once the particular relay receives 5V, it goes from open (off) to closed (on), allowing the current to pass through that line. Then, when the Board no longer sends the 5V, the relay opens and that sequence stops illuminating. Using a pas-sive matrix allowed for manipulation of the lighting sequence. A control test was done

Figure 7— Relay Design

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with a function generator that supplied 2V to the breadboard controlled by the relays. The relays would let the 2V pass only when the Arduino Board sent the output to high. However, they would not conduct when output was sent to low, as shown in the code below. Through the three relays, a small light sequence occurred, illuminating one of the LEDS in a one second interval and leaving them on for two seconds.

The EL display successfully light up 8 out of the 9 segments. The one failed segment was prob-ably due to a weak connection between the wire and the trace. After about a minute, heat from arcing occurred at the front electrode and the ITO began to burn, causing smoke on the glass

//First test relay code for three relays//assign relay numbers:const int relayOne = 0;const int relayTwo = 1;const int relayThree = 2;

void setup() { //initialize the relay as an output: pinMode(relayOne, OUTPUT); pinMode(relayTwo, OUTPUT); pinMode(relayThree, OUTPUT);}

void loop(){ digitalWrite(relayOne, HIGH); digitalWrite(relayThree, LOW); delay (1000); digitalWrite(relayOne, LOW); digitalWrite(relayTwo, HIGH); delay (1000); digitalWrite(relayTwo, LOW); digitalWrite(relayThree, HIGH); delay (1000); }

Figure 8—Complete Display with Graphic

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of the picture frame. This arcing could have been caused by pinholes in the dielectric layer, created during the printing process.

After producing a functional segmented EL display, multiple recommendations can be made for future circuit designs. Trace lines should be incorporated into the graphics without being too noticeable, especially if the background needs to be transparent. Another recommendation for trace lines is to not cross over phosphor areas in order to avoid illuminating unwanted seg-ments. Also, the travel distance of the trace should be kept short to provide less resistance. The 156 tpi screens seemed to produce better quality circuits than the 305 tpi screens, because a 156 tpi screens tend to produce less resistance in the silver trace lines. Lastly, a very important design consideration is to figure out how to securely fasten the wires to the ITO film while still making the display look presentable.

Figure 9 - The eight functioning segments illuminated.

1 2 4 5

6 987

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Conclusion

The intent of this study was to explore the design and production tactics for a segmented electroluminescent display and provide recommendations for the growing field of printed elec-tronics. The area of a display and the proximity of the common are all important variables to take into consideration when designing a segmented display. The preliminary test revealed problems with a universal dielectric housing multiple segments. Also, the preliminary test contributed to the design considerations of the graphic display in relation to silver trace lines. Results from the segmented display design provided a functional display that concluded in multiple recommendations for future experiments.

The findings and recommendations from this study can be used as a foundation for further studies such as finding a more efficient and secure way of attaching the wires to the ITO film. Also, ways to prevent arcing can be developed to solve the problem of potential burning of the ITO.

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[2] Author Unknown. (n.d.) “Billing & Payment = Understanding Tiered Rates.” Southern California Edison. Retrieved from http://www.sce.com/CustomerService/billing/tiered-rates/understanding-tiered-rates.htm

[3] Author Unknown. (n.d.) “Preventing Pollution in Screen Printing,” Missouri Department ofNatural Resources. Retrieved from http://dnr.mo.gov/pubs/pub459.pdf

[4] DuPont. (2006). “Datasheet for DuPont Luxprint.” DuPont de Nemours and Company, Retrieved from http://www.dupont.com/mcm.

[5] Fjelstad, Joseph. (2010). “Flexible Printed Electronics: Past, Present, and Future.” Industrial Specialty Printing. ST Media Group International. Retrieved from http:/ industrial-printing.net/content/flexible-printed-electronics-past-present-and-future?page=0,6.

[6] Ford, R and C. Coulston. (2007). Design for Electrical and Computer Engineers. McGraw-Hill. p. 37

[7] Hart, Jeffery, Stefanie Lenway, and Thomas Murtha (1999). “A History of Electroluminescent Displays.” Indiana University. Retrieved from http://www.indiana.edu/~hightech/fpd/papers/ELDs.html.

[8] Hino, Y., Yamazaki, M., Kajii, H., and Ohmori, Y. (2003). “Fabrication and characteristics of layered polymeric electroluminescent diodes by all wet-process for flexible display,”

Lasers and Electro-Optics Society. The 16th Annual Meeting of the IEEE, vol.2 pg. 535-536 Retrieved from http://ieeexplore.ieee.org.

[9] IEEE Std 1233. (1998) Edition, p. 4 (10/36), DOI: 10.1109/IEEESTD.1998.88826

[10] Iskander M. (1992). Electromagnetic Fields and Waves, Long Groce. Illinois: Waveland Press, Inc.

[11] Klimchuk, M and S. Krassovec. (2006). Packaging Design-Successful Product Branding from Concept to Shelf, John Wiley & Sons.

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[12] Krebs, Frederik, Mikkel Jorgensen, et al. (2009). “A Complete Process for Production of Flexible Large Area Polymer Solar Cells Entirely Using Screen Printing—First public demonstration.” Solar Energy Materials & Solar Cells. 422-441. Retrieved from <www.elsevier.com/locate/solmat>.

[13] Leurs, L. (n.d.). “Dot Gain,” Prepressure.com. Retrieved from http://www.prepressure.com/design/basics/dot_gain

[14] Nixon, Chris. (2012). “Printed Electroluminescent Display.” Retrieved from http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1174&context=eesp

[15] Numakura, Dominique. (2009). “Advanced Screen Printing - Practical Approaches forPrintable & Flexible Electronics.” Print.

[16] Ryonet. (2011). “What is Mesh/Thread Count?” Ryonet’s Help Desk & Screen Print Library.Retrieved from http://support.silkscreeningsupplies.com/entries/20451617-what-is-mesh-thread-count.

[17] Schofield Printing. (2011). What Is Screen Printing? Graphic. Retrieved from http://www.schoprint.com/screenprinting.html>.

[18] Schroeter, Klaus. (2007). “Printed-Electronics Technology Flexes Its Muscle.” EngineeringEssentials. 49-54. Print.

[19] Xie, Y. and S. Qin. (2011). “Principle and Application of Inorganic Electroluminescence andOrganic Electroluminescence,” International Conference on Electric Information andControl Engineering (ICEICE), p. 6027-6029 Retrieved from htt//ieeexplore.ieee.org.

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Appendix A - Preliminary Test Layers

Phosophor Layer

Dielectric Layer

Silver Layer with Labels

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Appendix b - Ink Layers for Graphic Test

Phosphor Silver Ink - Back Electrode

Dielectric

Silver Ink - Front Electrode

Graphic

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Appendix C - Display Layout

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Appendix D - Graphics Layer Cover Up

The Graphics Layer is used to cover the Silver (Back Electrode) and Dielectric Layers that would detract from the design appeal of the display. The Graphics Layer was printed separately and then placed on top of the display. Note the black borders to hide the other layers due to the transparent substrate requirement.

13 mm 13 mm

Graphics Layer Silver and Dielectric Layers

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The True Value of

Value-Added Services

in Digital Print

Noemi Garcia

59

Abstract

This study compares the success of five digital printers in California’s central coast based on whether they choose to charge for value-added services. It questions past re-search that shows digital printers who implement an additional fee for such services are more successful than digital printers who do not always bill the customer for the extra services. It focuses on determining the reasons behind each printer’s strategy through a questionnaire. The study concludes printers not charging are not necessarily losing money because they have found ways to eliminate non-value-adding steps in their value chain. Therefore success must be redefined other than building a competitive advantage by boosting sales and profit.

Chapter 1: Introduction

Statement of Problem

This study will answer the following question: why are there a number of digital printers who do not charge for value-added services when past research clearly shows that digital printers who do charge an additional fee are more successful than the digital printers who do not? For this study success is defined as building a competitive advantage by boosting sales and profit.

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This study will focus on the various value-added services local digital printers offer, whether or not they charge for them, and their reasoning behind that. Research will be limited to digital printers operating in California’s central coast. The goal of this research is to be able to find pat-terns that may be applicable to the digital print sector of the graphic communication industry.

Significance of Research

Printing has become a commodity where people are turning to the digital printer who offers the least expensive print. In response to this shift in customer behavior three types of compa-nies have developed: one that provides value-added services and charges a bit more, one that makes value-added services available but does not charge for them, and a company that does not offer value-added services and therefore can charge less. In today’s economy, the printer with value-added services will be more profitable than traditional printers.

Chapter 2: Literature Review

Defining Value-Added Services

Two common reasons why value is added to a product or service in the digital printing mar-ketplace are: [5]

1. To satisfy customer needs.

2. To create profits for the company and shareholders.

For the consumer, value-added services are “service options that are complimentary to but also ancillary to a core service offering” [5].

On the other hand, a managing director of EP Credit Management and Consultancy, states “value-add, in it’s purest form, is only found in relationships [6]. Value-add requires a business to deliver a consistent message of interest and, above all, inspire trust [6]. Because they are seen from different angles, unlike the consumer, value-added services are seen as a form of strategy to a company.

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Digital Printers Shift Along with Consumers

In today’s market, digital printers must provide additional services to consumers to beat the competition, as demonstrated in their company tag lines. Table 1 below gives examples of digi-tal printers’ tag lines or slogans and how they emphasize value-added services.

Company Tag Line Market PositioningThe Ace Group Inc. “The Total Digital Solution” A complete 24hr. digital

facility, conveniently located in midtown Manhattan. We offer high quality prepress services as well as the latest in personalized and variable data, on-demand, 6-color offset digital printing and digital asset management.

Banta “Single Source. Multiple Solutions.” Providing single-source solu-tions for supply chain manage-ment and the capture, manage-ment, and distribution of print and digital information.

RR Donnelley “Imagine…Create…Release” We try to anticipate as well as service your needs. Avoid ob-stacles as well as solve problems. Turn you on to new opportuni-ties and the latest innovations.

Table 1. Examples of Company Tag Lines and Marketing Messages Source: Pellow & Sorce, 2003

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Tag lines, in part, help a company spread their objective to inform customers about the extra services they offer. This is further reflected in their business’ market positioning. “The results indicated that, across the board, printers are increasing focus on value-added services to protect their customer base, grow revenues, and increase profitability” [7].

The tag lines and marketing positions demonstrate that digital printers comprehend the shift in a customer’s needs. Customers prefer a one-stop shop that offers a larger amount of services other than printing, saving the customer time and money.

Does Offering and Fee Influence Success?

As statistics from A Research Monograph of the Printing Industry Center at Rochester Institute of Technology (RIT) assert, not all commercial digital printers have value-added service and of the companies who do, not all charge a fee for non-print services. Focusing on the first row of mailing and fulfillment in Table 2, out of seventy-five digital commercial printers, 75% charge for mailing and fulfillment, 4.4% don’t charge, and 20.6% of the digital printers do not include this service [7].

Non-Print Service OfferingN=75 Fee (%) Free (%) Don’t Offer (%) Successful Digital Printers (%)

Mailing/Fulfillment 75.0 4.4 20.6 82.0Variable Data Printing (VDP) 52.8 3.3 43.9 69.0Prepress/Design 82.8 14.1 3.5 98.0Digital Asset Management 27.5 19.2 53.3 57.0E-commerce Supply Chain Management 8.9 12.5 78.6 30.0Digital Photography 29.8 1.8 82.2 43.0Online Template Services 8.4 9.3 82.2 25.0Web Development 20.5 0.0 79.5 30.0CD-ROM Duplication 42.7 3.4 53.8 61.0Digital Proofing 54.8 26.7 18.5 86.0Finishing/Assembly 78.8 16.8 4.4 100.0

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Of the printers surveyed, 43.9% do not offer variable data printing services due to the high ex-pense of collecting data for printing [7]. Also, the fact that not all digital printers are charging for value-added services stands out. For example, according to this same study, digital proofing is the added service that is least charged with 26.7% of the digital printers surveyed saying it is a free service in their business [7]. Digital printing, a still relatively new printing technology when compared to offset, is trying to achieve acceptance from consumers; therefore, not charg-ing for certain services allows them to charge less overall.

The economy has digital printers “scrambling to find the most cost-effective means of commu-nicating with their customers” [8]. Offering extra services seems to be the answer as customer loyalty expert Frederick Reichheld states, “it can cost five times as much to acquire a new client as it does to grow an existing one” [8]. Value-added services in printing can be what convince customers to keep doing business with a certain digital printer.

The results indicate that digital printers who do charge for value-added services are more suc-cessful than those businesses that offer them at no extra cost. Again, looking at Table 2 in mail-ing/fulfillment row, the percentage of successful digital printers is at 82%, which has a positive correlation with a printing company charging a fee [7]. In the majority of cases, as the number of digital printers charging a fee for value-added services increases, the percentage of successful printers also increases. There are two groups of digital printers: digital printers who are more successful and those that are less successful [7]. The three main reasons as to why some are more successful are because of revenue generated from non-print services, revenue generated from data, and internet services [7]. Print service providers have reached the realization that value-added services require additional resources and need to generate revenue. As a result, the majority of digital printers are assessing a fee for non-print related activities.

More distinctively, research by InfoTrends/CAP Ventures in 2004 reveals that “in many cases, production color digital print owners were two times more likely to offer value-added services than other print service providers” [4]. Below, Figure 1 differentiates the amount of value-

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added services provided in digital print shops versus value-added services provided in other printing technologies.

Digital printers are twice as likely to provide value-added services to their customers because they have the extra time to do so. The advanced technology in digital printing takes out nu-merous steps of the traditional workflow, and replaces them with the digital front end (DFE). The DFE is able to load files from various network sources and process the files so they can be output on digital equipment, able to accept and process files for variable data applications and to pull information from a database for personalized documents, and provides overall consis-tency in color, quality, and accuracy [2]. The automation of the prepress steps results in more time to focus on value-added services [5].

Bolger Vision Beyond Print “produces catalogs, magazines, brochures, and sales and market-ing collateral for verticals ranging from insurance and healthcare to the manufacturing sector.” This company is an example of a successful digital printer that offers value-added services [1]. transition into digital printers becoming a one-stop-shop, simplifying the process of printing and managing a complete project for consumers.

0%

17.5%

35.0%

52.5%

70.0%

Design & Creative Services Client Training

35.6%

59.4%66.3%69.3%

21.2%30.6%30.0%

39.3%

Figure 1. Value-Added Services Offered –Digital Production Color Owners vs. All Print Service Providers Source: InfoTrends, 2004

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Bolger Vision Beyond Print’s customers show interest in fulfillment and variable date [1]. Economically, Bolger “derives about 40% of its gross margin from print-on-demand and fulfillment services. Its mailing operation churns out two million pieces per month, while 180 Creative, its design agency, provides strategic marketing and branding services” [1]. In the future, Bolger Vision Beyond Print is “projecting 10 percent growth for the current fiscal year, with contributions coming from across all product and service lines. Future growth will be predicated on the full-service printer’s ability to continue pushing the total package concept to customers” [1].

Because everything is vastly automated in digital printing, faster turnarounds are achievable and the custom solutions become the value-added services. One value added service is digital asset management (DAM): the management, organization, and distribution of digital assets from a central warehouse [3]. Managing all this data is an advantage for a digital printer be-cause it can offer the customer access to a web-based portal where all their previous job submit-tal information and documentation is stored. DAM is “helping print businesses reduce costs of operation, increase productivity and streamline workflow” by “enabl[ing] them to develop profitable solutions that drive new business, expand geographic reach and provide value-added services to customers” [3].

The different types of value–added services create a competitive advantage for all printing technolo-gies. Providing value-added services leads to a more successful business, especially for digital printers.

Chapter 3: Research Methodology

Introduction

The purpose of this study was to identify reasons as to why not all digital printers in California’s central coast provide value added services to their customers, and why are there a number of digital printers who do offer value-added services but do not charge for them. Past research clearly shows that digital printers who do charge an additional fee are more successful, in terms

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of building a competitive advantage by boosting sales and profit, than the digital printers who do not implement an additional fee. The importance in this research lies on determining the best way to run a digital print company that offers value-added services in today’s print market.

Data Collection Plan

Case studies were performed on digital printers found in California’s central coast to determine whether they provide value-added services and whether they charge an extra fee for such ser-vices. Questions were emailed to the digital printers and phone interviews were scheduled to gather more information.

Questionnaire Design

The case studies asked structured questions regarding value-added services and whether they are offered or not and the digital printer’s reasoning behind it. For digital printers that do offer value-added services, the study asked whether or not organizations currently employed a fee for value-added services and their method of calculating the additional fee.

To understand the customer preference and buying practice better, those who do provide value-added services were asked to rank examples of extra services offered based on customer popularity. Also, digital printers who currently do not provide value-added services were ques-tioned if they are considering offering such services in the future. If they currently are making value-added services available at no extra cost, digital printers were requested to state if they are looking to charge in a future date.

Data Analysis Plan

Interview responses were recorded and data was divided into the following three groups:

1. The digital printer does offer value-added services and it does charge for them.

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2. The digital printer does offer value-added services and it does not charge for them.

3. The digital printer does not offer value-added services.

Furthermore, answers to open-ended questions were categorized in order to be able to compare results among the different types of digital printers.

Chapter 4: Results and Findings

Five digital printers located throughout California’s central coast participated in this study. Those companies were: Central Coast Design Pros, Central Coast Printing, Sigman Graphics, San Luis Print and Copy, and CRS Coastal Reprographics. The questionnaire as explained earlier was sent out to these five digital printers

Central Coast Design Pros

Central Coast Design Pros provides many value-added services including data asset manage-ment, design, package specials, mailing/fulfillment, web services, and wide-format print-ing. The company allows consumers to subscribe through their website for email offers for discounts.

Central Coast Printing

Central Coast Printing believe value-added services are at the core of their strategy and opera-tions. Central Coast Printing provides seven additional services to customers (see Table 3). During the interview, Central Coast Printing has noticed the increase in customers utilizing value-added services. They provide design services and mailing and fulfillment services with variable data printing, which “becomes beneficial when a client wants to perform a targeted marketing campaign but does not have the resources to follow through.”

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Sigman Graphics

Sigman Graphics specializes in custom signs and graphics and makes wide-format print avail-able as an ancillary service. Design, package specials, and installment of wide format signs are part of their value-added services. Sigman Graphics has created “The Business Package”, which includes everything one needs to open a shop: store front signs, window and door lettering, vehicle graphics, parking and directional signs, magnetic vehicle signs, job site and construc-tion signs, Americans with Disabilities Act (ADA) required and regulatory signs, banners, hats, shirts, and uniforms.

San Luis Print and Copy/ CRS Coastal Reprographics

San Luis Print and Copy and CRS Coastal Reprographics are similar in that both offer wide-format print, binding, finishing, mailing/fulfillment, and have a digital storefront for consum-ers’ convenience. However, they do differ in that San Luis Print and Copy has the capability of variable data printing, while CRS Coastal Reprographics has data asset management, project management, file manipulation, and personal delivery of their products. Also, in their website, CRS Coastal Reprographics’ delivery and shipping services are less expensive and more conve-nient than local competitors.

Value-Added Services Per Digital Printer

Table 3 lists what value-added services each digital printer provides. There is no single value-added service that all five digital printers provide to their customers. Four out of the five print-ers offer design, mailing/fulfillment, and wide-format.

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San

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Data Asset Management ◊ ◊ ◊Design ◊ ◊ ◊ ◊Digital Storefront ◊ ◊Finishing ◊ ◊Inventory Management ◊Mailing/Fulfillment ◊ ◊ ◊ ◊Package Specials ◊ ◊PhotographyPost Press Binding ◊ ◊ ◊Project Management ◊Variable Data Printing ◊Warehousing ◊Web Services ◊Wide Format ◊ ◊ ◊ ◊Other ◊ ◊

Table 3. Value-Added Services Offered Per Digital Printer Source: Garcia, 2012.

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The graph below visually demonstrates the data on Table 3. The different value-added services offered among the surveyed digital printers are shown as a value that can range from zero to five, representing how many of the five printers offer that service.

Figure 2. Value-Added Services Offered for Every Five Digital Printers Source: Garcia, 2012.

Printers then ranked the importance of their ancillary services. The value-added services are ranked from most important at the top to least important at the bottom.

Central Coast Design Pros

Central Coast Printing

CRS Coastal Reprographics

San Luis Print and Copy

Sigman Graphics

Design Design Digital Storefront

Digital Storefront

Wide Format

Web Services Mailing/Fulfillment

Delivery Mailing/Fulfillment

Package Specials

Mailing & fulfillment

Variable Data Print

Mailing/Fulfillment

Design Other: Installment

Package Specials Data Asset Manage

Data Asset Management

Post Press Binding

Design

0

1

2

3

4

Design

Data Asse

t Man

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ent

Finish

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anag

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0

11111

2222

33

444

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Data Asset Management

Post Press Binding

Project Management

Finishing

Wide Format Inventory Manage

Wide Format Wide Format

Warehousing File ManipulationPost Press Binding

Finishing

Figure 3. Tables representing each digital printer’s rank on the importance of value-added for their clientele. Source: Garcia, 2012.

The five individual tables in Figure 3 reveal which services are more prominent among con-sumers at the time of purchase. Convenience, ease of use, accuracy, simplicity, and rapid re-sponse are a few reasons why consumers approve of a digital storefront. Wide format is another value-added service with unique results. Although, it is a service that is offered in 80% of the digital printers, in all but one individual table it is ranked in the bottom half, meaning custom-ers do not find wide format printing as important.

Fee or No Fee?

All five digital printers were asked if they charge an additional fee for value-added services. San Luis Print and Copy, Sigman Graphics, and Central Coast Printing responded yes. All three also reported a cost plus profit way of calculating the price a customer pays. This final price includes direct costs, indirect costs, fixed costs and a profit of 15-20% is also added. San Luis Print and Copy charge for value-added services because, “some of our customers come in with the decision of only printing with us, but after mentioning to them everything else we do, they agree to take advantage of some of our value-added service; the price doesn’t

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hold them back.” Sigman Graphics made a similar comment during the interview, “If we have an opportunity to make money off of a service our customers find value in, then it only makes sense to offer the service.”

The remaining two digital printers, CRS Coastal Reprographics and Central Coast Design Pros, answered the same question with “sometimes.” More specifically, CRS Coastal Reprographics does not charge to digitally archive the project that is to be printed. This advantage does come with its limits though, as the digital archive copy can only be viewed but not downloaded, shared, or collaborated. Along with the free digital archive, CRS Coastal Reprographics also does not charge for personal delivery if the delivery address is within the city. Central Coast Design Pros is similar to CRS Coastal Reprographics in that they do not charge for the first thirty minutes of design time. They hope this creates a win-win situation where the customer receives a price break from a service needed and the printer can attract customers from their competition that charge for ancillary services.

The five digital printers interviewed were grouped into one of these three categories. However, because all the digital printers offer value-added service the third category was deleted. The results are shown in Figure 4.

1. The digital printer does offer value-added services and it does charge for them.

2. The digital printer does offer value-added services and it does not charge for them.

3. The digital printer does not offer value-added services.

Sixty percent offer and charge for value-added services, whereas 40% do offer value-added services, but do not always charge for such services.

Digital printers implementing a fee for ancillary services charge customers this additional fee to cover the expense that comes when offering each value-added service. They try to optimize their sales and therefore see this as an opportunity to boost their profit per print order. When

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a customer walks into a digital print shop and finds value in the extra services provided, the customer is more willing to pay a higher price for those services. These are the customers a digital printer charging for value-added services targets.

Central Coastal Design Pros does not charge for value added services because when they “see it is strategically possible to not charge or even reduce the price for our customers and still be even the slightest successful, then we will keep it that way.” When questioned about their thoughts on charging for all value-added services in the near future they replied, “We have considered it because it would be a way to bring in more revenue, but that is not our priority.” CRS Coastal Reprographics answered in a similar way stating, “We do not increase our price for every value-added service as a courtesy to say thanks for choosing us over our competitors.” They are able to do this because they have “become more efficient in our printing.”

Chapter 5: Conclusions

Research shows that customers are actually responding to value-added services even if they are charged. Digital printers that do charge for additional services find themselves in a better economical benefit than those printers that do not charge for additional services.

So why are there a number of digital printers who do not charge for value-added services when past research clearly shows otherwise? The answer lies on how success is determined. At the beginning of this study success was defined as: building a competitive advantage by boosting sales and profit. However, after reviewing the questionnaire responses, success may have mul-tiple meanings. According to the previously stated meaning of success, the two digital printers that do not always charge for ancillary services would be considered unsuccessful, but only if everything else were kept constant. The only way to make that statement is if the fee were the single difference between the two groups. Stating digital printers who do not charge for value-added services are less successful does not take into account the other functions of the business.

Digital printers that charge for ancillary services are obviously making a higher profit. However,

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the printers not charging are not necessarily losing money because they have found ways to eliminate non-value-adding steps in their value chain.

Value-added services give the five digital printers studied an opportunity for a competitive advantage. The questionnaire revealed the ratio of digital printers charging for ancillary ser-vices to those not charging for ancillary services to be 60 to 40 percent. There is a clear winner but not strong enough for it to be the preeminent strategy. Along with reasons stated above, a digital printer’s target market, may determine whether they charge for value-added services, but that is left for further research.

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Appendix

Case study questions:

1. Do you offer ancillary value-added services to digital print? Circle all that apply. If yes, skip to sub-question a.)

If no, why not?

If no, are you considering offering value-added services in the future? Yes No

a.) Which value-added services do you believe your customers consider the most important? Please rank 1-14, with 1 being the most important and 14 being the least important.

Data asset management Design

Photography

Mailing/Fulfillment

Inventory Management

Warehousing finished product

Digital Storefront

Variable Data Printing

Post Press Binding

Package Specials

Finishing

Web Services

Wide Format

Other: (Please List)____________

___________________________

Data asset management Design

Photography

Mailing/Fulfillment

Inventory Management

Warehousing finished product

Digital Storefront

Variable Data Printing

Post Press Binding

Package Specials

Finishing

Web Services

Wide Format

Other: (Please List)____________

___________________________

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b.) Thinking of your customers that do use value-added services, why do you think they utilize these additional services?

c.) Do you charge an additional fee for those customers that choose the value-added services? Yes No

i. If yes, how do you determine or calculate the price?

ii. If no, why do you not?

iii. If no, have you considered charging them in the near future? Yes No

2. Any comments or additional information that you believe is relevant and important for the research?

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References[1] Cagle, E. (2007, January). New Ways To Add Value. Printing Impressions, 49(8), 24-26.  Retrieved from ABI/INFORM Global. (Document ID: 1206427881).

[2] Digital Printing Tips. Glossary of Printing Terms. “Digital Front End” (n.d.) http://digitalprintingtips.com/email-term/t--2645/digital-front-end.asp

[3] Fox, J. (2004). Printers Profit from New Business Model. Information Today, 21(8), S5 http://search.ebsco-host.com/login.aspx?direct=true&db=afh&AN=14386227&site=ehost-live

[4] InfoTrends. (2004, July). New InfoTrends/CAP Ventures Research Indicates Satisfaction Among Production Digital Color Printer Owners, http://www.capv.com/public/Content/Press/2004/07.27.2004.html

[5] “Managing value adding.” (1995). Facilities, 13(5), 3.  Retrieved from ABI/INFORM Global. (Document ID: 6747494).

[6] Pacey, E.. (2011, July). The real meaning of value-add. Computer Reseller News,19. Retrieved from ABI/INFORM Global. (Document ID: 2552886661).

[7] Pellow, B. A., & Sorce, P. The Role of Value-Added Services in Successful Digital Printing. Printing Industry Center http://print.rit.edu/pubs/picrm200302.pdf

[8] Sherburne, C.. (2009, April). Add One-to-One Services. Printing Impressions, 51(11), 50.  Retrieved from ABI/INFORM Global. (Document ID: 1682397841).

[9] Value, worth, merit, importance. (n.d.). In Encyclopedia Britannica online. Retrieved from http://www.britannica.com/bps/dictionary?query=value

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The Exploration

of Gravure inPhotovoltaic Processes

Rosie Bubb

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Abstract

Gravure, arguably an outdated process, has the potential for a renewed resurgence in the realm of printed electronics. Although the high front end cost and detrimental effects of the process previ-ously served as drawbacks, currently the need for a high-quality, accurate process such a gravure is apparent in the context of printing polymer solar cells. Polymer solar cells are unrivalled in terms of processing cost, processing speed, processing simplicity and efficiency. Research is currently being conducted to maximize the efficiency of the process of producing these cells in large quantities. The comparison between current polymer coating techniques and gravure has been made indicating that the roll-to-roll compatible process of gravure is superior in terms of cost, high-production suit-ability, quality, and potential power conversion. The ability to use low viscosity inks with varying concentrations of solvents gives a lot of flexibility in determining the optimal printing process for coating the polymer solar cells. The solar cells must be coated so they achieve a perfect balance of efficiency, stability, and a suitable production method. Because gravure has the flexibility to adjust various printing parameters such as a wide range of printing speeds, ink viscosities, placement of the doctor blade, and cell geometry, gravure is an ideal process for the printing solar cells. As gravure be-comes the prominent method for this application, it has the potential to retake a significant market share – only not in the traditional print market, but in a unique market that would present gravure as a sustainable and necessary process.

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Introduction

Although some may question gravure’s dominance, the process consistently yields a high definition, vibrant, and very attractive product. The high initial cost of copper plating, engraving, and chrome plating the cylinder is in stark contrast to the other processes utilizing computer to plate technology. However, the value of gravure is unmatched for long runs. Yet, with increasingly tighter margins and shorter run lengths becoming more and more the norm, the gravure market’s dominance is still diminishing [1]. Gravure has been non-existent – declining in usage steadily over the last 10 years. The projected use of gravure processes is forecasted at 11% by 2015 [1].

In addition to the shift in market demand, gravure printing is undeniably not an attractive process in terms of sustainability. Despite efforts to minimize the volatile organic compounds released and control emissions, the process is more harmful than not. Most gravure inks con-tain toluene – a common, highly flammable solvent that has the potential to be harmful to humans. EPA standards require printing plants to recover 96-99% of the solvent; thus solvent-recovery systems are quite effective but there still remains some minute amount of unrecover-able solvent. Winfrid Schoen, head of publication gravure inks at Gebr. Schmidt, Frankfurt, Germany claims “it has become physically impossible to develop a water-based ink which can work effectively on the thin papers required for high-speed publication gravure presses” [5].

Yet despite all of this, gravure has the potential to become dominant in a field where it could have a positive effect on the environment. New research reveals that gravure printing may be the perfect option for the printing of photovoltaic cells. The challenge in production lies in finding the proper unification of production, stability, and efficiency. The solar cells should be produced rapidly at a low-cost through a reliable process that allows a high power conversion efficiency of the final product [3]. Typically solar polymer cells are produced via film forming techniques such as spin coating and casting. These processes are commonly used although not the best choice for high volume production. Polymer solar cells could be more efficiently produced through more desirable film forming techniques – including direct print gravure.

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The simplicity of the direct printing method paired with the viscosity of the inks as well as high speed capabilities, make gravure a natural choice for coating the polymer layer of solar cells. Ink factors such as surface energy and surface tension are to be controlled to allow a smooth, wet pattern to be produced without smearing or running. Through the study of the effects of process parameters such as contact angle, ink concentration, ink viscosity, solvent characteris-tics, the power conversion efficiency of photovoltaic cells is found to be unmatched by other printing processes. All three layers have been demonstrated to have been printed by gravure at a high power conversion efficiency [7].

Roll-to-roll processes are relatively simple as they include unwinding, coating, and rewind-ing with the possibility of cleaning, heating, and drying stages. Solar polymer cells are ideally printed via a process such as gravure. The roll-to-roll compatibility of gravure implies high volume production at a low process cost. Roll to roll processes also implicate the use of low basis weight substrates such as film. Because the polymer is a thin, flexible substrate, roll-to-roll gravure is a natural choice.

The shape of the cell used to print is an important factor in any facet of printing. Cell geometry takes on a new importance in the printed electronic application. Because ink can dry in the cell during printing, not all the ink is applied to the substrate. Research has been conducted to determine the ideal cell shape for printing as well as the other printing parameters that affect ink transfer.

The idea of printing gravure on solar cells is contingent on the process. The exploration of the possibilities for gravure in this potentially environmentally minded process is necessary to determine if gravure is the best method and what factors make it so.

Methodology

In order to examine how gravure printing is best suited for printing photovoltaic cells, second-ary research was conducted resulting in analysis of a compilation of scientific studies.

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In order for gravure to become the most widely accepted method for the printing of polymer solar cells, a direct comparison must be made between the current processes and the gravure process for printing on polymer solar cells. As stated, the current and accepted processes in-clude spin coating and casting. The challenge existing in selecting the best process is known as the unification challenge – this is pictorially represented in figure 1 [2].

The film-forming technique of casting is the simplest. The solution is cast onto a substrate and dried. While a simple and stable process, this method lacks the control over film thickness and has inconsistent drying due to surface tension inconsistencies. Spin coating has been the most dominant over the years in the field of coating polymer solar cells. It is also a stable process that is highly reproducible. A very consistent film over a large surface area can be achieved with this method. However, the thickness that results, the morphology and the surface structure are influenced by the rotational speed, viscosity, and concentration of the solutes. Spin coating fails to meet the unification challenge in that the process is not efficient. Another downfall of the process is that it is not roll-to-roll compatible. Because it is not compatible as a roll-to-roll process, it may not be as efficient to produce in a high-volume production context. Another crucial downfall of the process is the lack of the ability to print a pattern on the film. Without a pattern, the electronic component will not function.

To determine the efficiency of gravure printed solar cells and the effects of the printing pa-rameters, researchers in Finland carried out a series of trials. Using an Schläfli Labratester, a simple gravure print run was conducted in which various conditions were altered to determine the most ideal parameters for printing the surface with the highest efficiency. The Schläfli Labratester demonstrated the simple process of gravure: the printing cylinder with engraved cells on the surface comes in contact with the ink pan and then the doctor blade, which in turn removes the excess ink before the ink is transferred to the surface of the substrate. The machine has the capacity to run at different speeds with various nip pressures, doctor blade angles, distance between the doctor blade and printing plate, and doctor blade pressures [3].

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PET film covered with tin oxide served as the test substrate. The substrate was cleaned, rinsed with de-ionized water and dried in an oven for a few hours. Specially formulated ink was ap-plied on top of the substrate through the gravure process. The next layer, the photoactive layer, was also processed via gravure printing. To measure the voltage of the cell, a Keithley 2400 source unit was used. The thickness of the film layer was measured using a Detak 150 surface meter. The viscosity of the ink was determined with a rheometer.

To find the optimum printability of the gravure printed photoactive layer, ink concentration, ratio of solvent mixtures, cell shape, line density, and speed of the press were all varied. The optimal ink should result in controlled ink, not spreading out from engraved pattern. The pro-cess was tested at a printing speed of 7 m/min and 18 m/min while two different line densities were used: 80 l/cm and 45 l/cm.

To assert gravure’s potential for printing electronics, it is necessary to demonstrate that the pattern thickness is adequate to cover the product in a fine film and to determine what charac-teristics of ink are necessary to achieve this. Research done at Microelectronics Laboratory in Finland aimed to demonstrate this while determining the best way to determine this and the best way to address quality on electronic substrates [4].

The experiment was done with a gravure printer form Grauel GmbH, a doctoring device with fixed angles; an engraved cylinder with 30 micrometers deep, rectangular cells. The speed of the ink doctoring was 5-30 cm/s, while the pickup speed of the ink was near to the same. The viscosity and yield stress measurements were recorded with a Bohlin rheometer. Surface thick-ness and line height were measured via a Veeco Detak surface profiler. The parameters recorded after each trial were the compression-thickness where ink is picked up, the compression thick-ness when the ink is laid down, the time from doctoring to pickup, the speeds of doctoring, pickup, and print.

A further point of research involves how the engraved pattern affects the performance of the substrate. The geometry of the engraved cells – whether it be square, diamond, or hexagonal

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– can influence the outcome. Researcher, Leonard Schwartz, examined these affects and built a mathematical model to determine which cell geometry was the most desired. Based on the amount of ink that was left after each rotation and the amount of ink not transferred as it was dried up in the base of the cell, the productivity of the process can be calculated [6].

Results

The comparison of all current and potential polymer solar cell coating methods is displayed in the following table. The current and most common method of spin coating stands out due to its high ink waste. Based on the comparison, gravure appears to be a good compromise of all factors. The ink waste is low as the direct print process is highly efficient in terms of ink usage. A two-dimensional pattern is achievable with the potential for more dimensions as more layers of the cell are printed via gravure. The speed is among the highest as gravure is roll to roll com-patible, meaning more surface area can be covered in less time as the substrate web is pulled through the unit at a controlled speed. Because of other factors currently under examination, including gravure cell geometry and the numerous printing parameters that can be adjusted in the gravure process, gravure looks to be a standout option for printing polymer solar cells.

The results of the Finnish study are evident in Table 2 and Figure 3. The printing speed of 7 m/min was unsuccessful as the ink spread outside of the cells, accumulating outside of the engraved area. When the speed was increased to 18 m/min, the ink flow was improved and the ink was contained to the patterned printing area. To get the uniformity required, it was necessary to test a lower line density or a greater cell volume. As apparent in figure 3, sample e was the most successful at an 80 l/cm screening, 18 m/minute speeds and 150 mg/ml. The layer thickness for this sample also had the least variation when the total concentration and line density was increased.

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(Risø National Laboratory for Sustainable Energy, Technical University of Denmark) Ink waste: 1 (none), 2 (little), 3 (some), 4 (considerable), 5 (significant). Pattern: 0 (0-dimensional), 1 (1-dimen-sional), 2 (2-dimensional), 3 (pseudo/quasi 2/3-dimensional), 4 (digital master). Speed: 1 (very slow), 2 (slow<1 m min−1), 3 (medium 1–10 m min−1), 4 (fast 10–100 m min−1), 5 (very fast 100–1000 m min−1). Ink preparation: 1 (simple), 2 (moderate), 3 (demanding), 4 (difficult), 5 (critical). Ink viscosity: 1 (very low <10 cP) 2 (low 10–100 cP), 3 (medium 100–1000 cP), 4 (high 1000–10,000 cP), 5 (very high 10,000–100,000 cP).

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Figure 2

Figure 3

P3HT:PCBM 50 mg/ml in o-DCB (80 l/cm), speed 7 m/min, (b) 50 mg/ml, 80 l/cm, speed 18 m/min, (c) 50 mg/ml, 45 l/cm, speed 18 m/min, (d) 100 mg/ml, 80 l/cm, speed 18 m/min, (e) 150 mg/ml, 120 l/cm, speed 18 m/min. (both images: Microelectronics Laboratory)

The overall highest power conversion efficiency achieved in this fully gravure print experiment was 2.8%. This in effect, asserted gravure’s potential to manufacture polymer electronics.

Results from the study done at Microelectronics Laboratory demonstrate that inks that are high in viscosity and in internal cohesion, give the best results. Inks with high viscosity require

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lower doctor blade speeds. The experiment with the more solid the ink contained, the better transfer occurred as the printed mass increased with the solid content of the ink (as seen in figure 4).

Figure 4

(Micorelectronic Laboratory) Printed mass vs. solid content of inks.

In the case of the more viscous, more solid ink, 100% ink transfer to the substrate occurred; thus, beneficial for electronic products such as photovoltaic cells where a complete coating is necessary to functionality.

The research involving the cell geometry and the affect of cell performance can be summarized in mathematical models formulated by research Leonard Schwartz.

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Figure 5

(University of Delaware, Department of Mechanical Engineering) figure 5. The three cell patterns considered. The dimensions a, b, c are input parameters. Because of symmetry, only a portion of the domains shown need to be calculated. Note that (iii) is the square pattern (i) rotated 45 degrees

The above diagram demonstrates each of the input parameters used by Schwartz used to cal-culate the efficiency of each cell shape: hexagonal, diamond, and square. He found the cell size rather than the geometry was the main determinant of how much ink was life the in the cell. In general, increased cell sizes will empty more completely. However, cells too large will create a non-uniform surface, which is an undesirable result – especially in printed electronics ap-

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plications where the uniformity of the surface is necessary to the function of the final product. Cells too large also have the potential to damage the web. Through his calculations, Schwartz discovered that the surface tension is also directly proportional to the liquid left in the cells. He found that it is the refilling process that influences the final pattern as he states “The pattern influence is restricted to the refilling process, with the hexagonal pattern, for which the cells are more closely packed, suffering a greater degree of refilling” [6].

Concluding Remarks

Gravure, previously a process linked with environment maltreatment, can now be associated with decreasing the cost of solar energy; thus, reducing reliance on non-renewable sources. Gravure, being the standout option for printing polymer solar cells has the potential to be at the forefront of the renewable energy movement. Although the traditional market for gravure may be diminishing, the new application in a sustainable rather than harmful process could be just what the gravure industry needs to reassert itself among other printing processes. The im-plication of gravure in photovoltaic polymer printing is profound. Gravure, previously a harm-ful process could become a process linked with improving energy efficiency; thus, a potential for a resurgence of gravure is possible outside of the conventional markets that currently exist.

Gravure in the context of printing electronics is an up and coming topic in the print industry. New research is required to further solidify gravure’s potential to infiltrate the elec-tronics market. The need for continued exploration of gravure in this application is obvious. The rise of gravure and other printing methods in unconventional markets will likely rise even as traditional print media declines.

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References:

[1] “Converting Today - One Foot in the Gravure.” (2010). Converting Today - The Leading Magazine for the Converting, Packaging and Printing Industry. Globe Trade Media. Retrieved from http://www.convertingtoday.co.uk/story.asp?storycode=6422

[2] Krebs, Frederik C. (2009). Fabrication and processing of polymer solar cells: A re-view of printing and coating techniques. Solar Energy Materials and Solar Cells. Retrieved from http://www.sciencedirect.com/science/article/pii/S0927024808003486

[3] Kopola, P.P. Aernouts, T. T., Guillerez, S. S., Jin, H. H., Tuomikoski, M. M., Maaninen, A. A., & Hast, J. J. (2010). High efficient plastic solar cells fabricated with a high- throughout gravure printing method. Solar Energy Materials & Solar Cells.

[4] Pudas, Marko, Hagberg, Juha & Leppävuori, Seppo. (2004). Printing parameters and ink components affecting ultra-fine-line gravure-offset printing for electronics applications. Journal of the European Ceramic Society. Retrieved from http://www.sciencedirect.com/science/article/pii/S095522190300863X

[5] Schoen, Winfrid. (2002). Officials debate future of gravure: while some see brighter future built on quality, others see solvent issues leading to further decline. Retrieved from http://www.inkworldmagazine.com/articles/2002/08/officials-debate-future-of-gravure

[6] Schwartz, Leonard W., (2001). Numerical modeling of liquid withdrawal from gravure cavities in coating operations; the effect of cell pattern. Journal of Engineering Mathematics. Retrieved from http://dx.doi.org/10.1023/A:1016136130268

[7] Voigt, M. M., Mackenzie, R. I., Yau, C. P., Atienzar, P., Dane, J., Keivanidis, P. E., & Nelson, J. (2011). Gravure printing for three subsequent solar cell layers of inverted structures on flexible substrates. Solar Energy Materials & Solar Cells.

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Cal Poly TAGA 2013

Officers & Members

Sharon Hart

President

Mallory Willard

Vice President

Shannon Whitehill

Creative Director

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Sean Garnsey

Treasurer & Research Chair

Emma Lacey

Marketing Chair

Audrey Magwilli

Secretary

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Sarah Flores

Social Media Chair

Corrinna Powell

Kelly Learn

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Colophon

This journal was produced entirely by students of the TAGA chapter at the Graphic Communication department of California Polytechnic State University, San Luis Obispo. All design, print production, and overall production work was completed in on-campus facilities.

Design

This journal was designed using Adobe InDesign, Illustrator, and Photoshop CS5. The type-faces used were Adobe Garamond Pro, Governor, Novecento Wide, and QumpellkaNo12.

Prepress

Printing

This journal was printed in-house using the Cal Poly Graphic Communication Department’s Konica Minolta C8000.

Finishing

Materials

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Acknowledgements

The Cal Poly TAGA Student Chapter would like to recognize the following companies and individuals for their genorous support in the production of the 2013 journal.

Cal Poly Graphic Communication Department

Special Thanks

**Company logos here**

Dr. Penny Bennett Kevin Cooper Lorraine Donegan Dr. Malcolm Keif Brian P. Lawler Dr. Harvey Levenson Dr. Ken Macro Korla McFall

Bob Pinkin Dr. Xiaoying Rong Gordon Rivera Vince Vince Uhler Eric Johnson Lyndee Sign Colleen Twomey University Graphic Systems