1. Plastic and Polymer Composite Fabrication Processes

3. Molding Processes for PE:
Molding Processes for Nylon (30% GF):

5. You Tube Videos:
Blow Molding:
Extrusion:
Injection:
Thermoforming:

6. Injection Molding – most common (60-70%)
Process
Plastic pellets are heated in the injection unit and forced through a runner system/gate(s) into a cavity in a mold.
Batch Process 6

7. Injection Molding Equipment Clamping Unit (Ejection System)
Injection (Plasticating) Unit
Frame 7

8. Injection Molding Main functions of Plasticating unit
Convey solid material/melt
Mix to produce homogeneous melt
Melt material
Range of 300º F (PVC) to 740º F (Polysulphone)
Develop pressure for injection 8

9. Injection Molding Materials
Both amorphous and semi-crystalline are done easily
Narrow molecular weight distribution
With modifications to the equipment – thermoset materials and liquid Silicone can be used 9

10. Injection Molding Parts Three dimensional Can be very complex
Multiple cavitation is common (128 cavities) 10

11. Injection Molding Tooling - Molds
Generally steel, but some Aluminum tooling is used
High pressure process – molds are ‘beefy’
Plastic pressures around 30,000 psi
Weight – LXWXH/4 (in inches)
Tooling is expensive and can take a long time to create 11

12. Extrusion
Process
Plastic pellets or powders are heated in a plasticating unit and the melt is forced through a forming die.
Continuous Process 12

13. Extrusion
Equipment
Injection (Plasticating) Unit
Frame 13

14. Extrusion
Materials
Both amorphous and semi-crystalline are done easily
Wide molecular weight distribution 14

15. Extrusion Parts Two dimensional Sheet Hoses Line Rod Vinyl siding
Pipes 15

16. Extrusion Tooling - Dies Generally steel – Aluminum is common though
Low pressure process
Tooling can be expensive
Shorter lead times 16

17. Thermoforming Process Sheet is heated and formed to the desired shape
Can be a batch or continuous process
Some consider Thermoforming to be a secondary process because the material needs to be formed into sheet prior to being thermoformed. 17

18. Thermoforming
Process 18

19. Thermoforming
Process 19

20. Thermoforming
Process 20

21. Thermoforming
Equipment
Heating unit
Vacuum unit
Tool or die 21

22. Thermoforming Materials Both amorphous and semi-crystalline are done
Semi-crystalline are more difficult
Wide molecular weight distribution 22

23. Thermoforming
Parts
Three dimensional
Generally simple shapes 23

24. Thermoforming Tooling – Dies or molds
Generally Aluminum, but prototypes are commonly made epoxy, wood, plaster, and composite materials
Low pressure process
Tooling is relatively inexpensive
Shorter lead times 24

25. Blowmolding Process 2 basic types Extrusion Blow Molding
consists of an extruder that melts the plastic and forms it into a molten tube called a parison. Die closes around parison which seals both ends. Blow pin is insereted and inflates the parison to assume the contoru of the die. See
Injection Blow Molding (large volumes)
Uses preforms - The preform is transferred on a metal shank, called the core rod and into a blow mold. 25

26. Blowmolding Equipment
Depends on type of blowmolding you are doing
Extrusion
Extruder
Dies and Blowpins
Clamping system
Injection
Preforms (Injection molding machine)
Heating unit
Blowing machine 26

27. Blowmolding Materials Both amorphous and semi-crystalline are done
Semi-crystalline are more difficult
Highly Crystalline materials (Nylon) are very difficult
Wide molecular weight distribution 27

28. Blowmolding Parts Three dimensional Generally simple shapes Hollow
May need trimmed 28

29. Blowmolding Tooling – Dies or tools
Generally Aluminum (some may have brass inserts)
Steel Pinchoff areas
Low pressure process
Tooling is relatively inexpensive
Shorter lead times 29