Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THIS INVENTION
This invention is an improvement over Hoey, U. S. Patent
No. 3,618,754, issued November 9, 1971, which is also the
closest prior art of which the applicants of the present inven-
tion are aware. Hoey discloses a continuous fabric web which is
conveyed in a fully stretched condition and which is adhesive-
coated in such stretched condition using high heat calender
rolls. Hoey's method causes two problems. First, by applying
the adhesive to a fully stretched fabric',`the bandaging material
has poor breathability when used. That is, in use, the bandag-
ing material is stretched and the adhesive layer is thick and
uniform in depth, preventiny air passage through the adhesive
layer. Second, by heating the fully stretched elastomeric warp
yarns to between 240 and 270F., the stretch warp yarns lose a
great deal of their power of recovery and a great deal of their
elasticityO
This is preçisely the opposite way in which applicants'
bandaging material is produced, i.e. applicants' fabric is first
steamed and is then coated with an adhesive layer, both steps
occurring while the fabric is being conveyed in a fully relaxed
condition. Applicants avoid using high heat throughout their
process.
Because of this difference in the methods by which ~oey's
bandaging material and applicants' bandaging material are pro-
duced, the resulting materials have different physical charac-
teristicsO Hoey does not initially steam his fabric whereas ap-
plicants do steam their fabric. This steaming step exfoli
ates
and spreads the interwoven filling and warp yarns of appl
icants'
fabFic and also expands and loosens non-stretch yarns the
reby
facilitating a fuller retraction of applicants' stretch w
arp
yarns. As a result, applicants' bandaging material strong
ly and
repeatedly recovers to its original relaxed length after
being
stretched, whereas the Hoey bandaging material has a weak
er
snap-back and has reduced elasticity especially after an
extend-
ed period of full stretch.
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Furthermore, applicants' fabric preferably receives
an acrylic polymer coating which improves the tearability of
applicants' bandaging material and which inhibits fraying at the
edges of the material. ~oey's material does not receive such a
coating.
For all of the foregoing reasons, applicants'
bandaging material is an improvement over the Hoey material and
is a decided advance in the art.
SUMMARY OF T~IE IN~ENTION
This invention is a breathable, conformable, elas-
tic, pressure-sensitive, permanently tacky, adhesive bandaging
material comprising:
(a) a fabxic having face and back sides and formed by
filling yarns interwoven with warp yarns, said warp yarns con-
sisting essentially of non-stretch textile warp yarns interspers-
ed with stretch warp yarns, said filling and warp yarns woven
in a pat~ern such that said stretch warp yarns have an average
float length on the back side of said fabric which exceeds the
average float length of said non-stretch warp yarns on said back
side, said fabric normally being in a relaxed condition; and
(b) a pressure-sensitive, permanently tacky, adhesive
applied in a level layer to the entire back s.ide of said relaxed
fabric to produce an adhesive bandaging ma-terial which in its
relaxed state has an adhesive layer which has a smooth exposed
surface and a substantially uniform depth throughout, and which
in its stretch state has an adhesive layer which has a nonuniform,
discontinuous surface and which has a depth which is relatively
great where said non-stretch warp yarns extend to said back
side of said fabric and which has a depth which is relatively
slight or zero whexe said non-stretch warp yarns oxtend away
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from said back side of said fabric.
The invention also involves a method of producing
the aforesaid bandaging material comprising the steps of:
(a) conveying a continuo~ls web of said fabric in a sub-
stantially relaxed condition and applying heat and moisture to
said relaxed fabric to exfoliate and spread said interwoven
filling and warp yarns and to expand and loosen said non-stretch
yarns thereby facilitating a fuller contraction of said stretch
yarns; and
(b) applying a layer of pressure-sensitive, permanently
tacky adhesive to said back side of said conveyed fabric while
said conveyed fabric is in a substantially rela~ed condition.
The method comprises the use of a fabric which is
conveyed in a continuous web in a relaxed condition. Steam is
preferably applied to the relaxed fabric, the fabric is dried
with low heat, a release coating and/or a non-fray coating is
applied to the fabric, the layer of adhesive is applied to the
back side of the conveyed relaxed fabric, and the adhesive is
dried with low heat. The material is then wound into a roll and
is then slit into a plurality of rolls having the desired roll
width.
DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of the roll of
bandaging material of this invention.
Fig~lre 2 is a schematic bottom plan view on an
enlarged scale of the stretched fabric showing the back side
thereof with the adhesive layer omitted.
Figure 3 is an elevational view, in cross-section,
of a fabric in its relax~sd condition, showing the non-stretch
warp yarns extending towards and away from the back side of the
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68817-34
fabric, showing the elastomeric stretch warp yarns extending
along the back side of the fabric, and showing the adhesive
layer on the back side of the fabric, the adhesive layer having
a smooth level surface and a uniform dep-th.
Figure 4 is a similar schematic elevational view, in
cross-section, of a fabric in its stretched condition, showing
the adhesive layer having a non-uniform, discontinuous surface
and a depth which is relatively grea-t where the non-stretch warp
yarns extend to the back side of the fabric and which is
relatively slight ox zero where the non-stretch warp yarns ex-
tend away from the back side of the fabric.
Figure 5 is a schematic elevational view showing
the conveying of the fabric web in a relaxed condition through
a spray of stsam, and then over low-heat drying rolls, and then
showing the rewinding of the fabric in a relaxed state.
Figure 6 is a schematic elevational view showing
the conveying of the fabric web in a relaxed condition under a
spray of a combined release and non-fray coating, and then under
low heat drying elements, and then showing the rewinding of the
fabric in a relaxed state.
Figure 7 is a schematic elevational view showing
the drawing of adhesive under a blade-coating means, and then
the application of the adhesive under very llght pressure to a
web of relaxed fabric, the drying of the adhesive under low heat
conditions/ and then the rewinding of the fabric in a rela~ed
state.
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Fig. 8 is a schematic elevational view showing the convey-
ing of the fabric web in a relaxed condition over several
spreading rolls, and then showing the rewinding of the fabric on
l a core in a relaxed state so that the adhesive covered back side
¦ of the fabric is oriented inwardly towards the core and so that
the release coated face side of the fabric is oriented outwardly
away from the coreO
Fig. 9 is a top plan view showing the slitting of a roll of
the bandaging material to the desired width.
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DESCRIPTION OF THE PREFERRED METHOD AND MATERIAL
In order to produce the roll of bandaging material shown in
Fig. 1, applicants start with a continuous web of rolled fabric
1O. An example of a suitable fabric is one which has been
formed by the interweaving of essentially non-stretch filliny
yarns 12, such as cotton, with warp yarns consisting of
non-stretch warp yarns 14, such as cotton, interspersed with
stretch warp yarns 16, such as corespun Dupont Lycra spandex
filaments around which are wrapped fibers of cotton and
polyester. An example of a suitable warp yarn arrangement is
one in which two ends of cotton warp yarn lie next to one end of
spandex core stretch warp yarn in a repeating pattern. The
spandex core stretch warp yarns, when stretched, have an average
float length on the back side of the fabric which exceeds the
average float length of the cotton warp yarns on the back side.
For example, each end of stretch warp yarn 16 floats over five
picks of cotton filling yarn 12 on the back side, then weaves
under, over, and under three picks of cotton filling yarn 12,
then floats over five picks of cotton filling yarn 12 in a re-
peating pattern. Of course, this is but one example of a suit-
able fabric, and the materials and the weaving pattern could be
modified in a wide variety of ways.
The process begins, as shown in Fig. 5, by mounting a roll
18 of fabric 10 on a specially constructed roll stand 20 which
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is adapted to be precisely driven to pay off the continuous web
of fabric 10 at a rate which will keep the fabric in a tension-
free, relaxed condition throughout the first processing step
shown in Fig. 5. The fabric moves over two non-driven rolls 22
and 24 between which the fabric receives a spray of steam from a
steam box 26. The steam spray is spread so that steam is di-
rected against the entire surface of the fabric. Altho~gh not
crucial, it is preferred to apply the steam spray to the back
side of the fabric (the side shown in Fig. 2) in order to maxi-
mize the steam's effect on all of the non-stretch yarns and
fibers.
The purpose of the steam application is to exfoliate and
spread and loosen the cotton filling and cotton warp yarns and
to spread and loosen the cotton fibers to permit the spandex
core filaments to retract and contract to the maximum extent.
This steaming step opens the pores and enhances the
breathability of the fabric, especially when the fabric is
stretched, and increases the capability of the fabric to be
stretched for extended periods of time and to powerfully return
to substantially its original length time after time. This
steaming operation is not disclosed by the prior art Hoey patent
and, as a result, applicants' bandaging material possesses
superior breathability and superior snap-back and elasticity.
Even after applicants' bandaging material has been stretched for
a long time, it retains substantially all of its original
snap-back and elasticity.
After steam has been applied to the relaxed fabric by steam
box 26, the fabric 10 is further conveyed in a relaxed condition
over drying means consisting of low heat rolls 28. After the
fabric passes the last heated roll, the fabric has become almost
completely dry and is then rewound on a specially constructed
roll stand 30 which is designed to take up the fabric 10 in a
relaxed condition. It will be understood that the drying means
can take other forms so long as it does not raise the tempera-
ture of the fabric above approximately 235F.
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Applicants take great care ~a) to avoid stretching their
fabric and (b) to avoid applying high heat. ~y keeping the
fabric relaxed throughout the entire process and by avoiding
heating the fabric to above approximately 235F., applicants
ensure that their fabric retains its pronounced snap-back and
elastic characteristics.
The next processing operation is illustrated in Fig. 6.
Although Fig. 6 is shown as a separate processing operation with
relation to Fig. 5, this separatiqn is not mandatory.
Specifically, the two processing operations could be made
contiguous. This would be accomplished by omitting take-up roll
stand 30 (in Fig. 5~ and pay-off roll stand 32 ~in Fig. 6).
Then, the fabric would run directly from the Fig. 5 operation to
the Fig. 6 operation without being wound or unwound. The fabric
would be kept in a relaxed condition throughout the steaming,
drying, coating, and drying steps. At the end of Fig. 6, a
take-up roll stand (like 30) would rewind the fabric 10 in a
relaxed condition.
However, for purposes of clarity, Fig. 6 shows ~ pay-off
roll stand 32 which is similar to the pay-off roll stand 20 in
Fig. 5. The web of fabric 10, after leaving pay-off roll 32 in
a relaxed condition, moves to a conveyor 36. The conveyor is
driven by two rolls 38, 40 in the direction shown in Fig. 6.
The surface of the conveyor belt is porous and the fabric lies
on the upper run of the conveyor in a relaxed condition.
A spray head 42 is mounted above the conveyor and is
arranged to spray the entire face side of the fabric with a
fluid coating/ the nature of which will be described
subsequently. The spray head is preferably cam-driven so that
it swings from side to side in a precisely timed manner causing
the entire surface of the fabric to be covered with an equal
amount of the sprayed fluid.
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1 The sprayed fluid contains a release agent which aids in
¦ the unwinding of the roll of adhesive bandaging material A
¦ good release agent is a water-borne silicone polymer. In
l addition, the sprayed fluid could advantageously also contain an
¦ acrylic polymer which stiffens the fabric making it easier to
¦ laterally tear by hand and which reduces the fraying of the
edges of the fabric when the fabric is manually torn. The
acrylic polymer prevents unraveling of the yarns during tearing,
l resists twisting of the yarns, gives more dimensional stability
¦ to the yarns, and gives the fabric ~a'crisper "handn. The
combined release agent and acrylic polymer constituents are
sprayed in a latex form for ease of application to the fabric.
Of course, the latex could be applied by means other than by a
spray head.
After the latex has been sprayed on the face side of the
fabric, the relaxed fabric is conveyed under a bank of low-heat
drying elements 44. Then, the dried fabric is rolled up in a
completely relaxed condition on roll stand 34, which is similar
to roll stand 30.
It should be understood that the release agent and the
non-fray agent can be combined and applied, or can be
independently applied, and do not necesesarily have to be
applied together or in sequence. They are independent, but it
may be convenient to apply the two agents together. In fact,
depending upon the nature of the yarns used, one or both agents
could be omitted.
.
Fig. 7 shows the processing operation in which the adhesive
is applied to the back side of the fabric. As previously stated
with regard to the option of making contiguous the processing
steps shown in Figs. 5 and 6, the processing step shown in Fig.
7 can be made cvntiguous with the immmediately preceding and/or
the immediately su~ceeding steps. However, for purposes of
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illustration, Fig. 7 shows a conveyor 46 which is driven by
rolls 48 and 50. The conveyor belt has a release-coated surface
l and contin~ously travels in the direction shown in Fig. 7.
¦ A doctor blade 52 is mounted over a coating roll 54 in con-
ventional fashion such that the blade can be accurately adjusted
to provide the desired spacing between the blade and the convey-
or belt being carried by coating roll 54. The process operator
manually (or with the aid of appropriate equipment) continuously
or periodically applies a quantity of adhesive material 56 onto
the conveyor belt immediately upstream of the doctor blade. The
conveyor belt carries the adhesive material against and under
the doctor blade which causes the adhesive material to be coated
onto the conveyor belt in a level layer having a uniform depth.
At the same time, the fabric 10, having been previously steamed
(Fig. 5) and release and/or non-fray coated (Fig. 6), is unroll~
ed from a roll stand 58 in a completely relaxed condition. The
fabric 10 drops onto the conveyor belt which has been previously
coated with the layer of adhesive by the doctor blade 52. Thus,
the back side of the fabric is brought into contact with the
level upper surface of the adhesive. The fabric is completely
relaxed and the adhesive has a uniform depth and has a smooth
and level upper planar surface (in contact with the back side of
the fabric) and a smooth and level lower planar surface ~in
contact with the conveyor belt). The fabric and adhesive, in
engagement with each other, are then conveyed over and around a
series of steam containing rollers 60, an unheated roller 62,
and a chilled roller 64, all for the primary purpose of causing
the adhesive to strongly and permanently adhere to the back side
of the fabric.
Small idler rollers 66 cooperate with the conveyor belt to
keep the belt taut and to directionally guide it during its
travel over and around the other rollers. After the web of
fahric 10, to which the layer of adhesive now adheres, passes
over chilled roller 64, it is peeled away from the release-coat .
ed conveyor belt by the take-up roll stand 68. The fabric is
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rolled up by roll stand 68 in a completely relaxed condition.
Thus, it will be seen that the fabric has passed from roll stand
20 (shown in Fig. 5~ to roll stand 68 (shown in Fi~. 7) in a
continuously relaxed condition.
The adhesive 56 used in this process is a pressure-sensi-
tive, permanently tacky adhesive material. Preferably, the ad-
hesive material is primarily rubber with various other constitu-
ents which increase the tackiying and anti-oxidizing properties
of the material. The material preferably has a high viscosity
and a high solids content and is dissolved in solvent~ If it is
desired ~o use the bandaging material primarily for the health
care market, rather than for the athletic market, an adhesive
material which is hypo-allergenic should be used. Such a hypo-
allergenic material could be formulated from a solvent-based or
a water-based compound and such material could be applied to the
back side of the fabric by the Fig. 7 process or by a different
process, such as by spraying.
It i5 important to note that the adhesive material 56 is
applied to the back side of the fabric 10 by a very light
pressure contact. The conveyor belt is kept only taut enough to
prevent slippage on the rollers, but is kept loose enough so
that the belt gently urges the layer of adhesive only against
the back side of the fabric and not up into the interstices of
the relaxed fabric to any significant extent. By this method,
the upper surface of the adhesive material remains virtually
parallel to the lower surface of the adhesive material during
the entire adhesive coating step and during the entire take-up
step on roll stancl 68~
The web of fabric 10, after being coated with adhesive and
rolled up on roll stand 68, has its adhesive coated back side
oriented away from the center of the roll and has its release
agent coated face side oriented towards the center of the roll.
The rolled fabric is in a relaxed condition which causes the
rolled fabric to roll up into a very fat fabric roll on roll
stand 68. Therefore, the necessary next step in the process,
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which is shown in Fig. 8~ is the tensioned rewinding of the web
of fabric onto a cardboard or other type of core. Fig. 8 shows
the unrolling of the fabric from a driven roll stand 70. The
fabric first passes over a non-driven bow roll 72 (such as Mount
Hope roll) which laterally spreads the fabric and centers it on
the roll surface~ The spread fabric next proceeds to a
non-driven roll 74 and then on to a driven pull roll 76 which
has an adhesive covered surface for longitudinally pulling the
fabric. The web of fabric next proceeds to another non-driven
Mount Hope roll 78, then on to another non-driven roll 80, and
finally onto a roll stand 82 which uses a long thin arbor 84, a
long, small diameter cardbore core 86, and a driven take-up
mechanism to slightly stretch and roll up the web of fabric on
the core 86. In the rewinding operation, the ribbed face side
of the web (containing the release coating) is positioned to
face outwardly, and the back side of the web (containing the
adhesive coating) is positioned to face inwardly.
Finallyr as shown in Fig. ~, the arbor-carried cored roll
of fabric is mounted in a lathe-like device, between two oppos-
ing spindles 88, and the roll of fabric is rotated. A rotating
circular blade 90, on a movable swin~ arm, is programmed so that
(a) it swings forward towards and into the roll of fabric a
specified distance in order to slit the cored roll without con-
tacting the arbor 84, (b) it swings back to its original
position, and (c) it moves laterally a specified distance in
order to set the desired roll width before the blade swings
forward again to make the next slit in the cored roll. After
the wide roll has been slit into a number of narrow rolls having
the desired roll width, the spindles are spread, the arbor is
removed from the lathe-like device, and the rolls of bandaging
material are removed from the arbor. Each roll of material has
the appearance of the roll shown in Fig. 1. This completes the
description of the process of this invention.
The bandaging material of this invention will now be
described in detail~ The roll of material is shown in Fig. 1
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It is rolled on a cardboard core 86, has its adhesive coated
back side positioned towards the core, and has its release
coated face side positioned away from the core. The bandaging
material is made from a fabric 10 which is formed by essentially
non-stretch filling yarns 12 interwoven with warp yarns consist-
ing of stretch yarns 16 interspersed with essentially
non-stretch yarns 14 in a weave such that the stretch warp yarns
have a relatively long float length on the back side of the
fabric and the non-stretch warp yarns have a relatively short
float length on the back side of the ,fabric. This is clearly
shown in Fig. 2 and causes the fabri,c to become extremely
corrugated when in a relaxed condition (Fig. 3) and to become
substantially planar when in a stretched condition (Fig. 4)~
The fabric 10 has substantially open pores which were pro-
duced by the steaming operation. This increases the breath-
ability of the bandaging material. The fabric also has power-
ful and long-lasting elastic stretch warp yarns, the power and
the long-lasting nature of the stretch yarns being enhanced by
the application of steam to the cotton yarns and fibers which
loosens their grip on the elastomeric core filaments of the
stretch yarns. The steaming increases the capability of the
bandaging material to powerfully and fully recover over and over
even after being stretched for long lengths of time.
Figs. 3 and 4 show what happens to the fabric when it is in
the relaxed and the stretched conditions. Fig. 3 shows the
fabric relaxed. The stretch warp yarn is planar and on the back
side of the fabric. The non-stretch warp yarn 14 extends to-
wards and away from the back side of the fabric. At the points
where the non-stretch warp yarn 14 touches the back side of the
fabric, it is in the same plane as the stretch warp yarn 16.
This is clearly shown in Fig. 3. Also clearly shown is the uni-
form depth of adhesive material 56 and its smooth and flat lower
exposed face. The adhesive material is attached to the relaxed
fabric only at the back side of the fabric and does not extend
upwardly to any significant extent into the interstices of the .
fabri~.
~ig. 4 shows the fabric in its stretched condition. The
stretch warp yarn 16 remains p1anar and remains on the back side
of the fabric. The non-stretch warp yarn 14 has become closer
to the fabric's back side, but still extends towards and away
from the back side of the fabric. The major difference is that
the adhesive layer 56 has assumed a quite different form. Its
depth has become non-uniform and discontinuous. Where it
touches the non-stretch warp yarns 14 at the back side of the
fabric, it has retained its original depth. However, at all
other locations, its depth has become shallower to varying de-
grees. In many locations, the adhesive layer is absent. If one
were to hold the adhesive coated fabri~ up to the light, one
would see that the adhesive layer was thickest where the
non-stretch warp yarns 14 touch the back side of the fabric and
was thinner or was absent everywhere else to varying degrees.
Because of this variance of adhesive layer depth when the
bandaging material is stretched, the material has superior
breathability when wrapped around a person's arm or leg. This
is an important characteristic and is produced to a great extent
because the web of fabric is coated with adhesive when the
fabric is in a relaxed condition. The combination of a ribbed
fabric and a fabric coated in a relaxed condition strongly
contributes to the breathability of and the air flow through the
bandaging material which reduces irritations to and increases
the comfort of the user.
The nature of the adhesive material has already been
described. It has a smooth exposed surface and a substantially
uniform depth throughout when the bandaging material is in a
relaxed condition. When the bandaging material is stretched,
the adhesive material has an und~lating exposed surface and a
depth which is relatively shallow or completely absent where the
non-stretch warp yarns 14 extend away from the back side of the
fabric and a depth which is relatively great where the
non-stretch warp yarns extend to the back side of the fabric.
The nature of the release coating has also been already
described. It is applied tn the entire face side of the
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preferably relaxed fabric to improve the ability of the roll of
bandaging material to be easily unwound. This release coating
preferably contains an additional constit~ent which is an
acrylic polymer that somewhat stiffens the material making it
easier to tear off a piece of material and preventing the
material edges from fraying during and after the tearing
operation.
The resulting bandaging material is extremely breathable,
tears quite easily, and hardly frays ~t~the edges. It is most
absorbent and has a strong and long-lasting power of recovery
after long and numerous stretchings. Its adhesive coating and
its release coating are both very effective. Some prior art
competitive bandaging materials have limited recovery
capability. Once stretched for a short while, they permanently
lose their ability to powerfully retract to their original
length. Not so with the present invention. Its power of
recovery is extremely impressive.
These features of excellent breathability and great and
long-lasting power of recovery are produced by the method's
application of steam to the relaxed abric and application of
adhesive to the relaxed fabric. The method's advantages are
maximized by the maintenance of the temperature of the fabric
below approximately 235 F.
The above description obviously suggests many possible
variations and modifications of this invention which would not
depart from its spirit and scope. It should be understood,
therefore, that the invention is not limited in its application
to the details specifically described or illustrated and that,
within the scope of the appended claims, it may be practiced
otherwise than as specifically described or illustrated.
We claim:
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