US2462842A - Process for forming yarns - Google Patents

Description

Patented Mar. 1, 1949 FFICE Robert Burgess, Jr., Wilton, Conn.

No Drawing. Application May 8, 1943, Serial No. 486,208

This invention relates to the art of making yarn V staple fibers, taking the cotton system of spinning as an example. the cotton fibers are carded, and then formed into sliver, which is a continuous strand of loosely matted fibers. Two or more slivers are then doubled and drawn one or more times and twisted slightly to form roving, which is also a continuous strand of fibers, but in which the fibers are somewhat more closely matted than in the sliver stage, due, in part, to the slight twist imparted. Two or more rovings are then doubled and drawn one or more times and are then twisted considerably to form yarn. The above steps are varied, of course, depending on the particular type of yarn being made, but in general it is true that in the case of the manufacture of yarn from staple fibers by the cotton system of spinning the succession of stages between fibers and yarn includes sliver and roving stages. By staple fibers I mean fibers of determinate, relatively short length such as cotton fibers, for example, as distinguished from fibers in the form of continuous filaments of indeterminate length such as silk or various synthetic fibers such as rayon or nylon for example. The process of my invention as hereinafter described is limited to use with staple fibers as above defined which are susceptible of being doubled and drawn in the rovin stage. However, in addition to natural staple fibers, I include synthetic or natural fibers originally in continuous filament form which have been cut to staple length and which are customarily formed into yarn by using the cotton system of spinning, as for example the staple rayon fibers now used in the manufacture of so-called spun rayon yarn, for such fibers may be and customarily are doubled and drawn in making yarn therefrom.

In the sliver stage the strand formed from such staple fibers is exceedingly fragile and tenuous. It cannot be wound on a bobbin and cannot be safely handled without danger of damagin or breaking the strand. In the roving stage, however, the strand is considerably stronger and after reaching this stage may be, and customarily is, wound on a bobbin. In the sliver stage the doubling and drawing operations are usually performed on drawing frames, and the transition from sliver to roving is usually made in machines known as slubbers, which in addition to doubling and drawing the strand, impart a slight twist as the roving is wound on the bobbin. Subsequent doubling and drawing operations are usually performed in fiy frames and roving frames, sometimes 5 Claims. (Cl. 57-156) called intermediates and finally the roving is transferred to a spinning frame where the final yarn making steps are performed. Such steps customarily include doubling, drawing and twisting.

In the manufacture of colored fabrics it is customary either to dye the fibers before carding (stock dyeing), or to dye the yarn before weaving (yarn dyeing), or to dye the fabric after weaving (piece dyeing), roving, in practice roving which is to be subsequently.used for making yarn is seldom dyed as there has heretofore been no particular advantage in so doing except for special purposes.

Stock dyeing is considerably more expensive than yarn dyeing or piece dyeing, and has no advantage over yarn dyeing, for example, if the yarn is to be formed from fibers of a single color. Stock dyeing has been confined for the most part, therefore, to the making of woolen-yarn, where it has long been known that very beautiful color effects may be obtained in the yarn, and thereafter in fabric woven therefrom, by mixing or blending different colored fibers, and thereafter forming yarn'therefrom by the usual processes. The successful blending of such different colored fibers requires great skill, however, and the practice has seldom been used in the making of yarn from fibers other than woolen fibers.

Thus, in the manufacture of cotton fabrics, dyeing has been confined for the most part to the dyeing of yarn before weaving or dyeing of the fabric after weaving, and with the exception of woolen fabrics this is generally true of colored fabrics. One variation may be mentioned, however. It is known that viscose rayons and acetate rayons react differently to some dyes. For example, viscose rayons will not accept certain. dyes which are accepted by acetate rayons and vice versa. In the manufacture of spun rayon yarns, therefore, made from staple fibers, it has been well known practice to mix staple viscose rayon fibers with staple acetate rayon fibers and to form yarn from such mixtures by usual methods. Then the yarn has been subjected to a dye which is accepted by the viscose fibers, for example, but not by the acetate fibers, resultin in a yarn containing a blend of dyed viscose fibers and undyed acetate fibers. Such yarn is sometimes used for weaving in that state. Other times the yarn is subjected to a second dye of a different color which is accepted by the acetate fibers, but not by the viscose fibers, thus resulting in a yarn containinga blend of fibers of different colors, the viscose fibers being of one color and the acetate and while it is possible to dye fibers being of a different color. Similar results may be obtained by piece dyeing a fabric woven from yarns containing mixtures of viscose and acetate rayon fibers. Such processes, however, are usually limited to two colors.

It is an object of the present invention to provide a process for making yarns containing fibers of a plurality of different colors, which said process may be carried out by existing machines and with only'slight variation of existing practices now used in the cotton system of spinning, whereby the beautiful effects of blending different colored fibers in making woolen yarn, and which are achieved only at costs which are prohibitive in yarns made from cheaper materials, can be obtained at costs comparable to those of ordinary dyed yarn, thus opening up entirely new possibilities of novel and beautiful color effects in cotton fabrics, for example.

Other objects and advantages of the invention will appear hereinafter.

According to the present invention, I proceed according to present practices prevailing in the cotton system of spinning up to the stage where roving is formed, that is, sliver is formed from carded fibers, and then by the usual methods of doubling and drawing, together with slight twisting, roving is formed, and wound on bobbins. At this point, however, before proceeding with the subsequent operations customarily performed to form yarn, such roving is then dyed by any suitable method, preferably by package dyeing as commonly practiced.

In the simplest form of the invention two rovings of different colors are then selected,. which said rovings are then doubled and drawn together. In the process of doubling and drawing, the fibers of one roving become intermingled with the differently colored fibers of the other roving, so that a dispersion and mixture of the difierently colored fibers occurs throughout the strand.

In another form of the invention three, four or more rovings each of a different color may be selected, which said rovings are doubled and drawn together as before with resulting intermingling of the fibers of different colors. Alternatively, two rovings of one color and one or more rovings of different color may be selected and doubled and drawn together as before with resulting intermingling of the fibers of different colors.

After having thus effected the initialintermingling of the fibers of different color, the resulting roving may be doubled and drawn together with a similar roving having similarly intermingled fibers of different color. For example, a roving of color a may be doubled and drawn with a roving of color 1), resulting in a roving having intermingled fibers of color a+b,' while simultaneously a second roving of color a may be doubled and drawn with a second roving of color b, resulting in a second roving having intermingled fibers of color a+b. The two rovings each of color a+b may then be doubled and drawn together. In this case the second doubling and drawing operation results in a still more thorough intermingling of the fibers of different color, and it will be understood that repeated doubling and drawing of similar rovings will increase the thoroughness of the intermingling of the fibers of different color. a

Similarly rovings of colors 41, b, c, d may be doubledand drawn together, resulting in a roving having intermingled fibers of color a+b+c+d. Such roving may then be doubled and'drawn with a second roving having intermingled fibers of color a+b+c+d, or three or four rovings of color a+b+c+d may be doubled and drawn together. In either. case the thoroughness of intermingling 'of the fibers of different color is increased. In the event that limitations of available machinery make is inconvenient to double and draw together more than two rovings, a

roving of color a may be doubled and drawn' cal cotton mill practice, roving is customarily.

subjected to several doubling and drawing operations before being placed in a spinning frame for the final yarn making operation. As willbe understood from the foregoing description, one of these operations as customarily practiced may be utilized to effect the initial intermingling of the fibers of different color, and the subsequent doubling and drawing operations as usually performed may be utilized to increase the thoroughness of the intermingling, or an extra doubling and drawing operation may be utilized to effect the initial intermingling of the fibers of different color, and the subsequent doubling and drawing operations as usually performed may be used to increase the thoroughness of the intermingling.

As a specific example of the latter, and illustrating the manner in which an extra operation may be adapted to typical cotton mill practice, the following may be considered. As previously stated, I proceed to form roving in the usual manner, using the usual drawing frames and slubbers for this purpose. Such roving might be prefer: ably taken off the slubbers as approximately 1.6 hank roving, as such roving is sufiiciently strong to withstand the dyeing operation, and yet has so little twist that subsequent intermingling will be facilitated. Such roving is then dyed in whatever colors are desired.

Assuming then that it is desired to form a yarn containing fibers of colors a, b, c and d,

roving of each of these colors is selected, and the four ends are doubled and drawn together as an extraoperation. Preferably this operation is so conducted that the single roving produced is of approximately the same size as each of the rovings introduced, 1. e. 1.6 hank roving, and having approximately the same twist. That is, in the example given in which four ends are introduced, the doubled roving would be given a draft of four.

Any suitable machine may be used for this purpose, but for convenience, I suggest the use of a specially adapted slubber or fly frame. In package dyeing,.the-material to be dyed is customarily wound on so-called "springs which are shaped somewhat like short bobbins, but comprise a tubular knitted fabric stretched taut by a spring, which said fabric serves as the cylindrical base on which the material is wound. By

adapting a slubberor fly frame to receive such duces substantial fibers of color a+b+c+d is wound on bobbins, of course, and from this point on, the mill procedure is as usual. In each subsequent doubling and drawing operation the rovings which are doubled and drawn together are of similar color characteristics.

The advantage of the above procedure lies in the fact that the doubling and drawing operation which produces the initial intermingling of the fibers of different color results in a roving of substantially the same size and twist as the original undyed roving, so that for any given yarnthe ordinary mill procedures do not need to be altered in any way. In cases where the roving is sent to a dye plant for dyeing, it would thus be possible for the dye plant to perform the extra doubling and drawing operation before returning the roving to the mill, so that if the mill sent out 1.6 hank undyed roving, it would receive back 1.6 hank roving containing intermingled fibers of different colors.- Such roving would then be handled in the ordinary way until formation of the yarn was completed.

Many other specific variations might be described, but it will be apparent from the foregoing that the common features of various exemplifications of the invention are (1) dyeing the strand while in the roving stage before the strand has been twisted sufflciently to prevent subsequent intermingling of the fibers of one roving with those of another roving, (2) utilizing subsequent doubling and drawing of rovings of different color to cause intermingling of the fibers of one color with the fibers of another color, and (3) after thus efiecting the initial intermingling of fibers of different color, utilizing subsequent doubling and drawing of rovings of similar color characteristics to increase the thoroughness of the intermingling, all such operations being performed prior to transfer to the spinning frame to form a yarn.

I am aware that in the past a yarn of one color has been twisted with a yarn of a difierent color to form a plied yarn, but the effect of this procedure is wholly different from that obtained in the practice of my invention. Where two yarns are twisted together there is no intermingling of the fibers of diiferent color. The effect obtained may be roughly described as a striped or "barber pole effect, for the yarn of one color simply alternates with the yarn of the other color, the twist in the individual yarns preventing any intermingling of the fibers. Fabrics woven from such yarns present a somewhat speckled appearance.

I am also aware that in the past two rovings of different color have been supplied to a spinning frame and twisted together to form a yarn. Here again the effect is wholly different from that obtained in the practice of my invention. By the time the roving has been attenuated sulficiently to be used on a spinning frame the strand is fine and twisted to an extent suchas to prevent intermingling of the fibers as they pass through the drawing rollers of the spinning frame. The efiect, therefore, is similar to that obtained by twisting two yarns of different color, namely, a striped or barber pole effect as above described. In fact, this practice has been employed to imitate, at lower cost, the effect of twisting two yarns of different color.

As contrasted with such striped effects, the intermingling oi the fibers of different color, according to the practice of my invention, =prouniformity of dispersion throughout the yarn and a softness and richness of color effect which greatly enhances the beauty of fabrics woven from such yarns. Such fabrics provide a depth of color and a visual color interest wholly lacking in fabrics made from ordinary dyed yarn or in piece dyed fabrics.

In the foregoing description where I have referred to the use of rovings of difierent colors I include the use of rovings of difierent shades or tints of the same color. For example, a yarn may be formed of roving of different shades or tints of brown, different shades or tints of blue within the scope of my invention. Furthermore, I include the use of one or more rovings of natural (undyed) color with one or more dyed rovings. For purposes of this specification, therefore, I intend the phrase different color to include such variations.

It will be understood that the invention may be variously modified and embodied within the scope of the subjoined claims.

I claim as my invention:

1. In the cotton system for forming yarn from staple fibers of cotton or rayon, the process for forming yarn containing intermingled fibers of a plurality of different colors which comprises forming a plurality of rovings from staple fibers, dyeing at least one of said rovings a color different from that of at least one other of said rovings, doubling and drawing said rovings of different color to form a roving in which the fibers of the rovings of different color are intermingled, thereafter repeatedly doubling and drawing said roving with another similarly doubled and drawn roving of similar color characteristics to increase the thoroughness of the intermingling, and spinning the resulting roving to form a yarn.

2. In the cotton system for forming yarn from staple fibers of cotton or rayon, the process for forming yarn containing intermingled fibers of a plurality of different colors which comprises forming a plurality of rovings from staple fibers, dyeing said rovings a plurality of different colors, doubling and drawing a roving of one color with at least one other roving of difierent color to form a roving in which the fibers of different color are intermingled, thereafter repeatedly doubling and drawing said roving with another similarly doubled and drawn roving of similar color characteristics to increase the thoroughness of the intermingling, and spinning the resulting roving to form a yarn.

3. In the cotton system for forming yarn from staple fibers of cotton or rayon in which the fibers are processed successively in drawing frames, slubbers, intermediates and spinning frames, the process for forming yarn containing intermingled fibers of a plurality of different colors which comprises carrying undyed fibers through such drawing frames and slubbers and forming rovings from such fibers in such slubbers, dyeing such rovings a plurality of different colors, doubling and drawing a roving of one color with at least one roving of different color at a stage prior to said intermediates to form a roving in which the fibers of different color are intermingled, thereafter carrying said roving through said-intermediates and repeatedly doubling and drawing said roving in said intermediates with another similarly doubled and drawn roving of similar color characteristics to increase the thoroughness of the intermingling, and spinning the re sulting roving to form a yarn.

4. In the cotton system for forming yarn from staple fibers of cotton or rayon in which the fibers are processed successively in drawing frames, slubbers, intermediates and spinning frames, the process for forming yarn containing intermingled fibers of a plurality of different colors .which comprises carrying undyed fibers through such drawing frames and slubbers and forming rovings from such fibers in such slubbers, dyeing such rovings a plurality of different colors, doubling a plurality of rovings of diflerent color and drawing said rovings to form a roving of a hank size not less than that of the rovings introduced and in which the fibers of different color are intermingled, thereafter repeatedly doubling and drawing said roving with another similarly doubled and drawn roving of similar hank size and similar color characteristics to increase the thoroughness of the intermingling while reducing the hank size on each draft, and spinning the resulting roving to form a yarn.

5. In the cotton system for forming yarn from staple fibers of cotton or rayon in which the fibers are processed successively in machines which draw the fibers without twisting and deliver a strand in sliver form, then in a machine which draws the sliver strands, imparts twist thereto and delivers a strand in roving form, then in machines which draw the roving strands, impart additional twist thereto and again deliver a strand in roving form, then in a machine which draws the roving strands, imparts additional twist thereto and delivers a strand-in yarn form, the process of forming yarn containing intermingled fibers of a plurality of different colors which comprises carrying undyed fibers through such machines to the stage where rovings are delivered,

dyeing such rovings, then doubling and drawing a strand of roving of one color with at least one strand of roving of different color in a machine which draws the strands, imparts twist thereto and delivers a strand of roving in which the fibers of diflerent color are intermingled,

thereafter repeatedly doubling. and drawing said strand of roving with another similarly doubled REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,058,620 Petitimermet Oct. 2'1, 1936'" FOREIGN PATENTS Number Country Date 25,611 Great Britain 1903 OTHER REFERENCES Technical Terms in the Textile Trade, by Midgley; published by Emmott & Co. Ltd., Manchester, England? pages 152-153.

Textile Design and Color, by Watson; published by Longmans, Green 8: 00., London, England; Pa es 144145.