US3414957A - Process for dyeing textile fibers and preparing high-bulk fabrics - Google Patents

Description

3,414,957 PROCESS FOR DYEING TEXTILE FIBERS AND PREPARING L A T 4 E F m M T K 5 mm m m A ww L n I F Dec. 10, 1968 YARN OF HEAT STABLE F/BRES AND LOW TEMPERATURE any DYED HEAT .SHR/N/(ABLE INVENTORS,

W/TT LANGSTAFE THOMAS L. SHEALY, JR.

ATTORNEY 8 AGENT United States Patent 3,414,957 PROCESS FOR DYEING TEXTILE FIBERS AND PREPARING HIGH-BULK FABRICS Witt I. Langstalf and Thomas L. Shealy, .Ir., Kingsport,

Tenn., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed June 26, 1964, Ser. No. 378,266

' 16 Claims. (CI. 28-74) This invention relates to dyeing textile fibers, particularly acrylic textile fibers and to the preparation of highbulk yarn and fabrics.

In the manufacture of high-bulk knit and woven fabrics such as sweater fabrics, the common practice is to blend in a yarn two types of fibers, fibers stabilized against heat shrinkage and fibers undergoing substantial linear shrinkage upon heating. When yarns containing these fibers are dyed at the boil as is customary, the fibers differentially shrink and a yarn is obtained having characteristic high bulk and loft readily distinguished from other yarns prepared from non-shrinkable fibers.

The process has several disadvantages residing partly in the fact that since dyeing is carried out after the yarn is prepared, the yarns are obtained only in single colors. Yarns containing blends of different colors are thus not obtainable. Also, since many types of fiber such as polyester and acrylic fibers cannot be successfully dyed together and since the high-shrink fiber cannot be dyed prior to blending, it has not been possible to make highbulk blend yarns of this type.

Attempts have been made to use tow dyed material, such as acrylic tow, subsequently to impart the heatshrink property to the dyed fibers. However, the dyed fibers may gradually lose their heat-shrink property on natural aging at temperatures common in warehouses and knitting mills. More particularly, the processing of towdyed fiber has been unsatisfactory in yarn making. The process also has limitations in dyeing method.

A common method of dyeing nonbulky yarns is to wind the yarn on perforated tubes and dye the resulting packages by forcing dye liquor through them. This operation is less expensive than skein dyeing, in which the yarn must be wound onto skeins and tied with strings before dyeing. It has not been possible to dye high-bulk yarns by, the package dyeing process since at temperatures normally used, the shrinkable fiber undergoesshrinkage and .the resulting yarn can no longer be bulked.

We have discovered that fibers composed of hydrophobic; synthetic fiber-forming polymers, particularly acrylic and modacrylic polymers, modified so as to be dyeableat low temperatures, can be treated to impart heat shrinkage properties thereto, for example by drafting and cooling the fibers without relaxing, and the heat-shrinkable fibers can be dyed alone or combined in a composite yarn with the heat-stable fibers, for example in package form, at a temperature below that causing the fibers to shrink; thus, dyeing can be carried out at temperatures below 160 F., preferably between 140 F. and 160 F. Subsequent drying of the fibers should also be carried out at temperatures below that causing loss of heat shrinkage, for example at about 180 F. to 220 F. The lean composite yarns thus obtained containing heat-shrinkable and heat-stable fibers are susceptible to heat treatment to produce high-bulk fabrics. As mentioned, it is customary to dye most synthetic fibers, such as the acrylics, at the boil since shrinkage is ordinarily of no consequence and it was previously not believed possible to satisfactorily dye at temperatures much below boiling.

The staple heat-shrinkable and heat-stable fibers may be combined in the desired system such as the cotton systern employing the usual picking, carding, drawing, roving and spinning operations. The staple heat-shrinkable 3,414,957 Patented Dec. 10, 1968 fiber may first be dyed and dried at temperatures below which shrinkage occurs before combining with the heatstable fibers into yarn in the cotton system. Otherwise, the yarn containing colorless heat-shrinkable fiber and heatstable fibers can be package or skein dyed before forming into fabric as by knitting or weaving after which the fabric is heated to give high bulk. Similarly, slivers of dyed or undyed heat-shrinkable fibers can be blended with slivers of heat-stable fiber by known methods to produce the heat-shrinkable yarn. While the yarn comprising heatshrinkable and heat-stable fiber is primarily designed for dyeing at low temperature especially prior to fabrication, the fabric or garment can be dyed at the low temperature followed by bulking with heat or dyeing and bulking of the fabric can be carried out at one time by dyeing at the boil.

It should be noted that the dyeing of the lean yarns from the spinners containing a mixture of colorless heatshrinkable and heat-stable fibers, at the low temperatures required to retain the shrinkage properties, may not dye the heat-stable fibers since they may be dyeable only at higher temperatures. However, fabrics containing the partially dyed yarn are pleasing in appearance. Accordingly, if desirable, the dye heat-shrinkable fibers can be combined with heat-stable fibers which have been dyed as usual at the boil and the two types of fibers spun into a lean yarn susceptible to bulking by means of heat. In preparing the high-bulk yarns, different deniers of the heat-stable and heat-shrinkable fibers can be, e.g., ranging from about 1 to 16 denier. In some cases, it may be desirable to use substantially different deniers for e two types of fibers to obtain the desired result.

Representative synthetic hydrophobic fiber-forming polymers susceptible to such treatment to impart the high heat-shrinkage property thereto and which, in the shrinkable form, can be expected to be readily dyeable without substantial loss of shrinkage are, for example, acrylonitrile homopolymers and copolymers including acrylonitrilevinyl halide copolymers and acrylonitrile-vinylidene halide copolymers, which fiber-forming polymers have been modified to improve their dyeability by blending or otherwise incorporating into the polymer alkylacrylamide polymers such as poly-N-alkylacrylamides, acrylic ester polymers including polyethylacrylate and polymethylmethacrylate, polyvinylpyridines, poly(vinylpyrrolidones), polyvinyl acetals, e.g. polyvinylbutyral, epoxy resins, e.g. epichlorohydrin-sulfide or epichlorohydrinbisphenol condensates, polyalkylimines, polycarbonates, pollyoxyalkenes, divalent metal salts of aliphatic carboxylic acids, metal sulfonates, etc.

Upon dyeing such heat-shrinkable polymers at relatively low temperatures at which little shrinkage occurs, when originally containing as much as 35 to 45% linear shrinkage, the polymers can be expected! to lose no more than about 2 to 10% of their heat-shrinkage property, and dyed fibers and yarns are readily obtainable possessing as much as 30 to 40% retained shrinkage. The shrinkage of the fiber before or after dyeing is determined by placing a given length in boiling water for two minutes followed by quenching with cold water and measuring the change in length. More accurate results are obtained using samples of tow in the test prior to cutting it into short staple fiber lengths. Yarn shrinkage is determined similarly except that the measurements of length of yarn before and after heating in water is made with a standard amount of tension per denier on the sample of yarn. Accordingly, by heatshrinkable fiber or yarn, we mean the fiber or yarn capable of about 20% or more shrinkage on heating to elevated temperatures. An especially useful group of polymers, to which substantial heat-shrinkage can be imparted which is retained on dyeing at relatively low temperatures, are the acrylonitrile polymers and copolymers preferably containing at least about 35% combined acrylonitrile units and up to about 95% acrylonitrile units, and modified, so as to be dyeable at low temperatures without substantial loss of shrinkage while retaining good dye fastness, for example, by 85-5 of vinyl pyridine units as described in U.S. Patents 2,990,393 (Re. 25,533) and 3,014,008 (Re. 25,539) or modified by 655% of vinylpyrrolidone units, for example as described by U.S. Patent 2,790,783 or modified with 655% acrylic ester or acrylamide units as described in U.S. Patents 2,879,253, 2,879,254 and 2,838,- 470. Similar amounts of the other polymeric modifiers mentioned above are also useful. The polymers will thus retain a useful amount of shrinkage under conditions that lead to significant dyeing of the fibers. A typical copolymer composition can be prepared as follows: 93 parts of acrylonitrile, 7 parts of 2-vinylpyridine, 1500 parts of water, 1.5 parts of ammonium persulfate, 1.5 parts of sodium metabisulfite, 10 parts of phosphoric acid, and 2.0 parts of sodium lauryl sulfate were heated at 40 C. for hr. The resultant polymeric slurry, which had an intrinsic viscosity in dimethyl formamide of 1.4, was washed and dried, and after solution in dimethylformamide, was spun under conditions that gave a fiber having an appreciable degree of residual shrink. This material could be dyed under conditions that gave a dyed fiber that still retained about 70% of its original shrinkage.

A preferred group of copolymers especially adapted to treatment to impart high heat-shrinkage property to fibers thereof and which are readily dyeable at low temperatures without appreciable loss of their shrinkage characteristics, are the modacrylic polymers such as described in U.S. Patent 2,831,826 composed of a mixture of (A) 70-95% by weight of a copolymer from 30 to 65% by weight of vinylidene chloride or vinyl chloride and 7035% by Weight of acrylonitrile, and (B) 305% by weight of a second polymer from the group consisting of (1) homopolymers of acrylarnidic monomers of the formula wherein R is selected from the group consisting of hydrogen and methyl, and R and R are selected from the group :onsisting of hydrogen and alkyl groups of 1-6 carbon atoms, (2) copolymers consisting of at least two of said acrylamidic monomers, and (3) copolymers consisting at at least 50% by weight of at least one of said acrylimidic monomers and not more than 50% by weight of a Jolymerizable monovinyl pyridine monomer.

A particularly efiicacious group of modacrylic polyners for use in the low temperature dyeing process of the ,nvention is an acetone soluble mixture of (A) 7095% W weight of a copolymer of 30-65% by weight of vinyldene chloride and 70-35% by weight of acrylonitrile and 1B) 305% by weight of an acrylamide homopolymer iaving the above formula wherein R R and R are as lescribed above. Specific polymers of that group contain 095% by weight of (A) a copolymer of from 30-65% y weight of vinylidene chloride and 70-35 by weight of tcrylonitrile and (B) 30-5 by weight of a lower N -alkyltcrylamide polymer such as poly-N-methylacrylamide, Ioly-N-isopropylacrylamide and poly-N-tertiarybutylacryltmide. It is polymers such as these which in heat-shrinktble form have the unique properties of dyeing to strong hades at relatively low temperatures such as below 160 without losing their heat-shrinkage properties.

The colored heat-shrinkable fibers described can then e combined into a yarn together with the heat-stable Inonshrinkable) textile fibers and after forming into a abric, for example by knitting or weaving, heat can be tpplied to differentially shrink the fibers to produce a tigh-bulk fabric. The method of applying heat to the abric to shrink the fibers is not critical, for example, hot it at a temperature not adversely affecting the fibers of he order of 250-300 F. can be applied. The increase in bulk is readily apparent from counting the increase in the number of courses and wales per inch and noting the increase in the weight of fabric per square yard. The improved fullness of hand will also be apparent. In this process, the combination of the specified shrinkable fibers and low temperature dyeing produces fibers whose heatshrink properties are maintained on natural aging under room conditions over an extended period of time.

The heat-stable fibers which are used in the high-bulk fabrics together with the shrinkable fibers (i.e. modacrylic fibers of U.S. Patent 2,831,826 having the above formula) include a wide variety of fibers such as cotton, mohair, wool, viscose, heat-stable acrylonitrile homopolymers and copolymers such as those sold under the names Creslan, Acrilan, Dynel, Zefran, Orlon, the linear terephthalate polyesters such as the linear cyclohexane-1,4-dimethanol terephthalate polyesters described in the Kibler et al. U.S. Patent 2,901,466, granted Aug. 25, 1959, which have been heat stabilized as described in the patent. The heat-stabilized glycol terephthalate polyesters, including polyethylene terephthalate, described in the Whinfield et al. U.S. Patent 2,465,319, granted Mar. 22, 1949, are also very useful as the heat-stable component of the high-pile fabric.

The dyes are particularly useful for dyeing the heatshrinkable fibers, particularly the mod-acrylic fibers described above include the cationic or basic dyes well known in the art for dyeing acrylic fibers, for example the Basacryl series of cationic dyes which are usually used for dyeing acrylonitrile polymers such as Acrilan and Dynel at the boil, for example: Basacryl Yellow 5RL (Cl. Basic Yellow 25), Basacryl Red 'GL (C.I. Basic Red 29), Basacryl Blue 3RL (01. Basic Blue 53) and Basacryl Blue GL (C.I. Basic Blue 54). The Sevron series of dyes also represent cationic dyes useful in the process and include, for example, the cationic cyanine, methine, anthraquinone, oxazine and triphenylmethane dyes such as Sevron Yellow L (0.1. Basic Yellow 13), Sevron Yellow R (0.1. Basic Yellow 11), Sevron Orange G (C.I. Basic Orange 21), Sevron Blue B (C.I. Basic Blue 21), Sevron Blue 2G (C.I. Basic Blue 22), Sevron Blue 5G (C.I. Basic Blue 4), Sevron Brilliant Red 4G (0.1. Basic Red 14) and Sevron Green B (C.I. Basic Green 3).

The following are representative of the useful disperse dyes: 4 (2 methanesulfonyl 4' nitrophenylazo)-N- ,3 cyanoethyl N ,9 acetoxyethylaniline; 4 (6 methanesulfonyl 2 benzothiazolylazo) N B cyanoethyl- B hydroxyethylaniline; 2 nitro 4 \I,N dimethylsulfonamido 4' ethoxydiphenylamine; and 2 nitro 4 sulfonanilidodiphenylamine. Representative of the useful premetallized dyes are: Cibalan Yellow 2BRL, C.I. Acid Orange 87; Cibalan Red 2GL, C.I. Acid Red 211; Cibalan Orange RL, C.I. Acid Orange 88; Cibalan Blue BL, C.I. Acid Blue 168; Cibalan Brown ZGL, no CI. number; and Cibalan Grey 2GL, C.I. Acid Black 62.

The usual stock or package dyeing methods can be used for dyeing the heat-shrinkable fibers. Dyeing assistants and leveling agents such as nonionic surfactants and phosphate compounds are useful as shown in the following examples.

Methods known in the art can be used for imparting the heat-shrink properties to the fibers such as the modacrylic fibers of U.S. Patent 2,831,826 described above. These methods include spinning the modacrylic fibers from solvent, passing the tow bundle over heated rolls and drafting the fibers to about 3-6 times their original length at a temperature of about 250-400 F. followed by cooling the fibers without relaxing or further heat treatment. A particularly useful method for imparting heat-shrinkage to the modacrylic fibers of the above patent include drafting the fibers at a temperature of the order of 250300 F. and spraying the fibers with chilled water or passing them over a cool roll without relaxing or further heat treatment. When fibers such as the above modacrylic fibers are to be utilized as the heat-stable component of the high-bulk fabric, they are drafted with heat and relaxed and heat-stabilized in accordance with the usual practice.

The accompanying drawings illustrate diagrammatically in Stage 1 the appearance of a representative corn= posite yarn composed of heat-shrinkable fibers and heatstable fibers, as obtained in a process such as the cotton process, the heat-shrinkable fibers having been dyed, before or after combining into the yarn, at a temperature below that causing heat-shrinkage. In Stage 2 the same yarn is shown diagrammatically substantially as it would appear after heating to cause differential shrinkage of the fibers and thus bulking of the yarn.

The following examples will serve to illustrate our invention.

EXAMPLE I A modacrylic fiber was prepared as described in US. Patent 2,831,826 comprising a mixture of a icopolymer of vinylidene chloride and acrylonitrile and a minor amount of a poly(lower N-alkylacrylamide), the fiber being drafted with heat and cooled without relaxing to impart high heat-shrinkage thereto, after which the tow was cut to staple length. Fifty pounds of this 3 d./f., l /f'length bright luster high shrinkage modacrylic staple fiber was dyed a medium brown shade in a Riggs and Lombard stock dyeing machine. The machine was filled to three-quarters capacity with water at 80 F. The fiber was loaded into the water by hand and distributed evenly. The machine was filled to the correct volume with water and circulation of the water was begun. The following chemicals were added to the machine and circulated for minutes.

Percent Acetic acid (56%) 1.0 Sodium acetate 0.5 Fatty ester sulphate 1.0 Self-emulsifying organic phosphate 1.5

Percentages based on fiber weight.

The following dyes based on the fiber weight were pasted with acetic acid and dissolved in water, then added to the dye machine and circulated for 10 minutes.

Percent Basacryl Blue'GL 0.36 Basacryl Red GL 0.52 Basacryl Yellow SRL 1.66

The dye bath temperature was raised from 80 F. to 140 F. over a period of 45 minutes. The fiber was dyed 60 minutes at 140 F. then rinsed at 120 F., removed from the machine and the water extracted in centrifuge. The fiber was then dried at 190 F.

Forty pounds of the dyed staple fiber was blended at the cotton picker with 60 pounds of a cyclohexane-l,4- dimethanol terephthalate polyester heat stable fiber of 4.5 d./ f., bright luster, 1%"cut. 'Using conventional cotton spinning procedures, a 14/1 yarn with 9.8 t.p.i. Z singles was spun. This was two-plied with 4.28 twist and cone'd.

I This yarn was knit into a fabric on a Dubied NHF-S V-bed knitter. It was knit from two cones of yarn. The greige'fabrie contained 6.5 courses/inch and 6 wales/ inch and weighed about 7 ounces per square yard.

The grei ge fabric was then placed in a boiling water bath for 20 minutes. It was removed and tumble dried at 220 F. The fabric showed a remarkable degree of bulking as evidenced by the change in construction to values of 10 courses/inch and 9 wales per inch and an increased weight to about 10 ounces per square yard. The fullness of hand of the finished fabric was remarkably improved as compared to the greige as-knit fabric. The finished fabric also had much improved cover. These improvements .are attributed to the retained shrinkage ability of the stock dyed fiber, which caused the fibers to Untreated Treated Greige Boiled Soeeific Volume, Cu. In./Lb 64 106 Yarn Count, Cotton System 13. 8/2 10. 2/2

The bulking potential of the yarn is not lost with age. This is shown by testing the contraction or shrinkage in length of the yarn over a period of time, illustrated by the following data obtained for a yarn similar to that used in the above example.

Shrinkage in boiling water, percent Freshly spun 24.6 Aged 11 days 28.2 Aged 3 months 29.0 Aged 3 months 24.2 Aged 4 months 29.2 Aged 4% months 26.0

Thus the dyed shrinkable fiber or a yarn or fabric containing it can be shipped or stored for significant periods of time before it is bulked without loss of bulking potential. This is of considerably advantage as often the fiber is dyed in one plant, spun into yarn in a second plant, knit into fabric in a third plant and made into a garment in a fourth plant and the final finishing of the garment may thus take place some time after the shrinking fiber is dyed.

While in this example, the heat-stable polyester fiber was not dyed, it can be stock dyed to any desired shade for cross dye or heather effects. Or, if desired, two or more yarns can be made from different colored stock dyed or natural staple fibers and used in knitting to produce bulky knit garments having stripe and other pattern color effects as desired.

Thus, it has been found that the shrink-ability of the fibers is not changed by the dyeing process. Accordingly, a natural yarn and a colored yarn can be knit together into a fabric and bulked to produce a color and whitestriped or patterned sweater or dress at low cost.

EXAMPLE II Example I was repeated using a heat-stable polyethylene terepthalate polyester fiber as the nonshrinking component in a blend with the shrinkable modacrylic fiber. A similar improvement in the bulk, hand and cover of the finished fabric was noted.

EXAMPLE llII Example I was repeated using a heat-stable unmodified acrylonitrile polymer staple fiber as the non-shrinking fiber component of the blend. When the knit fabric was finished, the same improvement in bulk found in Example I was noted.

EXAMPLE IV A blend yarn was spun from 40% of the 3 d./f., 2 /2 shrinkable modacrylic staple fiber and 60% of a cyclohexane-1,4-dimethanol terephthalate polyester staple fiber of 4.5 d./f. and 2 /2 length. Both fibers were bright luster. The yarn was spun on the cotton system into a 20/2 cotton count size yarn.

The yarn was package dyed according to the following procedure:

(1) Wind medium soft packages.

(2) Set machine on five minutcsin and five minutes out.

(3) Add dyeing assistants over two cycles at 80 F. and

run one cycle.

(4) Add basic dyes over two cycles on outsidein portion at 80 F.

() Raise temperature at 140 F. in 45 minutes.

(6) Run one hour at 140 F.

(7) Rinse, scour, rinse and dry at 190 F.

Untreated Treated Specific Volume, Cu. In./Lb 59 95 Cotton Count, Yarn Size 8 The shrinkage of this dyed yarn was 31% when exposed to boiling water immediately after dyeing. Three months after dyeing a second sample of the yarn was bulked in boiling water and was found to have 32% shrinkage.

The ability of the yarn of the invention represented by this example, to be bulked after package dyeing is unique. In the prior art, it has not been possible to produce a yarn from a blend of heat-stable and heat-shrinkable fibers of yarns, package dye the yarn and subsequently bulk the yarn in a fabric made from the yarn by shrinking the shrinkable fiber component of the yarn.

EXAMPLE V Example IV was repeated except that the yarn was skein dyed according to the following procedure:

(1) Wet out.

(2) Use a cycle of 6 minutes forward and 4 minutes reverse How on Hussong machine.

(3) Add dyeing assistants at 80 F. and run one cycle.

(4) Add one half of basic dye at 80 F. and run one cycle. Rotate skeins.

(5 Add remaining one half of basic dye at 80 F. and

run one cycle. Rotate skeins.

(6) Raise temperature to 100 F. in one cycle. Rotate skeins.

(7) Raise temperature to 120 F. in one cycle. Rotate skeins.

(8) Raise temperature to 140 F. in one cycle. Rotate skeins.

(9) Raise temperature to 160 F. in one cycle. Rotate skeins.

(10) Run for one hour at 160 F. Rotate skeins every two cycles.

(11) Rinse, scour, rinse, soften, extract, dry at 190 F.

The skein dyed yarn was knit into fabric and bulked with good results as in Example IV.

EXAMPLE VI Example IV was repeated except that polyethylene ter- :phthalate heat-stable fiber was substituted for the heat- ;table polyester yarn of Example IV. The yarn was packtge dyed, knit, and bulked by steaming. A similar improvement in the bulk of the finished fabric was noted.

EXAMPLE VII Example IV was repeated except that an unmodified acylonitrile polymer fiber was used as the heat-stable com- )onent of the blend. The knit fabric made from the package dyed yarn was steam treated to shrink the modacrylic component and a remarkable improvement in bulk was noted.

EXAMPLE VIII Example IV was repeated except that an apparel grade wool fiber was substituted for the heat-stable polyester fiber. Similar results were obtained as in Example IV.

EXAMPLE IX Example IV was also repeated using cotton fiber in place of the heat-stable polyester fiber. Similar results were obtained as in Example IV.

While the invention is demonstrated in the examples with knit fabrics, equally impressive results can be obtained in woven fabrics. For example, the package dyed unbulked yarn can be woven into a loose weave fabric. The fabric is then treated with steam or boiling in a relaxed state so that the dyed shrinking component can cause contraction and a resultant bulking of the fabric to give it improved fullness of hand, thickness, heat insulation ability and bulk. Or, if desired, the fabric can be woven from alternate multiple picks and Warp ends of a potentially shrinkable dyed yarn and a non-shrinkable dyed yarn. When such a fabric is then steamed or treated in hot water, a popcorn or wafiie texture woven fabric is obtained.

It should be pointed that there is a particular advantage in using cycl0hexane-1,4-dimethanol terephthalate heat-stable fiber in foregoing blends because of its low shrinkage in boiling water of 0.5% and low hot air oven shrinkage of 4% at 220 C. By contrast, heat-stable polyethylene terephthalate polyester has 2.8% shrinkage in boiling Water and 11.2% shrinkage in 190 C. hot air and some heat-stable acrylic fibers may have 3% or more shrinkage in boiling water and up to 20% shrinkage in 190 C. hot air. Since the bulking of a yarn composed of shrinking and non-shrinking fibers is based on the difference in potential shrinkage at a given temperature, it can be seen that with the same shrinkable fiber, the cyclohexane-1,4-dimethanol terephthalate polyester fiber will make it possible to achieve higher bulk levels than other less heat-stable fibers which have higher shrinkage values in hot water or air.

EXAMPLE X A staple yarn was spun from a blend of 40% of shrinkable modacrylic fiber such as used in Example I, 3 d./f., 2 /2 cut, bright luster fiber and 60% of a cyclohexane- 1,4-dimethanol terephthalate polyester staple fiber of 4.5 d./f. and 2% cut of bright luster. The yarn was of a 14/ 2 ply cotton count construction.

The yarn was knit into a fabric containing 6.5 courses/ inch and 6 wales/inch. The greige fabric was then dyed and bulked by the following procedure.

(1) Bag fabrics or garments.

(2) Wet out at F.

(3) Add assistants and circulate for 10 minutes at 80 F.

(4) Add basic dyes and circulate for 10 minutes at 80 F.

(5) Raise temperature to 160 F. in 45 minutes. Run one hour at 160 F.

(6) Rinse, scour, rinse.

(7) Bulk-Add 50% common salt and boil for 20 minutes. Cool slowly to F. Rinse, soften, extract and dry.

The dyed and bulked fabric exhibited good bulk, fullness of hand and cover. It contained 12 courses/inch and 9 wales/ in ch.

EXAMPLE XI Example X was repeated using in one case heat-stable acrylonitrile polymer fiber and in one case a heat-stable polyethylene terephthalate fiber in place of the heat-stable polyester of Example X. Similar bulking results were obtained.

EXAMPLE XII A blend of 50% 3 d./f., 2 /2 bright shrinkable modacrylic fiber of Example I and 50% of the same fiber but nonshrinkable 16 d./f., 2 /2 bright fiber was spun into an 8/1 yarn and knit on a Tompkins circular knit machine into a fiat knit fabricof about 28 ounces per square yard. Using low temperature dyeing techniques, the fabric was dyed according to .the following procedure:

Dyeing procedure The fabric was dyed in ropeform at 140 F. for one hour using the formula listed below to make a beige shade:

Percent Basacryl Blue GL, C.I. Basic Blue 54 (supplement) 0.027 Basacryl Red GL, Cal. Basic Red 29 (supplement) 33 Basacryl Yellow 5 RL, C.I. Basic Yellow 25 (supplement) 0.13 Direct Brown, (LI. 95 0.10 Superlitefast Blue 8 GLN 0.0064 Acetic acid (56%) 1.0 Sodium acetate 0.5 Sodium chloride 40.0 Fatty ester sulfate 1.0 Self-emulsifying organic phosphate 1.5

After dyeing, the fabric was rinsed and after treated with a cationic softener for 20 minutes at 120 F. To remove excess water, the fabric was vacuum extracted and dried at 190 F. The fabric was then passed through the normal pile fabric finishing operation of napping, shearing and heating at 280 to 300 F. to shrink the shrinkable fiber and provide a 2-pile height effect. The pile of the fabric was then heat-polished and an imitation fur fabric resulted.

The invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove, and as defined in the appended claims.

What we claim is:

1. The process of preparing an article having highbulk characteristics comprising blending heat-stable fibers and heat-shrinkable modacrylicfibers, forming the blend of fibers into a yarn, dyeing said yarn at a temperature below 160 F., drying the yarn at a temperature below 190 F. imparting any significant; shrinkage thereto, forming the article from said yarn, and subsequently heating said article at a temperature above 200 F. to thereby shrink said heat-shrinkable fibers and bulk the formed article.

2. The process of preparing an article having highbulk characteristics comprising dyeing a first quantity of heat-shrinkable modacrylic fibers at a temperature below 160 F., drying said fibers at a temperature below 190 F. without impairing the shrink characteristics thereof, dyeing and drying a second quantity of heat-stable fibers, blending said fiber and forming the blended fibers into a yarn, forming an article from the yarn, and subsequently heating said article at a temperature above 200 F. to thereby shrink said heat-shrinkable fibers and bulk the formed article.

3. The process of preparing an article having highbulk characteristics comprising dyeing a first quantity of heat-shrinkable modacrylic fibers at a temperature below 160 F., drying said fibers at a temperature below 190 F. without impairing the shrink characteristics thereof, blending said fibers with a second quantity of heat-stable fibers and forming a yarn therefrom, forming an article from the yarn, and subsequently heating said article at a temperature above 200 F. to thereby shrink the said heat-shrinkable fibers and bulk the formed article.

4. The process of preparing an article having highbulk characteristics comprising blending heat-stable fibers and heat-shrinkable modacrylic fibers and forming a yarn therefrom, forming said yarn into an article, dyeing the article at a temperature below F., drying said article at a temperature below F., without impairing the shrinkage characteristics thereof, and subsequently heating the dyed article at a temperature above 200 F. to thereby shrink said heat-shrinkable fibers and bulk the formed article.

5. The process of claim 1 wherein the heat-shrinkable fibers imparted heat-shrinkage include an acrylonitrile polymer.

6. The process of claim ,1 wherein the heat-shrinkable fibers imparted heat-shrinkage include a mixture of (A) 70-95% by weight of a copolymer of from 30 to 65% by weight of a member of; the class consisting of vinyl chloride and vinylidene chloride and 70 to 35% by weight of acrylonitrile, and (B) 30-5% by weight of a second polymer from the group consisting of (1) homopolymers of acrylamidic monomers of the formula wherein R is selected from the group consisting of hydrogen and methyl, and Rgand R are selected from the group consisting of hydrogen and alkyl groups of 1-6 carbon atoms, (2) copolymers consisting of at least two of said acrylamidic monomers, and (3) copolymers consisting of at least 50% byweight of at least one of said acrylamidic monomers and not more than 50% by weight of a polymerizable monovinyl pyridine monomer, dyed at a temperature below that causing the fibers to shrink.

7. The process of claim 6 wherein the heat-stable fibers include a linear terephthalate polyester.

8. The process of claim 6 wherein the heat-stable fibers include a linear 1,4-cyclohexanedimethanol polyester.

9. The process of claim 6 wherein the heat-stable fibers include a linear glycol terephthalate polyester.

10. The process of claim 1 wherein the heat-shrinkable fibers imparted heat-shrinkage include an acetone soluble mixture of (A) 70-95% of a copolymer of 30-65% by weight of vinylidene chloride and 70-85% by weight of acrylonitrile, and (B) 305% of poly-N-isopropylacrylamide dyed at a temperature below that causing the fibers to shrink.

11. The process of claim 2 wherein the heat-shrinkable fibers include an acrylonitrile polymer.

12. The process of claim 2 wherein the heat-shrinkable fibers include a mixture of (A) 70-95% by weight of a copolymer of from 30 to 65% by weight of a member of the class consisting of vinyl chloride and vinylidene chloride and 70 to 35 by weight of acrylonitrile, and (B) 305% by weight of; a second polymer from the group consisting of (1) homopolymers of acrylamidic monomers of the formula O R: (3H =o-o-N B R3 wherein R is selected from the group consisting of by drogen and methyl, and R and R are selected from the group consisting of hydrogen and alkyl groups of 1-6 carbon atoms, (2) copolymers consisting of at least two of said acrylamidic monomers, and (3) copolymers con sisting of at least 50% by weight of at least one of said acrylamidic monomers and not more than 50% by weight of a polymerizable monovinyl pyridine monomer, dyed at a temperature below that causing fibers to shrink.

13. The process of claim 12 wherein the heat-stable fibers include a linear terephthalate polymer.

14. The process of claim 12 wherein the heat-stable fibers include a linear 1,4-cyclohexanedimethanol terephthalate polyester.

r t 1 1 12 15. The process of claim 12 wherein the heat-stable 2,991,538 7/1961 Hendley 28-75 fibers include a linear glycol terephthalate polyester. 3,046,724 7/ 1962 Ward 57140 16. The process of claim 2 wherein the heat-shrinkable 3,177,644 4/1965 Aspy et al. 57-140 fibers include an acetone soluble mixture of (A) 7095% 3,199,281 8/ 1965 Maerov et al 57140 of a copolyrner of 30-65% by weight of vinylidene chloride and 70-35% by weight of acrylonitrile, and (B) FOREIGN PATENTS 305% of poly-N-isopropylacrylarnide, dyed at a tem- 1,363,235 6/ 1964 Fral'lceperature below that causing the fibers to shrink. 644,304 10/ 1950 Great Brltaln.

References Cit d 10 JOHN PETRAKES, Primary Examiner. UNITED STATES PATENTS Us CL XIR 2,810,281 10/1957 Appleton et al. 66202 2,831,826 4/1958 Coover,etal. 26032.8 28"75;57 153 164

Claims (1)

1. THE PROCESS OF PREPARING AN ARTICLE HAVING HIGHBULK CHARACTERISTICS COMPRISING BLENDING HEAT-STABLE FIBERS AND HEAT-SHRINKABLE MODACRYLIC FIBERS, FORMING THE BLEND OF FIBERS INTO A YARN, DYEING SAID YARN AT A TEMPERATURE BELOW 160*F., DRYING THE YARN AT A TEMPERATURE BELOW 190*F. IMPARTING ANY SIGNIFICANT SHRINKAGE THERETO, FORMING THE ARTICLE FROM SAID YARN, AND SUBSEQUENTLY HEATING SAID ARTICLE AT A TEMPERATURE ABOVE 200*F. TO THEREBY SHRINK SAID HEAT-SHRINKABLE FIBERS AND BULK THE FORMED ARTICLE.

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