International Journal of Mechanical Engineering and Technology (IJMET) Volume 7, Issue 5, September–October 2016, pp.117–126, Article ID: IJMET_07_05_014 Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJMET&VType=7&IType=5 Journal Impact Factor (2016): 9.2286 (Calculated by GISI) www.jifactor.com ISSN Print: 0976-6340 and ISSN Online: 0976-6359 © IAEME Publication

FUTURE OF MANUFACTURING TECHNOLOGY RAPID PROTOTYPING TECHNIQUE Yembadi Koushik Varma B. Tech, Mechatronics (Mechanical) Engineering Department, Mahatma Gandhi Institute of Technology, Hyderabad, India Samatham Madhukar B. Tech, Mechanical Engineering Department, VidyaJyothi Institute of Technology, Hyderabad, India Bootla Akhil B. Tech, Mechanical Engineering Department, VidyaJyothi Institute of Technology, Hyderabad, India Pokala Saiprasanna Kumar B.Tech, Mechanical Engineering Department, Joginpally B.R Engineering College, Hyderabad, India ABSTRACT The term “Rapid Prototyping” (RP) refers to a class of technologies that can automatically construct physical models from computer-Aided Design (CAD) data or is a group of techniques used to quickly fabricate a scale model of a physical part or assembly using three-dimensional computer aided design (CAD) data. . The edges and surfaces of a complex solid model and their information are used for defining a product which is further manufactured as a finished product by CNC machining. They make excellent visual aids for communicating ideas with co-workers or customers apart from design testing. Across the world, Engineering has the common language and common goal-“Improving the Quality of Life” of mankind without any boundary restrictions. The common goal can be attained by the engineers in less time by RAPID PROTOTYPING TECHNIQUE and this paper provides a better platform for researchers, new learners and product manufacturers for various applications of RP models. Subsequently it creates awareness among the peoples of recently developing RP method of manufacturing in product design, developments and its applications. A review is undertaken in this paper for the different types of rapid prototyping techniques Key words: Rapid Prototyping, computer aided design, product design. Cite this Article: Yembadi Koushik Varma, Samatham Madhukar, Bootla Akhil and Pokala Saiprasanna Kumar, Future of Manufacturing Technology Rapid Prototyping Technique. International Journal of Mechanical Engineering and Technology, 7(5), 2016, pp. 117–126. http://www.iaeme.com/ijmet/issues.asp?JType=IJMET&VType=7&IType=5

http://www.iaeme.com/IJMET/index.asp

117

[email protected]

Yembadi Koushik Varma, Samatham Madhukar, Bootla Akhil and Pokala Saiprasanna Kumar

1. INTRODUCTION Rapid Prototyping (RP) can be defined as a group of techniques used to quickly fabricate a scale model of a part or assembly using three-dimensional computer aided design (CAD) data. What is commonly considered to be the first RP technique, Stereo lithography, was developed by 3D Systems of Valencia, CA, USA. The company was founded in 1986, and since then, a number of different RP techniques have become available. Rapid Prototyping has also been referred to as solid free-form manufacturing, computer automated manufacturing, and layered manufacturing. RP has obvious use as a vehicle for visualization. In addition, RP models can be used for testing, such as when an airfoil shape is put into a wind tunnel. RP models can be used to create male models for tooling, such as silicone rubber molds and investment casts. In some cases, the RP part can be the final part, but typically the RP material is not strong or accurate enough. When the RP material is suitable, highly convoluted shapes (including parts nested within parts) can be produced because of the nature of RP.[1] There is a multitude of experimental RP methodologies either in development or used by small groups of individuals. In recent years, an industry of producing three dimensional models directly from 3D CAD data has grown rapidly. Several companies produce machines that can fabricate a physical three-dimensional model out of various materials including plastic, paper and metal. Generally, the machines run unattended and quickly produce an accurate model directly from CAD data without the need for a highly skilled model-maker or machinist. These machines are generally known as rapid-prototyping machines and the industry that has developed around these machines is called the rapid-prototyping industry. These methods are unique in that they add and bond materials in layers to form objects. Such systems are also known by the general name free form fabrication (FFF), solid freeform fabrication (SFF) and layered manufacturing. Rapid prototyping is the automatic generation of 3D free-form shapes from virtual 3D models is a crucial process in contemporary design and manufacture of commercial products. Current modeling applications are limited in that they may only generate a small subset of all realizable 3D shapes automatically. Typically only smooth and simple surfaces can be quickly designed using the latest ComputerAided Design (CAD) software such as AutoCAD or Computer-Aided Modeling (CAM) software. Modeling complex shapes using these software packages requires a large amount of time. In these cases Rapid Prototyping is used to create the model within minimum time. Rapid prototyping isn't a solution to every part fabrication problem. After all, CNC technology is economical, widely understood and available, offers wide material selection and excellent accuracy. However, if the requirement involves producing a part or object of even moderately complex geometry, and doing so quickly - RP has the advantage. It's very easy to look at extreme cases and make a determination of which technology route to pursue, CNC or RP. For many other less extreme cases the selection crossover line is hazy, moves all the time, and depends on a number of variably-weighted, case dependent factors. While the accuracy of rapid prototyping isn't generally as good as CNC, it's adequate today for a wide range of exacting applications. The materials used in rapid prototyping are limited and dependent on the method chosen. However, the range and properties available are growing quickly. Numerous plastics, ceramics, metals ranging from stainless steel to titanium, and wood-like paper are available. At any rate, numerous secondary processes are available to convert patterns made in a rapid prototyping process to final materials or tools.

2. AIMS OF RAPID PROTOTYPING • • • • • •

To increase effective communication. To decrease development time. To decrease costly mistakes. To minimize sustaining engineering changes. To extend product lifetime by adding necessary features and eliminating redundant features Rapid Prototyping decreases development time by allowing corrections to a product to be made early in the process. By giving engineering, manufacturing, marketing, and purchasing a look at the product early in the design process, mistakes can be corrected and changes can be made while they are still inexpensive.

http://www.iaeme.com/IJMET/index.asp 118

[email protected]

Future of Manufacturing Technology Rapid Prototyping Technique

• • • • • •

The trends in manufacturing industries continue to emphasize the following: Increasing number of variants of products. Increasing product complexity. Decreasing product lifetime before obsolescence. Decreasing delivery time. Rapid Prototyping improves product development by enabling better communication in a concurrent engineering environment.

3. PRINCIPLE OF RAPID PROTOTYPING Rapid prototyping works on the basis of adding or removing layers of material to form the desired shape. The majority of commercial rapid prototyping system build object by adding one layer after another. For simplicity, it can be visualized as stacking slices of bread until complete three-dimensional bread loaf is achieved. Rapid prototyping is a highly automated layer manufacturing process. The object is designed in any solid modeling software (CAD) and the data is converted into a standard format widely known as standard triangularisation language (STL) which is understandable by the rapid prototyping machine.[2] Rapid prototyping software receives data in this format and creates a complete set of instructions for fabrication on rapid prototyping machine such as tool path, layer thickness, processing speed, etc. Rapid Prototyping machine then manufactures the object using layer manufacturing method. Upon completion of a three-dimensional model, it is subjected to post processing treatment for removing support material that was used to support overhang features during fabrication.

4. BASIC STEPS IN RAPID PROTOTYPING Basic steps in all the RP techniques employ the same basic five step process. The steps are as follows: 1. Create a CAD model of the design 2. Convert the CAD model in to STL format 3. Slice the STL model in to thin cross sectional layers. 4. Construct the model one layer atop another’s. Clean and finish the model. CAD Model Creation: First the object to be built is modeled using a Computer added (CAD) software package. A large number of software packages are available in the market like PRO/ENGINEER. These tend to represent 3D models more accurately than the wireframe modelers such as AutoCAD and hence produce very good results. The designer can create a new file expressly for prototyping or may use the existing CAD file. The process is same for all the RP build techniques. Conversion to STL Format The various CAD packages use a number of different algorithms to represent solid objects. To establish consistency, the STL (stereo lithography, the first RP technique) format has been adopted as the standard of the rapid prototyping industry. The second step, therefore, is to convert the CAD file into STL format. This format represents a three-dimensional surface as an assembly of planar triangles, "like the facets of a cut jewel. The file contains the coordinates of the vertices and the direction of the outward normal of each triangle.[3] Because STL files use planar elements, they cannot represent curved surfaces exactly. Increasing the number of triangles improves the approximation, but at the cost of bigger files size. Large, complicated files require more time to pre-process and build, so the designer must balance accuracy with manageability to produce a useful STL file. Since the STL format is universal, this process is identical for all of the RP build techniques Slice the STL File In the third step, a pre-processing program prepares the STL file to be built. Several programs are available, and most allow the user to adjust the size, location and orientation of the model. Build orientation is important for several reasons. First, properties of rapid prototypes vary from [4]one coordinate direction to another. For example, prototypes are usually weaker and less accurate in the z (vertical) direction than in the x-y plane. In addition, part orientation partially determines the amount of time required to build the model. Placing the shortest dimension in the direction reduces the number of layers, thereby shortening build time. The pre-processing software slices the STL model into a number of layers from 0.01 mm to 0.7 mm thick, depending on the build technique. The program may also generate an auxiliary structure to support the model during the build. Supports are useful for delicate features such as http://www.iaeme.com/IJMET/index.asp

119

[email protected]

Yembadi Koushik Varma, Samatham Madhukar, Bootla Akhil and Pokala Saiprasanna Kumar

overhangs, internal cavities, and thin walled sections. Each PR machine manufacturer supplies their own proprietary pre-processing software. Layer by Layer Construction The fourth step is the actual construction of the part. Using one of several techniques (described in the next section) RP machines build one layer at a time from polymers, paper, or powdered metal. Most machines are fairly autonomous, needing little human intervention. Clean and Finish The final step is post-processing. This involves removing the prototype from the machine and detaching any supports. Some photosensitive materials need to be fully cured before use. Prototypes may also require minor cleaning and surface treatment. Sanding, sealing, and/or painting the model will improve its appearance and durability.

5. CLASSIFICATION OF RAPID PROTOTYPING PROCESSES: The professional literature in RP contains different ways of classifying RP processes. However, one representation based on German standard of production processes classifies RP processes according to state of aggregation of their original material and is given in figure

Figure 1 Classification of Rapid Prototyping Processes

Some of the important process in rapid technology are of Major RP Technologies: • • • • • • • •

Photo Masking or Solid Ground Curing technique. SLS (Selective Laser Sintering) FDM (Fused Deposition Modelling) LOM (Laminated Object Manufacturing) 3D Printing Solid ground curing Thermo Jet Process Contour crafting

http://www.iaeme.com/IJMET/index.asp 120

[email protected]

Future of Manufacturing Technology Rapid Prototyping Technique

6. APPLICATIONS OF RAPID PROTOTYPING Rapid prototyping is widely used in the automotive, aerospace, medical, and consumer products industries. Although the possible applications are virtually limitless, nearly all fall into one of the following categories: •

Prototyping

•

Rapid tooling or rapid manufacturing. a) Direct tooling b) Indirect tooling

•

Rapid Manufacturing

6.1. Proto Typing As its name suggests, the primary use of rapid prototyping is to quickly make prototypes for communication and testing purposes. Prototypes dramatically improve communication because most people, including engineers, find three-dimensional objects easier to understand than two-dimensional drawings. Such improved understanding leads to substantial cost and time savings by exchanging prototypes early in the design stage, manufacturing can start tooling up for production while the art division starts planning the packaging, all before the design is finalized. Prototypes are also useful for testing a design, to see if it performs as desired or needs improvement. Engineers have always tested prototypes, but RP expands their capabilities. [5] First, it is now easy to perform iterative testing: build a prototype, test it, redesign, build and test, etc. Such an approach would be far too time-consuming using traditional prototyping techniques, but it is easy using RP.

6.2. Rapid Tooling A much-anticipated application of rapid prototyping is rapid tooling, the automatic fabrication of production quality machine tools. Tooling is one of the slowest and most expensive steps in the manufacturing process, because of the extremely high quality required. Tools often have complex geometries, yet must be dimensionally accurate to within a hundredth of a millimeter. [6]In addition, tools must be hard, wear resistant, and have very low surface roughness (about 0.5 micrometers root mean square). To meet these requirements, molds and dies are traditionally made by CNC-machining, electro-discharge machining, or by hand. All are expensive and time consuming, so manufacturers would like to incorporate rapid prototyping techniques to speed the process. Peter Hilton, president of Technology Strategy Consulting in Concord, MA, believes that "tooling costs and development times can be reduced by 75 percent or more" by using rapid tooling and related technologies. Rapid tooling can be divided into two categories, •

•

Indirect Tooling: Most rapid tooling today is indirect: RP parts are used as patterns for making moulds and dies. RP models can be indirectly used in a number of manufacturing processes a) vaccum casting b)sad casting 3)investment casting 4)injection casting etc Direct Tooling: To directly make hard tooling from CAD data is the Holy Grail of rapid tooling. Realization of this objective is still several years away, but some strong strides are being made:a) Rapid tool b)LOM composite c)sand mouldingetc

6.3. Rapid Manufacturing A natural extension of RP is rapid manufacturing (RM), the automated production of salable products Global Journal of Computer Science and Technology. In 1996 Rubbermaid produced 30,000 plastic desk organizers from a SLS-built mold. This was the first widely sold consumer product to be produced from direct rapid tooling. Extrude Hone, in Irwin PA, will soon sell a machine, based on MIT’s 3D Printing process that produces bronze-infiltrated PM tools and products directly from CAD data. Currently only a few final products are produced by RP machines, but the number will increase as metals and other materials become more widely available. RM will never completely replace other manufacturing techniques, especially in large

http://www.iaeme.com/IJMET/index.asp

121

[email protected]

Yembadi Koushik Varma, Samatham Madhukar, Bootla Akhil and Pokala Saiprasanna Kumar

production runs where mass-production is more economical. For short production runs, however, RM is much cheaper, since it does not require tooling. RM is also ideal for producing custom parts tailored to the user’s exact specifications. A University of Delaware research project uses a digitized 3-D model of a person’s head to construct a custom-fitted helmet. NASA is experimenting with using RP machines to produce spacesuit gloves fitted to each astronaut’s hands. [7] From tailored golf club grips to custom dinnerware, the possibilities are endless. The other major use of RM is for products that simply cannot be made by subtractive (machining, grinding) or compressive (forging, etc.) processes. This includes objects with complex features, internal voids, and layered structures. Specific Surface of Franklin, MA uses RP to manufacture complicated ceramic filters that have eight times the interior surface area of older types.[8] The filters remove particles from the gas emissions of coal-fired power plants.5 Theirs, Inc. of NYC is using RP’s layered build style to develop "pills that release measured drug doses at specified times during the day" and other medical products.

7. GENERAL APPLICATIONS Here are list of some of the generalised applications which we can see in our day to day life.

7.1. Medical Application The RP model plays the vital role in medical applications. It is used in human facial scull transparency in the medical field. Figure 3 shows the damaged portion of the human facial scull. Figure 2 shows the damaged portion of the facial scull has been replaced by the RP model. [9, 10]

Figure 2 Damged facial scull replaced by RP Model

Figure 3 Human damaged facial scull

7.2. Textile Application The RP techniques models are widely used in textile industries. The complicated contour profile dresses are designing in the 3D model with aid of computer and directly inter connected with manufacturing machine. Figure 4 shows the RP model dresses with complicated contours.

http://www.iaeme.com/IJMET/index.asp 122

[email protected]

Future of Manufacturing Technology Rapid Prototyping Technique

Figure 4 Modeled by RP

7.3. Electronic Application The house holding electrical appliances are widely manufactured in the PR techniques. These RP techniques are very useful for manufacturing the special contours in an electrical item.[11] Figure 5 shows the RP models of electrical appliances.

Figure 5 RP Model of an electrical appliances

http://www.iaeme.com/IJMET/index.asp

123

[email protected]

Yembadi Koushik Varma, Samatham Madhukar, Bootla Akhil and Pokala Saiprasanna Kumar

7.4. Foot-Ware Design The foot-ware for a human comfort is manufacturing in RP technique. This type of foot-ware should have light weight and stronger than the conventional model. And also the complicated design of foot-ware is developed in the RP technique models without any fastener. The reliability of the RP model is very high compared with conventional model.[12]

Figure 6 RP Model of Foot-ware

7.5. Furniture Design The furniture is designed and manufacturing with a aid of RP techniques. This model has low weight and no temporary and permanent joints. It is made up of a single piece without any joints with different profiles. Figure 7 shows the furniture model developed in the RP technique.

Figure 7 RP Model of Furniture

http://www.iaeme.com/IJMET/index.asp 124

[email protected]

Future of Manufacturing Technology Rapid Prototyping Technique

8. CHALLENGES ASSOCIATE INSIGHT IN RAPID PROTOTYPING The following are the challenges associate insight in rapid prototyping. The RP models are manufacturing directly from the computer aided design model with automated machine. Hence, the following are to be considered for developing the RP system. a) Develop automatic recognition of appropriate geometric features from the STL file, such as; minimum wall thickness b) Develop the rules relating to prototyping metal components. c) Improve the user definition or classification of prototype use. d) Investigate which method of delivery best answer the needs of small companies and who would be responsible for its upkeep’s) Create a full system in a native programming environment suitable for delivery in the manner identified. [13]

9. FACTORS TO BE CONSIDERED WHILE DEVELOPING RP TECHNIQUES IN INDIAN SCENARIO The following are the factors to be considered for developing the RP techniques in Indian scenario. a) Initial investment Cost b) Availability of trained people c) Knowledge in the automatic system d) Availability of material e) Programming language f) Awareness of RP techniques g) Reality of the model h) Knowledge in the 3D modeling i) Selection of Modeling software [14]

10. FUTURE DEVELOPMENTS Rapid prototyping is starting to change the way companies design and build products. On the horizon, though, are several developments that will help to revolutionize manufacturing as we know it. One such improvement is increased speed. "Rapid" prototyping machines are still slow by some standards. By using faster computers, more complex control systems, and improved materials, RP manufacturers are dramatically reducing build time. As the Rapid Prototyping Technology gets further advanced, it can lead to substantial reduction in build-up time for manufacturing. • • • • • • •

1. Further improvement in laser optics and motor control can improve the accuracy. 2. The development of new materials and polymers so that they are less prone to curing and temperature induced war Pages. 3. Much anticipated development is the introduction of non-polymeric materials including metals, ceramics, composites and powder metallurgy. 4. Developments in ceramic composites can further increase the range of rapid prototyping. 5. Currently, the size is also a restriction; capability for larger parts shall be expected in the near future. 6. Currently, the demand is low and with the further technology advancement, awareness and training, this can be increased. 7. Advancement in computing systems and viability to support net designs from a distant country to be fed directly on the RP machines for manufacturing is a new possibility.

11. CONCLUSION RP is one of the fastest growing new technologies of manufacturing the various products by adding the material in layer by layer and directly from the 3D CAD model connected with the automated machine. This paper deals with the various RP model related to the field of applications. This paper provides a platform for researchers, new learners and product manufacturers to create an awareness of rapid prototyping and manufacturing technology for creating the complicated and different contour products in various field of applications. The various points are discussed in this paper for the researchers to insight the challenges associate in rapid prototyping. However, some of the factors are given for developing the RP techniques in Indian scenario.

http://www.iaeme.com/IJMET/index.asp

125

[email protected]

Yembadi Koushik Varma, Samatham Madhukar, Bootla Akhil and Pokala Saiprasanna Kumar

REFERENCE [1]

D. T. Pham, S. S. Dimov, Rapid Manufacturing: the Technologies and Applications of Rapid Prototyping and Rapid Tooling, Springer, London, 2001.

[2]

D. King, T. Tansey, Alternative materials for rapid tooling. Journal of Materials Processing Technology, Vol. 121, 2002, pp. 313–317

[3]

. P. F. Jacobs, Stereo lithography and other RP&M Technologies: From Rapid Prototyping to Rapid Tooling, ASME Press, New York, 1996.

[4]

D. T. Pham, R. S. Gault, A comparison of rapid prototyping technologies. International Journal of Machine Tools & Manufacture, Vol. 38, 1998, pp. 1257– 1287.

[5]

H. Yang, D. Xue, Recent research on development Web-based manufacturing systems: a review. International Journal of Production Research, Vol. 41, No. 15, 2003, pp. 3601–3629.

[6]

H. B. Lan, K. S. Chin, J. Hong, Development of a teleservice system for RP service bureaus. Rapid Prototyping Journal, Vol. 11, No. 2, 2005, pp. 98–105. 1. Cooper, K.G., Rapid Prototyping Technology, Marcel Decker Publishing, New York, 2001.

[7]

Prinz, F.R., Ed., Site Reports Vol. I, II, JTEC/WTEC panel on rapid prototyping in Europe and Japan, Baltimore, MD: Loyola College, NTIS Rep. #PB96-199583, 1997

[8]

Beaman, J.J., Barlow, J.W., Bourell, D.L., Crawford, R.H., Macrus, H.L., McAlea, K.P., Solid Freeform Fabrication: A New Direction in Manufacturing,” Boston, Kluwer Academic Press, 1997.

[9]

C. K. Chua, K. F. Leong, K. H. Tan, F. E. Wiria, C. M. Cheah, Development of tissue scaffolds using selective laser sintering of polyvinyl alcohol/hydroxyapatite bio composite for craniofacial and joint defects. J. Mater. Sci. Mater. Med., Vol. 15, No. 1, 2004, pp. 113–1121.

[10]

Raju B S, Chandra Sekhar U and Drakshayani D N, Web Based E- Manufacturing of Prototypes by Using Rapid Prototyping Technology. International Journal of Mechanical Engineering and Technology (IJMET), 4(2), 2013, pp.32–38.

[11]

N. K. Vail, L. D. Swain, W. C. Fox, T. B. Aufdlemorte, G. Lee, J. W. Barlow, Materials for biomedical applications. Mater.Des., Vol. 20, 1999, pp. 123–132. [15] O. Abdelaal, S. Darwish, Fabrication of Tissue Engineering Scaffolds Using Rapid Prototyping Techniques. World Academy of Science, Engineering and Technology, International Science Index 59, Vol. 5, No. 11, 2011, pp. 1325 – 1333.

[12]

Rahul M. Sherekar and Anand N.Pawar, A Review: Rapid Prototyping Techniques for Designing and Manufacturing of Customized Anatomical Implants. International Journal of Mechanical Engineering and Technology (IJMET), 5(3), 2014, pp.77–90.

[13]

L. Novakova - Marcincinova, J. Novak - Marcincin, Testing of Materials for Rapid Prototyping Fused Deposition Modelling Technology. World Academy of Science, Engineering and Technology, International Science Index 70, Vol. 6, No. 10, 2012, pp. 396 - 399.

[14]

R. Patil, S. Kumar, S. Ajmera, Bioengineering for Customized Orthodontic Applications - Implant, Bracket and Dental Vibrator. World Academy of Science, Engineering and Technology, International Science Index 72, Vol. 6, No. 12, 2012, pp. 1291 - 1295.

[15]

Campbell, I., ed., Rapid Prototyping Journal, Emerald Journals, Bradford, UK. 13. Ghee, S., “The Virtues of Visual Products,” Mechanical Engineering, pp. 60-64, June 1998.

[16]

Sharke, P., “Rapid transit to Manufacturing,” Mechanical Engineering, pp. 63-66, March 2001. [15]. Thilmany, J., “Printing in Three Dimensions,” Mechanical Engineering, pp. 58-61, May 2001. [16]. Thilmany, J., “Walkabout in another World,” Mechanical Engineering, pp. 98-101, Nov., 2000. [17]. Orfe, G., Publisher, Table of RP Distributors, Time Compression Technologies, July/Aug, pp. 5759, 2001.

http://www.iaeme.com/IJMET/index.asp 126

[email protected]