Static mixer and a method of manufacture thereof

• US 7,198,400 B2
• Filed: 05/03/2003
• Issued: 04/03/2007
• Est. Priority Date: 05/03/2003
• Status: Active Grant

• Current Assignee: Husky Injection Molding Systems Limited
• Original Assignee: Husky Injection Molding Systems Limited
• Inventors: Brelski, Maciej, Craig, Denise, Schad, Robert, Lacza, Peter, Unterlander, Richard
• Primary Examiner(s): SOOHOO, TONY GLEN
• Application Number:
  US10/429,600
• Publication Number:
  US 20040218469A1
• Time in Patent Office: 1,431 Days
• Field of Search: 366/336, 366/340, 366/80, 425/197, 425/199, 425/205, 425/207
• US Class Current: 366/336
• CPC Class Codes: B01F 25/43231 the channels or tubes crossing each other several times
• CPC Class Codes: B29B 7/325 Static mixers in general B01F25/42
• CPC Class Codes: B29B 7/88 Adding charges , i.e. additives
• CPC Class Codes: B29C 45/30 Flow control means disposed within the sprue channel, e.g. "torpedo" construction
• CPC Class Codes: B29C 45/581 Devices for influencing the material flow, e.g. "torpedo constructions" or mixing devices
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material

Abstract

A static mixer comprising a mixer body with a first and a second array of intermeshed and interconnecting passageways formed therein that connect, and provide a convoluted flow path between, flow faces at ends of the mixer body. The first and second arrays of passageways preferably interconnect such that the boundaries of adjacent intermeshed passageways overlap to form mixing portals. When used in an injection molding system, a singular melt flow is initially divided at the first flow face of the static mixer, wherein the melt flow divides into the intermeshing passageways and further divides and re-combines at the locations of mixing portals before exiting the static mixer at the second flow face as homogenized melt.

Claims

1. A static mixer for use in a melt flow channel of an injection molding system, said static mixer comprising:

a mixer body (500);

a first flow face (504) configured at an end of said mixer body (500);

a second flow face (505) configured at an opposite end of said mixer body (500) from said first flow face (504);

an outer surface (501) configured around the mixer body (500) between the ends thereof;

a plurality of first passageways (512) configured in said mixer body (500);

a plurality of second passageways (514) configured in said mixer body (500);

said plurality of first and second passageways (512, 514) configured to extend along substantially straight longitudinal axes;

said plurality of first and second passageways (512,514) being arranged into a first and a second array, respectively, said arrays being intermeshed and interconnected to configure a plurality of mixing portals (516) between said first and second passageways (512, 514);

said first and second arrays of passageways (512, 514) including;

a first subset of passageways (546, 549) each passageway of which extend between the flow faces (504, 505) with a corresponding plurality of fluid portals (518, 520) being configured along each flow face (504, 505);

a second subset of passageways (547, 550) each passageway of which extend about half way through the mixer body (500) from the first flow face (504), without opening to the outer surface (501) of the mixer body (500), with a corresponding plurality of fluid portals (518, 520) being configured along the first flow face (504);

a third subset of passageways (548, 551) each passageway of which extend about half way through the mixer body (500) from the second flow face (505), without opening to the outer surface (501) of the mixer body (500), with a corresponding plurality of fluid portals (518, 520) being configured along the second flow face (505);

an end of each passageway of said second and third subset (547, 550), (548, 551) being enclosed within said mixer body (500) and having a mixing portal (516) defined therebetween;

whereby said plurality of intermeshed and interconnected first and second passageways (512, 514) provide a convoluted flow path between said flow faces (504, 505).

2. The static mixer of claim 1, wherein said first array of passageways are arranged with the longitudinal axes of said first passageways (512) disposed along one of a first set of flow planes (513), and the second array of passageways are arranged with the longitudinal axes of said second passageways (514) disposed along one of a second set of flow planes (515).

3. The static mixer of claim 2, wherein the first and second sets of flow planes (513 and 515) are parallel, perpendicular to a reference plane (502) that bisects the mixer body (500) along its longitudinal axis, oriented with the longitudinal axis of the mixer body (500), and intermeshed in an regular-spaced alternating arrangement.

4. The static mixer of claim 3, wherein the first and second passageways (512 and 514) inclined relative to each other.

5. The static mixer of claim 4, wherein the longitudinal axes of the passageways (512 and 514) within an array are oriented on their respective flow planes (513 and 515) such that the passageways are mutually parallel.

6. The static mixer of claim 5, wherein the passageways of the first and second arrays (512 and 514) are inclined at opposite angles with respect to the reference plane (502).

7. The static mixer of claim 6, wherein the opposite angle is 45 degrees.

8. The static mixer of claim 5, wherein the passageways (312 and 314) are formed as straight cylindrical bores of a constant and equal diameter.

9. The static mixer of claim 8, wherein the mixing portals (516) have the same cross-sectional area as the passageways (512 and 514).

10. The static mixer of claim 9, wherein an array pitch of the first and second arrays is identical.

11. The static mixer of claim 10, wherein relative spacing between adjacent flow planes (513 and 515), of the first and second set, is about one-half of the spacing of the array pitch.

12. The static mixer of claim 11, wherein the mixer body (500) is cylindrical with ends providing the flow faces (504, 505).

13. The static mixer of claim 1, wherein the plurality fluid portals (518 and 520) of the first subset of passageways (546 and 549) extend across the periphery of the flow faces (504, 505) in opposed parallel rows for the first and second arrays of passageways (512 and 514) respectively.

14. The static mixer of claim 13, wherein the plurality fluid portals (518 and 520) of the second subset of passageways (547 and 550) extend across the first flow face (504) in a pair of closely-spaced rows that stagger the reference plane 502, each row corresponding to the passageways of the first and second arrays (512 and 514) respectively, and are parallel to the rows of fluid portals from the first subset of passageways.

15. The static mixer of claim 14, wherein the plurality fluid portals (518 and 520) of the third subset of passageways (548 and 551) extend across the second flow face (505) in a pair of closely-spaced rows that stagger the reference plane 502, each row corresponding to the passageways of the first and second arrays (512 and 514) respectively, and are parallel to the rows of fluid portals from the first subset of passageways.

16. The static mixer of claim 15, wherein the passageways (512 and 514) are formed as straight cylindrical bores of a constant and equal diameter.

17. The static mixer of claim 16, wherein the mixing portals (516) have the same cross-sectional area as the passageways (512 and 514).

18. The static mixer of claim 13 wherein an alignment hole (508) is provided through the bearing surface (506) of the annular shoulder (507) on both sides of the mixer body (500).

19. The static mixer of claim 18, wherein the alignment holes (508) on opposing flow faces (504, 505) are rotationally displaced by 90°

.

20. The static mixer of claim 1, wherein each flow face (504, 505) includes a recessed face (552) covering a substantial central portion of the end of the mixer body (500) at a uniform shallow depth, an annular shoulder (507) with a bearing surface (506) atop the annular shoulder (507) and a tapered face (554) that tapers inwardly and extends between the bearing surface (506) and the recessed face (552).

21. The static mixer of claim 20, further comprising a plurality of routing grooves (530 and 540) that extend across the flow faces (504, 505) to connect the fluid portals (518 and 520) along each row thereof.

22. The static mixer of claim 21, wherein the fluid portals (518 and 520) along each row of the first subset of passageways (546 and 549) are connected by a plurality of lateral routing grooves (540).

23. The static mixer of claim 22, wherein each lateral routing groove (540) has a rounded profile 542 with semi-spherical ends that blends into the tapered face (544).

24. The static mixer of claim 23, wherein each flow face (504, 505) further includes a radial spherical routing groove (553), formed through the recessed face (552), that extends between the ends of the lateral routing groove (540) along a path that is tangential with the tapered face (554) and is adjacent the outside edge of the lateral routing groove (540).

25. The static mixer of claim 24, wherein the radial spherical routing groove (553) is further blended into the lateral routing groove (540) by a tapered face (544) that extends along the outside edge of the lateral groove (540) and is tapered inwardly towards the center thereof.

26. The static mixer of claim 25, wherein the fluid portals (518 and 520) of the second and third subsets of passageways (547, 550, 548, and 551) are connected, along the first and second flow faces (504, 505) respectively, by a medial routing groove (530).

27. The static mixer of claim 26 wherein each medial routing groove (530) has a rounded profile (542) with semi-spherical ends that blends into the tapered face (544).

28. The static mixer of claim 27 wherein the medial routing groove (530) is blended into the recessed face (552), along both sides of the groove, by tapered faces (534) that extend along the edges of the lateral groove and are tapered inwardly towards the center thereof.

29. The static mixer of claim 1, wherein each flow face (504, 505) includes a conical face (624) covering a substantial central portion of the end of the mixer body (600), the conical face (624) has an inward taper towards the center of the flow face (604, 605) at a shallow angle, and is recessed at a shallow depth relative to the bearing surface (606) of a narrow annular shoulder (607) that surrounds the flow face (604, 605).

30. The static mixer of claim 29, wherein each flow face (604, 605) further includes a medial routing groove (620) that extends across the recessed conical face (624) to connect the fluid portals of the second and third subsets (547, 548, 550, and 551) of the first and second arrays of passageways (612 and 614) across the first and second flow faces (604) respectively.

31. The static mixer of claim 30, wherein each medial routing groove (630) has a rounded profile (642) with semi-spherical ends.

32. The static mixer of claim 1, wherein the mixer is configured to be arranged in a nozzle adapter assembly (700) having a flow channel (753) extending through it, the nozzle adapter assembly (700) providing a connection between a barrel (750) and a sprue of an injection mold runner system in an injection molding system (800).

33. The static mixer of claim 1, configured to be arranged in a runner system of an injection mold (850).

34. The static mixer of claim 1, wherein the first and second passageways are interconnected as a distinct series of intermeshed and interconnected passageways.

35. The static mixer of claim 1, wherein the mixing portal is a connection passageway.

36. The static mixer of claim 1, wherein the passageways are formed as interconnected helixes.

37. The static mixer of claim 1, wherein the passageways are formed with straight longitudinal axes but with a helical outer form.

38. An injection molding system including a static mixer configured in a melt channel thereof, the static mixer comprising:

a mixer body (500);

a first flow face (504) configured at an end of said mixer body (500);

a second flow face (505) configured at an opposite end of said mixer body (500) from said first flow face (504);

an outer surface (501) configured around the mixer body (500) between the ends thereof;

a plurality of first passageways (512) configured in said mixer body (500);

a plurality of second passageways (514) configured in said mixer body (500);

said plurality of first and second passageways (512, 514) configured to extend along substantially straight longitudinal axes;

said plurality of first and second passageways (512, 514) being arranged into a first and a second array, respectively, said arrays being intermeshed and interconnected to configure a plurality of mixing portals (516) between said first and second passageways (512, 514);

said first and second arrays of passageways (512, 514) including;

a first subset of passageways (546, 549) each passageway of which extend between the flow faces (504, 505) with a corresponding plurality of fluid portals (518, 520) being configured along each flow face (504, 505);

a second subset of passageways (547, 550) each passageway of which extend about half way through the mixer body (500) from the first flow face (504), without opening to the outer surface (501) of the mixer body (500), with a corresponding plurality of fluid portals (518, 520) being configured along the first flow face (504);

a third subset of passageways (548, 551) each passageway of which extend about half way through the mixer body (500) from the second flow face (505), without opening to the outer surface (501) of the mixer body (500), with a corresponding plurality of fluid portals (518, 520) being configured along the second flow face (505);

an end of each passageway of said second and third subset (547, 550), (548, 551) being enclosed within said mixer body (500) and having a mixing portal (516) defined therebetween;

whereby said plurality of intermeshed and interconnected first and second passageways (512, 514) provide a convoluted flow path between said flow faces (504, 505).

39. The injection molding system of claim 38, wherein said first array of passageways are arranged with the longitudinal axes of said first passageways (512) disposed along one of a first set of flow planes (513), and the second array of passageways are arranged with the longitudinal axes of said second passageways (514) disposed along one of a second set of flow planes (515).

40. The injection molding system of claim 39, wherein the first and second sets of flow planes (513 and 515) are parallel, perpendicular to a reference plane (502) that bisects the mixer body (500) along its longitudinal axis, oriented with the longitudinal axis of the mixer body (500), and intermeshed in an regular-spaced alternating arrangement.

41. The injection molding system of claim 40, wherein the first and second passageways (512 and 514) inclined relative to each other.

42. The injection molding system of claim 41, wherein the longitudinal axes of the passageways (512 and 514) within an array are oriented on their respective flow planes (513 and 515) such that the passageways are mutually parallel.

43. The injection molding system of claim 42, wherein the passageways of the first and second arrays (512 and 514) are inclined at opposite angles with respect to the reference plane (502).

44. The injection molding system of claim 43, wherein the opposite angle is 45 degrees.

45. The injection molding system of claim 42, wherein the passageways (312 and 314) are formed as straight cylindrical bores of a constant and equal diameter.

46. The injection molding system of claim 45, wherein the mixing portals (516) have the same cross-sectional area as the passageways (512 and 514).

47. The injection molding system of claim 46, wherein an array pitch of the first and second arrays is identical.

48. The injection molding system of claim 47, wherein relative spacing between adjacent flow planes (513 and 515), of the first and second set, is about one-half of the spacing of the array pitch.

49. The injection molding system of claim 48, wherein the mixer body (500) is cylindrical with ends providing the flow faces (504, 505).

50. The injection molding system of claim 38, wherein the plurality fluid portals (518 and 520) of the first subset of passageways (546 and 549) extend across the periphery of the flow faces (504, 505) in opposed parallel rows for the first and second arrays of passageways (512 and 514) respectively.

51. The injection molding system of claim 50, wherein the plurality fluid portals (518 and 520) of the second subset of passageways (547 and 550) extend across the first flow face (504) in a pair of closely-spaced rows that stagger the reference plane 502, each row corresponding to the passageways of the first and second arrays (512 and 514) respectively, and are parallel to the rows of fluid portals from the first subset of passageways.

52. The injection molding system of claim 51, wherein the plurality fluid portals (518 and 520) of the third subset of passageways (548 and 551) extend across the second flow face (505) in a pair of closely-spaced rows that stagger the reference plane 502, each row corresponding to the passageways of the first and second arrays (512 and 514) respectively, and are parallel to the rows of fluid portals from the first subset of passageways.

53. The injection molding system of claim 52, wherein the passageways (512 and 514) are formed as straight cylindrical bores of a constant and equal diameter.

54. The injection molding system of claim 53, wherein the mixing portals (516) have the same cross-sectional area as the passageways (512 and 514).

55. The injection molding system of claim 50 wherein an alignment hole (508) is provided through the bearing surface (506) of the annular shoulder (507) on both sides of the mixer body (500).

56. The injection molding system of claim 55, wherein the alignment holes (508) on opposing flow faces (504, 505) are rotationally displaced by 90°

.

57. The injection molding system of claim 38, wherein each flow face (504, 505) includes a recessed face (552) covering a substantial central portion of the end of the mixer body (500) at a uniform shallow depth, an annular shoulder (507) with a bearing surface (506) atop the annular shoulder (507) and a tapered face (554) that tapers inwardly and extends between the bearing surface (506) and the recessed face (552).

58. The injection molding system of claim 57, further comprising a plurality of routing grooves (530 and 540) that extend across the flow faces (504, 505) to connect the fluid portals (518 and 520) along each row thereof.

59. The injection molding system of claim 58, wherein the fluid portals (518 and 520) along each row of the first subset of passageways (546 and 549) are connected by a plurality of lateral routing grooves (540).

60. The injection molding system of claim 59, wherein each lateral routing groove (540) has a rounded profile 542 with semi-spherical ends that blends into the tapered face (544).

61. The injection molding system of claim 60, wherein each flow face (504, 505) further includes a radial spherical routing groove (553), formed through the recessed face (552), that extends between the ends of the lateral routing groove (540) along a path that is tangential with the tapered face (554) and is adjacent the outside edge of the lateral routing groove (540).

62. The injection molding system of claim 61, wherein the radial spherical routing groove (553) is further blended into the lateral routing groove (540) by a tapered face (544) that extends along the outside edge of the lateral groove (540) and is tapered inwardly towards the center thereof.

63. The injection molding system of claim 62, wherein the fluid portals (518 and 520) of the second and third subsets of passageways (547, 550, 548, and 551) are connected, along the first and second flow faces (504, 505) respectively, by a medial routing groove (530).

64. The injection molding system of claim 63 wherein each medial routing groove (530) has a rounded profile (542) with semi-spherical ends that blends into the tapered face (544).

65. The injection molding system of claim 64 wherein the medial routing groove (530) is blended into the recessed face (552), along both sides of the groove, by tapered faces (534) that extend along the edges of the lateral groove and are tapered inwardly towards the center thereof.

66. The injection molding system of claim 38, wherein each flow face (504, 505) includes a conical face (624) covering a substantial central portion of the end of the mixer body (600), the conical face (624) has an inward taper towards the center of the flow face (604, 605) at a shallow angle, and is recessed at a shallow depth relative to the bearing surface (606) of a narrow annular shoulder (607) that surrounds the flow face (604, 605).

67. The injection molding system of claim 66, wherein each flow face (604, 605) further includes a medial routing groove (620) that extends across the recessed conical face (624) to connect the fluid portals of the second and third subsets (547, 548, 550, and 551) of the first and second arrays of passageways (612 and 614) across the first and second flow faces (604) respectively.

68. The injection molding system of claim 67, wherein each medial routing groove (630) has a rounded profile (642) with semi-spherical ends.

69. The injection molding system of claim 38, wherein the mixer is arranged in a nozzle adapter assembly (700) having a flow channel (753) extending through it, the nozzle adapter assembly (700) providing a connection between a barrel (750) and a sprue of an injection mold runner system in an injection molding system (800).

70. The injection molding system of claim 69, wherein the nozzle adapter assembly (700) comprises a tubular nozzle adapter (706) with a bore therein adapted to receive at least one static mixer (510), and an annular nozzle tip (702) fastened to an end of the nozzle adapter (706).

71. The injection molding system of claim 70, wherein the nozzle adapter assembly (700) includes a stacked set of static mixers (510) that are kept mutually aligned with alignments pins (708) received in alignment holes (508) provided on the static mixers (510).

72. The injection molding system of claim 71, wherein adjacent static mixers (510) in the nozzle adapter assembly (700) have a relative angular orientation of 90°

about their longitudinal axis.

73. The injection molding system of claim 72, wherein the nozzle adapter assembly (700) further includes a tubular spacer (704) received and retained in the bore of the nozzle adapter (706) by an end face of the barrel (750), wherein the static mixers (510) are positioned and retained along the bore of the nozzle adapter (706) between a shoulder of the nozzle tip (702) and the tubular spacer (704) that extends into the bore of the nozzle adapter (706).

74. The injection molding system of claim 38, arranged in a runner system of an injection mold (850).

75. The injection molding system of claim 38, wherein the first and second passageways are interconnected as a distinct series of intermeshed and interconnected passageways.

76. The injection molding system of claim 38, wherein the mixing portal is a connection passageway.

77. The injection molding system of claim 38, wherein the passageways are formed as interconnected helixes.

78. The injection molding system of claim 38, wherein the passageways are formed with straight longitudinal axes but with a helical outer form.