Induction heating using dual susceptors

• US 20040129924A1
• Filed: 02/23/2004
• Published: 07/08/2004
• Est. Priority Date: 06/28/2002
• Status: Abandoned Application

• Current Assignee: Emabond Solutions, LLC
• Original Assignee: Emabond Solutions, LLC
• Inventors: Stark, Philip
• Application Number:
  US10/432,278
• Publication Number:
  US 20040129924A1
• Time in Patent Office: Days
• US Class Current: 252/500
• CPC Class Codes: B29C 2035/0811 using induction
• CPC Class Codes: B29C 35/0272 using lost heating elements, i.e. heating means incorporated and remaining in the formed article for preforms with internal stresses B29C61/0625; joining using lost heating elements B29C65/34; making electrically conductive articles B29C70/882
• CPC Class Codes: B29C 65/3612 comprising fillers
• CPC Class Codes: B29C 65/368 with a polymer coating
• CPC Class Codes: B29C 65/3696 with a coating
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/73751 the to-be-joined area of at least one of the parts to be joined being uncured, i.e. non cross-linked, non vulcanized
• CPC Class Codes: B29C 66/73753 the to-be-joined area of at least one of the parts to be joined being partially cured, i.e. partially cross-linked, partially vulcanized
• CPC Class Codes: B29C 66/7392 characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/7394 characterised by the material of at least one of the parts being a thermoset
• CPC Class Codes: B29C 66/91216 enabling contactless temperature measurements, e.g. using a pyrometer
• CPC Class Codes: B29C 66/91221 of the parts to be joined
• CPC Class Codes: B29C 66/91411 of the parts to be joined, e.g. the joining process taking the temperature of the parts to be joined into account
• CPC Class Codes: B29C 66/91443 following a temperature-time profile B29C65/38 takes precedence
• CPC Class Codes: B29C 66/91651 by controlling or regulating the heat generated by Joule heating or induction heating
• CPC Class Codes: B29C 66/91655 by controlling or regulating the current intensity
• CPC Class Codes: B29C 66/919 characterised by specific temperature, heat or thermal flux values or ranges specific electrical resistance values B29C66/81262
• CPC Class Codes: B29C 66/91931 in explicit relation to the fusion temperature or melting point of the material of one of the parts to be joined
• CPC Class Codes: B29C 66/91951 in explicit relation to time, e.g. temperature-time diagrams
• CPC Class Codes: B29K 2001/00 : Use of cellulose, modified cellulose or cellulose derivatives, e.g. viscose, as moulding material
• CPC Class Codes: B29K 2021/00 : Use of unspecified rubbers as moulding material
• CPC Class Codes: B29K 2023/0633 : LDPE, i.e. low density polyethylene
• CPC Class Codes: B29K 2023/065 : HDPE, i.e. high density polyethylene
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2025/04 : Polymers of styrene
• CPC Class Codes: B29K 2025/06 : PS, i.e. polystyrene
• CPC Class Codes: B29K 2027/06 : PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2027/12 : containing fluorine
• CPC Class Codes: B29K 2027/18 : PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: B29K 2031/04 : Polymers of vinyl acetate, e.g. PVAc, i.e. polyvinyl acetate
• CPC Class Codes: B29K 2033/08 : Polymers of acrylic acid esters, e.g. PMA, i.e. polymethylacrylate
• CPC Class Codes: B29K 2033/12 : Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B29K 2063/00 : Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2067/06 : Unsaturated polyesters
• CPC Class Codes: B29K 2069/00 : Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2071/00 : Use of polyethers , e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2071/12 : PPO, i.e. polyphenylene oxide; PPE, i.e. polyphenylene ether
• CPC Class Codes: B29K 2075/00 : Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2075/02 : Polyureas
• CPC Class Codes: B29K 2077/00 : Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2079/00 : Use of polymers having nitrogen, with or without oxygen or carbon only, in the main chain , not provided for in groups B29K2061/00 - B29K2077/00, as moulding material
• CPC Class Codes: B29K 2079/08 : PI, i.e. polyimides or derivatives thereof
• CPC Class Codes: B29K 2079/085 : Thermoplastic polyimides, e.g. polyesterimides, PEI, i.e. polyetherimides, or polyamideimides; Derivatives thereof
• CPC Class Codes: B29K 2081/04 : Polysulfides, e.g. PPS, i.e. polyphenylene sulfide or derivatives thereof
• CPC Class Codes: B29K 2081/06 : PSU, i.e. polysulfones; PES, i.e. polyethersulfones or derivatives thereof
• CPC Class Codes: B29K 2083/00 : Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material
• CPC Class Codes: B29K 2995/0005 : Conductive

Abstract

The invention relates to an agent for heating materials comprising (a) at least one plurality of electrically non-conductive susceptors and (b) at least one plurality of electrically conductive susceptors. Preferably the electrically non-conductive susceptors comprise micron-sized ferrimagnetic particles and the electrically conductive particles comprise ferromagnetic particles or intrinsically conductive polymer particles.

Claims

1. A heating agent for heating thermoplastic materials comprising (a) electrically non-conductive susceptors and (b) electrically conductive susceptors.

2. The agent according to claim 1, wherein the electrically non-conductive susceptors comprise micron-sized ferrimagnetic particles.

3. The agent according to claim 1, wherein the electrically conductive susceptors comprise ferromagnetic particles.

4. The agent according to claim 1, wherein the electrically non-conductive susceptors have a size of from about 1.0 μ

m to about 50 μ

m.

5. The agent according to claim 1, wherein the electrically conductive susceptors have a size of from about 5 μ

m to about 100 μ

m.

6. The agent according to claim 5, wherein the electrically conductive susceptors have a size of from about 10 μ

m to about 50 μ

m.

7. The agent according to claim 2-6, wherein the electrically non-conductive susceptors comprise iron oxide particles, hexagonal ferrite particles, or magnetically soft ferrite particles.

8. The agent according to claim 7, wherein the hexagonal ferrites have the composition SrF, Me_a-2W, Me_a-2Y, and Me_a-2Z, wherein 2W is BaO:

2Me_aO;

8Fe₂O₃, 2Y is 2(BaO;

Me_aO;

3Fe₂O₃), and 2Z is 3BaO;

2Me_aO;

12Fe₂O₃, and wherein Me_a is a divalent cation, and the magnetically soft ferrite particles have the composition 1Me_bO;

1Fe₂O₃, where Me_bO is a transition metal oxide.

9. The agent according to claim 8, wherein the Me_a comprises Mg, Co, Mn or Zn and Me_b comprises Ni, Co, Mn, or Zn.

10. The agent according to claims 1, wherein the electrically conductive susceptors comprise elemental ferromagnetic particles or ferromagnetic alloys.

11. The agent according to claim 1, wherein the electrically non-conductive susceptors comprise from about 10^v/_o (20 ^w/_o) to about 30^v/_o (58 ^w/_o).

12. The agent according to claims 1, wherein the electrically conductive susceptors comprise nickel, iron, and cobalt and combinations thereof and of their alloys.

13. The agent according to claim 1, wherein the electrically conductive susceptors comprise an intrinsically conductive polymer (ICP).

14. The agent according to claim 1, wherein the electrically conductive susceptors comprise from about 5^v/_o to about 15^v/^o.

15. The agent according to claim 13, wherein the intrinsically conductive polymer comprises polyaniline, polypyrrole, polythiophene, polyethylenedioxythiophene, and poly (p-phenylene vinylene).

16. A welding agent comprising (a) a matrix material and (b) an agent for heating the material, wherein the agent comprises (1) at least one plurality of electrically non-conductive susceptors and (2) at least one plurality of electrically conductive susceptors.

17. The agent according to claim 16, wherein the electrically non-conductive susceptors comprise micron-sized ferrimagnetic particles.

18. The agent according to claim 16, wherein the electrically conductive susceptors comprise ferromagnetic or ICP particles.

19. The agent according to claim 16, wherein the ferrimagnetic particles have a size of from about 1.0 μ

m to about 50 μ

m.

20. The agent according to claim 18, wherein the electrically conductive susceptors have a size of from about 5 μ

m to about 100 μ

m.

21. The agent according to claim 20, wherein the electrically conductive susceptors have a size of from about 10 μ

m to about 50 μ

m.

22. The agent according to claim 16-21, wherein the electrically non-conductive susceptors comprise iron oxides, hexagonal ferrites, or magnetically soft ferrite particles.

23. The agent according to claim 22, wherein the hexagonal ferrites have the composition SrF, Me_a-2W, Me_a-2Y, and Me_a-2Z, wherein 2W is BaO:

2Me_aO;

8Fe₂O₃, 2Y is 2(BaO;

Me_aO;

3Fe₂O₃), and 2Z is 3BaO;

2Me_aO;

12Fe₂O₃, and wherein Me_a is a divalent cation, and the magnetically soft ferrite particles have the composition 1Me_bO;

1Fe₂O₃, where Me_bO is a transition metal oxide.

24. The agent according to claim 23, wherein the Me_a comprises Mg, Co, Mn or Zn and Me_b comprises Ni, Co, Mn, or Zn.

25. The agent according to claim 16, wherein the electrically conductive susceptors comprise elemental ferromagnetic particles or ferromagnetic alloys particles.

26. The agent according to claim 25, wherein the electrically conductive susceptors comprise nickel, iron, and cobalt and combinations thereof and of their alloys.

27. The agent according to claim 16, wherein the electrically non-conductive susceptors comprise from about 10^v/_o (20 ^w/_o) to about 30^v/_o (58 ^w/_o).

28. The agent according to claim 16, wherein the electrically conductive susceptors comprise from about 5^v/_o to about 15^v/_o.

29. The agent according to claims 16, wherein the electrically conductive susceptors comprise an intrinsically conductive polymer (ICP).

30. The agent according to claim 29, wherein the intrinsically conductive polymer comprises polyaniline, polypyrrole, polythiophene, polyethylenedioxythiophene, and poly(p-phenylene vinylene).

31. The agent according to claims 16, wherein the matrix material comprises at least one thermoplastic material.

32. An article of manufacture comprising (a) a matrix material and (b) an agent for heating the material, wherein the agent comprises (1) at least one plurality of electrically non-conductive susceptors and (2) at least one plurality of electrically conductive susceptors.

33. The article according to claim 32, wherein the electrically non-conductive susceptors comprise micron-sized ferrimagnetic particles.

34. The article according to claims 32-33, wherein the electrically conductive susceptors comprise ferromagnetic particles.

35. The article according to claims 32-34, wherein the electrically conductive susceptors comprise intrinsically conductive polymer (ICP) particles.

36. The article according to claim 32, wherein the electrically non-conductive susceptors have a size of from about 1.0 μ

m to about 50 μ

m.

37. The article according to claim 32, wherein the electrically conductive susceptors have a size of from about 5 μ

m to about 100 μ

m.

38. The article according to claim 37, wherein the electrically conductive susceptors have a size of from about 10 μ

m to about 50 μ

m.

39. The article according to claim 32, wherein the electrically non-conductive susceptors comprise iron oxides, hexagonal ferrites, or magnetically soft ferrite particles.

40. The article according to claim 32, wherein the electrically conductive susceptors comprise elemental ferromagnetic particles or ferromagnetic alloys.

41. The article according to claim 40, wherein the electrically conductive susceptors comprise nickel, iron, and cobalt, and combinations thereof and of their alloys.

42. The article according to claim 32, wherein the electrically non-conductive susceptors comprise from about 10^v/_o (20 ^w/_o) to about 30^v/_o (58 ^w/_o).

43. The article according to claim 32, wherein the electrically conductive susceptors comprise from about 5^v/_o to about 15^v/_o.

44. The article according to claim 32, wherein the matrix material comprises at least one polymeric material or at least one ceramic material.

45. The article according to claim 32, wherein the electrically conductive susceptors comprise an intrinsically conductive polymer (ICP) particles.

46. The article according to claim 32-45, wherein the susceptors are on a surface of the matrix material.

47. The article according to claim 32-45, wherein the susceptors are embedded in the matrix material.

48. A method of rapid heating of a thermoplastic material comprising

(a) providing a first thermoplastic material,

(b) providing at least one plurality of electrically non-conductive susceptors having a specific Curie temperature (T_c) in the first thermoplastic material,

(c) providing at least one plurality of electrically conductive susceptors,

(d) applying an alternating magnetic field to the first thermoplastic material to heat the susceptors, and

(e) ceasing the applying of the alternating magnetic field when the susceptors reach the desired temperature.

49. The method of claim 48, wherein T_c of the susceptors in (b) is less than the melting temperature of the thermoplastic material.

50. The method of claim 48, wherein T_c of the susceptors in (b) is greater than the melting temperature of the thermoplastic material, and the magnetic field is applied so that the susceptors melt the first thermoplastic material.

51. The method of claim 48, further comprising the step of providing a second thermoplastic material in contact with the first thermoplastic material before applying the alternating magnetic field.

52. The method of claim 48-51, further comprising initially placing the first thermoplastic material on an uncured or partially cured thermoset material and bonding the thermoplastic material and the thermoset material while curing the thermoset material.

53. The method of claim 48-52, further comprising initially juxtaposing the first thermoplastic material on the thermoset material, bonding the thermoplastic to the thermoset while curing the thermoset material, and juxtaposing the bonded assembly with the second material.

54. The method of claim 53, wherein the second material is a second thermoset material with a second thermoplastic material and wherein the bonding comprises flowing and bonding the first and second thermoplastic materials while curing the thermoset material.

55. The method of claim 51, wherein the second material is a second thermoplastic material.

56. The method of claim 51, where the second material has a different chemical composition than the first thermoplastic material.

57. The method of claim 51, wherein the second thermoplastic material has susceptors embedded therein.

58. The method of claim 51, wherein the susceptors are embedded in adjacent surfaces of the first and second thermoplastic materials.

59. The method of claim 51, wherein the susceptors are embedded in a surface of the first or second thermoplastic material.

60. The method of claim 48, wherein the applying comprises applying an alternating magnetic field at about 2 MHz to about 30 MHz.

61. The method of claim 60, wherein the applying comprises applying an alternating magnetic field at about 10 MHz to about 15 MHz.

62. The method according to claim 48, wherein the electrically non-conductive susceptors comprise iron oxides, hexagonal ferrites, or magnetically soft ferrite particles.

63. The method according to claim 48, wherein the electrically conductive susceptors comprise elemental ferromagnetic particles, ferromagnetic alloy particles or ICP particles.

64. A method of rapid heating of a polymeric material comprising

(a) providing at least one polymeric material,

(b) heating the polymeric material,

(c) dispersing at least one plurality of electrically non-conductive susceptors having a specific Curie temperature (T_c) in the polymeric material,

(d) dispersing at least one plurality of electrically conductive susceptors,

(e) forming the polymeric material,

(f) applying an alternating magnetic field to the polymeric material,

(g) heating the susceptors and heating the polymeric material, and

(h) ceasing the application of the alternating field when the susceptors reach the desired temperature.

65. The method according to claim 64, wherein the applying comprises applying an alternating magnetic field at about 2 MHz to about 30 MHz.

66. The method according to claim 64, wherein the applying comprises applying an alternating magnetic field at about 10 MHz to about 15 MHz.

67. The method according to claim 64, wherein the electrically non-conductive susceptors comprise iron oxides, hexagonal ferrites, or magnetically soft ferrite particles.

68. The method according to claim 64, wherein the electrically conductive susceptors comprise elemental ferromagnetic particles or ferromagnetic alloy particles.

69. The method of claim 68, further comprising varying the amount of zinc in the ferromagnetic particle as to control the Curie temperature of the particles.

70. The method according to claim 64, wherein the matrix material comprises at least one thermoplastic material.

71. The method according to claim 64, wherein the electrically conductive susceptors comprise ICP particles.

72. A method of heating a material comprising

(a) providing at least one plurality of electrically non-conductive susceptors in the material having a specific Curie temperature (T_c) in the material,

(b) providing at least one plurality of electrically conductive susceptors in the material,

(c) applying an alternating magnetic field to the material, wherein the susceptors in (a) generate heat due to hysteresis loss and the susceptors in (b) generate heat due to eddy current flow.

73. The method of claim 72, wherein the applying comprises applying an alternating magnetic field at about 2 MHz to about 30 MHz.

74. The method of claim 73, wherein the applying comprises applying an alternating magnetic field at about 10 MHz to about 15 MHz.

75. The method according to claim 72, wherein the electrically non-conductive susceptors comprise iron oxides, hexagonal ferrites, or magnetically soft ferrite particles.

76. The method according to claim 72, wherein the electrically conductive susceptors comprise elemental ferromagnetic particles or ferromagnetic alloys.

77. The method according to claim 76, wherein the electrically conductive susceptors comprise nickel, iron, cobalt, aluminum and combinations thereof and of their alloys.

78. The method according to claim 72, wherein the matrix material comprises at least one polymeric material or at least one ceramic material.

79. The method according to claim 72, wherein the electrically conductive susceptors comprise ICP particles.

80. A sealable apparatus comprising

a first element having a shaped matrix and having a rim;

a second element having an annular area for bonding to the rim of the first element,

at least one plurality of electrically non-conductive susceptors and at least one plurality of electrically conductive susceptors disposed in the rim of the first element or in the annular area of the second element, for heating the rim or the annular area to a desired temperature upon application of an alternating magnetic field, for bonding the first element and the second element together.

81. The apparatus according to claim 80, wherein the susceptors are disposed in both the rim and the annular area.

82. The apparatus according to claim 80, wherein the matrix comprises a thermoplastic material.

83. The apparatus according to claim 80, wherein the electrically non-conductive susceptors comprise micron-sized ferrimagnetic particles.

84. The apparatus according to claim 80, wherein the electrically conductive susceptors comprise ferromagnetic particles or ICP particles.

85. The apparatus according to claim 83, wherein the electrically non-conductive susceptors have a size of from about 1.0 μ

m to about 50 μ

m.

86. The apparatus according to claim 80, wherein the electrically conductive susceptors have a size of from about 5 μ

m to about 100 μ

m.

87. The apparatus according to claim 86, wherein the electrically conductive susceptors have a size of from about 10 μ

m to about 50 μ

m.

88. The apparatus according to claim 80, wherein the electrically non-conductive susceptors comprise iron oxides, hexagonal ferrites, or magnetically soft ferrite particles.

89. The apparatus according to claim 80, wherein the electrically conductive susceptors comprise elemental ferromagnetic particles or ferromagnetic alloys.

90. The apparatus according to claim 80, wherein the matrix material comprises at least one thermoplastic material.