Heat treated profile extruded hook

• US 20050101926A1
• Filed: 12/20/2004
• Published: 05/12/2005
• Est. Priority Date: 01/15/2002
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Seth, Jayshree, Ausen, Ronald W., Unruh, William C., Miller, Philip
• Application Number:
  US11/016,992
• Publication Number:
  US 20050101926A1
• Time in Patent Office: Days
• US Class Current: 604/358
• CPC Class Codes: A44B 18/0049 obtained by moulding processes compression moulding or articles of indefinite length characterised by the shape of the surface B29C43/222; screen moulding B29C67/08
• CPC Class Codes: A44B 18/0065 of a mushroom type
• CPC Class Codes: A61F 13/625 characterised by the hook
• CPC Class Codes: B29C 48/00 Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor extrusion blow-moulding B29C49/04
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/12 Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: Y10T 24/27 including readily dissociable fastener having numerous, protruding, unitary filaments randomly interlocking with, and simultaneously moving towards, mating structure [e.g., hook-loop type fastener]
• CPC Class Codes: Y10T 24/2783 having filaments constructed from coated, laminated, or composite material
• CPC Class Codes: Y10T 24/2792 having mounting surface and filaments constructed from common piece of material

Abstract

A method for forming a unitary polymeric projection or fastener comprising a thin, strong flexible backing, and a multiplicity of thin spaced hook members projecting from the upper surface of the unitary backing the method generally including extruding a thermoplastic resin through a die plate which die plate is shaped to form a base layer and spaced ridges, ribs or hook elements projecting above a surface of the base layer. When the die forms the spaced ridges or ribs the cross sectional shape of the hook members are formed by the die plate while the initial hook member thickness is formed by transversely cutting the ridges at spaced locations along their lengths to form discrete cut portions of the ridges. Subsequently longitudinal stretching of the backing layer (in the direction of the ridges on the machine direction) separates these cut portions of the ridges, which cut portion then form spaced apart hook members. The extruded hook members or cut rib hook members are then heat treated resulting in shrinkage of at least a portion of at least the hook head portion thickness by from 5 to 90 percent, preferably 30 to 90 percent.

Claims

1-69. -69. (canceled)

70. A fastener strip of a resiliently flexible, thermoplastic resin comprising a base layer having generally parallel upper and lower major surfaces, with spaced upstanding integral polymeric projections projecting from the upper surface of said base, wherein the base layer has a substantially continuous thickness across its width and wherein at least a first portion of the projections on the upper surface have a thickness or molecular orientation, less than at least another second portion of the projections on the same upper surface.

71. The fastener strip of claim 70 wherein a portion of the upstanding projections have a molecular orientation of less than 10 percent.

72. The fastener strip of claim 71 wherein a portion of the upstanding projections have a molecular orientation different than another portion of the upstanding projection.

73. The fastener strip of claim 70 wherein the projections comprise hook members having a stem portion and a hook head portion where the hook members having a height from said upper surface of less than 5000 μ

m and each comprising a stem portion attached at one end to said base, and a head portion at the end of said stem portion opposite said base, at least the head portions having a thickness from 50 to 1500 μ

m, a first direction generally parallel to the surfaces of said base.

74. A fastener strip according to claim 73 wherein said stem portion has a width in the range of 50 to 500 μ

m in a second direction generally at a right angle to said first direction and parallel to the surfaces of said backing;

said head portion having a width greater than said stem portion and a total width of from 100 to 5000 μ

m in said second direction.

75. The fastener strip according to claim 74 wherein the hook members are provided at a density of at least 10 per square centimeter.

76. A fastener strip according to claim 72 wherein a portion of the upstanding projections have a molecular orientation of from 20 to 100 percent.

77. A diaper having a fastener strip of claim 70.

78. A disposable absorbent article comprising a fastener tab or patch formed of a thermoplastic resin comprising a base layer having generally parallel upper and lower major surfaces, with spaced upstanding integral polymeric projections projecting from the upper surface of said base, wherein the base layer has a substantially continuous thickness across its width and a degree of molecular orientation in more than one direction and wherein said upstanding polymeric projections have a density of less than 150 projections per square centimeter and the fastener tab or patch has a base layer thickness of less than 75 microns and an area of 10 cm or greater.

83. The disposable absorbent article of claim 78 wherein said fastener tab or patch has said projections having a height from said upper surface of less than 1000 μ

m and each comprising a stem portion attached at one end to said base, and a head portion at the end of said stem portion opposite said base, at least the head portions having a thickness of from 50 to 200 μ

m in a first direction generally parallel to the surfaces of said base.

84. The disposable absorbent article of claim 83 wherein said stem portion has a width in the range of 50 to 500 μ

m in a second direction generally at a right angle to said first direction and parallel to the surfaces of said backing;

said head portion having a width greater than said stem portion and a total width of from 100 to 800 μ

m in said second direction and an arm droop of from 100 to 500 μ

m.

85. The disposable absorbent article of claim 83 wherein said polymeric material is a thermoplastic resin and the hook head has rounded corners.

86. The disposable absorbent article of claim 85 wherein said base has a generally uniform thickness between said upper and lower surfaces of between 30 to 200 μ

m.

87. The disposable absorbent article of claim 86 wherein said thermoplastic resin comprises polyethylene, polypropylene, polypropylene-polyethylene copolymers or blends thereof.

88. The disposable absorbent article of claim 83 wherein at least the hook head portion has a molecular orientation of less than 10 percent.

89. The disposable absorbent article of claim 88 wherein the hook member base portion adjacent the base has a molecular orientation of at least 10 percent.

90. The disposable absorbent article of claim 88 wherein the base film layer has a degree of molecular orientation in at least one direction.

91. The disposable absorbent article of claim 88 wherein the base film layer has a degree of molecular orientation in two directions.

92. The disposable absorbent article of claim 84 wherein the hook portion thickness is less than a stem portion thickness below the hook portion.

93. The disposable absorbent article of claim 84 wherein the hook portion thickness is substantially the same as the stem portion thickness below the hook portion.

94. The disposable absorbent article of claim 92 wherein the hook portion has an arm extending past the stem portion the hook portion arm increasing in thickness from a tip of the hook portion arm to a portion of the hook portion arm adjacent the stem.

79. A disposable absorbent article comprising a fastener tab or patch wherein the polymeric projections have a density of less than 60/cm².

80. A disposable absorbent article comprising a fastener tab or patch wherein the polymeric projections have a density of less than 50/cm².

81. A disposable absorbent article comprising a fastener tab or patch wherein the polymeric projections have a density of less than 150/cm² wherein the fastener tab has an area of from 20 cm² to 100 cm² and the disposable absorbent article is a diaper.

82. A disposable absorbent article comprising a fastener tab or patch wherein the polymeric projections have a density of less than 150/cm² wherein the disposable absorbent article is a feminine hygiene article and the hook fastener is a patch forming all or part of the liquid impermeable backing attached to the garment.

95. A garment comprising a low loft nonwoven surface and a microhook mechanical fastener for engagement with the low loft nonwoven material;

the microhook mechanical fastener having at least 50 hooks/cm², where the hooks have a height of less than 100 μ

m and an arm droop of from 50 to 700 μ

m.

96. The garment of claim 95 wherein the garment is a disposable garment.

97. The garment of claim 96 wherein the microhook has a density of from 70 to 150 hooks/cm.

98. The garment of claim 96 wherein the microhook has an arm droop of from 50 to 500 μ

m.

99. The garment of claim 96 wherein the microhook has a Gurley stiffness of from 10 to 2000.

100. The garment of claim 96 wherein the microhook has a Gurley stiffness of from 10 to 200.

101. The garment of claim 96 wherein the microhook has a backing with a thickness of from 200 to 1000 μ

m.