1. Injection Molding Plastics Tech 1

2. Composition of Plastics Lesson Essential Question: What is injection molding & how do we achieve part fabrication from the process?

3. What is it? A manufacturing technique used for making identical parts from forcing melted thermoplastic material into a mold.

4. How? Thermoplastic material is placed in a hopper Ex: Polypropylene or Polystyrene From the hopper the material goes through the feed hole Barrel made of heavy steel to withstand the pressure and temperature involved in melting the resin

5. How? Molten plastic is injected at high pressure into a mold. 325°F to 600°F 2 types of injection systems used Reciprocating Screw Ram injector

6. Mold’s Mold The mold is an inverse of the desired shape. Made from metal Steel or aluminum Molten material flows from the sprue through the runner (connecting channel) to the mold cavities

7. Mold’s

8. Sprue Runner Gate Mold Cavity

9. How it looks in the Class Specifications Cap:2/3 oz. shot Manual Ram System Electric Heat Control Teflon Coated Heater Block

10. How it looks in Industry

11. Plastics Video Clips Injection Molding

12. Review What type of plastic is used for Injection Molding? What happens to the material when it is in the barrel? What are the two types of injection systems? What is the purpose of the runner in a mold? Thermoplastic Heat is applied to the material. Ram & Reciprocating Screw Channels the molten material to the mold cavity.

13. Review Complete the review worksheet with a partner. The worksheet will be submitted for course credit.