Note: Descriptions are shown in the official language in which they were submitted.
CA 02270403 2003-05-O1
WATERPROOF, BREA'TI~ABLE ARTICLES OF APPAREL
BACKGROUND OF T~ INVEuITION
1. Field of the Invention
The present invention relates generally to articles of apparel. More
particularly, the
invention concerns articles of apparel used to cover the wearer's extremities
such as an irn-
proved, waterproof sock that will permit perspiration to transpire through the
sock, but will keep
water fmm external sources away from the wearer's foot.
2. Description of the prior art
Various attempts have been made in the past to produce breathable, waterproof
articles
of apparel such as gloves and socks that will keep the wearer's hands and feet
dry and at the
same time permit perspiration to transpire through the article. Materials
which will accomplish
this desired function have been known for sometime. Fox example, U.S. Patent
No. 3,953,566
discloses a method of making an expanded polyrctrafluoroethyleae (PTFE) that
possesses the
properties of being both breathable and waterproof. An impmvctnent of thus
mattrial is
described in U.S. Patent No. 4,194,041. While both of these materials have
been used in the
construction of footwear, they exhibit the drawback that they have liaaitad
stretchability, thereby
making them less than ideally suited for construction of footwear such .as
socks. In addition,
such footwear typically has sewn scams and tapes which make it bulky and
uncomfortable.
In an apparent attempt to overcome the problems discussed in the preceding
paragraph,
a ruulti-component sock type article was suggested. This article, which is
described in U.S.
Z5 Patent No. 4,809,447 issued to Pacanowsky, et al., comprises a waterproof,
nonelastic,
non-stretch sole component, a non-stretch calf component and a vamp component
attached to the
sole and calf components.
As will be better appreciaited from the discussion which follows, the footwear
article of
the present invention provides, for the first time, footwear such as socks
construction which
exhibit the comfort and stretchability of a traditional type of sport sock and
at the same time are
both breathable and completely waterproof.
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SU,MMARX OF THE INVENTION
It is an object of the present invention to provide comfortable articles of
apparel and the
method of making the same which will allow water vapor due to perspiration to
transpire
through the article but will prevent water from external sources from reaching
the wearer's
extremities.
A particular object of the invention is to provide a footwear article of the
aforementioned
character which fits well, is pliant and is durable in use.
Azzother object of the invention is to provide an article such as a glove or
sock in which
water vapor from perspiration can be transmitted from inside to outside so
chat the natural
evaporative cooling effect can be achieved.
Another object of the invention is to provide a method of making articles of
the character
described in the preceding paragraphs which is simple and straight forward,
does not require the
use of complicated equipment such as sewing and seaming equipment and can be
performed by
unskilled workmen with a minimum of training.
A particular object of the invention is to provide a sock as described in the
preceding
paragraphs which is of simple constnlction and is easy to manufacture.
In its preferred form, the footwear article of the invention comprises a sock
which is of
three-ply construction with the inside and outside plies being knit and the
intermediate ply being
made from an elastomeric polyurethane film. The three-plies are uniquely
bonded together using
a pliant, waterproof adhesive.
BItTEF DLSCRIP't'ION OF TAE DRAWINGS
Figure 1 is a side-elevational view illustrating the method of making the
footwear article
of the invention and showing the components of the article in position over a
foot-shaped planar
mandrel.
Figure 2 is ari enlarged cross-sectional view taken along lines 2-2 of Figure
1.
Figure 3 is a side-elevativnal view of ozte form of the footwear article of
the invention.
Figure 4 is an enlarged cross-sectional view taken along lines 4-4 of Figure
3.
Figure 5 is a side-elavational view illustrating the method of malting an
alternate form
of the footwear article of the invention and showing the components of the
article in position
2
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over a foot-shaped planar mandrel.
Figure 6 is a side-elevational view of the completed alternate form of the
footwear article
of the invention of Figure 5.
Figure 7 is an enlarged, cross-sectional view taken along lines 7-7 of Figure
6.
Figure 8 is a top plan view illustrating the method of making the glove of the
invention
and showing the inner liner of the glove in position over a hand-shaped planar
mandrel.
Figure 9 is a top plan view similar to Figure 8, but showing the stretchable
bladder
component of the glove in position over the mandrel and inner liner
components.
Figure IO is a top plan view similar to Figure 9 but showing the outer
covering
component of the glove in position over the mandrel, the inner liner and the
bladder
components.
Figure l I is an enlarged, cross-sectional view taken along lines 11-I1 of
Figure 10
pETAILED 1~ESC1~LPTYON OF THE YNVENTION
16
Xxx the description which follows:
The term "breathable" means the ability of an article co transport interior
moiswz~e vapor
to the external environment.
As used herein, the term "waterproof" means the ability of an article to
substantially
prevent liquid water from external sources from reaching the interior of the
article.
Similarly, the term "fabric" as used herein means a sheet suucture made from
fibers,
filaments or yarns. Non-limiting examples include ucoven or nonwoven sheets
made by
weaving, knitting, feltiztg, hydroentangling or meltblowing fibers, filaments
or yarns.
The term "sock" as used herein means a short, close-fitting covering for the
foot and
ZS lower leg constructed from any suitable material such as natural and
synthetic fibers.
Referring to the drawings, Figures 3 and 4 show one form of the clothing
article of the
present invention. The article here comprises a sock construction including a
thin, pliant bladder
12 constructed from a waterproof, breathable material, such as polyurethane
sheet. The
polyurethane sheet can be of various thickness ~as, for example, between about
0.5 mils and
about 3 mils. Bladder 12 zncludes a foot portion 14 having an outer surface 16
and an inner
surface 18. Bladder 12 has the unique capability of generally conforming to
the contours of the
human ;foot so that it can be comfortably worn inside a boot or shoe.
3
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Bonded to the inner surface x 8 of the elastomeric bladder is a light-weight
covering
member such as a fabric ituaer sock 20 of standard construction which is
preferably made from
knitted natural or synthetic fibers.
The article of the invention shown in Figure 3 also includes a~n outer sock 22
which is
bonded to the outer surface of bladder 14. Outer sock 22 can also be
constructed from flament
or spun yarns. The sock can also be constructed from natural fibers; such as
wool fibers, or
from a variety of synthetic fibers such as polyester nylon and combinations
thereof.
Tnner sock 20 and outer sock 22 are preferably bomded to bladder 12 by means
of a
waterproof, heat activated adhesive. A hot melt adhesive in powder form sold
by l3ostik,
Middleton, Massachusetts, product #511.6, a polyester type, has proven
satisfactory for this
purpose. Other adhesives can, of course, also be used, including breathable
adhesives. Tn any
event, the adhesive should be selected and applied in a manner that the
breathabiliry of the
footwear is not destroyed ox substantially reduced.
For certain applications the footwear article of the invention can be
constructed by
bonding to the bladder only a single iraxier or outer sock. This two, rather
than three-ply
construction, can be used in a number of applications in which the three or
more ply
constructions are too bulky or too expensive.
The thin pliant, thermoplastic material from which the waterproof, breathable
bladder
will be made is of a character that will prevent penetration of liquid water
while at the same
time permitting free passage of moisture vapor such as perspiration. This
material can be a
polyurethane sometimes described as thermoplastic urethane. A suitable
material of this type
is sold by Fabrite Laminating Corp_ of Woodridge, New Jersey. Other suitable
materials
include elastomers made from polyesters, co-polyesters, polyamides, cellulose
derivatives,
polyacrylic acid and its holologs, natural or synthetic rubber with
hydrophilic impurities,
copolyozamides, polyureas, polyelectrolytes, polyphosphates, polyvinylamid,
polyvinylalcohol,
polyether, and copolymers thereof, polythioether, polythioether-polyether,
copolyepichlorohydnirt-ether, polysulphosphates, copolyester-ether and
derivatives or mixtures
thereof.
Considering now the method of the invention, the thin, pliant bladder material
is first
coated with a light coating of the powdered hot melt adhesive, Bostik #5116.
The adhesive
particles randomly cover the bladder evenly to a density of about 20 'Yo
coverage of the surface
area. This bladder material with adhesive is then heated to a temperature
slightly above the
4
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softening point of the adhesive, thereby causing the discrete particles of
adhesive to fuse to the
surface of the bladder material_ Izt the case of $ostik #5116, the softening
point is 268 degrees
Fahrenheit. This means is also used to coat particles of adhesive on both
sides of the bladder
material .
The next step is the construction of the waterproof. breathable bladder. In
once form of
the method of the invention this is accomplished by overlaying two sheets of
the previously
described adhesive coated bladder material and to define on the sheets of
material a line
circumscribing the boundary of the bladder. This done, the sheets of material
are heated along
the boundary line to a temperature sufficient to sealably bond the sheets
together along the
boundary line.
The heating-fusion step can be accomplished in several ways well known to
those skilled
in the art, including using a heated wire or die having the shape of the
bladder-boundary.
Heating can also be accomplished through the use of well-known radio frequency
and ultrasonic
welding techniques. One technique which has proven to be satisfactory in
making the footwear
of the invention, involves the use of a heated platen press embodying a die
having the shape of
the outer boundary of the bladders. The die is electrically heated to about
500 degrees
Fahrenheit. One of the cooperating platens of the platen press is maintained
at room
temperature and, is lined with a flexible fabric such as felt_ The two sheets
of the
adhesive-coated bladder material are placed betweezt two sheets of
polytetrafluoroethylene coated
fiber glass sheets which act as separator material and also allow the heat
from the die to
penetrate to the film_ Appropriate heating of the dies causes the sheets of
bladder material to
be effectively welded, or sealably joined together along the boundary line to
make the
sock-shaped bladder. After the welding process, the excess material outside
the bladder
boundary is manually stripped away and the bladder is removed from the platen
press. By these
means, a sock-shaped bladder component with discrete particles of hot melt
adhesive both inside
atxt outside has been produced.
h is to be noted that the proper application of the adhesive to the inner and
outer surfaces
of the bladder is critical to the success of the manufacturing process, since,
when completed,
the sock must be breathable, flexible, pliant and waterproof and it must
withstand laundering and
physical abuse while being worn. It is to be ztoted that the adhesives can
also be applied to the
fabric components as an alternative means of construction.
As illustrated in Figures 1 and 2 of tile drawings, the zaext step in the
process of the
5
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invention is to place the f rst covering member, or inner sock 20 over a
generally foot-shaped,
approximately l/8th inch thick, generally planer mandrel Z7. Inner sock 20,
which has inner
and outer surfaces 20a and 20b is placed over the mandrel so that inner
surface 20a thereof is
disposed in engagement with the faces 27a of txsandrel 27. As previously
discussed, inner sock
20 can be constructed from a variety of materials. However, a sock which is
made by Wigwam
Mills, Inc. of Sheboygan, Wisconsin special knit pattern of its staztdard BK-1
J.88 has proven
satisfactory. An alternate inner sock, also made by Wigwam, is intended to
impart cold weather
comfort to the waterproof footwear article of the present invention depending
on the climate
encountered. Fox cold weather comfort, the inner sock can be made utilising
ThermaxR made
by E_ I. duPont de Nemours and Co. of Wilmington, r7elaware_ For warm weather
comfort the
inner sock can be made utilizing CoalmaxR made by duPont_
After inner sock ZO has been placed over mandrel 27 and smoothed out so that
its inner
surface is in close engagement with the faces of the ma~ndreI 27, the bladder
12, which has been
adhesive coated with particles of hot melt adhesive inside and outside is
carefully placed over
the assemblage of inner sock 20 and mandrel 27. The bladder is smoothed to be
in close
engagement with the outer surface of inner sock 20. Outer sock 22 is placed
over both the inner
sock 20 and the adhesive coated bladder assemblage on mandrel 27.
The precursor assembly comprising first inner sock 20, the adhesive coated
bladder 12
and the outer sock 22 is then heated and compressed in the direction of the
arrows 34 in Figure
2 to form the finished article. This step is accomplished by placing the
mandrel, upon which
the precursor assembly is mounted, between two platens which can be
controllably heated and
urged together. More particularly, the platens are preferably electrically
heated to a temperature
of about 280 degrees Fahrenheit az~d are controllably moved into pressural
engagement with the
precursor assembly by any type of hydraulically actuated pressure imparting
assembly of a
character well known to hose skilled in the art, A commercially available
press suitable for
carrying out the method of the inventian is sold by PHI of the City of
Industry, California.
During this temperatu~ce-pressure step, the heat activated adhesive is thereby
fused making a
P~nanent, water resistant bond of inner sock 20 to one side of the bladder and
the outer sock
22 to the other side of the bladder. The minimum temperature required to
activate the Bostik
#5116 adhesive is 268 degrees Fahrenheit. Accordingly, a temperature range of
between about
270 degrees Fahrenheit and 290 degrees Fahrenheit is preferred.
The precursor assembly is then removed from the press and allowed to cool
thoroughly
6
CA 02270403 1999-04-30
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prior to doffing the completed waterproof footwear article from the mandrel.
When removed from the mandrel, the footwear article is generally planar in
shape.
However, upon inserting the foot into the open cuff of the article, the foot
engaging portion of
the sock will neatly and smoothly conform to the shape of the wearer's foot.
$ Depending upon the end use of the article, other commercially available
adhesives can
also be used in the practice of the method of the invention. By way of
example, these include
an adhesive sold by Stahl U.S.A. of Peabody, Massachusetts under the
designation UE-41.72 and
an adhesive sold by Reichhold Chemicals, Inc. under the product code EA 6494.
Further, a
mixture of the Reichhold EA 6494 and a SOLUCOTER 1024 adhesive made by 5oluol
Chemical
Co., Ine. can be used for some end product applications-
When the adhesive used is in liquid form it can be sprayed, bzushed or
otherwise applied
to the elastomeric bladder or sock fabric. As previously stated when the
adhesive is applied to
the bladder it must be applied in the mariner, such as a dot matrix coating,
which will not
degrade the breathability characteristics of the bladder material. An
alternate form of the
method of the invention will next be considered. This foz~zn of the invention
is similar in many
respects to the method described in the preceding paragraphs. However, in this
latest form of
the invention a different powdered adhesive is used and, importantly, the
bladder and the outer
sock are both wetted with water during the assembly step to expedite the
assembly of the
m~enlbers and to improve the integrity of the finished product.
In the practice of this alternate form of the invention, the thin, pliant
bladder material
or membrane is frst coated with a Iight coating of a powdered hot melt
adhesive sold under the
name and style of Bostik #Si82. The adhesive is uniformly distributed over the
membrane
material preferably at the raze of about 16.5 grams per square yard and is
thermally fused to the
membrane in the manner previously described. The second side of the zrtembrane
material is
similarly coated and fused with Bostik #5x82 at a rate of about 16.5 grams per
square yard. To
develop a properly sealed final lamination, the fusing of the adhesive to the
membxarie must be
done with great care to carefully control the radiant heating of the adhesive
coated membrane_
Too high a temperature will cause the membrane to melt, while too low a
temperature will fail
to adequately melt and bond the adhesive particles to the bladder surfaces_
Following the coating of the membrane surfaces with Bostik #5182, the next
step in this
alternate method of the invention
is accomplished by cutting the coated membrane into first and second segments
and overlying
7
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the first and second segments to form a coated assembly. Next, a line is
formed on the coated
assembly which circumscribes the boundary of the bladder which generally
corresponds to the
extremity to be covered, in this case the human foot. This done, the sheets of
material are
heated along the boundary Iine to a temperature sufficient to sealably bond
the sheets together
along the boundary line.
This heating-fusion step is here accomplished using a heated platen press
embodying a
die having the shape of the outer boundary of the bladders. The aluminum die
is electrically
heated to about S30 degrees Fahrenheit. The two sheets of the adhesive coated
bladder material
arc placed between two sheets of polytetrafluoroethylene (said under the mark
TEFJ ,ON coated
fiber glass sheets which act as separator material and also allow the heat
from the die to
penetrate to the film. Appropriate heating of the dies causes the sheets of
bladder material to
be effectively welded, or sealably joined together aloztg the boundary Iine to
make the
sock-shaped bladder. During the welding step, the assemblage is backed by a
112 inch thick
sheet of temperature hardboard and a pressure is exerted on the assemblage
sufficient to cleanly
pinch off the membrane material surrounding the die.
As illustrated in Figures 1 and 2 of the drawings, the next step in the
alternate process
of the invention is to place the first covering member, or inner sock 20, over
a generally
foot-shaped, approximately l/8th inch thick, generally planer mandrel 27.
Inner sock 20, which
has inner and outer surfaces, is disposed in engagement with the faces 27a of
n~tandrel 27. As
previously discussed, inner sock 20 can be constructed from a variety of
materials. Mandrel 27
can also be constructed of various materials but here is formed a sheet of
aluminum having a
thickness of about 0 032 inches. The edges of the mandrel are smoothed and
rounded and
preferably coated with a thin strip of 'TEFLON which may comprise a 112 inch
wide strip of
pressure sensitive adhesive coated 'TEFLON tape.
After inner sock 20 has been placed over mandrel 27 and smoothed out so that
its inner
surface is in close engagement with the faces of the mandrel 27, the bladder
12, which has been
adhesive coated with particles of hot melt adhesive inside and outside is
imlxlersed in water
causing it to expand slightly. The water saturated, expanded bladder is then
carefully placed
over the assemblage of inner sock 20 and mandrel 27. The bladder is smoothed
to be itt close
engagement with the outer surface of inner sock 20. Outer sock 22 is then also
wetted by
immersiuag it in water or otherwise wetting it and is carefully placed over
both the inner sock
20 and the adhesive coated bladder assemblage on mandrel 27.
8
CA 02270403 1999-04-30
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The precursor assembly eomprisiug inner sock 20, the adhesive coated bladder
I2 and
the outer sock 22 is then placed between heated platens and heated to about
275 to 325 degrees
F for about three to five minutes. Preferably the bottom platen is a rigid
sheet of aluminum
covered wish a 114 inch thick sheet of about 50 derometer silicone rubber. The
heated
assezxtblage is then compressed by substantial compressive force in the
direction of the arrows
34 in Figure 2 to form the finished article.
The compressive forces can be exerted on the heated precursor assembly in
various 'ways
such as hydraulically-actuated, pressure-imparting assembly, or press,
previously described
herein. Alternatively, the compressive forces can be applied by passing the
precursor assembly
between pressing rollers of a character well known to those skilled in the an.
Preferably, a
pressure of at least two pounds per square inch is exerted on the precursor
assembly for about
four minutes, hollowing the compression step, the precursor assembly is
immediately plunged
into a bath of cool water for several minutes. This step quenches the
adhesive, arresting
crystalline growth and thezeby providing a more amorphous molecular structure
and pliam
adhesiozt_ Additionally, the bladder is softened and expanded by the water for
ease of removal
from the mandrel. The wet sock assemblage is then removed from the mandrel and
allowed to
dry.
Referring now to Figures 5, 6, and 7, still another fort~n of the method and
azticle of the
invention is there illustrated. This form of the invention is similar in many
respects to that
earlier described. However, in this latest form of the method of the
invention, still a different
adhesive is used. The bladder material is changed and the time and temperature
parameters of
the laminating process are changed. Additionally, several new steps have been
added to the
method earlier described. Further, the inner, liner sock is provided with a
longer cuff to
provide a novel wicking action.
In the practice of this latest form of the method of the invention, the thin,
pliant bladder
material ox n~eznbrane 50 comprises an extruded film made by The Dow Chemical
Company and
sold under the name and style "PEL.LETHANE No. 2103-$9AE". The membrane, which
comprises polytetramethylene glycol ether, is preferably about 0.001 inches
thick is f rst coated
with a light coating of a powdered hot melt adhesive sold under the name and
style of Bostik
HM 5184-AB which is available from Bostik, Inc. of Middleton, Massachusetts.
This particular
adhesive is a powdered hot melt adhesive with a low activation temperature of
about 260
Fahrenheit. The particle size is such as can be sieved thxough a mesh with
approximately 200
9
CA 02270403 1999-04-30
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micron apertures.
In carrying out the method of tJne invention, the adhesive is uniformly
distributed over
the membrane material preferably at the rate of about 16.5 grancxs per square
yard and is
thermally fused to the membrane by passing a radiant heater over the adhesive-
coated
membrane. In practice, the radiant heater is controllably passed over the
adhesive coated
membrane in a manner to elevate the temperature of the adhesive above its
melting point,
thereby fusing the adhesive to the membrane without melting the membrane. More
particularly
with the temperature of the heater set at about 764 degrees Fahrenheit, the
heater is preferably
passed over the assemblage at a rate of travel of about 92 inches per minute.
During this step,
the face of the radiant heater is preferably positioned about 2 114 inches
above the membrane.
The membrane with adhesive fused to one side is them turned over with the
uncoated side facing
up. Again, a coating of the powdered adhesive is distributed on the second
side of the
membrane and is fused to the membrane in the manner just described, thus
providing a
membrane with adhesive particles fused uniformly to both sides.
Following the coating of the membrane surfaces with adhesive 53, the next step
in this
latest method of the method of the invention is accomplished by means of a
thermo plastic
welding process which is carried out in a suitable platen press. More
particularly, in
accomplishing this welding step, the bottom platen of the press is preferably
covered with a thin
sheet of silicone rubber of about 70 shore hardness. This layer is in tuns
covexed with a sheet
of fiberglass material which has been coated with a fluorocarbon polymer. This
done, two
thicknesses of the adhesive coated membrane are laid together crud placed onto
the bottom platen
of the press. A second sheet of fluorocarbon polymer coated fiberglass
material is next placed
over the sheet of adhesive coated membrane. The upper platen of the press
which is equipped
with a die in the desired shape of the sock is then heated and controllably
forced against the two
thicknesses of adhesive coated membrane which are resting an the lower platen
of the press.
The lower platen is not heated and remains at room temperature. The welding
press is equipped
with controls so adjustments may be made to vary temperature, dwell times and
the force
imposed by the platens one against the other.
Disposed between the upper and lower platens is a movable heat shield which
protects
the adhesive coated membranes from the heat of the upper platen as it is
forced into
juxtaposition wzth the lower platen. In this regard, the die is strategically
desiened to have a
depth sufficient to accept the heat shield within the sock shape and
effectively prevent the two
CA 02270403 1999-04-30
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thicluiesses of adhesive coated bladder material from welding one to the
other. Suitable process
parameters for carrying out the membrane welding step are:
a) Upper platen temperature 572 to 625 degrees Fah~renk~eit;
b) Dwell time 2.5 to 3.5 seconds; and
c) Inter-platen force 2800 to 3200 pounds.
Adherence to these process parameters, causes the sheets of bladder material
to be
effectively welded, or sealably joined together along the boundary line to
make the continuous
surface sock-shaped bladder.
It is to be understood that in constructing the bladder, any of the previously
described
bladder materials and any of the previously described adhesives could be used
so long as the
process parameters are appropriately adjusted.
Following formation of the sock-shaped bladder, the first covering member, or
inner sock
52 (Figure 7) is placed over a generally foot-shaped, aluminuri~ mandrel 54
(Figure 5), which
has a thickness of about 1132 ir~h- In this instance, the inner sock is
constructed from a fabric
comprising a polyester fiber and a texturized nylon fiber. A suitable,
commercially available
material for constructing the inner sock is one sold by IauPont under the name
and style
"COOLNIAX" . One reason for selecting this particular material is the
excellent water-wickizig
characteristics exhibited by the fibers, the importance of which will
presently be described.
After inner sock S2 has been placed over mandrel 54 and smoothed out so that
its inner
surface is in close engagement with the faces of the mandrel 54, the bladder
50 which has been
adhesive coated with particles of hot melt adhesive inside and outside is
carefully placed oven'
the assemblage of inner sock 52 and mandrel 54. Outer sock 56 is then placed
over both the
inner sock 52 and the adhesive-coated bladder.
The precursor assembly comprising inner sock 52, the adhesive coated bladder
50 and
the outer sock 56 is then smoothly arranged over the aluminum mandrel with
sock 52 against
the mandrel, sock 56 on the outside and adhesive coated bladder 50 disposed
intermediate the
firs and second socks.
The precursor assembly is next laminated using a commercial platen press of
the
character having a cornrollably healable upper platen. Suitable process
parameters for the
lamination step axe:
(a) Platen temperature - 260 degrees Fahrenheit minimum:
(b) Platen pressure - I to 2 pounds per square inch; and
11
CA 02270403 1999-04-30
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(c) pwell time - 1 to 3 minutes.
After completion of the laminations step, the laminated precursor assembly is
pulled from
the mandrel and allowed to cool to room temperature. During cooling, the
precursor assembly
normahy shrinks to a size only minimally smaller than the size of the mandrel.
An optional step ie this latest method of the invention is to inflate the
laminated precursor
assembly with several pounds of air pressure and then submerge it in water in
order to test it
for leaks. Leaks axe evidenced if a stream of bubbles emanate anywhere from
the sock.
Whether the precursor assemblage is leak tested or not, the assemblage is
preferably
wetted and then dried in a heated tumble dryer of the character used in a home
laundry. 'This
causes the nylon sock to shrink markedly and also causes the assemblage to
become quite elastic
so that it will comfortably fit feet of differing sizes.
Still another optional step in the method of the ixiventioz~ is to stitch
together the inner
and outer socks and the bladder at a location proximate the cuff of the
assemblage. This tends
to stabilize the assemblage and prevent delamination during extended use.
As previously mentioned, the chosen material for the inner liner 52, namely
buPont's
Goolmax polyester fiber, is an efficient wicking fiber which rapidly moves
water moisture along
the fibers. This capillarity action is due in Large measure to four
longitudinal grooves formed
along the length of each fiber. In use it has been observed that the fibexs
enhance transport of
the perspiration over a wide area Inside the sock thereby exposing a greater
area of the bladder
to the moisture source. By thus moving the perspixatior~ along the wicking f
bets, the wearer
is made much more comfortable than is the case where the inner liner is not
constructed from
wicking fibers.
When the iz~z~ex sock is constructed with a longer cuff so that the cuff
extends above the
bladder and the outer sock in the manner shown in Figure 6, the perspiration
will be drawn
upwardly out of the waterproof portion of the sock thereby allowing it to
evaporate directly to
atmosphere.
'Iltrning now to Figures 8 through 11 of the drawings, another form of the
clothing
article of the present irtve;rition is there shown. This article comprises a
clove construction
including a thin, pliant bladder constructed from any of the waterproof,
breathable materials
previously identified herein. As before, the bladder can be of various
thieknesses ranging from
about 0.5 mils to about 3.0 mils. The previously idezttified extruded material
available from the
Dow Chemical Company having a thickness of about 1.0 miI has been proven to be
quite
12
CA 02270403 1999-04-30
A~:~. ~~, i~~yn 5: i2i'M JVUi~AK ~ U~uM ~.~N~. i~~~~~~~. 14/31
satisfactory for use in constructing both the sock and glove articles of the
invention.
In the practice of this latest form of the method of the invention, the thin,
pliant bladder
material or membrane is first coated with a light coating of the previously
identified, powdered
hot melt adhesive sold under the name and style of Bostik HM 5184-AB which is
available from
Bostik, Inc. of Middleton, Massachusetts. The adhesive is uniforn'tly
distributed over the
membrane material in the z~nanner previously described herein in connection
with the sock
embodiments preferably at the rate of about 1G.5 grams per square yard and is
~h,exmahy fused
to the membrane by passing a radiant heater over the adhesive-coated membrane
as earlier
described. The second side of the membrane material is then coated and fused
with Bostik HM
5184-AB.
Following the coating of the membranie surfaces with the adhesive, two
thieknesses of
adhesive coated membrane are laid together and placed onto the bottom platen
of a suitable
platen press. The upper platen of the press, which is equipped with a die in
the shape of the
outer contour of a glove of desired size and shape is then heated and
controllably forced against
the two thickztesses of adhesive coated membrane which are resting on the
lower platen of the
press. Disposed between the upper and lower platens is a movable heat shield
which protects
the adhesive coated membranes from the heat of the upper platen as it is
forced into
juxtaposition with the Lower platen. Suitable process parameters for carrying
out the membrane
welding step are:
(a) Upper platen temperature-572 to 625 degrees Fahrenheit;
(b) Dwell time-2.S to 3.5 secoztds; and
(c) Inter-platen force-2800 to 3200 pounds.
Adherence to these process parameters, causes the sheets of bladder material
to be
effectively welded, or sealably joined together along the boundary line to
make the glove-shaped
bladder 60 (Figure 9).
In the manner shown in Figure 8, the first covering member or inner ,glove 62
is next
placed over a generally hand-shaped, aluminum mandrel 64 which is shown by the
dotted lines
in Figure 8). Mandrel 64 preferably has a thickness of about 1J32 inch. In
this instance, the
inner glove is constructed from a fabric comprising a polyester fiber and a
texturi,zed nylon
fiber. A suitable, cotnnnercially available material for constructing the
inner glove is a material
sold by DuPont under the name and style "COOLMAX" .
Referring particularly to Figure 8,- it should be noted that mandrel 64 has
the shape of
13
CA 02270403 1999-04-30
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a hand, the fingers and thumb of which have been splayed considerably beyond
that Which is
anatomically comfortable with a human hand. The reason for this exaggerated
splaying will be
discussed in the paragraphs which follow.
As illustrated in higure 9, after glove 62 has been placed over mandrel 64 and
smoothed
out so that its inner surface is in close engagement with the faces of tlae
mandrel, the bladder
60, which has been adhesive coated with particles of hot melt adhesive inside
and outside, is
carefully placed over the assemblage of glove 62 and mandrel 64. Outer glove
66 is then placed
over both the glove 62 and the adhesive-coated bladder in the manner shown in
Figure 10. Prior
to this step, the cuff portion 60a of the bladder can, if desired, be trinnmed
along a tine shown
by the dotted line 61 in fzgure 10.
The precursor assembly shown in Figure 10 comprising glove 62, the adhesive
coated
bladder 60 and the second glove 66 (see also Figure il) is then arranged over
the aluminum
mandrel. As indicated in Figure 11, the adhesive 67 which coats the inner
surface of bladder
60 is in engagement with the outer surface 62a of glove 62. Similarly, the
adhesive (designated
as 67a) which coats the outer surface of the bladder 60 is in engagement with
the inner surface
66a of outer glove 66. Next, the precursor assembly is laminated using a
commercial platen
press of the character previously described. Suitable process parameters for
the lamination steps
are:
(a) Platen temperature - 260 Fahrenheit minimum;
(b) Platen pressure - 1 to 2 pounds per square inch; and
(c) Dwell time - 1 to 3 minutes.
After completion of the Lamination step, the laminated precursor assembly is
pulled from
the mandrel and allowed to cool to room temperature. During cooling, the
precursor assembly
shrinks to a size slightly smaller than the size of the mandrel.
In this regard, it should be understood that when the glove is donned and
worn, the
material at the crotches is not stretched and ruptured, rather, the material
is compressed and
folded together between the ~utgers since the human hand cannot splay wide
like the glove,
thereby relieving any possibility o~ damaging stresses. In practice, it is
preferable that not only
are the fingers and thumb splayed, but also the membrane bladder 60 be
fashioned larger than
the mandrel 64, as shown in Figure 9, thereby eliminating further possible
stresses upon
assembly and insuring a leak-tight glove assemblage.
An optional step in this latest method of the invention is to inflate the
laminated precursor
I4
CA 02270403 1999-04-30
Hr ic. c~, m~~~! ~: ~~r!vi uuunn!t & unu:Y! pC!WU. !COCy46~r. ! ~/~ r
assembly with several pounds of air pressure and then submerge it in water to
test it for leaks.
Leaks are evidenced if a stream of bubbles emanate anywhere from the stack
'Whether the precursor assemblage is leak tested or not, the assemblage is
prefez~ably
wetted and then dried in a heated tumble dryer of the character used in a home
laundry. This
causes the nylon glove to shrink markedly and also causes the assemblage to
become quite elastic
so that is will comfortably fit hands of differing sizes.
As previously mentioned, the chosen material for the glove 62, namely DuPont's
Coolmax polyester fiber is an efficient wicking fiber which rapidly moves
water moisture along
the fibers in the manner earlier described. In use, the fibers enhance
transport of perspiration
over a wide area inside the glove thereby exposing a greater area of the
bladder io the moisture
source. By thus moving the perspiration along the wicking fibers, the wearer
is made much
more eomfortable'than is the case where the inner liner is not constructed
from wicking fibers.
It is to be understood that the method of the invention can be used to produce
articles of
clothing such as socks and gloves in various sizes and design configurations
to fit a wide variety
of users.
Having now described the invention in detail in accordance with the
requirements of the
patent statutes, those skilled in this art will have no difficulty in making
changes and modifca-
tions in the individual parts or their relative assembly in order to meet
specific requirements or
conditions. Such changes and modifications may be made without departing from
the scope and
spirit of the invention, as set forth in the following claims.
CA 02270403 1999-04-30
