Claims
- 1. A method of forming a fastener, comprising:
forming, from a thermoformable material, a preform product having a sheet-form base and an array of preform stems integrally molded with and extending from the base to corresponding terminal ends; heating the terminal ends of the stems to a predetermined softening temperature, while maintaining the sheet-form base and a lower portion of each stem at a temperature lower than the softening temperature; and contacting the terminal ends with a contact surface that is at a predetermined forming temperature, to reform the terminal ends to form heads therefrom that overhang the sheet-form base sufficiently to engage loops, the geometry and material of the preform structure and the condition of reforming the terminal ends of the structure being so related that the formed heads are capable of peel-resistant engagement with loops formed by fibers of thin or ultrathin nonwoven fabrics.
- 2. The method of claim 1 wherein said step of heating the terminal ends of the stems to a predetermined softening temperature is performed by a non-contact heat source.
- 3. The method of claim 2 wherein said non-contact heat source comprises a convective heat source.
- 4. The method of claim 3 wherein the convective heat source comprises a flame.
- 5. The method of claim 1, wherein the preform stems are formed from a polymer, the polymer being unoriented.
- 6. The method of claim 5, wherein the step of heating the terminal ends of the stems to a predetermined softening temperature forms a ball-like configuration at the terminal ends of the stems.
- 7. The method of claim 1 wherein said forming temperature is sufficiently low that said thermoformable material does not adhere to the contact surface.
- 8. The method of claim 1 wherein water of combustion or steam is introduced to the contact surface to provide a non-adhering agent.
- 9. The method of claim 3 wherein said water of combustion is formed as a by-product of said step of heating the terminal ends of the stems to a predetermined softening temperature.
- 10. The method of claim 1 wherein said forming temperature is lower than the softening temperature of the thermoformable material.
- 11. The method of claim 1 wherein said contact surface comprises the cylindrical surface of a roll.
- 12. The method of claim 1 wherein said contact surface is cooled to maintain said forming temperature during said step of contacting the terminal ends.
- 13. The method of claim 1 wherein, in said step of contacting the terminal ends with a contact surface that is at a predetermined forming temperature, the heads that are formed are substantially disc-shaped.
- 14. The method of claim 13 wherein the thickness of each disc-shaped head is from about 5 to 35% of the equivalent diameter of the disc.
- 15. The method of claim 13 wherein the thickness of each disc-shaped head is from about 5 to 15% of the equivalent diameter of the disc.
- 16. The method of claim 1 wherein, in said step of contacting the terminal ends with a contact surface that is at a predetermined forming temperature, the heads that are formed are substantially mushroom-shaped.
- 17. The method of claim 16 wherein said head has a substantially dome-shaped surface overhanging said base.
- 18. The method of claim 1 wherein said step of forming, from a thermoformable material, a preform product comprises molding said stems in molding cavities in a mold roll.
- 19. The method of claim 1 wherein, in said step of heating the terminal ends of the stems to a predetermined softening temperature, heat is additionally applied to a region extending from the terminal end towards the base a distance equal to from about 15 to 30% of the total distance from the terminal end to the base.
- 20. The method of claim 1 wherein, in said step of heating the terminal ends of the stems to a predetermined softening temperature, heat is additionally applied to a region extending from the terminal end towards the base a distance equal to from about 15 to 25% of the total distance from the terminal end to the base.
- 21. The method of claim 1 or 11 wherein said contact surface has a surface finish selected from the group consisting of dimpled, smooth, textured, and combinations thereof.
- 21. The method of claim 20 wherein said surface finish comprises dimples and said contact surface includes a density of dimples per unit area of the contact surface that is greater than or equal to a density of stems per unit area of the base.
- 22. The method of claim 21 wherein, in said step of contacting the terminal ends with a contact surface that is at a predetermined forming temperature, said dimples are in at least partial registration with said stems.
- 23. The method of claim 22 further comprising, during said step of contacting the terminal ends with a contact surface that is at a predetermined forming temperature, transforming displacement through a thickness of the head to modify a surface of the head opposite a contacted surface of the head.
- 24. A method of forming a fastener, comprising:
forming a plurality of stems, extending from a common base to a terminal end structure, from a thermoformable material; heating a region of the stem structure to a predetermined softening temperature, to soften the material in the region, while maintaining the remaining portion of the stems at a temperature lower than the softening temperature; and contacting the terminal ends with a contact surface to form heads at the terminal end of said stems, at least a portion of the contact surface having a sufficiently rough texture to impart a loop-engaging surface roughness to at least a portion of said heads.
- 25. The method of claim 24 wherein said contact surface comprises the cylindrical surface of a roll.
- 26. The method of claim 24 wherein said contact surface has a sandpaper-like texture.
- 27. The method of claim 24 wherein said contact surface has a rugosity of about 10 to 200 microns.
- 28. The method of claim 26 or 27 wherein said contact surface defines a plurality of dimples.
- 29. The method of claim 28 wherein said contact surface includes a density of dimples per unit area of the contact surface that is greater than or equal to the density of stems per unit area of the base.
- 30. The method of claim 24 wherein the surface roughness imparted to the heads is sufficient to increase the peel strength of the fastener by from about 10 to 100%.
- 31. The method of claim 24 wherein the contact surface in contacting an upper surface of the head effectively transmits displacement of the thermoformable material of the heads to impart a degree of texture or surface roughness to at least one of a peripheral edge of the heads and a surface opposite the upper surface of the head.
- 32. A fastener element comprising:
an elongated stem extending and molded integrally with a substantially planar base; and a head disposed at a terminal end of the stem, at least a portion of said head having a rough surface having a sandpaper-like surface texture.
- 33. The fastener element of claim 32 wherein said rough surface has a surface roughness of from about 10 to 200 microns.
- 34. The fastener element of claim 32 wherein said rough surface has sufficient surface roughness to increase the peel strength of the fastener by from about 10 to 100%.
- 35. The fastener element of claim 32 wherein said head is substantially disc-shaped.
- 36. The fastener element of claim 32 wherein said head is substantially mushroom-shaped.
- 37. The fastener element of claim 36 wherein said head includes a substantially planar surface overhanging said base.
- 38. An attachment strip for attaching a mesh screen to a surface, comprising:
a substantially planar base; a plurality of elongated stems extending from said base; and a plurality of heads, each head being disposed at a terminal end of one of said stems, at least a portion of said heads having a rough surface having a sandpaper-like surface texture.
- 39. An attachment strip for attaching a mesh screen to a surface, comprising:
a substantially planar base; a plurality of elongated stems extending from said base; and a plurality of heads, each head being disposed at a terminal end of one of said stems, and each head being substantially disc-shaped and having a thickness equal to from about 5 to 15% of the equivalent diameter of the disc.
- 40. A method of forming a loop engaging fastener product, the method comprising:
providing a pre-form stem product having a plurality of stems, each of which rises from a base to a distal end; contacting the distal end of at least some of the stems with an ultrasonic horn to form loop engaging heads.
- 41. The method of claim 40 wherein the ultrasonic horn is rotating while contacting the distal end of at least some of the stems.
- 42. The method of claim 40 wherein the pre-form stem product is introduced between a gap formed by the ultrasonic horn and an anvil, the gap sized to cause the distal ends of at least some of the stems to contact the rotary horn.
- 43. The method of claim 40, wherein the ultrasonic horn is positioned parallel to a plane defined by the base.
- 44. The method of claim 40, wherein the ultrasonic horn is positioned perpendicular to a plane defined by the base.
- 45. A method of forming a loop-engaging touch fastener product, the method comprising:
forming, from a thermoformable material, a preform product having a sheet form base and an array of preform stem formations integrally with and extending from the base to corresponding terminal ends, each of the stem formations including a first portion joined to the base and a terminal second portion extending from the first portion to a terminal end, there being a discrete transition to a lesser cross-sectional area in the second portion relative to the first portion according to cross-sections taken parallel to the sheet-form base; and deforming substantially all of the second portion of at least some of the stem formations to form, for each portion so deformed, an engaging feature overhanging the base sheet while leaving the first portion substantially as initially formed.
- 46. The method of claim 45, wherein the discrete transition occurs at a distance from the base sheet surface at least half way to the distal end of the stem formation.
- 47. The method of claim 46 wherein the discrete transition comprises a substantial decrease in the cross-sectional area of the second portion relative to the first portion.
- 48. A hook fastener pre-form product for subsequent formation of a loop engaging hook fastener product, the pre-form product comprising:
a base sheet having a surface of thermoplastic resin; and a plurality of stem formations formed integrally with the surface to protrude therefrom, each of the stem formations including a first, first portion intersecting the surface and a second portion extending from the first portion to a distal end to define a height of the stem formation relative to the surface, an intersection of the second and first portions occurring at a distance from the surface equal to at least half the height of the stem formation, the intersection defining a discrete transition in structure of the stem formation, wherein the second portion is selected to be more susceptible to deformation energy than the first portion.
- 49. The hook fastener pre-form product of claim 48, wherein an area of any cross-section of the second portion taken parallel to the surface is less than an area of any cross-section of the first portion taken parallel to the surface.
- 50. The hook fastener pre-form product of claim 49, wherein the area of a cross-section taken parallel to the surface and near the distal end of the second portion has an area less than 50% of the area of any cross section of the first portion taken parallel to the surface.
- 51. The hook fastener pre-form product of claim 49, wherein the area of a cross-section taken parallel to the surface and near the distal end of the second portion has an area less than 25% of the area of any cross section of the first portion taken parallel to the surface.
- 52. A hook fastener pre-form product for subsequent formation of a loop engaging hook fastener product, the preform product comprising:
a base sheet having a continuous length, a width and a surface of thermoplastic resin; and a plurality of stem formations formed integrally with the surface to protrude therefrom, each of the stem formations including a first portion intersecting the surface and a second portion extending from the first portion to a central peak to define a height of the stem formation relative to the surface, wherein longitudinal edges of the second portion are tapered relative to longitudinal edges of the first portion toward the central peak.
- 53. The hook fastener pre-form product of claim 52, wherein each stem formation has lateral edges that taper continuously from the first portion continuously to the distal end of the stem formation.
- 54. The hook fastener pre-form product of claim 52, wherein each stem formation has a shape resembling a letter “A.”
- 55. A hook fastener pre-form product for subsequent formation of a loop-engaging hook fastener product, the pre-form product comprising:
a base sheet having a continuous length, a width and a surface of thermoplastic resin; and a plurality of stem formations formed integrally with the surface to protrude therefrom, each of the stem formations including a first portion intersecting the surface and a second portion extending from the first portion to define a height of the stem formation relative to the surface, wherein the second portion comprises a first peak along a first longitudinal edge, a second peak along a second longitudinal edge and a tapered surface defining a central valley devoid of resin therebetween.
- 56. The hook fastener pre-form product of claim 55, wherein each stem formation has opposite lateral edges that taper continuously from the first portion to the height of the stem formation.
- 57. The hook fastener pre-form product of claim 55, wherein each stem formation has a shape resembling a letter “M.”
- 58. A hook fastener pre-form product for subsequent formation of a loop-engaging hook fastener product, the pre-form product comprising:
a base sheet having a continuous length, a width and a surface of thermoplastic resin; and a plurality of stem formations formed integrally with the surface to protrude therefrom, each of the stem formations including a first portion intersecting the surface and a second portion extending from the first portion to define a height of the stem formation relative to the surface, wherein the second portion comprises a peak along a first longitudinal edge and a tapered surface extending downward from the peak to intersect the first portion at a second longitudinal edge.
- 59. The hook fastener pre-form product of claim 58, wherein the second portion of each stem formation has a shape resembling a wedge.
- 60. A hook fastener pre-form product for subsequent formation of a loop engaging hook fastener product, the pre-form product comprising:
a base sheet having a continuous length, a width and a surface of thermoplastic resin; and a plurality of stem formations formed integrally with the surface to protrude therefrom, each of the stem formations including a first portion intersecting the surface and a second portion extending from the first portion to define a height of the stem formation relative to the surface, wherein the first portion comprises a first cylindrical shape of a first diameter, and the second portion comprises a second cylindrical shape of a second diameter, the second diameter being smaller than the first diameter.
- 61. The hook fastener pre-form product of claim 57, wherein the second portion is concentric with the first portion.
- 62. A method of manufacturing a hook component for a hook and loop fastener comprising (a) providing a continuous length of a preform stem component of thermoformable resin, the component having a base layer from which extend a plurality of preformed stems with thermoformable extremities of predetermined geometry, the stem component having a machine direction, (b) heating said deformable extremities of said stems to provide on each a localized molten mass of resin which, under action of surface tension, so resides on the respective stem as to overhang a cross-machine extremity of the stem, and (c) deforming the molten mass with a forming surface in manner to produce a generally flattened, thin head at the cross-machine extremity of the stem, (d) steps (a),( b) and (c) being so conducted as to produce a loop engageable head defining, in a plan view, a general contour having a peripheral arc AB parallel to the base of the preform component, the head having an overhang aspect ratio OAR, defined as the ratio of the chord of the arc AB and the height “h” of the line perpendicular to said chord lying at the furthest point of the arc from the chord, OAR=AB/h, where the chord of the arc lies in the plane which defines the cross-machine extremety of the stem and is parallel to said machine direction, the chord lying in or being tangent to the surface of said stem that defines the cross-machine extremity of the stem, said aspect ratio OAR being less than 3.5, preferably about 2.
- 63. A hook component for a hook and loop fastener comprising a base layer from which extend a plurality of stems having respective loop-engageable heads, at least some of the heads each having a general countour in plan view, that has a peripheral arc AB parallel to the base, the head having an overhang aspect ratio OAR, defined as the ratio of the chord of the arc AB and the height “h” of the line perpendicular to said chord lying at the furthest point of the arc from the chord, OAR=AB/h, where the chord of the arc lies in the plane which defines the cross-machine extremity of the stem and is parallel to said machine direction, the chord lying in or being tangent to the surface of said stem that defines the cross-machine extremity of the stem, said aspect ratio OAR being less than 3.5, preferably about 2.
- 64. The method of claim 1 or the hook component of claim 2 in which the head has a vertical head thickness, down to its loop engaging region, of nor more than about 0.015 inch.
- 65. The method or component of any of the foregoing claims in which the combined height of each stem and its respective head, measured from the base layer, is no more than about 0.055 inch.
- 66. The method or component of any of the foregoing claims, in which the footprint area of each head is no more than about 4.30×10 to the −4 square inch.
- 67. The method of any of the foregoing claims in which the stem preform comprises a thin fin projecting from said base, said thin fin having a cross-machine component of orientation of at least about 45 degrees, the fin characterized by a length from the cross-machine extremity of the projection, along the length of the projection, that is greater than about twice the thickness of the fin, the length and thickness being measured at right angles in a plane parallel to the plane of the base of the hook component.
- 68. The hook component of any of the foregoing claims in which the stem comprises a thin fin projecting from said base, said thin fin having a cross-machine component of orientation of at least about 45 degrees, the fin characterized by a length from the cross-machine extremity of the projection, along the length of the projection, that is greater than about twice the thickness of the fin, the length and thickness being measured at right angles in a plane parallel to the plane of the base of the hook component.
- 69. A hook component for a hook and loop fastener comprising a base layer from which extend a plurality of stems having respective loop-engageable heads, the heads overhanging a cross-machine extremity of the respective stem, the component having a machine direction, the stem comprising a thin fin projecting from said base, said thin fin having a cross-machine component of orientation of at least about 45 degrees, the fin characterized by a length from the cross-machine extremity of the projection, along the length of the projection, that is greater than about twice the thickness of the fin, the length and thickness being measured at right angles in a plane parallel to the plane of the base of the hook component.
- 70. The method of claim 67 or the hook component of claims 68 or 69 in which said length is at least 2½ times such thickness.
- 71. The method of claim 67 or 70 or the hook component of any of claims 61, 69 or 70 in which the length of said thin fin extends in the cross-machine direction.
- 72. The method or component of any of the foregoing claims in which the stem preform, or the stem, as the case may be, is double-ended, there being a said length of thin fin extending inwardly in opposite directions from cross-machine extremities on opposite ends of the stem preform or stem.
The method claims 1 in which the stem preform comprises a thin fin projection having a cross-machine component of orientation of at least 45 degrees, the thin fin characterized by a length from the cross-machine extremity of the projection, along the length of the projection, that is greater than about twice the thickness of the fin, the length and thickness being measured at right angles in a plane parallel to the plane of the base of the hook component. The method of claim 1, 2 or 3 in which the stem preform has a stiffening feature spaced from its cross machine end or ends, that serves to stiffen the preform from columnar collapse during application of postforming force. The method of claim 6 in which the stiffening feature has a height that is less than that of the thin fin, such that it either is not reformed during the post-forming action, or, is not reformed to the degree to which the extremity of the thin fin is reformed. The method of claim 6 in which the strengthening projection itself comprises a thin fin prefrom having a length greater than about twice its thickness. The method of claim 8 in which the stem is cross form, having four projections from a central region, each of said thin fin form. The method of claim 9 which the pairs of oppositely extending fins are aligned with the cross-machine and machine directions. The method of claim 9 in which the pairs of oppositely extending fins all are arranged at acute angles to said machine and cross-machine directions. The method of claim 1, 2 or 3 in which the stem preform has its direction of elongation set at an acute angle to the machine direction, between about 30 and 45 degrees, and has an end surface at its cross-machine extreminmlity that is generally aligned with the machine direction. The method of claim 12 in which that extremity is defined by a planar end face that is perpendicular to the base of the hook component and aligned with the machine direction. The method of claim 12 in which the fin-shaped preform has long sides that are generally of planar, parallel form, the preform terminating at one comer at the cross-machine extremity with a horizontal profile included angle of substantially less than 90 degrees The method of claim 14 in which said included angle is 45 degrees. The method of claim 12 in which the horizontal cross-section of the stem is of parallelogram form, each cross-machine extremity of the profile ending in a stem portion defining an included angle of substantially less than 90 degrees. The method of claim 12 in which said included angle is 45 degrees. The method of claim 16 in which the profile of the stem is defined as two thin fins of said parallelogram profile, set at substantial angles to each other to form a cross. The method of claim 1, 2 or 3 in which the stem preform, in the cross machine direction, has the profile of an “M”, having substantially vertical straight sides at the cross-machine extremeties, and, effectively a generally “V”-shaped cut out in its central region, devoid of resin, so that the outermost portions of the preform closest to the non-contact heat source are tapered from an outward point to increasing horizontal cross sections, and whereby, as melting progresses, the molten resin preferentially moves in the cross-machine direction, tending to flow over the edge of the straight side and form a molten mass overhang at the cross-machine extremity that later is postformed, to provide the desired hook-engaging shape. The method of claim 1, 2 or 3 in which the forming surface that engages the molten resin has a molding surface that imparts a degree of roughness to the outer surface at the peripheral edges of the head that is formed, and by telegraphing imparts a degree of irregularity also on the under edge surface of the overhang. A method of forming, on a hook-forming machine having a machine direction, a hook component for a hook and loop fastener, the hook component having hooking capability in the cross-machine direction,
the method based upon, with a flattening roller of said machine, deforming the ends of an array of molded upstanding thermoplastic preform elements that extend from a common base into the form of flattened loop engageable hook heads on the ends of the preform elements, the method comprising the steps of
molding an array of thermoplastic preform elements that each has a geometric form that provides an effectively elongated distribution of displaceable thermo-plastic material in a flattening volume, with the concentration of the thermoplastic material in the flattening volume of the geometric form being at least as great in the vicinity of a cross-machine extremity of the preform element as it is spaced therefrom along the element, the preform elements having an overall length to thickness ratio, in coordinates parallel to said base from which they extend, of at least about 2, and heating and with said flattening roll, deforming the displacement volume of the thermoplastic material at the ends of said preform elements to form said loop engageable hook heads. The method of claim 1 in which the distribution of thermoplastic in said flattening volume is greater at least in part of the region of the cross-machine extremity of said preform elements, than it is spaced therefrom in the cross-machine direction. The method of claim 2 in which the majority of displaceable thermoplastic in said flattening volume is located in the vicinity of said cross-machine extremity. The method of claim 3 in which the geometric form of said preform has an outwardly directed edge slope inclining from a peak region in the vicinity of said cross-machine extremity, to a closer distance from said base at positions further from said cross-machine extremity. The method of claim 4 in which said slope is planar. The method of claim 5 in which the profile of said element, including its supporting stem, is an “N” when viewed in the machine direction. The method of any of said claim 1-6 in which said preform is substantially symmetrical about the center of the cross-machine extent of the preform element. The method of claim 7 in which said preform element, including its supporting stem, is an “M”, comprised of back to back “N”s. The method of claim 1 in which the main body of said preform element is in the shape of a parallelogram, having, at its cross-machine extremities, end surfaces extending in the machine direction, and having sides between said end surfaces that lie at a substantial angle to both the machine and cross-machine directions. The method of any of the foregoing claims in which a columnar strengthening formation is provided spaced from said cross-machine extremity. The method of any of the foregoing claims in which said columnar strengthening formation is elongated, and has a flattening volume of thermoplastic at its outer extremity that is deformed during the flattening with said flattening roller to provide a loop engaging hook formation. The method of claim 11 in which said columnar strengthening formations are on both sides of said preform element. The method of claim 11 in which said columnar strengthening formations are on the same side of said preform element. The method of claim 12 in which said columnar strengthening elements are aligned with each other. The method of claim 13 in which the cross-section of the preform element, taken parallel to the base, is cruciform. The method of claim 12 in which the columnar strengthening elements are offset from one another.
Parent Case Info
[0001] This application is a continuation in part of U.S. Ser. No. 09/870,063, filed May 30, 2001, which is a divisional of U.S. Ser. No. 09/231,134, filed Jan. 15, 1999, now U.S. Pat. No. 6,248,276. This application is also a continuation in part of U.S. Ser. No. 09/808,395, filed Mar. 14, 2001. This application also claims priority from U.S. Provisional Application Serial No. 60/295,937, filed Jun. 4, 2001. The entire contents of each of the foregoing are hereby incorporated by reference.
Provisional Applications (1)
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Number |
Date |
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60295937 |
Jun 2001 |
US |
Divisions (1)
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Number |
Date |
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Parent |
09231134 |
Jan 1999 |
US |
Child |
09870063 |
May 2001 |
US |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
09870063 |
May 2001 |
US |
Child |
10163169 |
Jun 2002 |
US |
Parent |
09808395 |
Mar 2001 |
US |
Child |
10163169 |
Jun 2002 |
US |