US3377973A - Tufting method and article - Google Patents

Description

APll 15, 1968 1c. WHITESEL. ETAL 3,37,973

TUFTNG METHOD AND ARTICLE Filed July 7', 1965 2 Sheets-Sheet l JOSEPH o. WHITESEL HENRY D. DAWBARN INVENTORS ATTORNEY April 16, 1968 .1.c. WHITESEL ETAL 3,377,973

TUFTING METHOD AND ARTICLE Filed July 7, 1965 2 Sheets-Sheet 2 INVENTORS ATTORNEY JOSEPH C. WHITESEL HENRY D DAWBARN United States Patent O 3,377,973 TUFTING METHOD AND ARTICLE Joseph C. Whitesel and Henry D. Dawbarn, Waynesboro, Va., assignors to W. R. Grace & Co., New York, N.Y., a corporation of Connecticut Filed July 7, 1965, Ser. No. 470,013 7 Claims. (Cl. 112-265) ABSTRACT OF THE DISCLOSURE A woven primary tufted carpet backing with the yarns comprised of polyolen, land the Warp yarn closely spaced and the warp and till yarns woven the axes of one of them at an angle of from about 3 to 10 from a right angle to the axes of the other, and with rows of tufts engaged through said primary backing and extending diagonally across more than one of the warp or fill yarns and perpendicularly to the other warp or lill yarns, all as further described hereafter.

This invention relates to primary backings for tufted pile fabrics, tufted pile fabrics comprising such primary backings, and to methods for preparing the backings and the tufted pile fabrics.

It is present practice to employ a flat woven burlaptype backing material having yarns composed of jute, sisal, or sometimes paper. A serious disadvantage of this backing resides in the fact that the backing fabric is not of uniform thickness nor density. This characteristic is, of course, due in part to the actual interstices between the individual yarns and in part to the wide variation in thickness between individual yarns and varying thicknesses in the same yarn. As a result, the tufting needles sometimes meet no resistance whatsoever. At the other extreme, the needles encounter maximum resistance due to the necessity for penetrating a thick yarn or double yarns. yIn still other instances the needles seem to push aside the yarns with litle or no penetration of the yarn itself. As a result, the rows of pile yarn stitches frequently jump back and forth between the same longitudinal yarns in the backing thus causing gaps between adjacent rows of stitches which include as few as one and sometimes as many as three yarns of the backing material. This causes grinning and uneven rows of pile. Heretofore it has been found necessary to overcome this disadvantage by producing tufted pile fabrics with sufficient pile length so that these irregularities are substantially concealed. These irregularities occur both longitudinally and transversely of the fabric since a relatively thick transverse yarn in the backing causes a lateral gap or irregularity in the stitch spacing which cannot be in any way controlled by adjustment of the tufting machine.

Since `the pile projections in a cut pile tufted fabric naturally tend to spread more effectively than in the case of an uncut pile fabric, it is, of course, feasible to tuft a lower cut pile fabric and obtain adequate coverage than is the case with an uncut or loop pile tufted fabric. The present invention permits the provision of a pile fabric having much lower pile projections, particularly in a loop pile construction, than has previously been possible and still produce a commercially saleable fabric.

ln view of the above causes of unevenness in a tufted pile fabric particularly in the case of loop pile or low pile height, it might have been assumed that theuse of a uniform sheet material would overcome these disadvantages. Efforts -to obtain satisfactory results using a non-woven sheet backing material have also proved fruitless because in this case there did not appear to be sufficient friction or bind on the yarns to permit uniform control of pile height, particularly after disengagement with the loop-ers. The precise reasons for unsatisfactory ICC results with sheet material are not yet completely understood. lIt is believed that in the case of a sheet material the needle merely punches holes which do not have sufficient tendency -to re-close or grip the yarn to provide adequate or at least uniform yarn engagement Ias the needles are removed.

ln a recent patent (U.S. 3,110,905, issued Nov. 19, 1963 to Travis M. Rhodes) there is disclosed an improved tufted pile fabric comprising .a at woven synthetic plastic backing. For information purposes the entire disclosure of the said Rhodes patent is hereby incorporated herein by reference thereto.

Some difficulty has been encountered in attempts to commercially apply the teachings of the Rhodes patent. ln particular it has been observed that tufting of the primary backings disclosed in the said patent (especially such backings woven of relatively flat cross section polypropylene yarns) causes considerable rupturing and shattering of the lill (or weft) yarns. This in -turn greatly reduces the strength of the tufted pile fabric produced. The considerable strength of the yarns prior to tufting somewhat alleviates this problem. However in many instances the strength of the tufted pile fabric product is low enough to make the product commercially unacceptable. To further complicate the problem it has also been observed that the appearance of the tufted pile fab-ric product is frequently unsatisfactory in that the pile is uneven. This is caused by tufting needles .actually breaking lill yarn ends so that tufting stitches pull through and -give Ia product having many loops.

It is a general object of this invention to alleviate the above-described difliculties.

It is another object of this invention to provide synthetic plastic primary backing material adapted for use in producing relatively strong tufted pile fabrics.

Another object of this invention is to provide relatively strong tufted pile fabric comprising a primary backing of synthetic plastic material.

Yet another object is to provide a method for increasing the fabric strength of tufted pile fabrics comprising a primary backing of synthetic plastic material.

Still .another object of the present invention is to provide ia method for increasing the fabric strength and quality of tufted pile fabrics comprising a synthetic plastic primary backing material.

Many other objects, together with the numerous advantages of this invention will become apparent to those skilled in the art in View of the following more detailed description.

In accordance with the present invention the axes of the yarns in one of the pluralities of yarns in woven primary backings adapted for use in tufted pile fabrics are at an angle of from about 3 to about 10 degrees (preferably about 7 degrees), from a right angle to the axes of the other of the pluralities of yarns. Preferably the ases of the lill yarns are at an angle to the axes of the warp yarns, so that the bank of tufting needles in the usual tufting machines (c g., about 1400 needles in a 12 foot span) will strike at least several different fill yarns in each reciprocal piercing operation, reducing the incidence of lill yarn shattering and thus increasing the fabric strength of the tufted pile fabric product.

The present invention provides primary backings as Adescribed, tufted pile fabrics comprising such backings, and methods for making the backings and tufted pile fabrics. The invention and its many advantages will be better understood from the following description thereof taken in connection with the accompanying drawings, in which:

FIGURE l is a bottom view, on an enlarged scale, schematically illustrating a tufted pile fabric of the present invention;

FIGURE 2 is a cross sectional view taken substantially on the line 2-2 of FIGURE 1;

FIGURE 3 is a bottom view like that of FIGURE l schematically illustrating several modifications thereof; and

FIGURE 4 is a plan view, on an enlarged scale, schematically illustrating a woven primary backing of the present invention.

As seen in FIGURES 1 and 2 one form of tufted pile fabric according to the present invention is made up of a primary backing comprised of a plurality of closely spaced, relatively flat (i.e., essentially rectangular cross section) polyolen warp yarns 2 and a plurality of closely spaced, relatively flat polyolefin fill yarns 1; and rows of tufting material 3 piercing the yarns of the primary backing. In the illustrated preferred embodiment the lill yarns '1 are lbiased at an angle of from about 3 to about 10 degrecs (preferably about 7 degrees) to the warp yarns 2. As a result, the tuftng stitches in any single row perpendicular to the axes of the warp yarns occur in at least several different till yarns (see FIGURE 2).

FIGURE 3 illustrates possible variations of the construction of FIGURES 1 and 2. Thus it is permissible'to originally form ribbons much wider than the iin-al desired width and to fold these one or more times to provide U- shaped or Z-shaped cross-sections. The upper portion of FIGURE 3 illustrates the use of folded U-shaped till yarns 4 with unfolded warp yarns 5. The lower portion of FIGURE 3 illustrates the use of folded U-shaped fill yarns 4 with folded U-shaped warp yarns 6. The tufting 3 is like that shown in FIGURES 1 and 2. Y In connection with FIGURE 3 it will be understood that folded ribbons will be used as lill yarns or warp yarns or both ll and Warp yarns throughout the primary backing and that FIGURE 3 is merely an illustration of these variations as opposed to an illustration of an actual tufted pile fabric.

In FIGURE 4 relatively round monoor multifilament warp yarns 8 are used with relatively round monoor multitilament fill yarns 7 to form a primary backing. As in the other illustrationsthe till yarns are biased at an angle of from about 3 to about 10 `degrees from a right angle to the Warp yarns.

Other variations, not illustrated, are also contemplated. Thus it is deemed within the scope of the present invention to use relatively lint warp yarns together with relatively round monoor multifilament till yarns; or vice versa; or to use relatively at foamed polyolen (densities 45 to 95 percent of normal density) warp yarns with unfoamed relatively at ll yarns; or vice versa; or to use relatively at foamed polyolein (density about 45 to about 95 percent of normal density) Warp yarns together with relatively round monoor multililament ll yarns; or vice versa in forming the primary backing. These constructional variations in the individual yarns, per se, do not form a part of the present invention. They are fully described and claimed in copending, coassigned U.S. application Serial No. 487,402, filed concurrently herewith in the name of one of the present inventors. The entire disclosure of the said application Serial No. 487,402 is hereby incorporated herein by reference thereto.

The individual yarns in the primary backings and tufted pile fabrics of this-invention can be comprised of any polyolen such as polyethylene, polypropylene, copolymers of ethylene and propylene and the like. Preferably the yarns, whether they be relatively flat, relatively round, foamed, unfoamed, folded or unfolded, are comprised of polypropylene.

When the preferred polyoletin (i.e., polypropylene) is used in the embodiment illustrated in FIGURES 1 and 2 the individual relatively at yarns 1 and 2 may have an individual denier of from about 300 to about 2000. Preferably individual denieris from about 350 to about 1200 and most preferably about 400 to about 1100, eg., 1080. These yarns, as is the usual oase, are oriented during 4 manufacture by stretching from about 4 to about 10 (e.g., 5, 51/2 or 6 times) times the length as originally extruded or otherwise shaped. The width of the relatively at yarns may range from about 20 to about 110 mils (i.e., 0.020 to 0.110 inch) with corresponding thicknesses of from about 6 to 8 mils down to about 2 or 21/2 mils. A typical relatively at yarn used in the embodiment illustrated is a 1080 denier polypropylene ribbon of essentially rectangular cross section, about 100 to 105 mils wide and 2 to 21/2 mils thick. The following tabulation indicates the variation in make-up of the primary backing with the varying deniers (relaively flat, unfoamed ribbons in all cases):

A typical preferred woven primary backing of the type illustrated in FIGURES 1 and 2 is made from 1080 denrer polypropylene ribbon as both the warp yarns and the ll yarns.

v en using round polypropylene monoor multilaments in primary backings like that illustrated in F-IG- URE 4 the denier of the warp yarns 8 may range from about 70 to about 800. Preferably the warp yarns are from about 100 to about 600 and most preferably from about 200 to about 500 denier, e.g., about 400 denier. The ll yarns 7 on the other hand should have an individual denier of from about 600 to about 1100. Preferably the denier of the ll yarns should be about 700 to .about 1000 and most preferably about 750 to about 900, e.g., 800.

In a typical woven primary backing like that illustrated there would be about 15 ends per inch of 400 denier polypropylene monoor multiilament warp yarns and about 10 or l2 ends per inch of 1000 denier polypropylene monoor multiiilament fill yarns.

In the constructions described (but not illustrated herein) where at warp yarns are used with round ll yarns, or vice versa; the sizes, deniers, etc., are substantially in the ranges set forth above.

As mentioned, relatively at yarns of foamed polypropylene having a density of from yabout 0.4 to about 0.85, more preferably about 0.58 to about 0.78, may also be used. Most especially preferred are relatively at foamed polypropylene yarns having a density of from about 0.65 to about 0.75, e.g., 0.68 or 0.70. Denier of foamed polypropylene ribbons may be from about 300 to about 2000, preferably about 350 to about 1200 and most preferably from about 400 to about 1100, e.g., 750 or 1000. Typical of such foamed polypropylene ribbons are ones having a density of 0.68, about 980 denier, 3 mils thick and mils wide; or having a density of about 0.70,

about 770 denier, about 74 mils wide and about 3 mils thick.

The bias angle between the axes of the respective warp and fill yarns is most readily accomplished by tentering in the usual manner with slight modification. Thus on a straight through tenter frame it is merely necessary to provide a slight difference in the speeds of the parallel gripping mechanisms so that one edge of the backing is pulled at a slightly higher speed than the other edge thus imparting the desired bias. In similar manner it is possible to use a tenter frame in which one gripping mechanism is disposed at a slight angle to the other gripping mechanism. Obviously combinations of these two procedures can be used, as well as other means and modes that will be apparent to those skilled in the art.

As mentioned the bias is preferably imparted to the ll yarns and is in the range of from about 3 to about degrees. Bias angles lower than 3 degrees do not provide substantial fabric strength increase. Bias angles greater than 10 degrees could be used but provide no substantial further benefits and may result in increased wastage. The preferred bias angle is about 7 degrees.

It has been found most economical and hence preferred to accomplish biasing at the same time that the primary backing is being tentered and heat set in the usual manner. Heat setting temperatures for primary backings comprised of polypropylene yarns are from about 270 to about 310 Fahrenheit. The preferred heat setting cycle is about 30 seconds at a temperature of about 290 Fahrenheit.

The primary backings of this invention can be woven and tufted in conventional manner with commercially available equipment. Typical tufting procedures will give about 6 to 10 (e.g., 7) tufts per inch of ll and about 5 to 10 (e.g., 6 or 8) rows of tufting per inch of warp.

Variations and modifications other than those specically illustrated or described will be apparent to those skilled in the art. It is intended therefore that the scope of the invention be limited only by the scope of the appended claims which are to be construed as including all obvious Variations or modifications.

What is claimed is:

1. Method for producing tufted pile fabrics having increased fabric strength comprising weaving the primary backing with polyolen warp and fill yarn, biasing said warp and till yarns relative to one another at an angle more than 3 degrees prior to tufting; inserting rows of tufts in said primary back with each row extending diagonally across more than one of said warp and ll yarns and perpendicular to said other wrap and fill yarns.

2. Method of claim 1 wherein said woven primary backing is tentered, prior to tufting the same, to thereby bias the fill yarns in said backing and wherein the rows of tufts are inserted diagonally across the ll yarns and perpendicular to the warp yarns.

3. Method of claim 2 wherein said primary backing yarns are biased at an angle of about 7 degrees and said biased primary backing is simultaneously heat set by tentering at a temperature of from about 270 to about 310 Fahrenheit.

4. Method of claim 3 wherein said heat setting temperature is about 290 Fahrenheit.

5. A tufted pile fabric comprising a woven primary backing, said backing woven of polyolen yarn with the warp yarns closely spaced and of substantially uniform dimension and the fill yarns of substantially uniform dimension with the axes of one of said warp and ll yarns at an angle of from about 3 to about 10 degrees from a right angle to the axes of the other of said yarns; rows of tufts engaged through said primary backing and extending diagonally across more than one of said warp and ll yarns and perpendicular to said other warp and ll yarns.

6. The tufted fabric of claim S wherein the wrap yarns have a relatively flat cross section and the tufts extend diagonally across the ll yarns and perpendicular to the warp yarns.

7. The tufted fabric of claim 6 wherein the yarns are comprised of polypropylene, the warp yarns have an individual denier of from 400 to 1100 and the fill yarns have an individual denier of from about 700 to about 960 and the primary backing has about l2 fill ends per inch.

References Cited UNITED STATES PATENTS 1,227,426 5/ 1917 Grabau et al. 3,106,507 10/1963 Richmond 139-420 X 3,110,905 11/1963 Rhodes 112--410 3,237,578 3/1966 Dietz 112-79 3,317,366 5/1967 Dionne 161-70 X JORDAN FRANKLIN, Primary Examiner.

I. R. BOLER, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE -OF CORRECTION Patent No. 3,377,975 April 16, 1968 Joseph C. Whtesel et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 39 and Column 6, line Z1, for "wrap", each occurrence should read y warp Signed and sealed this 9th day of September 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. JR.

Attesting Officer Commissioner of Patents

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