U.S. patent number 3,571,871 [Application Number 04/578,430] was granted by the patent office on 1971-03-23 for method of treating fibrous glass fabrics.
This patent grant is currently assigned to Owens-Corning Fiberglas Corporation. Invention is credited to Remus F. Caroselli, James J. Dillon, David E. Leary.
United States Patent |
3,571,871 |
Caroselli , et al. |
March 23, 1971 |
METHOD OF TREATING FIBROUS GLASS FABRICS
Abstract
Methods for imparting decorative weave effects and designs to
fibrous glass fabrics in post-weaving operations particularly
comprising the transformation of stresses existing in a given weave
design to yield a uniform weave pattern are provided.
Inventors: |
Caroselli; Remus F.
(Cumberland, RI), Dillon; James J. (Providence, RI),
Leary; David E. (Cumberland, RI) |
Assignee: |
Owens-Corning Fiberglas
Corporation (N/A)
|
Family
ID: |
26824280 |
Appl.
No.: |
04/578,430 |
Filed: |
September 8, 1966 |
Current U.S.
Class: |
28/163; 8/497;
D5/53; 28/167 |
Current CPC
Class: |
D06C
23/00 (20130101); Y10T 428/24636 (20150115); D06C
2700/31 (20130101); Y10T 428/24736 (20150115) |
Current International
Class: |
D06C
23/00 (20060101); D06p 003/80 () |
Field of
Search: |
;28/74,76 ;161/73,75
;8/18,137,138,147,158,159 ;26/18.5,69 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Rimrodt; Louis K.
Claims
We claim:
1. The method of imparting a nonrandom, pseudoembossed effect to
greige fibrous glass fabric comprising simultaneously suspending
the fabric free of tension, and applying repeated forces randomly
throughout the fabric until an equilibrium condition is
reached.
2. The method of modifying an original weave pattern and imparting
a uniform, reproducible pseudoembossed effect to fibrous glass
fabric, comprising exposing the fabric to turbulence, said
turbulence being sufficient to release, neutralize and reinforce
stresses present in yarns making up the original weave pattern.
3. The method of claim 2 wherein the turbulence is created in a
liquid medium.
4. The method of claim 2 wherein the turbulence is produced by
flowing gases.
5. The method of claim 3 wherein the liquid medium contains a
lubricating agent.
6. The method of imparting a patterned, pseudoembossed effect
throughout specific localized areas of glass fabric comprising
printing the fabric with a pattern of a water resistant film
forming substance which essentially immobilizes the fabric in the
printed areas, and then treating the film printed fabric by the
method of claim 2, so that only the specific localized areas retain
the pattern of the original weave.
7. The method of imparting a patterned, pseudoembossed effect to
fibrous glass fabric, different from the original pattern, which
comprises applying forces randomly throughout specific localized
areas of the fabric by exposing the localized areas to a turbulent
flow until equilibrium is reached.
8. The method of claim 7 wherein said turbulent flow is applied as
individual streams of fluid directed onto loosely suspended
fabric.
9. The continuous method of imparting a nonrandom, pseudoembossed
effect to a fibrous glass yarn fabric comprising advancing the
fabric into a treating zone, suspending the fabric in a fluid
within said treating zone, applying forces randomly throughout the
fabric while suspended in said fluid to allow shifting of the
fibrous glass yarns within the fabric weave pattern to relieve
stresses therein, until equilibrium is reached and advancing the
fabric from said treating zone.
10. The method of claim 9 wherein the pseudoembossed effect is
permanently set in the fibrous glass yarn fabric by heating the
fabric to a temperature slightly in excess of the softening point
of the glass yarns subsequent to advancing the fabric from said
treating zone and cooling the hot fabric.
11. The method of claim 9 wherein the forces randomly applied
throughout the fabric are inadequate by themselves to shift the
yarn within the weave pattern of the fabric, but which are adequate
when acting in concert with forces induced in the yarn by the weave
pattern to shift the yarn to a new equilibrium position within the
limits of the weave pattern.
Description
The present invention relates to methods for imparting decorative
weave effects and designs to fibrous glass fabrics in a
post-weaving process, and particularly to methods comprising the
transformation of stresses existing in a given weave design to
yield a uniform or nonrandom weave effect.
To date, weave effects other than post-weaving decoration such as
dyeing, screen-printing and the like, have been achieved either by
weave design or by post-weaving treatments other than finishing.
Typical of such weave designs are ribbed or corded fabrics such as
piques, Bedford cords, corduroy, or the like; crepe constructions
which rely upon the tensions inherent in highly twisted yarns; and
pile fabrics such as velvet, velour, terrycloth, and friezes which
employ projecting loops or severed loops. Post-weaving fabric
effects consist of selective shrinkage of a portion of the yarns
employed in a fabric, e.g. seersucker, the thermal treatment of
combination yarns having different coefficients of expansion or
contraction, or the chemical treatment or embossing of resin
treated fabrics, e.g. plisse and blister crepes.
While both of the foregoing groups of methods of achieving
decorative effects are operable, each type is hampered by certain
impediments. Unconventional weaving operations used to produce
unique weave effects such as Jacquard figures require modified or
special looms and increase weaving costs. Additional expense,
limited utility of equipment, and the necessity for the use of
auxiliary materials such as resins or resinous yarns, often make
post-weaving treatments prohibitive.
All of the foregoing impediments are multiplied in the case of
fibrous glass fabrics. In the case of novelty weaves, existing
looms are designed for the processing of yarns having conventional
tension and abrasion characteristics. While the tensions of fibrous
glass yarns are partially controllable by the selection and metered
application of different size compositions, the tension
characteristics of sized fibrous glass yarns vary considerably from
the corresponding characteristics of natural and other synthetic
yarns. In addition, glass fibers are mutually abrasive; prolonged
contact of the moving yarn with guide eyes and contact points tends
to yield quantities of fuzz or fly with attendant decreases in the
strengths of the yarn. Consequently, fibrous glass yarns are not
immediately adaptable to conventional weaving techniques, let alone
to more complex weaving operations.
The unique tension characteristics and tendency to produce fuzz in
weaving operations are results of the combined stiffness and
resiliency of glass fibers and fibrous glass yarns. For example,
fibrous glass yarns have a stiffness of 332 grams per denier, as
compared with values of 4 grams per denier for wool, 11 for rayon,
6 for acetate, 18 for nylon, 10 for acrylic and 21 for polyester
yarns. This unusual stiffness is accompanied by an elastic recovery
of 100 percent. As a consequence of such properties in fabrics
woven from glass yarns, the yarns are highly stressed by the
displacement of the individual glass filaments and the yarn itself
by the weave pattern. Such stresses are evidenced by the ease with
which a fibrous glass fabric may be unraveled. To relieve these
stresses, fibrous glass fabrics are subjected to a weave setting
treatment in which the fabric is heated to a temperature just in
excess of the softening point of the glass fibers. Upon cooling,
the yarns are permanently set in the pattern of the weave and
consequently relieved of weave induced stresses.
Again because of the stiffness of fibrous glass yarns, they have a
critical radius of curvature, correlated to the actual diameter of
the fibers, which may not be exceeded without breaking the fibers.
Such a limitation prohibits the use of weave designs which entail
the bending of the yarns through small radii. In addition, fabric
effects achieved by the use of combinations or blends of glass
fibers with other fibers or the use of fabric coating materials may
dilute the desirable properties of strength, translucency, ease of
cleaning, wrinkle recoverability, and dimensional stability which
fibrous glass fabrics naturally possess. As a result of those
properties which are unique to fibrous glass fabrics, and the
increased costs of the use of complex weaving or post-weaving
treatments, the use of fabric effects in fibrous glass fabrics has
been substantially restricted.
An object of the present invention is the provision of methods for
imparting weave effects and fabric design to a fibrous glass
fabric.
Another object is the provision of methods for imparting weave
effects and fabric design to fibrous glass fabrics without using
complex weaving operations, or special additional yarns, fibers or
coatings to cause the effects.
A further object is the provision of fibrous glass fabrics
possessing a weave effect and fabric design.
Other objects and advantages of the invention will be apparent from
the following description.
Specifically, it has been found that the stresses inherent in a
fibrous glass fabric may be employed to impart a new compacted
state of equilibrium which results in a fabric design different
from the original weave pattern, and capable of being permanently
preserved in its new or modified form.
The process entails the random application of controlled force to
the fabric, in which the force applied is in itself less than that
required to physically shift the yarns within the weave pattern.
Instead, the forces applied act both to relieve in some places the
stresses induced in the yarns by the weave pattern, and to
reinforce in other places those stresses thereby permitting and
achieving, respectively, shifting of the yarns within the weave
pattern to yield a new nonrandom pattern which is determined by the
stresses inherent in the yarns in the original weave pattern. That
is, the stiffness and resiliency of the fibrous glass yarns resist
the displacement of the yarns in the weave pattern, and these
forces, latent in the yarns as stressed in the weave pattern, may
be rendered operative by relief or reinforcement to yield a
compacted weave effect and psuedoembossed fabric design. The means
of rendering these forces operative is the application of outside
forces which are capable of overcoming, neutralizing, or
reinforcing the forces already present in the yarns in a weave
pattern, but said outside forces being inadequate by themselves to
shift the yarns physically within the weave pattern. However, the
sum of the forces induced in the yarns by the weave pattern and the
outside forces placed on the yarns by this method is sufficient to
shift yarns within the limits of weave pattern. As a consequence of
the release, neutralization, and reinforcement of such forces and
the shifting of the yarns, said yarns seek the path of least
resistance to assume a new configuration. The nonrandom character
of the new weave pattern is the result of the fact that the
original weave pattern produced nonrandom or patterned stresses in
the yarns, and the reflexive actions of the yarns upon the release
of those restrictive forces also act in a nonrandom fashion. In the
case of glass fabrics, this new effect may then be permanently
retained by means of subjecting the fabric to a temperature in
excess of the softening point of the glass fibers.
In the accompanying FIGS., forming a part of this
specification:
FIG. 1 is a top view of a fibrous glass fabric having the
pseudoembossed fabric effect, and viewed perpendicular to the plane
of the original fabric weave,
FIG. 2 is a greatly enlarged top view of a fibrous glass fabric
before being treated in accordance with the present invention,
again viewed perpendicular to the plane of the fabric weave,
FIG. 3 is a greatly enlarged top view of the same fibrous glass
fabric illustrated in FIG. 2, but after the fabric was treated in
accordance with the present invention, and again viewed
perpendicular to the plane of the original fabric weave,
FIG. 4 is a greatly enlarged top view of a single yarn from the
fabric of FIG. 2, viewed perpendicular to the plane of the fabric
weave,
FIG. 5 is a greatly enlarged top view of a single yarn from the
fabric of FIG. 3, viewed perpendicular to the plane of the original
fabric weave,
FIG. 6 is a greatly enlarged side view of a single yarn from the
fabric of FIG. 2, viewed in the plane of the fabric weave-- i.e.
rotated 90.degree. from the view in FIG. 4; and
FIG. 7 is a greatly enlarged side view of a single yarn from the
fabric of FIG. 3, viewed in the plane of the fabric weave-- i.e.
rotated 90.degree. from the view in FIG. 5.
The total fabric effect is shown in FIG. 1. The zones of differing
reflectivity 11 and 12 are obvious, and the angles 13 made by those
zones with the original warp and weft directions are also
shown.
FIG. 2, a greatly enlarged view of a fabric, shows in detail the
relationship of the yarns before the fabric is treated in
accordance with the present invention. The uniformly equal areas of
exposed yarn 14 are obvious here, and may be compared with the
unequal areas 17 shown in FIG. 3. FIG. 3, an equally enlarged view
of a fabric, shows in detail the relationship of the yarns after
treatment in accordance with the present invention. This figure
shows the zones of reflectivity 15 and 16 which are made up of
larger exposed yarn areas 17 which are in turn caused by the local
compaction 18 of the yarns in one direction. This FIG. also clearly
shows that both warp and weft yarns are similarly displaced in
their equilibrium configurations.
FIG. 4 shows an individual two-strand yarn from the unprocessed
fabric. This top view shows the highlighted areas 19 and 20
corresponding to the valleys and peaks, 19' and 20' in FIG. 6, in
the sinusoidal displacement of the yarns in the original fabric
weave.
FIG. 5 shows a corresponding yarn taken from a sample of the same
fabric after having been treated in accordance with the present
invention. The highlighted areas 21 and 22 corresponding to the
sinusoidal valleys and peaks, 21' and 22' in FIG. 7, caused by the
original fabric weave are shown, but, in addition, the yarn is
distorted with various sinuous valleys 23 and peaks 24 in the plane
of the fabric weave and in other planes, as schematically shown by
line 25. The major displacement here is in the plane of the fabric
weave, but there is vertical displacement, shown in FIG. 7, which
gives the fabric a slight loft.
FIG. 6 shows a side view, within the plane of the fabric weave, of
the single yarn shown in FIG. 4. Here the uniform, sinusoidal
valleys 19' and peaks 20' are readily seen.
FIG. 7 shows a side view, within the fabric weave, of the single
yarn shown in FIG. 5. The sinusoidal valleys 21' and peaks 22'
corresponding to the highlighted areas 21 and 22 of FIG. 5 are
obvious, but other sinuous displacements 26, as schematically shown
by line 27, are also visible, some of which correspond to the
displacements 23 and 24 of FIG. 5.
As an example of this effect, one may shift the weave of a fabric
with fingernails or the point of a pencil. However, it is difficult
to achieve a nonrandom or uniform effect by this means. Also, any
effect which is derived is dispelled by the application of tension
in the warp and fill directions. However, this illustration does
show that a series of such shifts could rearrange the original
weave pattern into a new fabric design.
It has been found desirable and expedient to apply a series of
forces to a fabric with none of the individual, applied forces
equaling the force required to shift the yarns within the weave
pattern. The repeated application of such moderate forces randomly
throughout the fabric allows the yarns to shift about locally
within the limits of the weave pattern and compacts the weave
pattern until a new equilibrium configuration is reached. Hence the
random application of force is not detrimental when continued until
every portion of the fabric has been exposed to such forces, and
each yarn has reached the new equilibrium configuration. As the
forces are randomly applied and stresses relieved in a given yarn,
that yarn and adjacent yarns shift. Naturally a given point upon a
certain yarn may experience a number of shifts since the shifting
of adjacent yarns will permit subsequent shifting of that point
upon the yarn. In this fashion, the reflexive shifting of yarns
throughout the entire fabric permits the realization of new and
uniform equilibrium configurations of the weave pattern despite the
nonuniform application of forces.
It should be noted that each weave design creates a distinct series
of stresses which accordingly yield a distinct, uniform effect upon
treatment in accordance with the present invention. It is also
significant that the stresses existing in a given weave design, and
the effect which may be realized by means of the present invention,
may be modified or altered through the degree of twist imparted to
the yarn or the use of plied yarns in the weaving of the fabric.
For example, yarns in a fabric possess certain stresses as a result
of their displacement by the weave pattern. However, additional
stresses may be designed into the fabric by changing the amount of
twist of the yarns or by plying the yarns before weaving. Then the
counteraction of such stresses and forces applied by means of the
present invention allows the reflexive shifting of the yarns in
even another mode. While the pattern of the effect differs for each
type of weave, and its extent may be changed by corresponding
changes in weaving tensions, yarn twist, or plied yarns, for
example, it should be noted that for a given weave, the effect
achieved is always reproducible.
It is significant that the effect is not locally isolated at random
positions throughout the fabric, but it is a uniform result of
shifts of all of the yarns within the weave pattern. For example,
in a plain taffeta weave, the effect, since it is three
dimensional, is most obviously seen in the sheen or reflectivity of
the fabric. The sheen of fibrous glass fabric in a plain taffeta
weave, before treatment in accordance with this invention, is quite
uniform, since this fabric is essentially flat. In contrast, the
same fabric when treated exhibits alternating zones of high and low
reflectivity or sheen in the form of elongate strips which
intersect the warp and fill directions at an angle of approximately
45 degrees. These zones of different degrees of sheen or
reflectivity give the fabric a pseudoembossed effect.
From the description of the invention and FIGS. 5 and 7 depicting
the changes in individual yarns, it should be obvious that fabrics
treated in accordance with the present invention undergo a
reduction in their two major dimensions. The term shrinkage has not
been employed due to the fact that glass yarns do not shrink in the
ordinary sense of the work-- that is, the individual fibrous glass
yarns do not compact throughout their mass. The reduction in net
length of the individual yarns is a result of the yarns assumption
of a sinuous position in the new equilibrium configuration of the
fabric. The sinuous position of the yarns also gives the fabric a
slight loft, enhancing the pseudoembossed effect.
While the process for achieving the described fabric effects may be
defined as the repeated random application of forces adequate to
counteract and relieve stresses inherent in the yarns in a weave
pattern and thereby permit the yarns to reflexively shift to
relieve stresses, but such forces inadequate to directly shift the
yarns, there are various means of accomplishing this effect.
EXAMPLE I
For example, an adequate force may be applied to a fibrous glass
plain weave fabric by subjecting the fabric, prior to weave
setting, to a "cotton cycle" of approximately 20 minutes in a
conventional household washing machine. The fabric treated in this
manner contains a fabric design made by the yarns shifted in the
weave pattern so that the new effect is uniformly achieved
throughout the entire length and breadth of the fabric. The
described effect is not easily removed by the application of
tension in the warp, fill or bias directions or by distortion such
as crumpling the fabric. In addition, the effect may be permanently
set by heating the fabric to temperatures just in excess of the
softening point of the glass fibers. This can be accomplished by
either a continuous or a batch process. Upon cooling, the yarns and
fibers in the new configuration are essentially free of stresses
and the new equilibrium weave effect is permanently set in the
fabric. The fabric may then be finished, dyed, or printed in the
conventional manner.
It should be noted that while moisture and moderate temperatures
(100--180.degree. F.) such as those experienced in a washing
machine cycle, appear to facilitate the achievement of the fabric
effect, neither is essential. Moisture or moderate temperatures may
assist by softening any adhesion between the yarns at their
crossover points which may result from the size composition which
is usually applied to glass fibers just after their formation.
Also, the moisture may act as a lubricant to facilitate the
slipping of the yarns one among the other within the bounds of the
weave pattern. Note that in addition to the water or other liquid
medium, a lubricant may be added specifically for the above
purpose. With water, any soapy substance will work as a lubricant.
With other media, other compatible lubricants must be chosen.
EXAMPLE II
The presence of moisture, lubricants, or heat is not necessary as
evidenced by the fact that the same effect may be partially
achieved by the action of a conventional textile swing frame. The
action of the swing frame is strictly mechanical. The presence of
liquid lubricants alone does not accelerate the achievement of the
effect in the absence of correspondingly accelerated applied force.
This was again demonstrated by placing a fibrous glass fabric in a
"rope soaper" which repetitively immersed and withdrew the fabric
from a hot water bath. The desired fabric effect was realized only
after prolonged treatment in that manner. Note particularly that
the agitation and turbulence provided by a rope soaper is mild
compared to that provided by a household washing machine. It is the
repeated random application of moderate forces to the loosely
suspended fabric which achieves the desired effect in any of these
methods.
EXAMPLE III
The effect is also achieved by loosely suspending the fabric and
subjecting it to a jet of liquid or gas. A series of such jets is
arranged in any desired pattern, so that a corresponding pattern of
the pseudoembossed effect is processed into the fabric. With this
system the pressure used in the fluid jets and the time of
treatment varies the extent of the achieved effect.
EXAMPLE IV
Another method of processing fibrous glass fabrics with a definite
pattern of the pseudoembossed effect is to use a stencillike die
which allows treatment of the desired areas, and essentially
immobilizes the areas of the fabric which are not to be treated.
Such a system can then be used with a turbulent bath of liquid, or
with pressurized fluid streams as disclosed in Example III.
EXAMPLE V
Still another method of processing fibrous glass fabric with a
definite pattern of the pseudoembossed effect comprises a two-step
process. First, the fabric is printed with a pattern of a water
resistant film forming substance which essentially immobilizes the
fabric in the printed areas. Note that the pattern of printed areas
is the negative of the desired pseudoembossed pattern areas. Then,
this printed fabric is treated by the repeated application of
forces randomly throughout the fabric as achieved by any of the
methods disclosed in the previous examples. Depending upon the
medium and other conditions used for the pseudoembossing process, a
film forming substance which is more than just water resistant may
be used. In any case, the film can afterward be removed during the
heat setting process, and the fabric may then be finished, dyed, or
printed in the conventional manner.
Note that the effects achieved by the methods of Examples III, IV,
and V will not correspond precisely to the pattern of the fluid
jets stencillike die, or printed pattern. This is due to the
stresses in the yarns in the weave patterns, particularly the
tension which remains in the unprocessed sections of the fabric.
Because of those forces a complete pseudoembossing in those
localized areas is not possible, although it is feasible enough to
give a definite effect.
EXAMPLE VI
Examples I, III, IV, and V describe methods for imparting the
present fabric effect which are essentially isolated or batch
processes. However, each of these methods can be modified so that
the process is adapted to the continuous processing of the fibrous
glass fabric. In such a system the fabric is advanced into a
treating zone wherein the section of fabric undergoing treatment is
suspended in a fluid, and forces are randomly applied throughout
the fabric while it is suspended to allow shifting of those
portions of the fabric yarns being treated. Said yarns are thereby
stress-relieved, and the fabric is advanced from the treating zone
having the desired pseudoembossed fabric effect. With this
continuous process, the fabric can then be continuously advanced
through a heat treatment zone, emerging from that treatment with
the pseudoembossed effect permanently set into the fabric.
This continuous system consists of a set of rollers which meters
the speed of the incoming fabric, followed by a length of slack
fabric. This slack area is followed by the actual treating zone in
which the fabric is loosely suspended in a fluid which applies the
appropriate forces to the fabric to bring about the pseudoembossed
fabric effect. The actual treating zone can consist of any one or
combination of the systems already shown in previous examples. This
may be a large bath of liquid which is violently agitated by a
series of reciprocating paddles. In any liquid bath system, the
fabric must be essentially horizontal, or slowly cascading
downward, to relieve internal stress insofar as possible. An
alternate system is a series of fluid jets which impart a definite
pattern into the fabric. Note that liquid jets may also be employed
to increase agitation in the liquid bath system. Or, alternatively,
a stencillike die can be used with either fluid streams or a liquid
bath. Likewise, the fibrous glass fabric printed with a pattern of
a water resistant film forming substance may be continuously
processed in the slack washer system or with fluid jets. In any of
these treating systems, the extent of the fabric effect may be
controlled by metering the treatment time by close control of the
speed with which the fabric passes through the treating zone and
the number of applications of force. The length of the treating
zone can be designed so that an appropriate amount of fabric
undergoes treatment for the desired length of time. After emerging
from the treatment zone, another leader section of slack fabric is
maintained before the fabric proceeds to heat treatment or other
processing.
Regardless of the specific method used, the extent or degree of the
fabric effect which may be achieved is limited for a particular
fabric structure or original weave pattern. The effect is achieved
progressively during the time of treatment, but the fabric
eventually reaches a stage at which additional treatment evokes no
further change in the fabric. For example, a plain taffeta weave
fabric achieves a degree of effect after a 20 minute wash cycle in
a household washing machine which is not increased or changed by
additional treatment. However, if one removes samples of the fabric
from the process at 2 minute intervals during the treatment, the
progressive achievement of the fabric effect may be observed. This
illustrates that the relief of stresses and compacting of the yarns
into a final equilibrium configuration is a progressive process
which is achieved only after the yarn stresses have been
substantially relieved by this mechanical process. The progressive
achievement of the fabric effect is not necessarily uniform, but
the final equilibrium configuration gives an essentially uniform
effect.
Although the present invention has been discussed as used on
fibrous glass fabrics woven from yarns made of glass fiber coated
only with the usual sizing compounds, it may be performed on
fabrics woven with yarns coated with any substance which does not
destroy the inherent stiffness and resiliency of the fibrous glass
yarns, and which provides a coating which is slick enough to allow
the yarn to shift easily within the limits of the weave pattern.
For example, fibrous glass yarns coated with polyethylene,
polypropylene, or polyvinyl chloride could be used in fabrics
suitable for treatment in accordance with the present invention.
Combinations yarns of fibrous glass strand plied with organic
strand may also be used. Such combinations of viscous and glass
yarns have been used. The same combination of glass and organic
strands may be used in core yarns with the glass strand as either
the core or the wrapper, and fabrics made with such yarns are
suitable for treatment in accordance with the present invention.
Indeed fabrics woven from yarns containing no glass whatsoever
could lend themselves to the present invention if the properties of
the yarns were such that stresses are produced in the yarns by the
weave pattern, and the yarns are slick enough and the stresses
large enough to allow the yarns to shift within the weave pattern
to relieve the stresses in the yarns when treated in accordance
with the present invention. Also, fabrics woven with blends of
different types of combination and coated yarns can be processed by
the method of the present invention.
Various modifications of the above described invention will be
apparent to those skilled in the art, and such modifications can be
made without departing from the spirit and scope of the present
invention.
* * * * *