U.S. patent number 3,594,873 [Application Number 04/805,419] was granted by the patent office on 1971-07-27 for fire-resistant fastening device and method of manufacture.
This patent grant is currently assigned to American Velcro, Inc.. Invention is credited to Peter P. Ferron, Clive E. Hockmeyer, Jr., Marcel C. Ouellette.
United States Patent |
3,594,873 |
Hockmeyer, Jr. , et
al. |
July 27, 1971 |
FIRE-RESISTANT FASTENING DEVICE AND METHOD OF MANUFACTURE
Abstract
A separable fastening device, resistant to flame 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; the loops are formed from
a flame and elevated temperature resistant nylon fiber of very low
denier, many filaments of which must first be twisted in an S
direction and two each of the twisted strands then reverse plied
together in the Z direction to produce a stabilized yarn having
sufficient strength and body to form the loops.
Inventors: |
Hockmeyer, Jr.; Clive E.
(Lowell, MA), Ouellette; Marcel C. (Bedford, NH), Ferron;
Peter P. (Manchester, NH) |
Assignee: |
American Velcro, Inc.
(N/A)
|
Family
ID: |
25191523 |
Appl.
No.: |
04/805,419 |
Filed: |
March 10, 1969 |
Current U.S.
Class: |
24/445; 139/384B;
139/384R |
Current CPC
Class: |
A44B
18/0034 (20130101); A44B 18/0092 (20130101); Y10T
24/2733 (20150115) |
Current International
Class: |
A44B
18/00 (20060101); A44b 013/00 () |
Field of
Search: |
;139/391,384B ;28/72
;24/204,205 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Jaudon; Henry S.
Claims
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 base material
with said loop elements secured thereto in positions extending
generally upright from one surface of the base, said loops being
formed from a flame and elevated temperature resistant
multifilament high-temperature nylon yarn, said multifilament
high-temperature nylon yarn comprising two plied high-temperature
nylon strands each of which comprises a number of high-temperature
nylon filaments which are twisted in the S direction to form said
strands and, subsequently, reverse plied with one another in the Z
direction.
2. A separable fastening device according to claim 1 wherein said
multifilament high-temperature nylon yarn is comprised of two plied
strands of 200-denier high-temperature nylon each of which
comprises 100 filaments per strand of 2-denier high-temperature
nylon twisted 21/2 turns per inch in the S direction and,
subsequently, each of said 200-denier strands then being reverse
plied together 21/2 turns per inch in the Z direction.
3. A separable fastening device according to claim 1 wherein the
base material of the loop-fastening member is woven, with the loop
elements interlaced within the base and extending generally upright
from one surface of the base material.
4. A separable fastening device according to claim 1 wherein the
base material is shrunk about the roots of the loop-fastening
member to interlock the loop elements into the base material.
5. A separable fastening device according to claim 1 wherein the
device is resistant to flame and elevated temperatures.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a flame and elevated temperature
resistant separable fastening device 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 members
comprising 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 umber 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
U.S. Pat. Nos. 3,009,235 and 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 apes may be fabricated from natural textile
material with an interwoven pile of synthetic material.
Engageable pile fasteners have found widespread use where ease of
opening and closing is desired such as use in clothing, footwear,
belts, curtains, tapestry, and for a variety of uses in commercial
aviation. However, because of the flammable nature of the polymeric
materials utilized in the manufacture of the interengageable pile
elements, such fasteners, when used on commercial aircraft, must
necessarily be resistant to flame and elevated temperatures and
must meet he United States Federal Aviation Agency standards in
this respect. It has generally been found that fasteners of the
type referred to herein, when produced from a standard polyamide
fiber such as the nylon monofilament produced by the Du Pont
Company, ill bun when tested under the conditions specified in
certain standard "burn tests" such as that disclosed in United
States Test CCC-T 191 b, method 5902, dated May 15, 1951.
Accordingly, it is an object of his invention to provide a
separable fastening device which will function satisfactorily as
such and yet be resistant to flame nd elevated temperatures.
SUMMARY OF THE INVENTION
Broadly stated, the invention relates to a separable fastening
device, resistant to flame and high 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.
The hook tape member is manufactured, in the warp and filling
ground weave, from a high-temperature nylon, and, for the hook
element, from a standard nylon monofilament. The pile loop
fastening member is manufactured from high-temperature nylon in
both the warp and filling ground weave and also for the pile loops.
By "high temperature nylon," there is meant a synthetic polyamide
fiber having good dimensional stability and excellent heat and
flame resistance. A high-temperature nylon such as Nomex (a nylon
manufactured by the Du Pont Company) which, at temperatures above
700.degree. F. (371.degree. C.) degrades to a friable char at a
rate proportional to the intensity of the heat source and in which
any flame produced during oxidation is self-extinguishing when the
fiber is withdrawn from the source of heat, is particularly
suitable for use in commercial aircraft.
A major drawback, to date, with respect to the use of
high-temperature nylon in producing the separable fastening device
described herein is its unavailability in a filament greater than 2
denier in size which is much too weak a filament for the production
of satisfactory loop elements. It has been found that a 20-denier
standard nylon is sufficient to produce a satisfactory pile loop
fastening member. The loops themselves must have sufficient
strength and body to withstand repeated engagements with the hook
elements, which is not possible with a weak filament. However, the
exceptional flame-resistant properties of high temperature nylon
makes highly desirable its adaptation for use in the separable
fastening device.
For the purpose of enhancing the firmness of engagement and
strength of flame resistant separable fastening device, the present
invention provides a method for weaving he fastening member which
comprises he pile loops from mutifilament yarns of the light-denier
high-temperature nylon. The high-temperature nylon, which is a
2-denier filament, may, of course, be twisted to form yarns of
greater denier size. Such yarns, however, are unsatisfactory for
producing the loops because of their tendency to twist upon
themselves and "close" after their formation during weaving thus
preventing engagement with the hooking element.
In the present invention a twisted yarn of high-denier
high-temperature nylon is produced and is then reverse plied with
another such twisted yarn to produce a dead yarn which has
sufficient strength and body to produce a pile loop that may be
fixed and stabilized and which will retain its shape. A separable
fastening device produced in accordance with this invention will be
flame and high-temperature resistant and will comprise a pile loop
member which affords increased probability of engagement of the
hooks with the loops so that a major percentage, if not all, of the
hooks on the hook-carrying member will become engaged with a loop
on the loop-carrying member.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view of a pile loop tape member of the
fastening device of the invention showing pile loop elements
extending from one surface thereof;
FIG. 2 is an enlarged fragmentary perspective of the pile loop
element in a fastening device of the invention;
FIG. 3 is an enlarged fragmentary perspective of a hook element in
a fastening device 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 loop fastening member is
manufactured by forming a base fabric which comprises a number of
weft threads 12 and warp threads 14. The loop 16 of said fabric
very 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, as well as said weft threads 12 and warp
threads 14 in the ground weave, are manufactured from Du Pont Nomex
nylon yarn which is resistant to flame and high temperature.
Because the Nomex nylon cannot be made in the larger denier size
required for satisfactory use in the regular pile loop element (20
denier), it is necessary to take a large number of the very fine
Nomex nylon filaments (2 denier) and apply twist to them to produce
a yarn of sufficiently high denier and then to take two such ends
(strands) and ply them in a reverse twist. The reverse twist is
necessary to produce what is known as dead yarn having sufficient
strength and body to produce satisfactory loops.
To produce the loops 16 shown in FIG. 2, the Nomex nylon was
prepared by twisting 100 filaments of 2-denier Nomex in 21/2 turns
per inch S. Two ends each of the 200-denier multifilament yarn thus
produced were then reverse plied together in 21/2 turns per inch Z.
The Nomex yarn thus plied has been found to be quite satisfactory
for use in producing the loop elements; it resists breaking, and is
sufficiently stabilized so as to be easily engageable, in repeated
use, with the hook element. The loops themselves are fanned out
during manufacture and remain so because of the stabilization
imparted to the yarn by the reverse twisting and plying of the
filaments. The pile loop member thus formed is shown in FIG. 1,
and, when said loop element is placed in face-to-face relation with
the hooking member as shown in FIG. 4, they may be pressed together
to fasten them to each other, and progressively peeled apart when
it is desired to separate the two members.
The ground weave fabric or base material, into which the pile loops
are woven, is also manufactured from Nomex nylon which has the
following yarn characteristics: The ground warp yarn used is a
200-denier Nomex nylon having 100 filaments per thread twisted 20
turns per inch in the S direction; the filling yarn or weft yarn is
a 200-denier Nomex nylon having 100 filaments per thread twisted
five turns per inch in the Z direction.
The hooking member, shown in FIG. 3, is manufactured from Du Pont
Nomex yarn in the warp 14 and filling ground weave 12 and standard
Du Pont nylon monofilament as the hooks 17. The hook element is
manufactured from the standard nylon monofilament because of its
ability to be thermoset and to retain its shape, necessary factors
for satisfactory engagement of the hooks and loops. The danger of
flammability of the hooks is negligible because of the smothering
effect of the pile loop member when the hooks are in engagement
therewith.
The loops are preferably woven with considerable firmness into the
base fabric 10, which is formed from warp yarns 14 and weft yarns
12 as shown in FIG. 2. After the weaving operation has been
completed, the loops 16 formed from multifilament Nomex nylon yarns
may be fastened or stabilized so that they retain their shape or
position. This may be effected by heat setting, by impregnation of
the fabric by adhesive products, by a heat-settable resin capable
of withstanding such temperatures as are likely to be encountered
in normal usage, or by a combination thereof. It must be
remembered, however, that the adhesive to be used must conform to
the standards of the "burn test" referred to herein when the
material is to be used under conditions where those standards will
apply. In this manner, a very large number of durable and firmly
anchored loops are provided.
* * * * *