1. EXTRUSION

5. Applications
Compounding
Profile

6. Types of Extrusion Single screw Twin screw
co-rotating, counter rotating

7. Extrusion Screw

8. Extrusion Screw

9. Extrusion Screw

10. Extrusion screw

11. Screws for various processes

12. Features of the screw

13. Melting stages

14. Screw Wear

15. Extrusion Die

16. Critical operation parameters
Melt temperature
Melt pressure
Barrel temperature
Die temperature
Heater power
Screw speed
Line speed
Finished products dimension
Cooling rate

17. Sharkskin or alligator hide Uneven flow and surging Degradation
Extrusion problems
Melt fracture
Sharkskin or alligator hide
Uneven flow and surging
Degradation
Poor mixing
Contamination
Bubbles in extrudate

18. Materials consideration
Most thermoplastics
Extrusion grade
High MW, low MFI <1
Broad MWD
Melt strength
Some materials (like PVC) need lubricant
Density differences can cause problems
Fiber breaking

19. Extrusion based processes
Other extrusion based processes include:
profile, pipe & tubing, wire coating, sheet & flat film, blown film, coating, calendaring, fiber spinning, netting, co extrusion