USRE38412EExpiredUtility

Coated substrate drying system with magnetic particle orientation

Assignee: IMATION CORPPriority: Sep 4, 1996Filed: Sep 29, 2000Granted: Feb 3, 2004

Est. expirySep 4, 2016(expired)· nominal 20-yr term from priority

Inventors:John D. Munter William Blake Kolb Gary L. Huelsman

F26B 7/002G11B 5/84G11B 5/845G11B 5/842F26B 25/006F26B 3/20F26B 13/105

PatentIndex Score

Cited by

References

Claims

Abstract

Drying a coated substrate which includes magnetic particles includes a condensing surface spaced from the substrate. This creates a longitudinal gap between the substrate and the condensing surface. Liquid is evaporated from the substrate to create a vapor and the vapor is transported to the condensing surface without requiring applied convection. The vapor is condensed on the condensing surface to create a condensate which is removed from the condensing surface. Removal is performed, using more than gravity, without allowing non-uniformities of the condensate film to occur. The magnetic particles are oriented on the coated substrate by subjecting the coated substrate to a magnetic field created at a location outside of the dryer space.

Claims

exact text as granted — not AI-modified

We claim:

1. A method for drying a coated substrate, wherein the coated substrate comprises magnetic particles, comprising:
locating a condensing surface spaced from and facing the substrate which substantially corresponds to the path of the substrate in the longitudinal direction to create a longitudinal gap between the substrate and the condensing surface;
evaporating the liquid from the substrate to create a vapor;
transporting the vapor to the condensing surface without requiring applied convection;
condensing the vapor on the condensing surface to create a condensate;
removing, using more than gravity, the condensate from the condensing surface without allowing non-uniformities of the condensate film to occur; and
orienting the magnetic particles on the coated substrate by subjecting the coated substrate to a magnetic field between the condensing surface and the coated substrate that is initially created at a location outside of the space between the condensing surface and the coated substrate.

2. The method of claim 1 wherein the orienting step comprises creating the magnetic field at least one of: a first location separated from the substrate by the condensing surface and a second location separated from the condensing surface by the substrate.

3. The method of claim 2 wherein the orienting step comprises creating the magnetic field at locations surrounding the condensing surface and the substrate.

4. The method of claim 1 wherein the orienting step comprises orienting the magnetic particles at the beginning of the evaporating step and holding the magnetic particles in a preferred direction during the evaporating, condensing, transporting, and removing steps.

5. The method of claim 1 wherein the removing step comprises at least one of: tilting the condensing surface to at least one transverse side of the coated substrate such that gravity is used to remove the condensate from the condensing surface; and using mechanical shear forces.

6. The method of claim 1 further comprising the step of providing relative movement between the condensing surface and the coated substrate.

7. The method of claim 1 further comprising the step of controlling the rate of drying by controlling the height of the gap and the temperature difference between the coated substrate and the condensing surface.

8. An apparatus for drying a coated substrate, wherein the coated substrate comprises magnetic particles, comprising:
a condensing surface locatable spaced from and facing the substrate which substantially corresponds to the path of the substrate in the longitudinal direction to create a longitudinal gap between the substrate and the condensing surface;
means for evaporating the liquid from the substrate to create a vapor;
means for transporting the vapor to the condensing surface without requiring applied convection;
means for condensing the vapor on the condensing surface to create a condensate;
means for removing, using more than gravity, the condensate from the condensing surface without allowing non-uniformities of the condensate film to occur; and
at least one magnetic field generator located outside of the space between the condensing surface and the coated substrate.

9. The apparatus of claim 8 wherein the magnetic field generator is located at at least one of: a first location separated from the substrate by the condensing surface and a second location separated from the condensing surface by the substrate.

10. The apparatus of claim 9 wherein the magnetic field generator is located at a location surrounding the substrate and the condensing surface such that the substrate passes through the magnetic field generator.

11. The apparatus of claim 8 wherein the magnetic field generator is located at the entrance to the condensing plate.

12. The apparatus of claim 8 wherein the evaporating means comprises a heated plate which supplies heat by conduction to increase the rate of heat transfer compared to conventional drying methods that use convection.

13. The apparatus of claim 8 wherein the removing means comprises at least one of: tilting the condensing surface to at least one transverse side of the coated substrate such that surface tension holds the condensate onto the condensing surface and gravity is used to remove the condensate from the condensing surface; forming the condensing surface of a foraminous material; and a wiper.

14. The apparatus of claim 8 wherein the condensing platen is sloped away from the horizontal in any direction to remove condensate by gravity.

15. The apparatus of claim 8 further comprising a belt, wherein the condensing surface is formed on the belt and means for providing relative movement between the condensing surface on the belt and the coated substrate.

16. The apparatus of claim 8 further comprising means for controlling the rate of drying by controlling the height of the gap and the temperature difference between the coated substrate and the condensing surface.

17. The apparatus of claim 8 further comprising: a plurality of condensing surfaces; wherein the evaporating means comprises a plurality of heaters, and wherein each heater corresponds to a respective condensing surface to form pairs of condensing surfaces and heaters; and means for independently controlling each pair of condensing surface and heater.

18. An apparatus for drying a coating on a substrate, wherein the coating comprises particles in a liquid, the particles being capable of being affected by a magnetic field, the apparatus comprising:
a condensing surface locatable spaced from the substrate along the path of the substrate to create a gap between the substrate and the condensing surface;
means for evaporating the liquid from the coating to create a vapor;
means for condensing the vapor on the condensing surface to create a condensate; and
a magnetic field generator located outside of the space between the condensing surface and the coated substrate for imposing a magnetic field upon the particles in the coating.

19. The apparatus of claim 18 wherein the coated substrate is useful for creating at least one of an audio, video, or data storage medium, wherein the magnetic field generator is configured to magnetically align the particles.

20. A method for drying a coating on a substrate, wherein the coating comprises particles in a liquid, the particles being capable of being affected by a magnetic field, the method comprising the steps of:
locating a condensing surface spaced from the substrate along the path of the substrate to create a gap between the substrate and the condensing surface;
evaporating the liquid from the coating to create a vapor;
condensing the vapor on the condensing surface to create a condensate; and
creating a magnetic field from outside of the space between the condensing surface and the coated substrate and imposing the field upon the particles in the coating.

21. The method of claim 20 wherein the coated substrate is useful for creating at least one of an audio, video, or data storage medium, wherein the magnetic field aligns the particles.

22. The method of claim 21 further comprising the step of converting the coated substrate into one of an audio, video, or data storage media product following the evaporating step.

23. A method for drying a coating on a substrate, wherein the coating has particles that can be affected by a magnetic field, comprising:

locating a condensing member adjacent and spaced from the substrate to create a gap between the substrate and a condensing surface of the condensing member;

forming a condensate on the condensing surface from the coating; and

subjecting the coating to a magnetic field created at a location outside the gap.

24. The method of claim 23 wherein the forming step comprises the step of causing vapor to emanate from the coating.

25. The method of claim 24 wherein the forming step comprises the step of heating the coating.

26. The method of claim 23 wherein the forming step comprises the step of evaporating liquid in the coating forming vapor in the gap.

27. The method of claim 26 wherein the liquid comprises a solvent.

28. The method of claim 23 wherein the forming step comprises the step of controlling the temperature of the condensing member.

29. The method of claim 23 wherein the forming step comprises the steps of:

causing vapor to emanate from the coating;

transporting the vapor across the gap to the condensing member; and

condensing the vapor on the condensing surface.

30. The method of claim 23 wherein the subjecting step comprises creating the magnetic field at least at one of a first location separated from the substrate by the condensing member and a second location separated from the condensing member by the substrate.

31. The method of claim 23 wherein the subjecting step comprises providing a magnetic field generator that surrounds the condensing member and the substrate.

32. The method of claim 23 wherein the subjecting step comprises magnetically orienting the particles.

33. The method of claim 32 wherein the forming step comprises the step of evaporating a solvent from the coating, and wherein the orienting step occurs during at least a portion of the evaporating step.

34. The method of claim 23 wherein the method further comprises the step of removing the condensate from the condensing surface.

35. The method of claim 34 wherein the removing step comprises the step of applying at least one of gravitational force, capillary force, and mechanical force to the condensate.

36. The method of claim 35 wherein the step of applying gravitational force comprises the step of configuring the condensing member such that at least a portion of the condensing surface is not horizontal.

37. The method of claim 35 wherein the step of applying capillary force comprises at least one of the steps of configuring the condensing member such that the condensing surface has capillary grooves, configuring the condensing member such that the condensing member comprises a foraminous member, and providing a foraminous member adjacent the condensing surface.

38. The method of claim 35 wherein the step of applying mechanical force comprises at least one of the steps of wiping condensate from the condensing surface and pumping condensate from the condensing surface.

39. The method of claim 23 wherein the condensing member is stationary, wherein the method further comprises the step of transporting the coating and substrate past the condensing member.

40. The method of claim 23 wherein the coating is at a first temperature and the condensing member is at a second temperature lower than the first temperature, and wherein the method further comprises the step of controlling the rate of forming condensate by controlling the temperature difference between the coating and the condensing member.

41. The method of claim 23 wherein the gap has a gap height, and wherein the method further comprises the step of controlling the rate of forming condensate by controlling the gap height.

42. The method of claim 23 wherein the substrate has a first substrate surface and a second substrate surface, wherein the coating is positioned on the first substrate surface, and wherein the condensing surface is adjacent the first substrate surface.

43. An article made using the method of claim 23 comprising one of an audio storage medium, video storage medium, and data storage medium.

44. An apparatus for drying a coating on a substrate, wherein the coating can be affected by a magnetic field, comprising:

a condensing member spaced from the substrate forming a gap between the substrate and a condensing surface of the condensing member;

means for forming a condensate on the condensing surface from the coating; and

at least one magnetic field generator located outside of the gap forming a magnetic field that is imposed upon the coating.

45. The apparatus of claim 44 wherein the magnetic field generator is located at least at one of a first location separated from the substrate by the condensing member and a second location separated from the condensing member by the substrate.

46. The apparatus of claim 44 wherein the magnetic field generator surrounds the substrate and the condensing member.

47. The apparatus of claim 44 wherein the magnetic field generator is located adjacent the condensing member.

48. The apparatus of claim 44 wherein the forming means comprises a heating member that heats the coating causing vapor to emanate from the coating.

49. The apparatus of claim 44 further comprising means for removing condensate from the condensing surface, wherein the removing means comprises at least one of a portion of the condensing surface being tilted, the condensing surface having capillary grooves, the condensing member comprising a foraminous material, a foraminous material adjacent the condensing surface, a wiper; and a pump.

50. The apparatus of claim 44 wherein at least a portion of the condensing surface is tilted around a web travel axis.

51. The apparatus of claim 44 wherein the condensing member comprises a belt and means for moving the belt past the coating.

52. The apparatus of claim 44 further comprising means for controlling the rate of forming condensate by controlling at least one of the height of the gap and a temperature difference between the coating and the condensing surface.

53. The apparatus of claim 44 wherein the condensing member comprises a plurality of condensing members, wherein the forming means comprises a plurality of heating members, wherein each heating member corresponds to a respective condensing member to form pairs of condensing members and heaters; and

means for independently controlling the pairs of condensing members and heaters.

54. An article made using the apparatus of claim 44 , comprising one of an audio storage medium, video storage medium, and data storage medium.

55. An apparatus for drying a coating on a substrate, wherein the coating comprises particles that can be affected by a magnetic field, the apparatus comprising:

a condensing member spaced from the substrate along the path of the substrate forming a gap between the substrate and a condensing surface of the condensing member;

a heating member adjacent the condensing member for heating the coating causing vapor to emanate from the coating and condensate to form on the condensing surface; and

a magnetic field generator located outside the gap for imposing a magnetic field upon the particles in the coating.

56. An article made using the apparatus of claim 55 comprising one of an audio storage medium, video storage medium, and data storage medium.

57. A method for drying a coating on a substrate, wherein the coating comprises particles that can be affected by a magnetic field, the method comprising the steps of:

locating a condensing member spaced from the substrate along the path of the substrate forming a gap between the substrate and a condensing surface of the condensing member;

heating the coating causing vapor to emanate from the coating;

condensing vapor emanating from the coating on the condensing surface; and

creating a magnetic field from outside the gap and imposing the magnetic field upon the particles.

58. The method of claim 57 further comprising the step of converting the coating and substrate into one of an audio storage medium, video storage medium, and data storage medium following the condensing step.

59. A method for drying a coating on a substrate comprising the steps of:

providing a substrate having a coating thereon, wherein the coating can be affected by a field imposed upon the coating, and wherein the coating has a coating temperature;

providing a first drying member, wherein the first drying member has a first drying member temperature, wherein the first drying member temperature is less than the coating temperature;

transporting the substrate adjacent the first drying member forming a gap between the first drying member and the substrate;

providing a field generator outside the gap; and

affecting the coating by imposing a field upon the coating with the field generator.

60. The method of claim 59 , wherein the field is a magnetic field.

61. The method of claim 60 , wherein the field generator comprises at least one of a magnet and a solenoid coil.

62. The method of claim 60 , wherein the affecting step comprises orienting particles in the coating.

63. An article made using the method of claim 60 , comprising at one of a magnetic audio storage medium, video storage medium, and data storage medium.

64. The method of claim 59 , wherein the first drying member is a condensing member for condensing vapor emanating from the coating.

65. The method of claim 64 , wherein the condensing member is a chilled plate.

66. The method of claim 59 , wherein the first drying member has a shape corresponding to a portion of a path through which the substrate is transported.

67. The method of claim 64 , further comprising the step of removing the condensate from the condensing structure.

68. The method of claim 67 , wherein the removing step comprises the step of applying at least one of gravitational force, capillary force, and mechanical force to the condensate.

69. The method of claim 59 , further comprising the steps of:

heating the coating to cause vapor to emanate from the coating; and

condensing vapor emanating from the coating on the first drying member.

70. The method of claim 69 , wherein the heating step evaporates liquid in the coating.

71. The method of claim 59 , further comprising the step of providing a second drying member for heating the coating to further facilitate drying of the coating.

72. The method of claim 71 , wherein the field generator surrounds the substrate and the first and second drying members.

73. The method of claim 59 , wherein the coating has a coating temperature, further comprising the step of providing a second drying member positioned relative to the first drying member such that the transporting step causes the substrate to be transported between the first and second drying members, wherein one of the first and second drying members is at a temperature higher than the coating temperature.

74. The method of claim 59 , wherein the field is at least one of a magnetic field, curing field, decontaminating field, sterilizing field, light field, ultraviolet light field, electron beam field, corona field, and radiation field.

75. A method for affecting a coating on a substrate comprising the step of:

providing a condensing member and a field generator along a process path;

providing a substrate having a coating thereon that can be affected by a field generated by the field generator; and

transporting the substrate through the process path such that the condensing member is between the field generator and the substrate, wherein the condensing member condenses vapor from the coating and the field generator generates a field that passes through the condensing member to the coating.

76. The method of claim 75 wherein the field generator generates at least one of a magnetic field, curing field, sterilizing field, decontaminating field, light field, ultraviolet light field, electron beam field, radiation field, and corona field.

77. The method of claim 75 wherein the field generator comprises a magnetic field generator.

78. The method of claim 77 wherein the coating comprises particles that can be affected by the magnetic field, and wherein the transporting step causes the magnetic field to orient the particles.

79. The method of claim 77 wherein the field generator comprises at least one of a magnet and a solenoid coil.

80. An article made using the method of claim 77 comprising at least one of a magnetic audio storage medium, video storage medium, and data storage medium.

81. The method of claim 75 wherein the condensing member comprises a chilled platen.

82. The method of claim 75 wherein the coating is at a coating temperature, and wherein the condensing member is at a lower temperature than the coating temperature.

83. The method of claim 82 , further comprising the step of controlling the temperature of the condensing member.

84. The method of claim 75 , further comprising the step of providing a heating member spaced from the condensing member, wherein the transporting step comprises transporting the substrate between the condensing member and the heating member causing vapor to emanate from the coating.

85. The method of claim 84 wherein the coating is at a coating temperature, wherein the condensing member is at a lower temperature then the coating temperature, and wherein the heating member is at a higher temperature than the coating temperature.

86. The method of claim 85 , further comprising the steps of controlling the temperature of the condensing member and controlling the temperature of the heating member.

87. The method of claim 75 , further comprising the step of removing condensate from the condensing member using at least one of gravitational force, capillary force, and mechanical force.

88. The method of claim 75 , wherein the condensing member has a shape corresponding to a portion of a path through which the substrate is transported.

89. A method for affecting a coating on a substrate, wherein the coating comprises a liquid and particles that can be affected by a field, and wherein the method comprises the steps of:

providing a member spaced from the substrate forming a gap between the substrate and the member;

providing vapor to the gap;

controlling the temperature of the member creating a vapor concentration gradient that achieves one of removing liquid from the coating, preventing removal of liquid from the coating, and adding liquid to the coating; and

subjecting the coating to the field generated by a field generator positioned outside the gap.

90. The method of claim 89 wherein the member comprises a condensing member and the subjecting step comprises orienting the particles to a desired orientation, and wherein the controlling step comprises removing liquid from the coating increasing a viscosity of the coating such that the particles substantially remain in the desired orientation after the subjecting step.

91. The method of claim 89 wherein the field is at least one of a magnetic field, curing field, sterilizing field, decontaminating field, light field, ultraviolet light field, electron beam field, corona field, and radiation field.

92. A method for drying a coating on a first surface of a substrate, wherein the coating has particles that can be affected by a magnetic field, the method comprising the steps of:

providing a condensing member and a heating member spaced from the condensing member to form a substrate path;

providing a magnetic field generator adjacent the substrate path;

transporting the substrate through the substrate path such that the condensing member is adjacent and spaced from the first surface of the substrate forming a gap between the condensing member and the first surface and such that the heating member is adjacent the substrate;

heating the coating with the heating member forming a vapor in the gap from the coating;

condensing the vapor on the condensing member; and

subjecting the coating to a magnetic field created outside the gap by the magnetic field generator, wherein the subjecting step comprises magnetically orienting the particles in the coating during at least a portion of the heating and condensing steps to hold the particles in a desired orientation while the coating is being dried.

93. The method of claim 92 , wherein the condensing member comprises a chilled platen and the heating member is a heated platen, wherein the transporting step comprises transporting the substrate onto the heated platen.

94. A method for drying a coating on a substrate comprising the steps of:

providing a substrate having a coating thereon, wherein the coating can be affected by a field imposed upon the coating;

providing a first drying member, wherein the first drying member is configured to dry the coating by substantially other than heated air blown onto the coating;

transporting the substrate adjacent the first drying member forming a gap between the first drying member and the substrate;

providing a field generator outside the gap; and

affecting the coating by imposing a field upon the coating with the field generator.

95. The method of claim 94 , wherein the first drying member comprises a chilled member.

96. A method for drying a coating on a substrate comprising the steps of:

providing a substrate having a coating thereon, wherein the coating can be affected by a field imposed upon the coating;

providing a first drying member, wherein the first drying member comprises a condenser;

transporting the substrate adjacent the first drying member forming a gap between the first drying member and the substrate;

providing a field generator outside the gap; and

affecting the coating by imposing a field upon the coating with the field generator.

97. The method of claim 96 , wherein the condenser comprises a chilled plate.

Cited by (0)

No later patents cite this yet.

References (0)

No backward citations on record.