1. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Plastics & FRP Associate Professor Su-Jin KimSu-Jin Kim School of Mechanical Engineering Gyeongsang National University

2. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Contents 1. Plastic Process Extrusion ( 압출 ) Injection molding ( 사출금형 ) Blow molding Thermo forming 2. Composite ( 복합재료 / 강화플라스틱 ) Composite process 3. Rapid prototyping ( 쾌속조형 )

3. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Processing of Plastics 1.Extrusion ( 압출 ) 2.Injection molding ( 사출 ) 3.Blow molding 4.Thermo forming

4. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Extrusion The molten plastic is forced through a die and cooled. Long products with constant cross-section are extruded. High production rates, low tooling cost. http://kr.youtube.com/watch?v=Ct34UCjOr-c&feature=related © 갈창우, GNU

5. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Injection molding http://ma.gnu.ac.kr/vod/Plastic/Plastic_Injection.wmv http://ma.gnu.ac.kr/vod/Plastic/Plastic_Injection_Molding.MP4 http://kr.youtube.com/watch?v=bit-D1NnfjI&NR=1 http://kr.youtube.com/watch?v=NedTUB7YQE0&feature=related Hopper Barrel Mold Plastics are melted in a heated cylinder and forced into a mold by hydraulic plunger of rotating screw. Complex shape and good dimensional accuracy can be achieved, as in die casting.

6. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Injection molding Die structure SLIDE CORE EJECTION PLATEEJECTION PINRETURN PIN GUARD BUSH GUARD PIN ROCKET RING SPRUE BUSHING ANGULAR PIN CORE 돌출판돌출핀 Injection Mold http://ma.gnu.ac.kr/vod/Plastic/Injection_Mold.wmvhttp://ma.gnu.ac.kr/vod/Plastic/Injection_Mold.wmv JY-Solutec http://www.jysolutec.comhttp://www.jysolutec.com

7. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Injection molding Vacuum Cleaner: Hand grip Blower: Housing http://www.tsmould.com/cyberpr01.htm

8. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Injection molding insert label in pet mold

9. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Multiple injection molding ( 복합사출 ) Product with hard and soft plastics. S778T + TPE Sliding split mold Turn table mold

10. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Design for Injection Molding Parting line is flat or simple-curved surface Flow path ratio (length/thickness < 200) Clamping force = Pressure x Area Draft angle 1~2˚ Shrinkage PE(1.5~6), PP(1~3), PS(.2~.6), PVC(0.1~0.5) Reinforcements (ribs and bosses) Defects : Sink mark, Weld line, Air traps, Deflection

11. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Injection Molding MIT Lecture Node http://ocw.mit.edu/courses/mechanical-engineering/2- 008-design-and-manufacturing-ii-spring-2004/lecture- notes/04_polymer_1_6_f.pdfhttp://ocw.mit.edu/courses/mechanical-engineering/2- 008-design-and-manufacturing-ii-spring-2004/lecture- notes/04_polymer_1_6_f.pdf http://ocw.mit.edu/courses/mechanical-engineering/2- 008-design-and-manufacturing-ii-spring-2004/lecture- notes/05polymer_2_6f1.pdfhttp://ocw.mit.edu/courses/mechanical-engineering/2- 008-design-and-manufacturing-ii-spring-2004/lecture- notes/05polymer_2_6f1.pdf

12. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Blow molding http://www.youtube.com/watch?v=vSabFFQUr9E&p=9B6D9EAE75875D9D http://kr.youtube.com/watch?v=grIPNOHkdOc&feature=related http://kr.youtube.com/watch?v=3haIAsECzRc http://www.youtube.com/watch?v=oR0gMKN58kY&p=9B6D9EAE75875D9D Blow up a plastic balloon to fill the mold. Hollow thin-wall parts; beverage and food containers.

13. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Blown film A thin-walled tube is extruded and expanded into a balloon shape by blowing air until the desired film thickness is reached. http://kr.youtube.com/watch?v=W0QbPtYXsRs&NR=1

14. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Thermo (Vacuum) forming http://kr.youtube.com/watch?v=deeENCiuKWM http://kr.youtube.com/watch?v=YCGEKT3iHMs&feature=related http://www.metacafe.com/watch/1685267/thermoforming_machine_by_europack1_gmail_com/ The thermoplastic sheet is heated by an oven until it is softened, pressed into the mold using vacuum pressure, and held until it cools. Medium production rates, low tooling cost.

15. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Economics of Processing Plastics Design and manufacturing decisions are based on costs of equipment, tooling and production volume. 1010 2 10 3 10 4 10 5 10 6 10 7 Number of parts Machining Extrusion Injection molding Blow molding Thermo forming Production rate

16. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Fiber Reinforced Polymer, FRP (Composites) FRP ( 복합재료 )  Fiber( 섬유 ) + Plastic matrix ( 모재 ) Fiber: Kevlar, Glass fiber, Graphite fiber, Boron Plastic matrix: Epoxy, Polyester Process 1.Impregnation: fiber+resin 2.Molding –Compression molding –Vacuum bag molding –Open molding –Resin transfer molding http://vimeo.com/13769356

17. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Molding Reinforced Plastics Prepreg & Autoclave Vacuum bag molding Open molding (Contact molding) Resin transfer molding (RTM) Filament winding

18. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Prepreg Prepreg is a term for "pre-impregnated" composite fibers containing polymer matrix. The pre-preg are mostly stored in cooled areas since activation is most commonly done by heat. Pultrusion: http://www.youtube.com/watch?v=9tlQn5_cko0http://www.youtube.com/watch?v=9tlQn5_cko0 Prepreg: http://www.youtube.com/watch?v=Eq6Xj1UcIKghttp://www.youtube.com/watch?v=Eq6Xj1UcIKg Nesting: http://www.youtube.com/watch?v=y_TDd3bzDeMhttp://www.youtube.com/watch?v=y_TDd3bzDeM

19. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Vacuum-bag molding Prepregs lay in mold and apply pressure in a vacuum. http://www.youtube.com/watch?v=sJlfzuxvESM Atmospheric pressure Clamping bar Vaccum trap Gel coat Gasket Vacuum trap Flexible bag Room temperature or oven cure hand or spray lay-up Mold release Resin and glass Mold © 갈창우, GNU

20. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Autoclave Hence, composite structures built of pre-pregs will mostly require an oven or autoclave to cure out. Temperature 180 °C, Pressure 600kPa, Time 3 h

21. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Sheet molding compound (SMC) & Compression Molding Compression molding: SMC is placed between two molds and pressure is applied. Sheet molding compound http://www.youtube.com/watch?v=IxaTwSBWz14http://www.youtube.com/watch?v=IxaTwSBWz14 SMC Compression Molded Composite

22. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Open-molding Open-molding process use single male or female mold and also called contact-molding Used in making products with high surface-area-to- thickness ratios. Hand lay-upSpray lay-up http://ma.gnu.ac.kr/vod/Plastic/FRP_Boat.MP4 http://www.youtube.com/watch?v=a7F5roYYvC8 http://www.youtube.com/watch?v=4Pw_tcgIiTQ

23. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Resin Transfer Molding (RTM) Resin Transfer Molding (RTM) allows the molding of components with complex shapes and large surface areas with a good surface finish on both sides. http://www.youtube.com/watch?v=1u-2GvhghQA

24. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Filament winding Glass fibers are embedded in thermosetting resin matrix materials and winded around a pipe. FRP pipe CNG tank http://www.youtube.com/watch?v=iOZl3v4RC18

25. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Composite Machining & Joining http://www.youtube.com/user/e1m1s#p/c/3B2C07E01F72869B/6/Kh_PO9O4BAs http://www.youtube.com/watch?v=Pi3MjF860fM

26. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Rapid prototyping 3d CAD  Real part

27. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Rapid prototyping Making a physical prototype directly from 3D CAD drawing. 1.CAD solid model 2.Translation to STL format 3.Slice the model into layers 4.Send data to RP machine 5.Curing each layer by laser

28. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Rapid Prototyping Usage

29. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Rapid Prototyping Usage

30. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes 3D Printing Roller spreads powder Inkjet traces the shape of each section http://ma.gnu.ac.kr/vod/Plastic/3d_printer.MP4 http://ma.gnu.ac.kr/vod/Plastic/3d_pirinter_objet.mpeg

31. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes SLA ( Stereo Lithography Apparatus ) Vat filled with photo-curable liquid resin Laser beam solidifies liquid resin of 2d cross-section Elevator drops enough to cover the solid polymer with another layer of liquid Cured Resin XY Scanning UV Laser Beam Photo-curable Resin (Liquid) Top of the Liquid Elevator Vat

32. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes SLS (Selective Laser Sintering) Roller spreads powder across the top of the elevator Laser traces the shape of each cross-section, fusing powder in the thin layer

33. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes FDM (Fused Deposition Manufacturing) Dispenser heats the plastic and extrudes it at the desired position. Deposited plastic solidifies to form a hardened layer.

34. © Pearson & GNU Su-Jin Kim Plastics Manufacturing Processes Reference Polymer Mixing (W. R. Whang) : http://rmp.gnu.ac.kr/http://rmp.gnu.ac.kr/ Mechanical Properties of Composite (J. H. Choei): http://gsnu.ac.kr/hb/11176/ http://gsnu.ac.kr/hb/11176/