machine design, Vol.5(2013) No.3, ISSN 1821-1259 pp. 111-114

*Correspondence Author’s Address: University of Novi sad, Faculty of Technical Sciences, Trg Dositeja Obradovica 6, 21000 Novi Sad, Serbia, plancak@uns.ac.rs

Research paper

RAPID PROTOTYPING AS A TOOL FOR EFFECTIVE PRODUCT DEVELOPMENT Miroslav PLANČAK1, * - Dejan MOVRIN1 - Stanislaw LEGUTKO2 1 University of Novi Sad, Faculty of Technical Sciences, Novi Sad, Serbia 2 Poznan University of Technology, Faculty of Mechanical Engineering and Management, Poznan,Poland

Received (15.05.2013); Revised (21.08.2013); Accepted (26.08.2013) Abstract: Increasing pressure at the dynamic industrial market to fabricate cost-effective high quality products has lead to the creation of new innovative production technologies and methods which would enable high competitive production of a new products in a short time. Amongst such a new, computer based technologies is Rapid Prototyping (RP). It makes possible to fabricate physical model out of CAD virtual model. Physical models are of great importance in the development phase of a new product as they, unlike virtual models, enable “touch feeling” contact with the object to be fabricated. This paper presents main principles of RP, gives insight of possible application. Furthermore, it describes two RP technologies which are applied in the Laboratory for Virtual Technologies at the FTN - UNI Novi Sad and in the Laboratory of Rapid Prototyping at the FMEaM - PUT Poznan. Key words: Rapid Prototyping, 3D printing, FDM 1. INTRODUCTION In the whole life time of one product most decisive is development phase. In this phase main product characteristics are defined and up to 75% of total costs are predetermined. Therefore, it is very important to create and perform this phase as effective as possible. There are a new circumstances and challenges at the modern industrial market which exert direct impact on the development phase of one product. The most significant circumstances are [1]. Fast changing customer desire

Increasing significance of product styling and design Lower price Shorter life time of the product Environmental requirements Legal regulations In order to cope with such requirements and changing conditions new technologies and methods have been created with the aim to shorten development phase of a new product and to enable fabrication of high quality products in cost effective way and in short time. In development phase physical models and prototypes play important role (“One physical model is more than thousand 2-d pictures”). They enable better visualization, direct sensation of touch and, in some cases, even interaction with the responsible persons, including iterative procedures in product development. Also physical models enhance communication between experts from different departments of the company involved in the development of a new product (technical departments, marketing, management…). Rapid Prototyping (RP) is a group of modern technologies which enables quick production of physical models and, in this way, speed up development phase and shorten so called “time to market” (time from the first idea of a new product to its introduction into the market).

Therewith RP is one effective tool for fast product formation and its optimization.(Rapid Prototyping is otherwise known as Solid Freeform Fabrication, Desktop Manufacturing or Layer Manufacturing Technology). It should be stressed that RP is used not only in the field of industrial and mechanical engineering but also in other fields such as medicine [2], [3] architecture, arts etc. Detailed statistics on RP application fields is given in Fig.1.

Fig.1. Application fields of RP

Current paper gives insight into the main Rapid Prototyping methods and their role in creation of physical models. Special focus has been placed at the 3D Printing and Fuse Deposition Modeling methods. 2. RAPID PROTOTYPING Rapid prototyping (RP) is a group of technologies which enable fabrication of physical models directly from the virtual 3D CAD models. These methods do not require dies and tools or any human intervention for the manufacturing of physical models. It should be emphasized that 3D data can be provided in different way: CAD design, reverse engineering (RE), computer tomography (CT) magnetic resonance tomography (MRT).In most cases RP models are made from materials which are different than those utilized in final production.

Miroslav Plančak, Dejan Movrin, Stanislaw Legutko: Rapid Prototyping as a Tool for Effective Product Development; Machine Design, Vol.5(2013) No.3, ISSN 1821-1259; pp. 111-114

112

Rapid prototyping is a typical additive process, models are formed by joining of volume elements, layer by layer, to create a final component. In the Fig.1 the main principle of RP is presented [1]. First step is creation of a virtual 3D model which is then mathematically cut into the horizontal layers. In this way whole body is represented in mathematical way by a number of layers which are then physically realized and joint together, creating the physical model. Every RP process consists of three distinctive phases: preprocessing processing postprocessing

Fig.2. Principle of Rapid Prototyping [1]

In preprocessing phase 3D geometrical description of the model is generated as well as the information of each layer. Outer surface of the body is represented by a number of triangles which makes possible to define every horizontal cross section through the model in STL format. Model is placed into the x-z-y coordinate system, supporting structures are defined, as well as the thickness of every single layer. These information are then sent to the RP device, so called prototyper, where the processing, i.e. generation of every layer as well as their mutual joining to a final physical component is carried out. Created physical model might need some additional interventions to be made such as curing, surface polishing or painting, drilling of holes etc. These operations are performed in post processing phase. Classification of RP technologies can be made upon different criteria. The most frequently applied is classification based on model material. Upon this criterion all RP methods can be divided into four groups (Fig.3). As it can be seen, most methods use liquid (photopolymer) as starting material which is subjected to the high power light during processing (laser, UV). These exposure to the high energy light results in solidification of the liquid (through so called “polymerization”), i.e. building a solid body – model. Detailed information on every specific RP method can be found in the numerous literatures [3], [4], [5]. In the Laboratory for Virtual Technology at FTN - University Novi Sad two different RP Systems have been installed recently: 3D – printing and Fuse Deposition Modeling. Further text is devoted to the presentation of these systems and operating experience.

Fig.3. Classification of the RP technologies

3. 3D PRINTING First step in generation of models and prototypes by 3D printing is deposition of thin film of powder material on the platform of the machine (“prototyper”). After that, printer prints liquid binder at selected regions of the spread powder, which results in creation of first solid

layer. Next step is lowering of the platform for the amount of the next layer thickness after which process is repeated: powder spreading on the previously created layer and gluing together of powder particles. The shape of all layers in X-Y plane (the shape of the regions which are glued together) corresponds to the virtual cross section of the CAD model.

Current Rapid Prototyping Technologies

Liquid phase Powder form Sheet form Gas phase

Stereolithoraphy (SL)  Fused Deposition Modeling (FDM)  Ballistic Particle Manufacturing (BPM)  Multi‐Jet Modeling (MJM)  Model Maker  Shape Deposition Manufacturing (SDM) 

Selective Laser Sintering (SLS)  Three‐Dimensional Printing (3D‐P)  Laser Engineered Net Shaping (LENS) 

Laminated Object Manufacturing (LOM)  Shape Maker 

Selective Area Laser Deposition (SALD) 

Miroslav Plančak, Dejan Movrin, Stanislaw Legutko: Rapid Prototyping as a Tool for Effective Product Development; Machine Design, Vol.5(2013) No.3, ISSN 1821-1259; pp. 111-114

113

Fig.4. 3D printer “Z310 plus” and models made by this printer at FTN

Once all layers are created platform is raised and excess powder which is not used is removed, usually by vacuum device. Finally, finished solid model is taken of the platform and subjected to the post processing operation, if needed. In the Fig.4. 3D printer Z310 plus, installed in the Laboratory for Virtual technology at FTN – University Novi Sad, as well as a number of models from the mechanical engineering and medicine fields, made by this printer are shown. The main technical characteristics of the printer are: monochrome, maximal model size 203x254x203 mm, vertical built speed 25 mm/hour, layer thickness 0,089-0,203 mm. Method is eco-friendly. 4. FUSE DEPOSITION MODELING (FDM) In FDM process initial material is in the form of solid filament. This filament is fed into the working head where it is heated to a semi-liquid state and then extruded on the working platform where it cools and solidifies, building a layer of future model. Main characteristics of FDM system MakerBot Replicator 2 are: type of filament PLA thermoplastic, filament diameter 1,75 mm, nozzle diameter 0,4 mm, build volume 28.5x15.3x15.5 cm , x-y precision 11 microns, z-precision 2,5 microns. In Fig. 5.the principle of FDM is illustrated and in Fig.6. prototyper Maker bolt replicator 2 is shown. Set of model examples produces by FDM is shown in Fig.7.

Fig.5. Principle of FDM method

Fig.6. FDM MakerBot Replicator 2

Miroslav Plančak, Dejan Movrin, Stanislaw Legutko: Rapid Prototyping as a Tool for Effective Product Development; Machine Design, Vol.5(2013) No.3, ISSN 1821-1259; pp. 111-114

114

Fig.7. Models made by FDM technique 5. CONCLUSION Rapid Prototyping technologies speed up development of a new product considerably, enabling significant shortening of whole “time to market”. Furthermore, it improves communication with various partners in all phases of a new product creation. Current paper gives a short overview of the main RP technologies, their principles and characteristics. Special focus has been placed on the 3D Printing and Fuse Deposition Modeling (FDM) methods, as these technologies are applied at the University Novi Sad, FTN, Laboratory for Virtual Technology. In frame of the regular laboratory exercises at FTN - Master study, students create their own CAD models and realize a physical models both, by 3D printer and FDM prototype.

ACKNOWLEDGEMENT Results of investigation presented in this paper are part of the research realized in the framework of the project TR 035020, financed by the Ministry of Science and Technological Development of the Republic of Serbia as well as of Ceepus CII-HR-0108. Authors are grateful for financial support.

REFERENCES [1] Gebhardt, A. (2003). Rapid Prototyping, Carl Hanser

Verlag, ISBN: 1-56990-281-X, Munich. [2] Drstvensek, I. (2004). Layered technologies,

University Maribor, ISBN: 86-435-0616-8, Maribor. [3] Gibson, I.; Rosen, D.W.; Stoker, B. (2010). Additive

Manufacturing Technologies, Rapid Prototyping to Direct Digital manufacturing, Springer, ISBN: 978-1-4419-1119-3, New York.

[4] Lozo,B.; Stanic,M.; Jamnicki,S.; Poljacek,S.; Muck,T. (2008). Three-Dimensional Ink Jet Prints –Impact of Infiltrants, Journal of Imaging Science and Technology, Vol.52, No.5, (September 2008.), pp.51004-1-51004-8(8), ISSN: 1062-3701.

[5] Pham, T.; Gault, R. (1998). A comparison of rapid prototyping technologies, Int. Journal of machine tools and manufacture, Vol.38, No,10-11, (October 1998), pp.1257-1287, ISSN: 0890-6955.