Textile detexturizing system

In order to produce random changes in texture of pile fabrics, continuous multifilament bulked yarn is treated to detexturize spaced portions along its length.

BACKGROUND OF THE INVENTION 
Pile fabrics are commercially produced in various conventional ways, such 
as applying tufting to a backing material, or by cutting between a double 
woven or double knit construction. It both cases continuous multifilament 
bulked yarn is often used to provide the upstanding pile fibers. The 
appearance of the final product is a major concern, and one significant 
factor governing appearance is the texture of the pile fabrics. Hence, it 
has been conventional to try to maintain uniform texture of the pile, by 
avoiding variations in the processing of the yarn from the time it is spun 
until completion of the pile fabric. However uniformly the yarn and fabric 
may be made, there will still be occasions when abberations of the 
machinery for incorporating the yarn into the fabric will result in small 
flaws, such as slubs or streaking, which will be faintly visible on close 
inspection of the pile but which do not otherwise affect the usefulness of 
the fabric. For purposes of economy it is desirable to avoid scrapping 
fabric with such flaws, and hence there has been a long standing need for 
a method of preventing such flaws from marring the appearance of the 
fabric to a commercially significant degree. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, the texture of multifilament 
bulked yarn is intermittently modified along the length of the yarn, so as 
to cause random variations in visible texture along the length of pile 
fibers formed from each length of such yarn incorporated in the final 
fabric. This produces visible streaks of texture variation distributed 
generally equally but in a random arrangement across the whole face of the 
pile, and thus obscures minor flaws such as those resulting from the 
above-mentioned mechanical abberations in forming the pile fabric. It may 
also have some ornamental appeal in its own right. 
The invention further provides means and methods for producing such 
variations in the final fabric by intermittent treatment along the length 
of the yarn, possibly after completion of production of the yarn, but 
preferably in the course of continuous production of the yarn at normal 
production speeds. The treatment must be such that its effects will 
survive or be completed during subsequent operations in making the pile 
fabric, such as the conventional curing of the latex backing of tufted 
fabrics. 
It would be difficult to provide such intermittent treatment through 
variations of operation of a jet of air or steam directed against bulked 
yarn, because it would be hard to do so at sufficiently close intervals, 
(at least a few hundreths of a second) to achieve reasonably short 
intervals of change of texture of the yarn (such as about one cycle of 
change per meter) while running the yarn at the speeds customary in 
commercial production (at least several hundred meters per minute). 
Instead, the present preferred practice of the invention achieves such 
intermittent treatment by operating on a limited portion of the yarn in 
wound form instead of on the yarn passing in unwound form through the 
production operation. Such treatment of a limited portion of a wound body 
of the yarn automatically results in the desired intermittent lengths of 
the yarn having been subjected to a treating step after it is unwound from 
the treated body of yarn. While this may be accomplished by treating one 
end of a wound body of yarn, such as by submerging it in a bath of 
treating fluid, the present preferred practice of the invention is to 
apply the treating fluid to a limited portion of the exposed surface of 
the body of yarn as it is being wound. 
As to the treatment itself, the invention contemplates applying a fluid to 
yarn formed from a polymer which undergoes a change in textural 
characteristics when exposed to the fluid, to an extent visible in the 
final pile product. In the case of yarn for tufted fabrics, such visible 
result must occur in spite of or with the aid of the heat and steam 
effects of curing of the latex backing of tufted fabrics into which the 
yarn will go. This has been demonstrated to be true in the case of nylon 
bulked yarn exposed to water as a result of a wound body of the yarn being 
partially immersed in water, or as a result of water being applied to part 
of the side of a body of the yarn while it is being wound. Water 
temperature is not critical in the case of unheatset nylon, so room 
temperature water can be used. However, if the nylon were to be heatset, 
water of about boiling temperature would be required. For example, a 
conventionally wound body of bulked nylon yarn was held for several 
minutes in an oven at 250.degree. F. before one end of the body was dipped 
in water at room temperature. The water-treated part of the yarn preheated 
at 250.degree. F. was not visibly detexturized, contrary to the result 
when the 250.degree. F. preheat is omitted. Normal tension for package 
winding is used, for conventional reasons, and also because absence of 
tension eliminates the desired detexturing action of the water on the 
yarn. 
Water, at least when at room temperature, does not detexturize polyester, 
polyethylene or polypropylene bulked yarns. For the latter yarns the 
detexturizing treatment must rely on some action other than absorption of 
water, such as heat.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
In the present preferred practice of the invention the following successive 
steps are performed (illustrated in the flow diagram shown in FIG. 1): 
(1) Molten polymer is extruded through a multiport die called a spinerette 
to form multiple filaments of yarn. The denier and number of filaments 
vary, depending on end use. Usually the number of filaments is over 100, 
and the denier is at least several hundred. 
(2) The extruded filaments are usually given a conventional finish coating, 
for lubrication and static control, as they pass onto a winder tube. 
(3) The yarn is "bulked", which means that the filaments are individually 
wrinkled so that as a group they tend to fluff out and thereby increase 
the apparent bulk of the yarn. Tension reduces such wrinkling, but the 
yarn rewrinkles itself when tension is relieved. In the present preferred 
practice of the invention this is done in equipment furnished by Textured 
Yarn Co., Inc., of Kennett Square, Pa., wherein the yarn is stretched and 
heated before being forced into a stuffer box. 
(4) The resultant bulked yarn is drawn, while under controlled back 
tension, onto the winder illustrated in FIGS. 2 and 3, where it is treated 
in accordance with the present preferred practice of the invention as it 
is wound onto a conventional body of yarn (known as a "package"). 
(5) The wound yarn produced in step 4 (as originally wound in the yarn 
plant, or possibly as rewound in a different package to suit the 
customer's equipment) is shipped to a tufted fabric manufacturer. There 
hundreds of such yarn packages are mounted in a creel, from which the yarn 
from each package is separately drawn off through tubes to a tufting 
machine containing a corresponding number of separate but closely spaced 
tufting units, each equipped with a tufting needle and cutting blade. The 
tufting machine mechanically forms each package of yarn into a series of 
closely spaced tufts extending in a straight line along the supporting 
fabric in which the tufts are implanted. Each tuft has the cut ends of the 
yarn projecting upwardly on one side of the supporting fabric to form the 
pile, and has the intermediate portions of the cut lengths of yarn 
extending through to the opposite side of the supporting fabric. 
(6) The resulting tufted fabric is coated with a latex solution on the side 
of the fabric opposite to the pile side, and then the latex coating is 
heat cured. This heat treatment results in evolution of steam to which the 
pile fibers are necessarily exposed. 
The above-described steps are conventional, but in step 4 the present 
preferred practice and apparatus of the invention is used, as hereinafter 
described. 
As shown in FIGS. 2 and 3, a length of bulked yarn 10, which has been drawn 
off with minimum tension from the stuffer box of the bulking unit, is 
passed around conventional means 11 for imparting conventional back 
tension to the yarn as it is being wound. The yarn passes from the 
back-tensioning means on to a winding roll 12 having a shaft 14 rotatable 
by drive means (not shown). 
The roll 12 has conventional grooves 16 indented in its face for receiving 
the incoming yarn 10 and traversing it back and forth across the width of 
roll 12 as the yarn is wound around a freely rotatable and vertically 
movable tube 18 to form a wound body of yarn 20. The yarn body 20 rolls 
upon and is frictionally driven by roll 12. All of the equipment so far 
described is conventional and is illustrated only schematically. 
In accordance with the present preferred practice of the invention, a felt 
or other porous applicator 22 is mounted in a fixed position adjacent the 
surface of the roll 12 moving toward rolling contact with the body of yarn 
20. A meter pump (not shown) supplies treating liquid through a tube 24 to 
the applicator 22, where the liquid seeps through the applicator and is 
transferred to the adjacent outer surface of the revolving roll 12. This 
surface coating of liquid on roll 12 in turn transfers to the outer 
surface of the yarn body 20. The axial length of the face of applicator 22 
against the yarn body thus determines the width of the liquid coating 
transferred to the body of wound yarn 20, as indicated by the space 
between dotted lines 26 in FIG. 3. 
As a result of this application of liquid to the yarn body 20, the yarn 
unwound from it, because it was wound helically back and forth across the 
length of yarn body 20, will have been treated by the liquid supplied 
through applicator 22 only in the portions of the yarn body between the 
dotted lines shown at 26 in FIG. 3. Consequently, only intermittent 
portions of the yarn length will have been treated with the liquid, and 
the length of these portions can readily be controlled by varying the 
axial length of applicator 22. The wetting of the intermittent portions of 
the yarn by the liquid reduces the re-wrinkling capability of the yarn and 
thereby changes the texture of the yarn where it is wetted to visibly 
contrast with the texture of the unwetted portions of the yarn. It will 
also be observed that the time during which the dewrinkling liquid is 
applied to the yarn body 20 is limited only by the length of time it takes 
the water to disappear through absorption and normal evaporation, and thus 
is independent of the speed of movement of the yarn through the operations 
shown in FIGS. 2 and 3. 
Water is the preferred treating agent supplied to applicator 22. 
In a specific example of practice of the invention, nylon polymer was spun 
into 144 filaments of 550 denier. The nylon was type 6 of Badische Corp. 
of Williamsburg, Va. The yarn was finished, bulked, treated, and wound as 
described above, using normal winding back tension (about 25 grams), and 
was used to make tufted fabric in a tufter having its needles 5/64 inch 
apart on centers, set to operate at 12 stitches per inch. The pile height 
was about 1/8", and the tufting was secured by a cured latex coating. In 
the course of curing the latex coating the tufting was heated and exposed 
to steam. The fibers were of the conventional trilobal cross-section, and 
the fabric showed the desired faint streaks of differently textured, less 
wrinkled, tufts randomly distributed across the face of the pile among the 
tufts of unmodified yarn which had not been water treated. This subdued 
variation has generated commercial interest demonstrating the practical 
utility of the practice of the invention. 
While present preferred embodiments and practices of the invention have 
been illustrated and described, it will be understood that the invention 
is not limited thereto but may be otherwise embodied and practiced within 
the scope of the following claims.