US3534780A - Flash resistant fastening device and method of manufacture - Google Patents

Description

United States Patent [72] Inventors Clive E. Hockmeyer Lowell, Massachusetts; 7 Marcel C. Ouellette, Bedford, New Hampshire [21 Appl. No. 804,202 [22] Filed March 4, 1969 [45] Patented Oct. 20, 1970 [73] Assignee American Velcro, Inc.

a corporation of New Hampshire [54] FLASH RESISTANT FASTENING DEVICE AND METHOD OF MANUFACTURE 8 Claims, 4 Drawing Figs.

[52] US. Cl 139/391, 24/204, 28/72, 161/48 [51] Int. Cl l. D03d 27/00 [50] FieldofSearch 161/48; 24/203, 204; 28/72; 139/391, 396, 420, 383, 46

[56] References Cited UNITED STATES PATENTS 2,239,457 4/1941 Gibbons v. 139/391 Primary Examiner-Henry S. .laudon Att0rneyPennie Edmonds, Morton, Taylor and Adams ABSTRACT: A separable fastening device, flash resistant at elevated temperatures, and having a very large number of closely spaced hooking elements of the hook and loop type such that pressing opposed surfaces of two fastening members together in face-to-face relation will engage a large number of hooks and loops, is disclosed; both the loop and hook-carrying members are comprised of a base material of woven glass fibers while the loops, extending upright from one surface of the loop-carrying fastening member, are formed from tight fiber bundles of polymeric tetrafluoroethylene and the hooks, extending from one surface of the hook-carrying fastening member. are formed from polyester monofilaments.

Patented Oct. 20, 1 970 FIG. 4

INVENTORS CLIVE E- HOCKMEYER MARCEL C.OUELLETTE BY M ATTORNEYS FLASH RESISTANT FASTENING DEVICE AND METHOD OFMANUFACTURE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a separable fastening device, flash resistant at elevated temperatures, of the type having two fastening members each provided with a very large number of closely spaced interengageable hooking elements of the hook and loop type, one of said members comprising hooks and the other of said memberscomprising loops. The fastening members are characterized by the property that opposed surfaces of the two can be pressed together in face-to-face relation so that a large number of hooks on one of the members will engage a large number of loops on the other member for several cycles of repeated engagement and disengagement without permanently deforming the hooks or loops and without substantially crushing the loops. The invention also relates to a method of making these fastening devices.

2. Description of the Prior Art US. Pat. Nos. 3,009,235, 3,083,737, and 3,154,837 disclose various forms of separable pile fastening devices, i.e., a fastener comprised of two separate fastening tapes having interengageable piles which contain loop elements and loop-engaging hook elements. The fastening devices described in these patents are recited as preferably being constructed from synthetic polymer materials such as nylon (polyamide fiber manufactured by the Du Pont Company). For some applications these tapes may be fabricated from a natural textile material with an interwoven pile of synthetic material.

Engageable pile fasteners have found a wide variety of uses where ease of opening and closing is desired such as in clothing, foot wear, belts, curtains, tapestry, and for a variety of uses in the manned space program. However, because of the flammable nature of the polymeric materials utilized in the manufacture of the interengageable pile elements, such fasteners are not suitable for applications in an atmosphere having a very high oxygen content. For example, materials to be used in the space program conducted by the National Aeronautics and Space Administration are burn-tested in atmospheres of 100 percent oxygen at a pressure of 6.2 p.s.i.a. and of 60 percent oxygen and 40 percent nitrogen at a pressure of l6.5 p.s.i.a., and must necessarily be flash resistant under these conditions. It has generally been found that fasteners of the type referred to herein, when produced from a standard polymide fiber such as the nylon monofilament produced by Du Pont, will, almost certainly, burn in any atmosphere approaching 100 percent oxygen, and especially when tested in accordance with the National Aeronautics and Space Administration standard bum tests. Accordingly, it is an object of this invention to provide a separable fastening device which will function satisfactorily as such and yet be flash resistant at elevated temperatures so that it may be used in an atmosphere having a very high oxygen content.

SUMMARY OF THE INVENTION Broadly stated, the invention relates to a separable fastening device, flash resistant at elevated temperatures, having two fastening members each provided with a very large number of closely spaced hooking elements of the hook and loop type such that pressing opposed surfaces of two fastening members together in face-to-face relation will engage a large number of hooks and loops.

A separable fastening device of the type disclosed herein must be used in applications which require a high resistance to flame and high temperatures. In the space program, where burn tests are conducted at atmospheres of 60 percent to l percent oxygen at various pressures, great care must be taken to use materials which are flash resistant to high temperatures under these conditions. Frequently such materials, although desirable from a standpoint of their resistance to flame and high temperatures, are unsuitable because of their brittleness,

The present invention provides a separable fastening device I which is flash resistant at elevated temperatures because of its unique adaptation of materials having these desired properties in the weaving process in which such fasteners are produced. Further, these materials, when woven in accordance with this invention, provide a stable hooking element both in the hookcarrying fastening member and in the pile loop-carrving fastening member, which has sufficient strength and body so as to retain its shape, even after repeated cycles of engagement and disengagement of the fastening members. The loops remain open" after their formation during weaving thus facilitating their engagement with the hooks, while the hooks have sufficient strength to withstand repeated engagement without undergoing deformation.

The flash-resistant fastening device of this invention is characterized by a very large number of closely spaced hooking elements of the hook and loop type such that pressing opposed surfaces of two fastening members together in face-toface relation will engage a large number of hooks and loops. Both the loopand hook-carrying fastening members are manufactured from materials which are flash resistant at elevated temperatures, a property which is necessary in applications involving atmospheres of up to percent oxygen at various pressures.

In this invention, the fastening tapes or members comprise a base material with hooking elements extending generally upright from one surface thereof. The base material is woven from glass fibers, a plied strand in the warp, and strands comprising tight untwisted bundles of plied glass fibers in the weft or filling weave. The loops are formed as supplementary warp threads which are formed from untwisted bundles of polymeric tetrafluoroethylene fibers. The hooks are formed from monofilaments of polyester fiber. While in the closed or mated condition, the base material also serves to protect the polyester hook against flash exposure to high temperatures.

These materials are woven in a manner which produces a fastening device having increased strength and stability and which is suitable for use in a variety of applications. The method of manufacture of the pile loops, which have increased strength because of the use of an extra strand in the selvedge (edge) fibers, also affords increased probability of engagement of the hooks with the loops. In this manner a major percentage, if not all, of the hooks on the hook-carrying fastening member will become engaged with a loop-carrying fastening member.

BRIEF DESCRIPTION OF THE INVENTION FIG. I. is a perspective view of a pile loop fastening member of the invention showing loop elements from one surface thereof;

FIG. 2 is an enlarged fragmentary perspective of the loop elements interwoven in the base material of a fastening member of the invention;

FIG. 3 is an enlarged fragmentary perspective of a hook element in a fastening member of the invention; and

FIG. 4 is a side elevation of two tape members forming a fastening device in opposed face-to-face relationship but spaced apart.

With reference to FIG. 2, the pile loopfastening member is manufactured by forming a base fabric which comprises a number of weft threads 12 and warp threads I4. The loops 16 of said fabric are formed as supplementary warp threads which are passed over metal lancets during the weaving operation, in a loom generally employed in weaving velvet ribbon. Said supplementary warp threads which form the loops, are formed from tight bundles of untwisted fibers of polymeric tetrafluoroethylene such as fibers that are produced by the Du Pont Company under the name Teflon.

In the present invention, untwisted bundles of Teflon fibers are used. In one embodiment of the pile loop fastening member, as shown in FIG. 1, both the left and right selvedges 18, of seven ends per selvedge, are formed from five-strand bundles of Teflon fibers to provide extra strength. The body or center portion 19 of said pile loop-fastening member shown in FIG. 1 is comprised of 19 ends of four-strand bundles of Teflon fibers.

The loops 16, as shown in FIG. 2, are woven into the base material as supplementary warp threads. The base material itself is comprised of glass fiber warp threads 14 and glass fiber weft threads 12. The glass fiber threads used herein are manufactured by Owens-Coming under the trademark Beta-Glas. These threads are silicone treated and twisted by Belding Corticelli.

The warp threads 14 are comprised of a three-ply glass fiber thread of a coarsness similar to that used in the sewing trade. In this invention, I filaments of two denier Beta-Glas T- OO1-I5082 is twisted six to seven turns per inch in the S direction to form each strand. Three such strands are then plied turns per inch in the Z direction to form each warp end thread, of which 1 l2 ends are used per inch of fastening tape base material.

The filling threads used in the base material are 450/3 Beta- Glas fibers each of which is twisted turns per inch in the S direction. Two of each such strands are then taken together as a tight untwisted bundle for each of the filling or weft strands 12. The base material is constructed with 3334 weft strands per inch woven in as the filling material.

The hook-carrying fastening member, shown in FIG. 3, is manufactured, in the base material, in the same fashion as in the loop-carrying member. The hook elements 17, however, are formed from an 8 mil diameter polyester monofilament about 400 denier in size. A polyester filament such as Dacron, a synthetic fiber manufactured by the Du Pont Company by the condensation of dimethyl tetephthalate and ethylene glycol, is quite satisfactory for use as the hook elements. The

hook elements are woven into the base material as supplementary warp threads at 33 ends per inch of base material tape.

The loops 16 and hooks 17 formed in accordance with the practice of this invention have been found to be quite satisfactory for use in the separable fastening device. Although glass fibers are quite brittle, the weave disclosed herein produces a strong, abrasion-resistant material. The pile loop element, fonned from bundles of Teflon fibers, are able to withstand abrasion as are the monofilament polyester fibers used to form the hooks. For added strength, the pile loop fastening member is manufactured with bundles of five-strand fibers in both the left and right selvedges, while the body of the pile loop material is manufactured from bundles of four-strand fibers. The pile loop-carrying fastening member, shown in FIG. 1, when placed in face-to-face relation with the hook-carrying fastening member, shown in FIG. 4, may be pressed together to fasten them to each other, and, alternatively, progressively peeled apart when it is desired to separate the two.

The loops, preferably, are woven with considerable firmness into the base fabric 10, shown in FIG. 2. After the weaving operation has been completed, the loops 16 may be fastened or stabilized so that they retain their shape or position. This may be effected by means of heat-settable resins, especially those which are bum-resistant in atmospheres of 100 percent oxygen. In this manner, a very large number of durable and firmly anchored loops are provided.

The hooks 17, which are formed from polyester monofilaments or, where advantageous, from monofilaments of nylon or polybenzimidazole are, preferably, subjected to heat from a hot-air blower before weaving to make it more flexible while the hooks are being formed around the lancets. The heating also serves to shrink the polyester yarn to produce a firmer hook.

The separable fastening device manufactured in accordance with the present invention has excellent body and stability for use as a fastening device of the type described herein. Most importantly, when it is to be used under conditions where there is an inherent danger of fire and high temperature, the fastening device is resistant to both, thus making it suitable for use under such conditions.

We claim:

1. A separable fastening device of the type having two fastening members each provided with a very large number of closely spaced interengageable hooking elements, one of said fastening members comprising hooks and the other of said members comprising loops and characterized by the property that pressing opposed surfaces of the two fastening members together in face-to-face relation, a large number of hooks will engage a large number of loops, the improvement in combination therewith comprising a woven base material, having left and right selvedges and a center portion, which comprises plied glass fiber warp threads and tight untwisted bundles of plied glass fiber weft threads, said warp fibers being first twisted in the 5 direction and the fibers so twisted then plied together in the Z direction, said loops and hooks being interwoven in said base material as supplementary warp threads and extending generally upright from one surface of the base, said loops being formed from tight untwisted bundles of polymeric tetrafluoroethylene fibers and said hooks being monofilaments of polyester fiber.

2. A separable fastening device in accordance with claim 1 wherein said loops interwoven in the base material are formed from untwisted bundles in the left and right selvedges and untwisted bundles in the center portion thereof, said selvedges being formed from bundles having a greater number of strands per bundle than said center portion bundles.

3. A separable fastening device in accordance with claim 1 wherein said hooks interwoven in the base material are monfilaments of 400 denier polyester fiber having a diameter of 8 mils.

4. A separable fastening device in accordance with claim 1 wherein the base material is comprised of plied glass fiber warp threads and untwisted bundles of plied glass fiber weft threads, each of said warp threads comprising filaments of two-denier glass fiber twisted six to seven turns per inch in the S direction and three of each such twisted threads being then plied 10 turns per inch in the Z direction, each of said weft threads comprising 450 filaments of three-denier glass fiber twisted 15 turns per inch in the S direction and two of each such twisted threads being taken together as a tight untwisted bundle.

5. In a method of making a flame and high temperature resistant separable fastening device of the type comprising two fastening members each provided with a very large number of closely spaced interengageable hooking elements, one of said fastening members comprising hooks and the other of said members comprising loops and characterized by the property that pressing opposed surfaces of the two fastening members together in face-to-face relation will secure the members together by the engagement of numerous hooks with numerous loops, the improvement which comprises forming a base material, having left and right selvedges and a center portion, by weaving plied glass fiber warp threads with tight untwisted bundles of plied glass fiber weft threads, forming said warp thread fibers by plying together in the 2 direction fiber warp threads which have been first twisted in the S direction, interweaving hooks and loops in said base material as supplementary warp threads, forming said loops from tight untwisted bundles of polymeric tetrafluoroethylene fibers and forming said hooks from monofilaments of polyester fiber.

6. A method of making a separable fastening device in accordance with claim 5 wherein said loops are woven in the base material to provide untwisted bundles in the left and right selvedges and untwisted bundles in the center portion thereof,

said selvedges being formed from bundles having a greater number of strands per bundle than said center portion bundies.

7. A method of making a separable fastening device in ac' cordance with claim 5 wherein said loops are woven in the base material as monofilaments of 400 denier polyester fiber having a diameter of 8 mils.

8.'A method of making a separable fastening device in accordance with claim 5 wherein said base material is formed by weaving plied glass fiber warp threads and untwisted bundles

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