US3114191A

US3114191A - Method for making a high flannel cover fabric of synthetic organic fibers

Info

Publication number: US3114191A
Application number: US70423A
Authority: US
Inventors: Chapin Robert Stuart
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1960-11-21
Filing date: 1960-11-21
Publication date: 1963-12-17
Anticipated expiration: 1980-12-17

Description

United States Patent 3,114,191 METHCB F011 MAKING A HIGH FLANNEL COVER FABRIC F SYNTHETIC QRGANHC FIBERS Robert Stuart Chapin, Wilmington, Del., assignor to E. I.

du Pont de Nemours and Company, Wilmington, Del.,

a corporation of Delaware No Drawing. Filed Nov. 21, 1060, Ser. No. 70,423 1 Claim. (CI. 28-76) This invention relates to flannel-like fabrics devoid of wool and to methods for preparing such fabrics.

In the past, many fabrics containing fibers of acrylonitrile polymers or of polyethylene terephthalate have been blends with wool, rayon or cotton in order to incorporate properties of the latter fibers. In certain instances the fibers which were added improved the cover, static resistance, hole melting resistance, liveliness, comfort, etc. For example, to obtain satisfactory cover in fiannels, it has been necessary to incorporate a high proportion of wool. In fact, it has been extremely difiicult to produce satisfactory cover without using wool.

It is, therefore, an object of this invention to provide a fabric which contains no wool yet gives flannel cover to a degree substantially equal to that of the best Worsted or woolen fiannels of 100% wool. Other objects will be apparent from the description that follows.

The objects of this invention are attained by preparing a fabric containing at least 20% by weight of yarn spun from spontaneously crimpable synthetic organic fibers, such as composite filaments of acrylonitrile polymer components (preferably a filament wherein one component is substantially polyacrylonitrile and the other component is a copolymer of acrylonitrile with from about 1 to 5% of styrene sulfonic acid said copolymer containing at least 50 milliequivalents of ionizable groups per kilogram of copolymer) differing in ionizable group content as described in copending and coassigned patent applications Serial No. 771,677 to Taylor, now Patent No. 3,038,- 237, and Serial No. 793,502 to Ryan and Tichenor, now Patent No. 2,988,420, and finishing the fabric so as to develop a high nap wherein the spontaneously crirnpable fibers have become crimped to the extent of at least about 40 crimps per inch. Up to 80% of the fabric may be constituted by other synthetic organic fibers, such as fibers of polyesters of terephthalic or other dicarboxylic acids, e.g., as polyethylene terephthalate fiber, acrylonitrile polymer fibers and/ or regenerated cellulose fibers.

It is preferred that the fabric be designed so as to be readily napped. Thus, in the case of woven fabrics relatively low twist filling yarns should be used. Low twist yarns should also be used in knit fabrics. In order to develop adequate nap and provided the desired high degree of crimp in the spontaneously crimpable fibers contained therein, the fabric is scoured at an elevated temperature, preferably at the boil, then heavily napped while wet and dried at about 400 F. Under these conditions the spontaneously crimpable fibers develop more than 40 crimps per inch and even as much as 50 or 60 crimps per inch. Dyeing may be substituted for the scour, decatizing may follow the scour and before napping or the fabric may be dyed between the napping and drying steps. Stock dyed fibers may be used in which case it is generally desirable in order to avoid bleeding of the dyes to scour the fabric at a lower temperature such as at about 120 F. and pad extract or the fabric may be wet out evenly on a padder. In either case, the fabric should then be steamed at atmospheric pressure for a period of from 5 to 20 seconds and thereafter wet-napped and dried at about 400 F.

The yarns from which the fabrics of this invention are made may vary widely in composition. If the filling yarn, which is most effective in providing the desired 3,114,191 Patented Dec. 17, 1963 cover, is entirely or preponderantly of spontaneous crimpable fibers in the form of bi-component fibers of acrylonitrile polymers then the warp may be composed entirely of other synthetic organic fibers. Preferably, however, both filling and warp yarns are composed of at least about 30% of the spontaneously crimpable fiber, the balance being of high or normal shrinking acrylonitrile polymer fibers, polyesterfibers of terephthalic acid that may contain up to 15% isophthalic acid or polyesters of other dicarboxylic acids as naphthalenedicarboxylic acid especially the 2,6- or 2,7-isomer, with ethylene glycol or cisor trans-p-hexahydroxylylene glycol, and with or without a very minor amount of rayon. For some uses, adequate cover may be provided by using filling yarns comprised of only 20% of the spontaneously crimpable fibers together with other synthetic organic fibers and with the warp yarns composed entirely of other synthetic organic fibers. Large filling yarns with relatively low twist favor napping and filling yarn counts from 10/ 1 cc. to 20/1 cc. with twist multi liers of 1.7 to 2.2 have been used with excellent results. A twill weave is preferred with loom tightness factors of from 21.4 to 28.8 since nappability depends to a large extent on tightness. This tightness factor is that discussed and described at pages 341 and 365 of Textile Fibers, Yarns, and Fabrics; Comparative Study of Their Behavior With Special Reference to Wool by Ernest R. Kaswell, a text published in 1953 by Reinhold. The tightness factor is also discussed and defined, in terms known to those skilled in the art, on pages 650 and 651 of volume 21 of the Textile Research Journal (1951) in an article entitled The Relationship Between the Structural Geometry of a Textile Fabric and Its Physical Properties-Part III by S. Backer and S. I. Tanenhaus. Smaller and more highly twisted yarns may be used in the warp.

Thus, the fiber blend is chosen which gives the desired fiber crimp potential and a yarn and fabric construction is selected which makes the fibers available. Finishing develops the cover through napping and crimping. The degree of cover is determined by the amount of fiber between the eye and the base structure. It is dependent upon the number of fibers in the nap and the length of each. The extent of napping controls the number of fibers, while the degree of crimp determines the acceptable length. Straight fibers in the nap cover very little because they tend to stand on end perpendicular to the fabric surface. Crimped fibers nestle close to a fabrics surface entangling with one another. A fiber 4 mm. long becomes 2 mm. or less in length when crimped and offers about 200 times the covering power of a fiber on end. Further, stability is offered through entanglement to give a uniform appearance. Straight fibers must be sheared closely to prevent shagginess. Only very slight cover is possible with a nap made up of straight fibers. Normal crimp (12-18 c.p.i.) of some spontaneously crirnpable fibers can give satisfactory results where only light cover is desired. Cover equivalent to or greater than 100% wool is possible when crimp reaches 40 c.p.i.

It is essential in finishing the fabric that no drying step is interposed between scouring and napping in the scour, nap, dry sequence. The degree of crimp, and hence cover, is dependent on the temperatures of scouring and drying. Scouring temperatures may be in the range of from to 212 F. and thedrying temperatures may vary from 250 to 400 F. Crimp frequency in the nap fibers varies directly as the temperature, and there is an increase of 1.2 c.p.i. (crimps per inch) for every 10 F. rise in either scouring or drying temperature. For the best possible cover, scouring should be at the boil and drying should be at about 400 C.

The following example is given to further illustrate the invention. All parts and percentages are by weight unless otherwise indicated.

a Example A blend of the following fibers in the indicated proportions was prepared for spinning by means of a picker and roll-top card: (1) 30% of 2 /2 inch cut, 3 denier sideby-side bi-cornponent fibers having 22.6 c.p.i. and prepared from acrylonitrile homopolyrner as one component and a 96/4 copolymer of acrylonitrile with styrene sulfonic acid as the other component. The side-b -side oi-component fiber was made as described in the first paragraph of Example VI of copending and coassigned application Serial No. 793,502 to Ryan and Tichenor; (2) 35% of 3 inch cut, 3 denier fibers of poly(ethylene terephthalate) containing about 2% of copolymerized S-(sodium suite) isophthalate and having about 20% boil-off shrinkage; (3) 30% of 3 inch cut, 3 denier fibers of the same poly (ethylene terephthalate) copolynier having about 10% boil-01f shrinkage, and (4) 5% of 2 /2 inch cut, 3 denier rayon made by the viscose process. Two yarns were spun from this blend, one for use as the filling yarn being 14/1 cotton count with 7.5 turns per inch 2 twist and the other for the warp being 18/1 cotton count with 12 turns per inch 8 twist.

A 50 inch wide 2 X 2 twill fabric was prepared in the usual way with 48 warp ends per inch and with 52 filling picks per inch. The gray fabric was scoured at the boil to desize, was wet-napped and dried at 400 B, after which it was dyed with a basic dye, dried and semi-decatized in the conventional manner. A latent fiber bonding solution consisting of sodium thiocyanate in water at about 1%.% concentration was padded onto the fabric to a wet pick-up of about 100% after which the treated fabric was dried in an oven at about 240 5., Beck scoured, again dried, sheared, pressed and finally warm blanket dccatized.

The fabric produced had excellent cover, a pleasing handle and good suppleness; and over-all aesthetics were considered substantially equal to fine imported woolen or Worsted fabrics, and much better than good quality domestic fabrics, of similar construction. Furthermore, performance tests on this fabric showed unusually good crease recovery, wash-wear wrinkle resistance and very acceptable resistance to pilling.

Similarly improved fabrics were obtained by this procedure with other fiber combinations. Satisfactory yarns are composed of at least 20% spontaneous crimpable fibers. Thus, for example yarns made up of 100% bicomponent fibers of acrylonitrile polymers, yarns made up of 60% of these bi-component fibers and 40% of fibers of polyesters of terephthalic or of other dicarboxylic acid of about 10-20% boil-off shrinkage, and yarns of bi-component fibers of acrylonitrile polymers, 25% acrylonitrile polymer fibers having about boilol'f shrinkage and 40% of fibers of polyesters or" terephthalic or of other dicarboxylic acid of about 10% boil-01f shrinkage are amenable to the process of the invention. Other similar combinations of fibers will be apparent to those skilled in the art.

What is claimed is:

A method for making a fabric devoid of wool and having high flannel cover which comprises preparing a fabric from yarn formed solely of synthetic organic fibers and containing about 30% by weight of staple fibers comprising side-by-side lei-component fibers wherein polyacrylonitrile constitutes one component and a 96/ r weight basis copolymer of acrylonitrile with styrene sulfonic acid constitutes the other component, hot scouring said fabric at the boil, wet-napping the fabric prior to any drying of the scoured fabric and then drying the fabric at about 400 F.

References Cited in the file of this patent UNITED STATES PATENTS 1,526,201 Bosshard Feb. 10, 1925 2,060,664 Cohn Nov. 10, 1936 2,109,223 Schmidt Feb. 22, 1938 2,268,160 Miles Dec. 30, 1941 2,303,534 Foster Dec. 1, 1942 2,586,105 Speakrnan et a1 Feb. 19, 1952 2,633,624 Meyer Apr. 7, 1953 FOREIGN PATENTS 228,825 Australia May 8, 1958 OTHER REFERENCES Fairchilds Dictionary of Textiles, copyrighted 1959 by Fairchild Publications, Inc, New York, NY.