Feb. 7, 1967 w. E. DAVIS ETAL 3,302,265 PROCESS FOR PREPARATION OF FLANNEL FABRICS FROM SYNTHETIC FlBERS Filed April 21, 1964 fr 3,302,265 United States Patent C) ICC Patented Feb. 7, 1967 .1 2 polyester and polyacrylic fibers are preferred. All such 3,302,265 fibers are well known to the art and can be employed PROCESS FOR PREPARATION 0F FLANNEL FABRICS FROM SYNTHETIC FIBERS in the practice of the present invention without regard Warren E. Davis, Arden, and Edward A. McAbee, Wil to their specfic chemistry or to the methods used in pre mington, Del., assignors to E. I. du Pont de Nemours paring them. While it is of the essence of the invention aud Company, Wilmington, Del., a corporation of Dela to provide a true fiannel from man-made fibers, small ware amounts of wool, cotton or the like can also be included, Filed Apr. 21, 1964, Ser. No. 361,546 if desired. . 2 Claims. (Cl. 28-76) The single figure of drawing is a flow chart of the basic 10 finishing sequence utilized with the invention. This invention relates to fabrics and in particular to It is important to the success of the procedure that the flannel fabrics made entirely of man-made fibers. fiber blend, whatever the chemical composition of the Flannel fabric is a basic type of textile fabric and fibers, contain fibers of two different residual shrinkage finds wide application in apparel, home furnishings, and levels. The preponderance of the fibers in the blend may industrial uses. True flannels are made entirely or pre have the low residual shrinkage that is characteristic of the process of fulling, which takes advantage of the com man made fibers, which is usually of the order of less bination of the relatively high shrinkage of wool fibers than 1% to about 5%. A minimum of about 30% of the dominantly of wool and are characterized by permanent fibers in the blend, by weight, should have relatively fiber disarangement on the surface of the fabric (surface higher shrinkage, i.e., at least about 10% and preferably cover) and permanent fiber disarrangement between the 20 from about 15 % to about 25%. lFibers with even higher yarns in the base of the fabric (bottom cover), both of residual shrinkage, eg., 30-50%, may, of course, be used which obscure the weave or pattern arrangement of the if available, but such high fiber shrinkage is not essential fabric. Thus fiber disarangement is achieved through to achieve the desired flannel fabrics. Usually, no more the process of fulling, which takes advantage of the com than about 40% of high-shrinkage fibers will be required bination of the relatively high shrinkage of wool fibers 25 to achieve the desired fabric effect; higher proportions of and the presence of epithelial scales on the surface of high-shrinkage fibers may be used but little or no addi the wool fibers, as is well known in the textile art. For tional ‘benefit is achieved thereby. By the term residual fabrics :made from fibers that do not have scales, e.g., cot shrinkage is meant the linear contraction that occurs ton and man-made fibers, a mechanical napping action when the fibers are allowed to relax without tension in is used in an effort to obscure the weave pattern. Fabrics 30 boiling water. made in this way are sometimes called flannels, |but it is Blending of the fibers, spinning of yarns, and weaving recognized in the textile industry that they are not true of fabrics are all carried out by procedures that are flannels. standard practice in the textile industry, with two impor It has long been desired to impart to flannel fabrics tant exceptions. First, the yarns should not be twist-set, some of the properties that are characteristic of man-made 35 since exposure to moisture may cause shrinkage of the fibers, notably their »outstanding durability, ease-of-care high-shrinkage component of` the yarns prematurely. properties, and resistance to attack by microorganisms Second, for the same reason, minimum temperatures and insects. The simplest approach to this objective has should be used in slashing. been to make flannels from blends of man-made fibers A typical finishing sequence that may be used with this with wool, but such fabrics have not been entirely suc 40 invention is as follows: nap, crop shear, hot-dry Schreiner cessful. In order to avoid interefering unduly with the calender, tack, hot full, dolly wash, beck dye, apply felting action of the wool fibers, it has been necessary to antistat, detack, frame, nap, shear, steam, press and restrict the proportion of man-made fibers in the blend semi-decate. As is evident, the foregoing are conven to a relatively low level. This limitation has prevented tional textile finishing operations and can readily be used taking full advantage of the beneficial characteristics of 45 by the artisan in their presently understood manner sub~ the man-made fibers. More complicated procedures have jefctt to the significant modifications mentioned herein also been tried. For example, it has been proposed to a er. f pulsate the feed of spinning solution in the manufacture The ­purpose of the calendering step is to compress of man-made fibers in an effort to produce minute projec and minutely crimp the fibers. While the applicant does tions on the surface of the fibers simulating the scales of 50 not wish to be held to any particular explanation, it may wool fibers. Also, a number of modified fabric finishing be speculated that the minute crimps imparted to the fibers operations, chemical treatments, and the like have been by the calendering operati-on operate in much the same proposed. Despite such atempts, widespread interest con fashion as the epithelial scales of wool to lock the fibers tinues in production methods for fiannel fabrics made in a disarranged position in the course of the fiber migra entirely of man-made fibers and possessing the desired 55 tion induced by the subsequent fulling operation. To and characteristic bottom and surface cover. achieve the desired fiber deformation, several important It has now been discovered that true fiannels, that is, variables in the calendering operation must be controlled. fabrics wherein the weave pattern is totally obscured by First, the temperature should be in lthe range of 100° F. good surface cover and good bottom cover, can be made to 450° F. (38° C. to 232° C.), and preferably 100° F. entirely of man-made fibers by a process in which a fabric 60 to 300° F. (38° CQ to 149° 0.). Pressure on the fabric of such fibers is subjected to hot dry Schreiner calender should be maintained in the range of 833 lbs. per linear ing prior to wet-finishing operations, followed by hot inch to 1666 lbs. per linear inch (149-298 kg./cm.) and fulling. By employing this process with a fabric com preferably between 1250 land about 1666 lbs. per linear posed of a fiber blend containing a proportion of rela inch (223-298 kg./cm.). Rate of calender-ing depends tively high-shrinkage ñbers as well as low-shrinkage fibers, 65 on the temperature and pressure employed. Typically, a true flannel is obtained easily, economically and by use of textile skills that presently available. the Ifabric is calendered twice, once on each face, at be Among the man-made fibers that can be used in the tween about 20 and about 100 yds/min. (18-91Ímeter-s practice of this invention are the cellulose and cellulose per minute). An important factor in the calendering op derivative fibers, polyamide fibers, polyester fibers, poly 70 eration is the nature of the surface of the calender roll. acrylic and modacrylic fibers, polyolefìn fibers, polyvinyl As is well known in the textile finishing art, a Schreiner chloride fibers, polyvinyl alcohol fibers, and the like. The roll is a heated, hard-surfaced roll having many fine lines 3,302,265 E 4 per inch engraved in it. Depending upon the number Y loom construction of 57 warp ends/in. (22.44 ends/cm.) of lines, the roll will compress about 50% lor more of and 54 filling picks/in. (21.26 picks/cm). The Z-twist the fabric surface `du-ring calendering. Its surface may yarns are used for the warp and the S-twist yarns are be made of alloy steel, pl-astic, ceramic or coated metal used for the filling. such as chromium or nickel plated steel. The surface The fabric is napped and sheared. The dry fabric is is preferably rust-resistant. The second roll of the calen then Schreiner calendered twice, once on each face. The der is made of a compressible composition, such as »cot-ton, Schreiner roll has a steel surface, engraved with 260 lines/ paper, wool, corn husk o-r other material that will present in. (102.36 lines/cm.) oriented at 27.5° to the warp a tough, resilient, unpatterned surface to t‘he fabric when yarns. The Schreiner roll is heated to 250° F. (121° C.). compressed against the first roll. The engraved lines on a Roll pressure is 1042 lbs/linear in. (186 kg./c1r1.). The Schreiner roll may be parallel to the warp threads of the fabric is calendered at a rate of 25 yds/min. (22.86 falbric being processed (that is, perpendicular to the axis meters/ min. ) . of rotation of the roll), or at some angle thereto. In the The fabric is then tacked (formed into an endless turbe), practice of this invention, best results are achieved with and placed dry in a fulling mill that has been modified a Schreiner roll having from about 200 to about 300 lines/ by the :addition Áof a steam line. Commercially available inch (79-118 lines/cm), oriented lat an angle of from liquid green soap is added to the extent of 12% of the about 20° to 40° from the warp yarns. dry fabric weight. The fulling mill is then closed and In the finishing of flannel fabrics made of wool, the started in operation. At the same time, the steam valve fulling operation is normally carried out at room tem is opened and live steam is admitted to the fulling mill at perature, with the fabric sufiiciently moist and lubricated 20 such a rate that in approximately 15 minutes van equilib to permit migration of the wool fibers. In the practice of rium maximum temperature of about 206° F. (97° C.) is the present invention, the fulling operation is somewhat achieved. Pulling is continued at this temperature for modified. The fabric is loaded into the fulling mill dry an additional 15 minutes. and conventional lubricants, such as green soap, sodium Upon completion of fulling, the fabric is subjected to oleate or the like, are added in an amount readily deter 25 a series of conventional wet-finishing operations, namely, mined by the skilled finisher, or the lubricant may be scouring in a dolly washer, dyeing in a beck, and applica padded on the fabric before the fabric is placed in the tion of an antistatic agent in the ybeck following dyeing. fulling mill. The fulling mill is modified by the provision The tacking stitches are removed and the fabric is re of a steam line for the admission of live steam. After stored from the tube form to the fiat form for the final addition of the lubricant, the fulling mill is started and 30 dry-finishing operations of framing to width on a tenter, steam is admitted at a rate such that maximum equili - napping, shearing, steaming, pressing and semi-decating. rium temperature is reached in about 15 minutes. Full The fabric so produced is a very desirable flannel ing is continued for about 15 minutes «or more after maxi wherein permanent disarrangement of the fibers is ob mum equilibrium temperature is reached. This tempera tained and the weave pattern is totally obscured. ture will ordinarily be from about 200° F. (93° C.) to 35 about 206° F. (97° C.) but in any event less than 212° F. Example Il ( 100° C.). Alternatively, the fabric may ‘be wet out with The fabric of Example I is finished according to the cold water, placed in the fulling mill, lubricant added, same procedure as in Example I except that the hot and fulling conducted according to the method of U.S. Schreiner calendering step is omitted. In the resulting Patent 2,972,177. By either of these mehtods or any 40 fabric, the diagonal weave pattern is apparent. equivalent procedure, the hot-fulling operation induces shrinkage «of the high-shrinkage fibers in the blend, with Example III the result that the fabric structure is compacted and the weave pattern obscured. As already discussed, the com The fabric of Example I is finished according to the pacting action is assisted and preserved by the minute 45 same procedure as in Example I except that the hot crimp introduced in the fibers by the hot, dry Schreiner fulling operation is omitted. In the resulting fabric, the calendering operation. diagonal weave pattern is apparent. The manner of conducting the remaining finishing op erations and the contributions they make to the final Example IV fabric are well known and understood. ' 50 The lfabric of Example I is finished according to the The invention will be further illustrated by the follow same procedure as in Example I, except that both the ing examples, wherein all parts are by weight unless Schreiner Ácalendering and the hot fulling steps are omitted. otherwise noted. In the resulting fabric, the diagonal weave pattern is ap Example l parent. The fabric is not a true flannel. 55 Commercially available acrylic and polyester fibers are Example V used to make the following fiber blend: A blend is made of equal parts of the following com Staple Nominal mercially available ñbers: Blend, Fiber Denìer/ Tex] Length Boilolî, 60 (a) Bicomponent acrylic fiber, 3.0` denier per filament percent Type Filament Filament Shrinkage weight Percent (01,33 tex/filament), two-inch (5.08 cm.) length, 4% boil 1n ern off shrinkage. (b) Polyester fiber, 3.0 denier per filament (0.33 tex/ 30 ______Polyester.. 3. 0 0. 33 2 5. 08 2. 5 filament), two-inch (5.0‘8' cm.) length, 2.5% boil-off d 3. 0 0.33 2 5. 08 <1. 0 4. 5 0. 50 2 5.08 17. 0 65 shrinkage. The fiber blend is spun to a 15/1 cc. (39.3 6. 0 0. 67 2 5. 08 2. 0 tex) yarn with 13.5 tur-ns per inch (531 turns per meter) of Z twist. This yarn is `woven in a 2 x 2 twill fabric with a 64 by 5S (25.19 ends/cm. x 22.83 picks/cm.) loom The fibers are blended together and the blend is spun to construction. This fabric is finished according to the full a 17/1 cc. (34.8 tex.) yarn with a twist of 14.5 turns/in. 70 finishing procedure of Example I and according to the (571 turns/meter). Part of the blend is spun to yarn variant procedures of lExamples II, III and IV. In all with Z twist, and part of the blend is spun to yarn with cases, the weave pattern remains visible 4and a true fiannel S twist. The blending, spinning and weaving operations is not achieved. This example shows the importance of are conducted according to common practice in the indus having a proportion of relatively high-shrinkage fibers in try. The yarns are woven in a 2 x 2 twill weave with a 75 the fiber blend. 3,302,265 5 6 Example VI flannels the additional advantages of outstanding dura bility, ease-of-care, vand resist-ance to attack by micro Commercially available fibers are used to make the fol organisms and insects. Surprisingly, the fiannel fabrics lowing blend: made according to this invention have been found to be remarkably yfree of the pilling that has Iheretofore been Staple Nominal Blend, Fiber Denier/ Tex/ Length Boiloff, generally characteristic of flannel -fabrics made at least in percent Type Filament Filament Shrinkage part of man-made fibers. weight _ Percent 1n. cm. Since a wide 4scope of fiber types and manufacturing procedures may be employed in the practice of this in vention -without departing from the spirit thereof, the 30 ______Acrylic. _ _ 4. 5 0. 50 2 5. 08 17. 0 10 38 ______do.___ 3.0 0.33 2 5.08 1.0 invention is intended 4to be limited only as `defined in the 32 ...... __ 64’s wool.. __. appended claims. ' What is claimed is: The blended fibers are spun to a l7/ l cc. (34.8 tex) yarn 1. A method for making flannel fabric having a weave with 11.3 turns per inch (445 turns/meter) of Z twist. 15 entirely obscured by good surface and bottom cover which The yarn is woven `in a 2 X 2 twill weave with a 68 by 56 comprises preparing a fabric from synthetic organic fibers (26.77 ends/cm. X 22.05 `picks/tern.) loom construction. containing fibers having at least two different residual When this fabric is finished according to the complete `shrinkage levels, about 50 to 70I percent of the fibers pres procedure of Example I, a good, true flannel is achieved, ent 'having a residual shrinkage below about 5 percent and wherein the weave pattern is totally obscured by perma the «remainder of the fibers lhaving a residual shrinkage nent disar-rangement of fibers. The weave pattern re of about 10 to 50 percent, napping the fabric, calender mains apparent wlhen the fabric is finished by the pro ing the resulting napped fabric to »compress and minutely cedures of Example II, III `and IV. crimp the fibers by passing the Idry fabric, at a speed of 'at The foregoing examples are intended to be illustrative least labout 20 yards per minute, through confining rolls of the invention and not limiting. It will be seen that 25 lat a temperature of 100° to 450° F. and at »a pressure true ñannels are achieved when the essential elements of applied by the rolls of yabout 833 to -1666 pounds per inch this invention are present, namely: of roll width, and subjecting the calendered fabric to com (a) A proportion of relatively high-shrinkage fibers in pressional working in the presence of moisture and a the blend, o ‘ lubricant :at a temperature of at least 200° F. but below (b) A bot, .dry Schreiner calendering prior to any wet 30 212° F. to shrink the fibers, compact lche fabric structure finishing operation, to compress :and minutely crimp the and obscure the weave pattern; the compaction assisted fibers, and and preserved by the minute crimp produced in the said (c) Hot fulling to compact the fabric structure because calendering step. of shrinkage of the high-shrinkage fibers inthe blend. 2. A method in accordance with claim 1 in which the It will be understood that a wide variety of fiber types, fibers with the higher residual shrinkage are present in blending and spinning methods, fabric weaves and con an amount of 30 to 40 percent and their residual shrink structions and yslashing procedures, may be used. Like age is about 15 to 25 percent. wise, once the essential finishing operations of Ihot-dry Schreiner calendering and hot-fulling Ihave beenaccom References Cited by the Examiner plished, the remaining finishing operations may be varied 40 UNITED STATES PATENTS according to the judgment of the skilled finisher to pro duce the effects desired in the final fabric. 2,828,528 4/1958 Gajjar ______28--76 The flannel Ifabrics made according to this invention 2,972,177 2/1961 Bid'gOOd ______26-19 X can lbe employed in the uses already known for flannel 12,980,492 4/ 1961 Jamieson et al. 2,985,940 5/1961 Weldon. fabrics, notably ín apparel fabrics, but also in home fur 45 nishings and industrial applications. Because they can be made entirely of man-made fibers, the flannel fabrics ROBERT R. MACKEY, Primary Examiner. made by this invention bring to these traditional uses of