Manufacturing Processes Plastics FRP Professor SuJin Kim Plastics

Manufacturing Processes Plastics & FRP Professor Su-Jin Kim Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University Mechanical Engineering Gyeongsang National University

OCW • Plastic injection molding, extrusion, blow molding: https: //youtu. be/qn 16 Jt. E_v. Lc • Plastic injection molding: https: //youtu. be/RMjtmsr 3 Cq. A • Thermo (Vacuum) Forming: https: //youtu. be/HWX_Xx. S 4 z. Y 8 • Tire (Rubber): https: //youtu. be/Li-MKob. Bg 5 w Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

OCW • Fiberglass Molding: https: //youtu. be/BOo 8 gxp 3 K 3 w • Carbon fiber: https: //youtu. be/a. Kp. Dyf. Jnx. QQ • Prepreg Carbon fiber, Molding, Curing: https: //youtu. be/k 4 Gd. Au. Nji 5 g Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

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

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

Plastic Injection molding • Molten plastic is injected into a mold by hydraulic plunger • Good dimensional accuracy as die-casting Hopper Mold Barrel Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

Injection mold • Mold structure Sprue busing Guard busing Ejection pin Plastics Manufacturing Processes Injection Mold http: //ma. gnu. ac. kr/vod/Plastic/Injection_Mold. wmv JY-Solutec http: //www. jysolutec. com © Su-Jin Kim Gyeongsang National University

Injection Mold Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

Flow analysis MAPS-3 D • Plastic injection process analysis Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University VMTech: http: //www. wincapa. com

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 Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

Plastic Extrusion • The molten plastic is forced through a die and cooled. • Long products with constant cross-section • High production rates, low tooling cost Barrel liner Hopper Barrel heater/cooler Wire filter screen Melt thermocouple Thermocouples Throat Barrel Breaker plate Adapter Die Feed section Melt-pumping section Gear reducer Box Screw Motor ©갈창우, GNU Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University https: //youtu. be/Tp 2 Rdx 69 SSo

Blow molding • Blow up a plastic balloon to fill the mold. • Hollow thin-wall parts; beverage and food containers. https: //youtu. be/Gt 9 DRif. Rwn 0 Plastics https: //youtu. be/8 W 6 P 5 KU 5 ONQ Manufacturing Processes © Su-Jin Kim Gyeongsang National University

Blown Film Extrusion • A thin-walled tube is extruded and expanded into a balloon shape by blowing air until the desired film thickness is reached. https: //youtu. be/O 7 BLsex. Jn 0 c https: //youtu. be/WLya. Zb. T 97 EI Gyeongsang National University https: //youtu. be/W 6 V 0 w-ajt. N 8 Plastics Manufacturing Processes © Su-Jin Kim

Thermo (Vacuum) forming • The thermoplastic sheet is heated, pressed into the mold using vacuum pressure • Medium production rates, low tooling cost Vacuum Plastics Manufacturing Processes http: //kr. youtube. com/watch? v=dee. ENCiu. KWM © Su-Jin Kim Gyeongsang National University

Economics of Processing Plastics Production rate • Design and manufacturing decisions are based on costs of equipment, tooling and production volume. Extrusion Injection molding Blow molding Thermo forming Machining 10 102 103 Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University 104 105 106 107 Number of parts

Reference • Wook-Ryol Hwang, GNU : http: //rmp. gnu. ac. kr • Plastic injection molding process analysis, VM Tech: http: //wincapa. com • Mold: http: //asis. co. kr • Mold: http: //www. naramnd. com • Mold http: //www. tsmould. com • Injection machine : http: //dongshin. net • Plastic : http: //lgchem. com Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

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 Plastics http: //vimeo. com/13769356 Manufacturing Processes © Su-Jin Kim Gyeongsang National University

Molding Reinforced Plastics 1. Prepreg 2. Vacuum bag molding 3. Curing in oven Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

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. Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

Vacuum-bag molding • Prepregs lay in mold and apply pressure in a vacuum. Clamping bar Atmospheric pressure Gasket Vacuum trap Vaccum trap Flexible bag Mold release Gel coat Resin and glass Room temperature or oven cure hand or spray lay-up Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University ©갈창우, GNU

Autoclave • Hence, composite structures built of pre-pregs will mostly require an oven or autoclave to cure out. • Temperature 180 °C, Pressure 600 k. Pa, Time 3 h Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

Reference • Polymer Mixing (W. R. Whang) : http: //rmp. gnu. ac. kr/ • Mechanical Properties of Composite (J. H. Choei): http: //gsnu. ac. kr/hb/11176/ • BMW CFRP production: https: //youtu. be/s. FYXHMZFqs. U Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

End Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

Injection molding • insert label in pet mold Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University

Multiple injection molding (복합사출) • Product with hard and soft plastics. Sliding split mold S 778 T + TPE Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University Turn table mold

Open-molding • Open-molding process use single male or female mold and also called contact-molding • Used in making products with high surface-area-tothickness ratios. Plastics Manufacturing Processes http: //ma. gnu. ac. kr/vod/Plastic/FRP_Boat. MP 4 © Su-Jin Kim Gyeongsang National University

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. Plastics Manufacturing Processes http: //www. youtube. com/watch? v=1 u-2 Gvhgh. QA © Su-Jin Kim Gyeongsang National University

Filament winding • Glass fibers are embedded in thermosetting resin matrix materials and winded around a pipe. CNG tank Plastics Manufacturing Processes © Su-Jin Kim Gyeongsang National University