sublimation print for textile material

98 SCREEN PRINT INDIA - July 2011

Colour is something, which makes the object more appealing, attractive and gives the pleasure of observation. The desire to create garments and other artefacts that refl ect the beauty of the world around us and provide for the expression of artistic nature has been evident from early in human history. Textile materials like fabric and garment can be coloured in two ways either by dyeing or printing. Dyeing is colouring the fabric or garment with the single color and printing is applying coloured patterns and designs to decorate a fi nished fabric. Textile printing is the most versatile and important of the methods used for introducing colour and design to textile fabrics. Textile printing requires the correct coordination between the printing machinery support and the human skill for producing the best of the results. Textile printing uses various printing techniques like, Screen, block, ink jet, hand, block, tie and die, kalamkari, batik, while garment printing can be done by Plastizol, Fluorescent, Metallic, Puff, Foil printing apart from above textile printing. Several techniques have been are in use and the colorants available have multiplied, the

Sublimation Print for Textile MaterialTextile printing requires the correct coordination between the printing machinery support and the human skill for producing the best of the results, says Vasant R. Kothari

latest and the most popular is Sublimation

Print for Textile Materials.

Dye sublimation printing work under the

process of sublimation, so it is necessary

to understand sublimation to understand

the dye sublimation printing process. We

have learnt in Chemistry that an element or

compound normally has 3 states viz. solid,

liquid and gaseous state and conversion from

one state to another can happen by applying

heat (solid >> liquid >> gaseous) or by

removing heat (gaseous >> liquid >> solid).

See Fig. 1.

Process

The technology works primarily on polyester

and special polyester coatings applied to

the surface of an object. Sublimation works

by dying the fabric with colour, allowing

the fabrics natural wicking properties to be

maintained. At high temperatures, the solid

dye converts into a gas without ever becoming

a liquid. The same high temperature opens

the pores of the polyester fabric and allows

the gas to enter. When the temperature

drops, the pores close and the gas reverts

to a solid state. It has now become a part

Technology

Fig 1 : The nomenclature for

different phase transitions

Fig 2

SCREEN PRINT INDIA - July 2011 99

of the fabric, meaning there is no chance

of colours bleeding, or washing out, and

one of the biggest advantages over 'screen

printing' and other processes. The only way

they are going to come out is possibly if

fabric is kept in the sun for the next two

or three years but then the material will

probably sun rot before the dyes go away.

Dye particles that are used for this type of

dye sublimation are designed to only bond

with polymers, so the higher the polyester

content in the material the more dye that will bond giving a brighter image. This is why dye sublimation can’t be done on natural materials, such as 100% cotton. Natural fi bers and noncoated materials which have no 'pores' to open cannot

accept the gas vapor. The dye particles

are designed to bond with polyester, and

ignore everything else. It is like trying to mix

oil and water with most natural materials.

Out of all of other printing methods, dye sub

is the most eco-friendly

Dye sublimation will produce fantastic

color on white and light colored fabrics.

The technology is perfect for high-margin

customization, certain sporting uniforms

or jerseys, performance apparel or any

application where photo-realistic images are

needed and durability a top priority.

Direct & Transfer

Dye Sublimation can be applied on the fabric

in two different ways either directly on fabric,

i.e. direct print or fi rst on the paper and then

on fabric i.e. transfer print

Transfer Dye Sublimation Print

The images are initially printed on coated

transfer paper as a reverse image of the fi nal

design. The paper is then placed on the pre-

cut polyester fabric pattern and both are

placed into a heat press. When the heating

cycle is completed, under high temperature

and pressure, the dye turns into a gas and

permeates the fabric and then solidifi es into

its fi bers, the image on the paper has been

transferred to the item and has actually

reformed into or underneath the surface.

The fabric is permanently dyed so it can be

washed without damaging the quality of

image. See Fig. 3 and Fig. 4.

Direct Dye Sublimation Print

The images are directly

printed on treated

polyester fabrics, which

are then heated by heat-

fi xation devise that fi xes

the color on the fabrics.

This method eliminates

Dye particles that are used for this type of dye sublimation are designed to only bond with polymers, so the higher the polyester content in the material the more dye that will bond giving a brighter image. This is why dye sublimation can’t be done on natural materials, such as 100% cotton.

Fig 3 : Process fl ow of Transfer Dye Sublimation Print

Fig 4 Process fl ow of Transfer Dye Sublimation Print


the need for

transfer papers.

This means no

paper cockling

and reduction

in defects such

as ghosting and

various wave or

tiger stripes that

are common in

roll-to-roll transfer

printing. This

type needs an ink

waste pit to collect

excess ink and prevents it from staining the

reverse side of the fabric. See Fig. 5.

Starch is coated on fabrics to avoid blur or bleeding of ink Print directly on pre-treated fabrics Non-contact heater fi xes color on the fabrics. See Fig. 6.

Method of selection

Dye sublimation transfer is relatively old as compare to direct dye sublimation and hence has a big market share. Both methods have their own advantages and disadvantages and the selection is purely based on the customer requirement, the type and quality of output required. Transfer yields higher quality and direct yields higher productivity.

The typical viewing distance of print is

again one of the most important factors to

determine which method to go with. Close-

up viewing with high-resolution requirements

on knit fabrics, normally used in sportswear,

would lead to paper transfer which gives the

most saturated color and crisp line detail as

compare to direct print. Further, in case of

panel printing transfer print is more suitable

as the prints are small in size and placement

of print design is of prime importance which

can be comfortably achieve with the help of

transfer print.

Direct printing gives less resolution and

suitable for distance viewing. So it is widely

used for the industrial purpose like home

furnishing, curtains, banners, and signage.

Another advantage is the production rate

which reduces the total production cost in

terms of longer length fabric.

Applications

Dye sublimation is perfect for printing to a

wide range of manmade and mixed content

textiles including :

Whether it is a printing a repeated textile

pattern design to be incorporated into a

garment, creating cushions, curtains, banners

and much, much more, the process of dye

Technology

Fig 5 : Process Flow of Direct Dye Sublimation Print

Fig 6 : Process Flow of Direct Dye Sublimation Print


sublimation is simple,

clean and easier than

other processes.

But dye sublimation is not limited to decorating the fabrics only. Many products such as ceramic tile, mouse pads, mugs and plates can all be decorated using practically the same equipment, so

generating multiple lives for dye sublimation is quite easy.

Comparison with Screen Printings

One of the main advantages is that dye sublimation papers used for high quality sublimation transfers are designed to print a wide gamut of vibrant colors while enhancing the release of ink during the sublimation process, allowing for a permanent 'color pop' that does not fade over time. While the colors produced by screen printing are comparable to dye sublimation, screen printing usually requires large minimum order quantities and tooling costs. Alternatively, sublimation enables the fl exibility to produce one-offs digitally with the image permanence of screen printing at a fraction of the cost, allowing print providers and sign shops to produce

One of the main advantages is that dye sublimation papers used for high quality sublimation transfers are designed to print a wide gamut of vibrant colors while enhancing the release of ink during the sublimation process, allowing for a permanent 'color pop' that does not fade over time.

Technology

Comparison of Direct and Transfer Dye Sublimation PrintsDirect Dye Sublimation Transfer Dye Sublimation

Prints directly on the fabricsNeeds the medium, normally paper, for transferring

the print on the fabric

Cost of printing machine is more Cost of printing machine is less

Material cost is less Material cost is high

Labour cost is less Labour cost is more

Production rate is high Production rate is less

Cost of printing is less Cost of printing is more

Less wastage More wastag

Best print are limited to flat, smooth surfaced

fabricsExcellent on knitted fabrics

Quality of print is not that much superior as

compare to TransferQuality of print is superior as compare to Direct

Suitable for longer length fabric Suitable for panel printing

More application are there in home furnishing,

banner, backdropsWidely used in apparel sector

Polyester Poly/Cottons Canvas Rayon

Acrylic Satins Dacron Poplin

Faux Suede Nylon Nylon 66 Ripstop

Poly Felts Voile Baize Lycra

Fig 7 Comparison of Screen Print

and Direct Sublimation Print


items as ordered rather than committing to a large inventory position. See Fig. 7.

Comparison with Digital Inkjet Printing

Dye-sublimation differs greatly from inkjet

in many ways; most signifi cantly in quality.

Dye-sub is known for its high quality and

continuous tone output. Continuous tone

means that all gradations of colour are used

when creating an image. For example, when

creating a grey scale, from black to white, a

continuous tone printer will show all shades

of grey in between the black and the white

by actually printing them. See. Fig. 8.

A half-toning device such as an ink-jet

printer will use a dithering technique of

placing dots close together in order to trick

the eye. In other words, ink jet printers use

a series of black dots placed close to white

dots in order to trick the eye into blending

the pixels when viewed. With magnifi cation

the difference can be seen where the dye-

sub output is clear and sharp, but dots can

be seen on ink-jet prints. Dye-sublimation

printing has an important advantage over

Inkjet printers - the ability to print a superior

range of colors. Dye-sublimation printers

are able to change

the temperature of

the thermal elements

in its head at 256

different degrees,

therefore producing

256 different shades

of each of the

colored panels. More

importantly, due to

its properties, the dye

is transparent and

colors can be laid on

top of each other,

combining to produce

16.8 million different

shades. The technology also features a fi nal

laminate coating which makes prints from a

dye-sublimation devices look as if they have

been developed from a photochemical lab.

Another advantage of dye sublimation is

that the prints are dried up and able to use

when they get out of the printer. Considering

that thermal head doesn’t have to sweep

backwards and forwards above the print

media, there can be fewer moving pieces

which could break down. Since the dye in

no way enters a liquid phase, the entire

printing cycle is extremely clean; one can

fi nd no liquid inks to clean up along with

no print heads for getting clogged. These

variables cause dye-sublimation usually a

more trustworthy technology over inkjet

printing. Dye-sublimation has another two

major advantages over Inkjet technology. UV

& Water Resistance.

However, dye-sublimation printers also have

some drawbacks over their inkjet rivals. Each

of the colored panels of the ribbons, and the

thermal head itself, match the size of the

media that is being printed on. This means

that dye-sublimation printers cannot match

the fl exibility of the inkjet printer's ability to

print on a wide range of media. In addition,

dye-sublimation printing media and ribbons

are sensitive to skin oils, which affect the

sublimation capacity, and must also be free of

dust particles which can lead to small colored

blobs appearing on the printed media. The

current standard is to include special fi lters to

reduce the likelihood of these incidents, but

keep in mind that a speck of dust can only

affect one print as it becomes attached to the

print during the whole process.

Pros and Cons of Sublimation Printing

Pros .....• Dye Sublimation has the highest print

quality for printing on fabric/textiles.

Technology

Fig 8 Comparison of Digital Print

and Sublimation Print

A half-toning device such as an ink-jet printer will use a dithering technique of placing dots close together in order to trick the eye. In other words, ink jet printers use a series of black dots placed close to white dots in order to trick the eye into blending the pixels when viewed.


• Dye sublimation offers excellent

durability, image detail and color

vibrancy.

• The fi nished print has no "hand," which makes them feel second to none.

• The technology is well-suited for popular newer trends in urban fashion and performance/wicking fabric markets.

• Additionally, dye sublimation offers the potential for product diversity that can benefi t a company since all of their business will not be in one product type.

• Sublimation dyes are permanent as they have become part of the fabric, and thus give the excellent fastness properties.

• It is the most eco-friendly printing.

• Dye sub is great for full color designs on white or light colored garments.

• There is no crack or fading of colors in this type of printing.

• Dramatically Reduced Waste and Maintenance Costs.

• Excellent Coverage and Extended Ink

Yield.

• Trouble-Free Unattended Printing and

Maximum Uptime.

• Can print larger print sizes screen

printing.

• Photographic quality image capability

Cons .....

• The drawbacks of dye sublimation

include higher cost of dyes.

• It can be applied to a limited, more

expensive apparel choice.

• Nevertheless, niche markets that match

technology with need do exist and some

offer a handsome return.

• It can only be printed on white colour.

• Suitable for limited fi bers like dryfi t, silk,

polyster fabric.

• It cannot be printed on black or dark

colour fabric.

• Metallic colours are not possible.

Conclusion

Over the last decade, textile printing sector

has redefi ned itself as the contemporary

fashion statement of textile industry. World

over it is emerging as not only the most

'in demand' area, but also as driver of the

further growth of the textile industry. One

of the factors to catalyze this is the rapidly

transforming consumers. Emerging and

changing consumer needs have forced

companies to redefi ne their business

approach. It is the diversity of ideas that is

deciding the product lines.

Emerging expectation from design is highly

evolved and much diverse nature. Providing

product that attracts the buyer because of

Over the last decade, textile printing sector has redefi ned itself as the contemporary fashion statement of textile industry. World over it is emerging as not only the most 'in demand' area, but also as driver of the further growth of the textile industry. One of the factors to catalyze this is the rapidly transforming consumers.

Technology


Technology

something other than the price is much

required. Many of the popular decorating

methods such as screen printing and

embroidery are time tested choices for

the apparel market. However, markets

inevitably change, fashion trends and

consumer tastes change rapidly as well.

What's "hot" today is old news tomorrow.

New techniques, materials and processes

are being implemented to realize the

consumer expectations and aspirations in

much sophisticated manner.

Sublimation print can be used mainly on

the polyester fi bre, in the past, nobody

wanted to wear the garments made

out of a polyester fi bre because they

were uncomfortable and lacked many

of the desirable qualities of cotton. But

today, a number of manufacturers have

come up with new processes that have

resulted in polyester garments that are

soft, breathable, and comfortable even

in warmer temperatures, and with the

increase in application of polyester fi bre in

the apparel segment sublimation will also

grow at the same rate.

Further, the increasing availability of new

and improved combinations of dyes, media, hardware and software are fuelling the usage of sublimation as a less expensive, long lasting, and customizable alternative to direct and screen printing methods. Breakthroughs in technology will also likely lead to sublimation playing a larger role in the sign industry, particularly in instances where it is preferable for signs and displays to be used multiple times.

With the new generation of wide-format digital printers, the creative possibilities for producing applications using dye sublimation are endless. Prior to these technological advancements, entering the dye sublimation market required a considerable investment of time and money, but now it is often favoured as a less expensive alternative to other printing methods.

Dye sublimation is a top contender for color vibrancy, durability and image detail. Newer urban fashion trends use dye sublimation and are generating a new wave in fashion apparel. Dye sublimation is rapidly gaining market share due to the increasing availability of new and improved combinations of dyes, media, hardware and software that have pushed the quality range to higher levels. In today’s market, it remains the preferred method over direct printing.

Vasant R. Kothari is Assistant Professor, Department of Fashion Technology, NIFT, Bangalore. Committee Member

of The Textile Association of India (TAI), Karnataka Unit. He can be contacted @ www.vasantkothari.com

Sublimation print can be used mainly on the polyester fi bre, in the past, nobody wanted to wear the garments made out of a polyester fi bre because they were uncomfortable and lacked many of the desirable qualities of cotton.

sublimation print for textile material

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