Gap seal between a nozzle and a mold component in an injection molding apparatus

1. A nozzle for an injection molding apparatus, comprising:

a nozzle body, said nozzle body defining a nozzle body melt passage, wherein the nozzle body has an upstream end that is configured for positioning against an injection manifold, and a downstream end that is configured for positioning proximate a gate into a mold cavity in a mold component;

a heater that is thermally connected to said nozzle body for heating melt in said nozzle body melt passage;

a tip, wherein said tip is removably connected to the nozzle body, wherein the tip defines a tip melt passage, wherein the tip melt passage is downstream from the nozzle body melt passage; and

a tip retainer, wherein the tip retainer is removably connected to the nozzle body, wherein the tip retainer retains the tip in position, wherein the tip retainer has a first gap seal surface thereon, wherein the tip retainer is configured for the first gap seal surface to be separated by a gap with respect to a second gap seal surface on the mold component, wherein said gap is sized to inhibit the flow of melt between said first gap seal surface and said second gap seal surface.

2. A nozzle as claimed in claim 1 , wherein the tip includes a conical portion that is configured to extend into the gate.

3. A nozzle as claimed in claim 1 , wherein, in use, a chamber is formed between the nozzle and the mold component proximate the gate and wherein the tip retainer further includes a first mechanical seal surface, wherein said mechanical seal surface is adapted to engage a mechanical seal surface on the mold component, and wherein the first and second mechanical seal surfaces are positioned behind said first and second gap seal surfaces with respect to the chamber.

4. A nozzle as claimed in claim 3 , wherein the tip includes a conical portion that is configured to extend into the gate.

5. A nozzle as claimed in claim 3 , wherein the tip is made from a thermally conductive material and wherein the tip retainer is made from a material that is less thermally conductive than the material of the tip.

6. A nozzle for an injection molding apparatus, comprising:

a nozzle body, said nozzle body defining a nozzle body melt passage, wherein the nozzle body has an upstream end that is configured for positioning against an injection manifold, and a downstream end that is configured for positioning proximate a gate into a mold cavity in a mold component;

a heater that is thermally connected to said nozzle body for heating melt in said nozzle body melt passage;

a tip, wherein said tip is removably connected to the nozzle body, wherein the tip defines a tip melt passage, wherein the tip melt passage is downstream from the nozzle body melt passage; and

a seal piece, wherein the seal piece is removably connected to the nozzle body, and wherein the seal piece has a first gap seal surface thereon, wherein the seal piece is configured for the first gap seal surface to be separated by a gap with respect to a second gap seal surface on the mold component about the gate, wherein said gap is sized to inhibit the flow of melt between said first gap seal surface and said second gap seal surface.

7. A nozzle as claimed in claim 6 , wherein the seal piece retains the tip in position.

8. A nozzle as claimed in claim 6 , wherein the seal piece is spaced from tip.

9. A nozzle as claimed in claim 6 , wherein the tip includes a conical portion that is configured to extend into the gate.

10. A nozzle as claimed in claim 6 , wherein, in use, a chamber is formed between the nozzle and the mold component proximate the gate and wherein the seal piece further includes a first mechanical seal surface, wherein said mechanical seal surface is adapted to engage a mechanical seal surface on the mold component, and wherein the first and second mechanical seal surfaces are positioned behind said first and second gap seal surfaces with respect to the chamber.

11. A nozzle as claimed in claim 10 , wherein the tip includes a conical portion that is configured to extend into the gate.

12. A nozzle as claimed in claim 6 , wherein the tip is made from a thermally conductive material and wherein the seal piece is made from a material that is less thermally conductive than the material of the tip.

13. A nozzle for an injection molding apparatus, comprising:

a nozzle body, said nozzle body defining a nozzle body melt passage, wherein the nozzle body has an upstream end that is configured for positioning against an injection manifold, and a downstream end that is configured for positioning proximate a gate into a mold cavity in a mold component;

a heater that is thermally connected to said nozzle body for heating melt in said nozzle body melt passage; and

a tip, wherein said tip is removably connected to the nozzle body, wherein the tip defines a tip melt passage, wherein the tip melt passage is downstream from the nozzle body melt passage, wherein the tip has a first gap seal surface thereon, wherein the tip is configured for the first gap seal surface to be separated by a gap with respect to a second gap seal surface on the mold component, wherein said gap is sized to inhibit the flow of melt between said first gap seal surface and said second gap seal surface.

14. A nozzle for an injection molding apparatus, comprising:

a nozzle body, said nozzle body defining a nozzle body melt passage, wherein the nozzle body has an upstream end that is configured for positioning against an injection manifold, and a downstream end that is configured for positioning proximate a gate into a mold cavity in a mold component;

a heater that is thermally connected to said nozzle body for heating melt in said nozzle body melt passage;

a tip, wherein said tip is removably connected to the nozzle body, wherein the tip defines a tip melt passage, wherein the tip melt passage is downstream from the nozzle body melt passage;

a tip retainer, wherein the tip retainer is removably connected to the nozzle body, wherein the tip retainer retains the tip in position; and

a seal piece, wherein the seal piece is connected to the tip retainer, and wherein the seal piece has a first gap seal surface thereon, wherein the seal piece is configured for the first gap seal surface to be separated by a gap with respect to a second gap seal surface on the mold component, wherein said gap is sized to inhibit the flow of melt between said first gap seal surface and said second gap seal surface.

15. A nozzle as claimed in claim 14 , wherein the tip is made from a thermally conductive material and wherein the seal piece is made from a material that is less thermally conductive than the material of the tip.

16. A nozzle as claimed in claim 15 , wherein the tip retainer is made from a thermally conductive material.

17. A nozzle as claimed in claim 14 , wherein the tip retainer is made from a thermally conductive material and wherein the seal piece is made from a material that is less thermally conductive than the material of the tip retainer.

18. An injection molding apparatus, comprising:

a manifold, wherein said manifold defines a plurality of runners, wherein said plurality of runners are in fluid communication with a manifold inlet, wherein the manifold inlet is configured for receiving melt from a melt source;

a mold component, wherein said mold component defines a plurality of mold cavities; and

a plurality of nozzles, wherein each nozzle includes a nozzle body, said nozzle body defining a nozzle body melt passage, wherein said nozzle body melt passage is downstream from one of said runners,

wherein each nozzle includes a heater that is thermally connected to said nozzle body for heating melt in said nozzle body melt passage,

and wherein each nozzle includes a tip, wherein said tip is removably connected to the nozzle body, wherein the tip defines a tip melt passage, wherein the tip melt passage is downstream from the nozzle body melt passage and upstream from one of said mold cavities,

and wherein each nozzle includes a tip retainer, wherein the tip retainer is removably connected to the nozzle body, wherein the tip retainer retains the tip in position, wherein the tip retainer has a first gap seal surface thereon, wherein the first gap seal surface is separated by a gap with respect to a second gap seal surface on the mold component, wherein said gap is sized to inhibit the flow of melt between said first gap seal surface and said second gap seal surface.

19. An injection molding apparatus as claimed in claim 18 , wherein the tip includes a conical portion that is configured to extend into a gate leading to the mold cavity.

20. An injection molding apparatus as claimed in claim 18 , wherein the nozzle and the mold component together define a chamber surrounding the gate, and wherein the tip retainer further includes a first mechanical seal surface, wherein said mechanical seal surface is adapted to engage a mechanical seal surface on the mold component, and wherein the first and second mechanical seal surfaces are positioned behind said first and second gap seal surfaces with respect to the chamber.

21. An injection molding apparatus as claimed in claim 20 , wherein the tip includes a conical portion that is configured to extend into a gate leading to the mold cavity.

22. An injection molding apparatus as claimed in claim 20 , wherein the tip is made from a thermally conductive material and wherein the tip retainer is made from a material that is less thermally conductive than the material of the tip.

23. An injection molding apparatus as claimed in claim 20 , wherein said gap is less than approximately 0.25 mm.

24. An injection molding apparatus as claimed in claim 20 , wherein said gap is approximately 0.15 mm.

25. An injection molding apparatus as claimed in claim 18 , wherein the mold component includes a plurality of cooling channels for the flow of coolant therethrough.

26. An injection molding apparatus as claimed in claim 18 , wherein said gap is less than approximately 0.07 mm.

27. An injection molding apparatus, comprising:

a manifold, wherein said manifold defines a plurality of runners, wherein said plurality of runners are in fluid communication with a manifold inlet, wherein the manifold inlet is configured for receiving melt from a melt source;

a mold component, wherein said mold component defines a plurality of mold cavities; and

a plurality of nozzles, wherein each nozzle includes a nozzle body, said nozzle body defining a nozzle body melt passage, wherein said nozzle body melt passage is downstream from one of said runners,

wherein each nozzle includes a heater that is thermally connected to said nozzle body for heating melt in said nozzle body melt passage,

and wherein each nozzle includes a tip, wherein said tip is removably connected to the nozzle body, wherein the tip defines a tip melt passage, wherein the tip melt passage is downstream from the nozzle body melt passage and upstream from one of said mold cavities,

and wherein each nozzle includes a seal piece for sealing between said nozzle body and the mold component about a gate into one of the mold cavities, wherein the seal piece is removably connected to the nozzle body, wherein the seal piece has a first gap seal surface thereon, wherein the first gap seal surface is separated by a gap with respect to a second gap seal surface on the mold component, wherein said gap is sized to inhibit the flow of melt between said first gap seal surface and said second gap seal surface.

28. An injection molding apparatus as claimed in claim 27 , wherein the seal piece retains the tip in position.

29. An injection molding apparatus as claimed in claim 27 , wherein the seal piece is spaced from tip.

30. An injection molding apparatus as claimed in claim 27 , wherein the tip includes a conical portion that is configured to extend into a gate leading to the mold cavity.

31. An injection molding apparatus as claimed in claim 27 , wherein the nozzle and the mold component together define a chamber surrounding the gate, and wherein the seal piece further includes a first mechanical seal surface, wherein said mechanical seal surface is adapted to engage a mechanical seal surface on the mold component, and wherein the first and second mechanical seal surfaces are positioned behind said first and second gap seal surfaces with respect to the chamber.

32. An injection molding apparatus as claimed in claim 31 , wherein the tip includes a conical portion that is configured to extend into a gate leading to the mold cavity.

33. An injection molding apparatus as claimed in claim 31 , wherein said gap is less than approximately 0.25 mm.

34. An injection molding apparatus as claimed in claim 31 , wherein said gap is approximately 0.15 mm.

35. An injection molding apparatus as claimed in claim 27 , wherein the tip is made from a thermally conductive material and wherein the seal piece is made from a material that is less thermally conductive than the material of the tip.

36. An injection molding apparatus as claimed in claim 27 , wherein the mold component includes a plurality of cooling channels for the flow of coolant therethrough.

37. An injection molding apparatus as claimed in claim 27 , wherein said gap is less than approximately 0.07 mm.

38. An injection molding apparatus, comprising:

a manifold, wherein said manifold defines a plurality of runners, wherein said plurality of runners are in fluid communication with a manifold inlet, wherein the manifold inlet is configured for receiving melt from a melt source;

a mold component, wherein said mold component defines a plurality of mold cavities; and

a plurality of nozzles, wherein each nozzle includes a nozzle body, said nozzle body defining a nozzle body melt passage, wherein said nozzle body melt passage is downstream from one of said runners,

wherein each nozzle includes a heater that is thermally connected to said nozzle body for heating melt in said nozzle body melt passage,

and wherein each nozzle includes a tip, wherein said tip is removably connected to the nozzle body, wherein the tip defines a tip melt passage, wherein the tip melt passage is downstream from the nozzle body melt passage and upstream from one of said mold cavities,

and wherein said tip has a first gap seal surface thereon, wherein the first gap seal surface is separated by a gap with respect to a second gap seal surface on the mold component, wherein said gap is sized to inhibit the flow of melt between said first gap seal surface and said second gap seal surface.

39. An injection molding apparatus as claimed in claim 38 , wherein the mold component includes a plurality of cooling channels for the flow of coolant therethrough.

40. An injection molding apparatus as claimed in claim 38 , wherein said gap is less than approximately 0.07 mm.

41. An injection molding apparatus, comprising:

a manifold, wherein said manifold defines a plurality of runners, wherein said plurality of runners are in fluid communication with a manifold inlet, wherein the manifold inlet is configured for receiving melt from a melt source;

a mold component, wherein said mold component defines a plurality of mold cavities; and

a plurality of nozzles, wherein each nozzle includes a nozzle body, said nozzle body defining a nozzle body melt passage, wherein said nozzle body melt passage is downstream from one of said runners,

wherein each nozzle includes a heater that is thermally connected to said nozzle body for heating melt in said nozzle body melt passage,

and wherein each nozzle includes a tip, wherein said tip is removably connected to the nozzle body, wherein the tip defines a tip melt passage, wherein the tip melt passage is downstream from the nozzle body melt passage and upstream from one of said mold cavities,

and wherein each nozzle includes a tip retainer, wherein the tip retainer is removably connected to the nozzle body, wherein the tip retainer retains the tip in position,

and wherein each nozzle includes a seal piece for sealing between said nozzle body and the mold component about a gate into one of the mold cavities, wherein the seal piece is connected to the tip retainer, wherein the seal piece has a first gap seal surface thereon, wherein the first gap seal surface is separated by a gap with respect to a second gap seal surface on the mold component, wherein said gap is sized to inhibit the flow of melt between said first gap seal surface and said second gap seal surface.

42. An injection molding apparatus as claimed in claim 41 , wherein the tip is made from a thermally conductive material and wherein the seal piece is made from a material that is less thermally conductive than the material of the tip.

43. An injection molding apparatus as claimed in claim 42 , wherein the tip retainer is made from a thermally conductive material.

44. An injection molding apparatus as claimed in claim 41 , wherein the tip retainer is made from a thermally conductive material and wherein the seal piece is made from a material that is less thermally conductive than the material of the tip retainer.

45. An injection molding apparatus as claimed in claim 41 , wherein the mold component includes a plurality of cooling channels for the flow of coolant therethrough.