Injection Molding

1. Injection Molding MFG 355

4. 15 Ton Injection Molding Machine Click on frame to start video

5. 77 Ton Injection Molding Machine Click on frame to start video

6. 150 Ton Injection Molding Machine Click on frame to start video

7. Feed hopper Barrel heaters Nozzle Screw drive arrangement Tool Screw Check valve Screw tip Equipment • Injection Unit

8. Equipment • Injection Unit

11. Injection • Parts of the injection screw • Screw • Head and check ring

12. Equipment • Molds

13. Molds

14. Mold Materials • Aluminum filled epoxy • Aluminum • Tool steel • Stainless steel • Hotwork die steel • Beryllium-copper

15. Mold Materials • Choice based on critical properties • Machinability • Coefficient of thermal expansion • Specific heat capacity • Thermal conductivity • Density • Hardness (abrasion resistance) • Yield strength • Weldability

16. Mold Parts • Bases • Standard sizes • Hold mold inserts • Can decrease overall mold costs

17. Mold Parts • Guide pins • Align mold cavities Guide pins

18. Mold Parts • Sprue Bushing • Hot sprue • Cold sprue

19. Mold Parts • Sprue Bushing • Hot sprue

20. Mold Parts • Sprue Bushing • Cold sprue • Sprue puller

21. Mold Parts • Sprue Bushing • Cold sprue • Sprue puller

22. Mold Parts • Runner

23. Mold Parts • Runner • Layout Improved Balanced “H” Circular Conventional

24. Mold Parts • Runner • Layout Improved Balanced “H” Circular Conventional

25. Mold Parts • Runner • Cold well

26. Mold Parts • Runner

27. Mold Parts • Gates Submarine Gate Fan or Edge Gate Pinpoint Gate

28. Mold Parts • Gates Tab Gate Sprue Gate Flash Gate

29. Mold Parts • Gates Internal Ring Gate External Ring Gate

30. Mold Parts • Gate

31. Mold Parts • Gate

32. Mold Parts • Gate

33. Mold Parts • Cavity • Where the part is made • Layout is critical to material flow

34. Mold Parts • Cavity • Knit/weld lines This shows where the weld lines (shown in red) will most likely occur withthe part gated in the center (yellow cone).

35. Mold Parts • Cooling • Reduce cycle time • Control formation of crystalline areas • Freeze part Mold cavity Cooling lines

36. Mold Parts • Ejector system Ejector pins Return Springs Ejector Plate

37. Equipment • Clamping Unit

38. Equipment • Clamping Unit • Toggle clamping • Hydraulic clamping • Hybrid hydraulic-toggle clamping

39. Equipment • Clamping Unit

40. Equipment • Clamping Unit • Toggle system Click on frame to start video

41. Plant Concepts

42. Safety • High clamping forces • High pressure lines • High voltage • High temperatures

43. Safety • Position switches • Mechanical, hydraulic and electrical • Shields • Lock out/tag out

44. Material and Product Considerations • Shapes • Possible to do very complex shapes • Structural features • Pins, ribs, bosses, threads, holes • Deep parts are possible • Internal or external threads • Undercuts require sliding mold sections

45. Sliding Mechanism

46. Material and Product Considerations • Part design • Uniform wall thickness • Helps reduce dimples, shrink marks and distortion • Ribs • Save weight at given strength • No sharp bends • Helps to fill the mold cavity easier • Oversize the mold • Shrinkage amount is dependant on material and additives/fillers

47. Operations and Control • Temperature of melt • Temperature of mold • Pressure of injection and hold • Injection or fill rate and time • Dwell time • Freeze time • Ejection (dead time)

48. Special Injection Molding Processes • Coinjection molding • Two separate screws • Two different material selections • Color, strength, flexibility

49. Special Injection Molding Processes • Coinjection molding 1 2 3

50. Special Injection Molding Processes • Coinjection molding Part 1 Part 2