US2247308A

US2247308A - Pile fabric

Info

Publication number: US2247308A
Application number: US224641A
Authority: US
Inventors: Frank R Redman
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-08-12
Filing date: 1938-08-12
Publication date: 1941-06-24
Anticipated expiration: 1958-06-24

Description

June 24, 1941. v F. R. REDMAN 2,247,308

FILE FABRIC Filed Aug. 12, 1938 s Sheets-Sheet 1- June 24-, 1941. R REDMAN 2,247,308

PILE FABRIC Filed Aug. 12, 1938 3 Sheets-Sheet 2 June 24, i941. F. R. 'REDMAN 2,247,308

PILE FABRIC Filed Aug. 12', 1938 I s Sheets-Sheet 3 Patented June 24, 1941 UNITED STATES 1 Claim.

This invention relates to pile fabrics, particularly cut pile fabrics, such as carpets and upholstery materials, including velvets, mohairs, velours, etc.

A pile fabric essentially consists of a base or 5 ground fabric composed of interwoven warps and wefts, with pile yarns arranged in the form of loops or tufts on one face of and tied'into the groundfabric at relatively closely spaced points over all or predetermined areas of the fabric. In velvets and similar pile fabrics the pile yarns are cut at each-side of each tie-point, leaving short lengths of the pile yarns incorporated in the ground fabric in the form of individual tufts, with the cut ends of the yarn of each tuft protruding from and extending to some extent beyond one face of the fabric, substantially perpendicular to said face, and collectively forming a resilient stubby surface on the finished. goods.

In the more expensive cut pile fabrics, the pile tufts are of the W type, i. e. the yarn forming each tuft is tied in the fabric by passing over one or more ground threads, at the center of each tuft, and under one or more ground threads, at each of the opposite sides of the center of the tuft, with one or more ground threads lying intermediate the adjacently disposed rows or courses of pile tufts.

The ground threads are closely compacted and rigidly secure each tuft in place against acci- 3O dental or malicious w i drawal from the ground 1 fabrics The close 0 mpacting of the ground threads produces a fabric having a firm substantial body, which, despite its closely woven nature, is of a'lsufliciently porous character to permit air to pass through completely the finished goods. I

The porosity of the fabric obviates the formation of mold or mildew on the back of the fabric under conditions of use or in, or on, the cushion or other structure covered by the goods. The ventilation afforded by the porosity of the fabric effectively prevents the generation of unpleasant or obnoxious odors under the fabric.

The current demand is for a less expensive fabric, for use in popular priced automobiles, and on inexpensive furniture, carpets, rugs, etc. However, ,the .trade demands a fabric of high quality which will compare favorably with the more expensive fabrics described above. In order to meet this demand the manufacturers have in the past produced fabrics having pile tufts of a V or U shape, 1. e., the yarn forming each pile tuft passes under but a single ground thread 535 interstices of the fabric.

at the center of the tuft, with the ends of the short length of yarn constituting each pile tuft extending upwardly, directly from the opposite sides respectively of the solitary tie thread.

Furthermore, the ground fabric of the cheaper grade of goods is of a more loosely woven nature and includes a relatively smaller number of threads per inch than the more expensive fabric. Consequently,'the \I,or' U pile tufts of this lower priced goods are normally quite susceptible to being pulled out, of the ground fabrics.

In order to anchor the V or U shaped pile tufts in the loosely woven ground fabric, the manufacturers have heretofore employed a supplementary binder for the pile tufts in the form of a continuous coating or film. of latex or pyroxaline applied to the backpf the fabric. The uninterrupted film of binder adheres to the pile tuft yarns and to the ground threads conjunctly.

The coating is sprayed or otherwise spread on the back of the fabric, after the fabric has been woven and the pile yarns have been cut, and

the surplus Ibinder'material is scraped off the back of the fabric as by a doctor blade or other equivalent device. This procedure causes the binder material to be spread as or to form into the above noted continuous film on the back of the ground fabric. Thus, the binder material fills all of the interstices of the fabric and destroys the natural porosity of the fabric. In addition, the continuous binder film covers the ground threads on the back of the fabric so completely and in such a manner that dyeing of the fabric after weaving and cutting is impossible. Thus the ground fabric must be composed of pre-dyed threads.

Attempts have been made to produce porosity in pile-fabricswhich employ'the V or U shaped tufts and include the supplementary binder, by

locally scouring the back of the ground fabric,-

prior to coating, to expel natural on working greases or oils from the groundthreads to render the threads more absorbent andto induce the binder to cling more closely to the various ground threads and pile yarns when the binder material is spread on the secured area instead of the binder material spreadingout and bridging the Regardless of the success or failure of this procedure in accomplishing the desired result, the coating still covers the ground threads and-pile yarns and is quite perceptible on the back of the fabric.

The object of the present invention is to produce a cut pile fabric employing the V or U shaped form of pile tuft and a supplementary binder of such a kind and applied in such a manner that the natural porosity of the fabric will be retained to substantially its fullest extent; and

in such a manner that the binder material will lie exclusively in a, plane intermediate the opposite faces of the ground fabric and be substantially invisible from either face, leaving the ground threads and tuft yarns exposed on the back face of the ground fabric to such an extent that the fabric, including the ground threads and pile yarns, may be readily and successfully dyed after the supplementary binder has been applied, set, and caused to effect a bond between the ground threads and the tuft yarns.

The pile forming yarns are usually composed of a multiplicity of individual filaments or fibres loosely twisted together to form a weavable yarn but which when out tend to untwist and reassume their individuality. These pile yarns may be composed of natural animal or vegetable fibres or of synthetic filaments of various kinds.

The ground threads likewise are composed of a multiplicity of filaments or fibres, usually of a less expensive and frequently of a different kind than the pile yarns. The ground threads are more tightly twisted than the pile yarns to provide the requisite strength in the body of the fabric.

The present invention resides in forming a' spot bond between individual filaments of the pile yarns and individual filaments of the ground threads, in a plane intermediate the planes of the opposite faces of the ground fabric, i. e. in place of the pile yarns and the ground threads being connected by a continuous film of the binder "material on the back of the fabric, as heretofore, single or relatively small groups of the individual filaments of the. ground threads and of the pile yarn of each tuft are connected or bound together in spots, intermediate the opposite faces of the ground fabric, leaving the interstices of the fabric open to substantially the same extent as in the more expensive fabrics, whereby air etc. may readily pass through the fabric from face to face thereof; and whereby the binding material is not perceptible on either face of the ground fabric; and whereby the completed fabric may be dyed'after weaving; and whereby objectionable or obnoxious odors are not generated under the fabric, in:-use,- from mold or mildew forming under the fabric as a result of a lack of sufficient ventilation through the fabric.

The present invention is predicated upon the incorporation in predetermined ground threads, prior to the weaving of such threads into the fabric, of the binder material; and the subsequent diffusion of the binder material along individual filaments of the prepared ground threads into contact with individual filaments of the pile tuft yarns, after the fabric has been woven, and either before or after the pile yarns are cut to produce the individual tufts.

The binder material may be incorporated in the chosen ground threads in any one of a number of difierent ways. For example, and preferably, the threads may be coated with the binder material, after which the coated threads are dried or the material is otherwise permitted to set, before the threads are woven into the ground fabric, or a filament composed of the binder material may be included in the chosen threads as a strand of the ground thread twisted with other fibers or strands, or one or more filaments of the binder material may be wound about the other strands or filaments of which the thread is composed.

The binder material is characterized by its ability of becoming cementitiously softened by a solvent or by heat below that at which the fabric itself is damaged. The binder therefore is .setting properties, and the binder material may consist of two or more synthetic resins of different kinds blended together or combined with one or more cellulosic derivatives. The addition of a suitable plasticizer or solvent-plasti'cizer may be used if desired.

In the accompanying drawings:

Fig. 1 is a perspective view of a magnified round thread, prior to incorporation of the binder material therewith;

Fig. 2 is a magnified view of the thread shown in Fig. 1 with the binder material applied thereto as a coating; Fig. 3 is a view similar to Fig.1 with the binder material in the form of a filament or strand intertwisted with the other filaments of fibrous material of which the thread is composed;

Fig. 4 is a view similar to Fig. 1 with the filament of binder material spirally wound about the fibrous thread;

, Fig. 7 is a view similar to Fig. 6 showing the binder material diffused as ar'esult of the application of a solvent or heat;

Fig. 8 is a view similar to Fig. '7, showing the pile yarns after cutting to produce the individual pile tufts;

Fig. 9 is a perspective view of one of the pile tufts interwoven with adjacent ground threads;

Fig. 10 is a sectional view taken on the .line lll-itl, Fig. 9;

Fig.'11 is a view similar to Fig. 6 but showing-- the pile yarns as being cut before application of the solvent or heat to binder; and Y Figs. 12 and 13 illustrate modification of the fabric.

The thread i, shown in Fig. 1, is composed of a multiplicity of cotton, woolen, flax or other fibres or filaments 2, twisted together in the usual manner to produce the thread I. In such threads the filaments 2 are usually of a discontinuous nature and, in twisting the fibres together to form the thread the ends 3, 3 of the filaments or fibres 2 project more or less haphazardly in all directions outwardly from the thread, as viewed through a microscope.

According to the preferred form of the present invention threads I, i are coated with the binding material, as illustratedat 5 in Fig. 2 by What is known as a slashing operation, i. e, the threads are passed into and through a body or bath of the binder material while the binder material is in a liquid or semi-liquid state, and individually emerge therefrom through dies or plane intermediate pile tuft is secured in partly submerged in the solvent small openings formed in'the slasher plates. The

die opening scrape off surplus binder material and reduce the coating to a substantially uni- .form thickness, in the form of a complete continuous film enveloping substantially the entire exterior of the thread I.

Drawing the threads through the die openings lays the ends 3 of the individual fibres 2 of which the thread I is composed, o that the coated thread la. has a relatively smooth appearance, as shown in Fig. 2.

After coating, the threads la are permitted to dry or set and are subsequently wound into bobbins for use as weft threads in the ground fabric, or wound onto spools or onto a beam. if the coated threads la are to be used as warp threads in the ground fabric.

In the present instance the binder containing threads la are used as weft threads and, as shown in Fig. 5, are interwoven .with two different groups of non-coated warps 6, ii to form a pair of superposed ground fabrics I, l, withpile yarns 8 extending from one to the other of said ground fabrics and passing around single alternate coated Wefts or filling thread la, la 'in'each fabric.

Obviously, instead of the ground fabrics being woven double, one fabric may be woven singly with the pile yarns 8 passing over pile wires laid on top of the single fabric, corresponding to the lower fabric in Fig. 5.

In Fig. 5, the pile yarns 8, t are severed in a th upper and lower, fabrics l, I by any suitable rotary, reciprocating, or stationary knife M), from which the two separated fabrics l, I! pass around plain guide or spike rolls H, M respectively, which may be operated and controlled by the take-up mechanism of the loom.

The separation of the two fabrics forms the pile yarns into individual pile tufts l2, l2. Each the ground fabric l by passing around a single weft, with other single weft thread lying intermediate adjacent rows of pile tufts.

In the present instance, the pile arns for forming the individual pile tufts it pass around coated wefts la and the intermediate wefts are also coated although it will be understood that either one or the other of these' weft threads may be plain, i. e. uncoated', if desired."

As shown in Figs. 5 and 6, the coating 5 lies in contact with the pile yarns 8, when the fabric is woven. The coating at such time is in a normal dry and generally non-adhesive state, per-. mitting the various yarns and threads to move relative to each other inassuming normal relative positions in the fabric as the weaving progresses.

At any desired time after weaving, either before or after the cutting of the pile yarns 8 to form the individual pile tufts l2, the coating 5 is treated to render the binder cementitious. In the event that a solvent is employed for this purpose, the solvent may be applied in any one of a number of ways, for example, as by a felt or other roller M (Fig. 5) saturated with or having a film of solvent on it peripheral face which is brought into contact with the back of the ground fabric. Or the solvent may be sprayed against the back'of the ground'fabric, as indicated at W in Fig. 5. Or the fabric may be wholly or after it is taken from the loom.

In any case the solvent is caused to make con- Figs. 9 and Ill, and into closely adjacent tact with the threads'and yarns in the ground fabric and to flow into contact with the more or less solid coating 5 on the predetermined ground wefts.

The solvent, upon coming into contact with the binder material 5, causes the more or less solid coating of binding material to change from its more or less solid form to one of a liquid or semi-liquid nature. This change of form releases the fibers 2 of the yarns l. The fibers or filament 2 tend to spread out. In so doing the filaments 2 come into contact with a greater number of the filaments 9 of which the pile yarns 8 are composed. At the same time .the liquefied coating 5 flows around and along the individualfilaments 2 of the ground threads lb. contact with and to some extent along and from one to another of the filaments 9 of the pile yarns t.

As the effects of the solvent, which preferably is of a more or less volatile nature, lessen, the flowing coating material 5 begins to coagulate in spots, at such points, for example, as indicated at 20, Figs. 9 and 10, where filaments t of the ground threads lb and filaments 9 of the pile yarns t touch or lie in intersecting contacting or relation one to another, whereby a spot-bond is formed between individual filaments of the ground thread and pile yarns or small groups thereof.

The spot-bonding of the filaments is sumciently strong to resist accidental or malicious pulling out of the pile tufts l 2, formed by cutting the pile yarns 8, although the spot-binding does not extend completely through the whole -number of filaments 9 which collectively constitute each tuft. The spot-bonding is of ammo or less superficial character as the flowing binder material 5, under the effects of the solvent, penetrates thespaces'between only those of the filaments 9 which lie at and near the outer surfaces of the tufts. This condition is due in part to the'n'ature of the binder which in its flowing form is somewhat vicious in character, and in part to the time required for the solvent to evaporate sufficiently to permit the binding material to become set."

In following the filaments 2 of the ground threads lb and the filaments 9 of the pile yarns and yarns as a result of the interweaving thereof, thus the fabric retains, to a major extent, the normally inherent porosity of other woven fabrics of this general class which do not include a supplementary binder.

Furthermore, the controlled flowing of the binder along the filaments of the ground threads,

as by predetermining the degree of volatility of the binder and the degree of viscosity of the binder material when under the influence of the solvent, holds the binder material from passing to either face of the ground fabric. Thus, the finished fabric retains the "feel of fabrics of like character which are devoid of supplementary binders.

. The flowing of the binder material while under the influence of the solvent may also be checked at will by application of heat to the fabric to drive off the volatile solvent, the temperature of the fabric heating agent determining the speed of evaporation of the solvent which in turn governs the extent of flow of the binder material.

In the event that the binder is capable of being rendered cementitious by heat, without the use of a solvent, such as in the case when a thermoplastic resin is employed, the pile fabric after its production, either before or after the pile has been cut, may be subjected to a heat treatment at a temperature high enough to cause the binder to flow sufiiciently to bind the pile as hereinbefore described. This may be accomplished in various ways, for example, by passing the fabric around a heated roller, such as the rollers ii, II, which may be formed'as hollow drums for the reception of electrical heating coils, steam, etc., or the fabric may be passed through a heated chamber. It will, of course, be understood that the temperature in any case will be applied for the length of time necessary to produce the extent of flow of the binder required to obtain the desired spot bonding hereinbefore noted, but will not be sufficient to damage the fabric itself.

When using binding materials which have a tendency to harden and thereby unduly stiffen the fabric, a plasticizer may be incorporated in the binding material prior to the incorporation of the binder material inthe ground thread, or a solvent-plasticizer may be employed to effect flowing of the material and to reduce the state of rigidity of the binder as it sets. In such instances the plasticizer will mix with the binder material when the latter is in its flowing state and will remain in the binder material to render the. binder more pliable. The extent of pliability in such instances would be determined by the percentage of plasticizer mixed with the binder material. The use of plasticizers is found to be advisable in cases where binders composed of synthetic resins, etc., which have an inherent tending'to set rigidly, orthose which have a low degree of flexibility, are. used.

In order to insure porosity of the fabric, the

fabric may be subjected to a beating operation to break up any formation of continuous films over all or any localized areas of the fabric, or the fabric may be subjected to a planar cracking operation wherein the fabric is gripped along opposite edges or on parallel transverse lines and the grippers simultaneously moved in opposite directions or relative to each other in the plane of .the fabric, to subject the fabric to reverse diagonal strains alternately, or the fabric may be dyed in piece in what is known as rope form, whereby the binder material is tensioned to a point beyond its normal elastic limit first in one direction and then in the opposite direction, and

cohering spot bonds, or film like areas are caused to separate or crack into small sections with fissures therebetween, which provide the requisite porosity.

If desired, when certain synthetic resins particularly those of thermoplastic properties are used as the binder material, after the binding material has set, the fabric may be subjected to'a resetting operation by saturating or submerging the fabric in a, liquid bath of relatively high temperature, 1. e., a temperature at which the binding material will be caused to assume a semi-plastic state. The bath may' be composed of dye or scouring liquor, plain water, etc/ 'the fibres the binder material, rendered semiplastic by the temperature of the bath, will iiow or settle into the fabric in the places where, and

' as, the grease or oil is leaving. This acccntu-- ates the bonding effect between the yarns as the fabric and binder cool.

Fig. 6 shows the coating of binder material 5 intact on the ground thread la after the fabric has been woven and before the pile yarns 8 have been cut. Fig. '7 shows the same fabric after the solvent has been applied .and evaporated leaving the binder material in a diffused 'spotbonding condition, before cutting of the pile yarns 8. Fig. 11 shows the coating of binding material intact in the fabric after the pile yarns have been cut and before the solvent has been applied. Fig. 8 shows the fabric resulting from either course of procedure, with the binder material diffused and set and with the pile yarns cut and forming the individual tufts I2.

Fig. 13 shows a modified fabric wherein the wefts lying between the rows of pile tufts have been eliminated.

Fig. 12 shows anothermodified fabric wherein backing warps it are interwoven with the wefts and pass around the bends of the pile tufts, whereby the pile tufts are completely hidden from view on the reverse face or back of the fabric.

As a matter of illustration, the following may be considered as representative as to the kinds of materials it is possible to use in putting the present invention into practice.

The ground and/or pile threads may be composed of any animal, vegetable or synthetic fibre suitable for use in the particular kind of finished goods desired, provided it is not affected by the treatment employed to render the binder cementitious, for example, cotton, linen, rayon silk, wool, or mohair. solvent is to be employed to render the binder ccmentitious which is also a solvent for cellulose acetate, this fibre or filament is not suitable for use as the pile or ground threads.

The ground threads, especially those about which the pile loops or tufts extend in the ground fabric, may be coated with the binder material or the binder material .may be otherwise incorpo-- rated in the ground threads as separate fibres interspersed with the fibers of which the ground threads are composed, or the binder material may be formed as a separate continuous filament or strand twisted with strands of others of the materials above noted which go to make up the thread, or the binder material may be wound about the ground thread in spiral convolutions of any desired number per inch. In any case the quantity of binder material per foot of the finished ground thread may be definitely and minutely controlled to give the result desired.

The binder material may be composed of a collulosic derivative such as a cellulose ester or ether, thermoplastic or thermosetting resin capable of being rendered cementitious, or it may be composed of different resins blended together, or resins blended with cellulose esters or others.

If more than a single binder is employed, such binders may be associated in the solution used for coating the ground threads, or, as individual continuous filaments or short lengths thereof intertwisted with each other or separately with the other constituent fibres of the ground threads, or, as separate filaments spirally wound about preformed ground threads.

A plasticizer or solvent plasticizer may be incorporated in the binder material in the ground thread coating solution, or in making a preformed continuous filament of the binder material for incorporation in or with the ground It will be obvious that if a.

thread, or the plasticizer or solvent plasticizer may be applied to the pile fabric which has a soluble coating or preformed binder filament incorporated in the ground threads and which is to be subsequently treated with a suitable solvent. Any suitable diluent may be used to retard the speed of evaporation of the solvent, or heat may be used to accelerate the evaporation of the solvent. Color may be added to the binder coating solution or to the preformed filaments of binder material in the production of such filaments. I

The solvent for the binder material may also include or constitute in itself a solvent for any oils, etc. which may be present in the ground or pile threads, such for example as those employed during spinning and/or weaving whereby, as the oil, etc. is dissolved the binder material is supplanted in place thereof to effect a more efiicient bond between the contacting fibres or filaments of which the ground and pile threads are composed.

In cases where the binder material is composed of cellulose acetate, acetone may be used as a solvent, dimethyl phthalate may be used as a solvent plasticizer, and methyl phthalyl ethyl glycollate may be used as a plasticizer.

If cellulose nitrate is used as the binder material, acetone may be used as the solvent, methyl phthalyl ethyl gly-collate as a solvent plasticizer, and butyl phthalyl butyl glycollate asa plasticizer.

If ethyl cellulose be employed as the binding material, ethyl acetate serves as a solvent and methyl phthalyl ethyl glycollate as a plasticizer.-

When the binder material is composed of benzyl cellulose, benzol, toluol or ethyl acetate functions as a solvent and butyl phthalyl butyl glycollate as a plasticizer.

Thermoplastic or thermosetting resins of the urea-formaldehyde, the thiourea-formaldehyde, the toluene-sulphemide-formaldehyde, the phenolic, the vinyl, or the hydrocarbon (cumarone),

' types maybe used.

Of the vinyl compounds, when polymer of vinyl acetate is used as the binder material, acetone or toluol would function-as an appropriate solvent, and butyl phthalyl butyl glycollate as a solvent plasticizer.

With, a copolymer of vinyl acetate and vinyl chloride as the binder, acetone serves as a solvent,

toluol as a dilutent, and butyl phthalyl butyl glycollate as a plasticizer.

Using vinyl benzene (polystyrene) as the binder, ethyl acetate or toluol may be used as a solvent, and butyl phthalyl butyl glycollate as a plasticizer.

Alkyl acrylate and alkyl alkacrylate resins, such as methyl acrylate or methyl methacrylate may also be used as a binder with acetone or toluol as a solvent, and butyl phthalyl butyl glycollate as aplasticizer.

Of the various synthetic resinous binders that V are applicable for use, it has been found that the vinyl resins, which term includes the acrylate and alkacrylate resins, have especially advantageous properties since they are thermoplastic.

Thus, the dispersion may be effected by applica- -tion of a solvent or heat alone may be used to form the spot bond hereinbefore described. Of the non-resinous binders, the cellulo sic derivatives, such as cellulose acetate, are preferred.

All types ofalkyd resins including glycerolphthalic anhydride resins can be employed as the binder with acetone acting as a solvent, and

butyl phthalyl butyl glycollate as a plasticizer.

In addition to or in place of using separate preformed filaments composed respectively of different types of the above noted materials in or with the ground threads as binder material, the differentmaterials may be applied to the ground threads separately as successive layers or coating with the materials in solution, either in a solvent or as an emulsion (water). Such coatings may be respectively composed of difierent types of resins or cellulosic derivatives. In applying the materials, one coating is applied and dried before the next coating is placed over it.

From the above it will be clear that many different kinds of materials may be used to obtain the porosity-producing, middle-plane spotbonding characteristic of the fabric made in accordance with the principles of the present invention which is basically different from porosity-destroying dye-sealing continuous film types of binding heretofore produced under the old methods by spreading a coating of latex, pyroxalin or other material on the back of the fabric and scraping the surplus off, by which the interstices ofthe fabric are clogged with the binding material and wherein the continuous film seals the fabric against penetration by dyesuifs, etc., as above noted.

'I claim:

A porous pile fabric including a series of iibrous warp threads, a series of fibrous weft threads, a series of -fibrous pile yarns, and a series of runsofdry, normally non-cementitious binding material intimately associated with predetermined threads respectively of one of said thread series, said threads, yarnsand runs being interwoven in said fabric witlrthe semi-annular bight portions" of the pile yarns passing around said predetermined threads respectively and exposed on one face of the fabric, and with portions of said dry runs interposed-between the inner surfaces of said semi-annular bights and the outer surfaces of those portions of said predetermined threads embraced by said semi-annular bights, the interwoven relationship of said threads, yarns and runs providing porosity-affording'interstices in said fabric, said interposed portions of said runs being diffused between and binding together only superficial fibres of said inner surfaces of said bights and of the outer.

embraced surfaces of said predetermined threads at the initial regions of interposition of said binder material solely, said diffused binder material being discontinuous between adjacently .disposed warp-and weft threads and cross-sectionally of said bights and preserving said porosity of the fabric.

FRANK R. REDMAN.