JP4916787B2 - Method for producing double layer yarn - Google Patents

Description

The present invention relates to a method of manufacturing a multi-layer yarn.

  Conventionally, untwisted spun yarn has been used for producing a woven or knitted fabric having a soft texture. Usually, the spun yarn is in a twisted state in order to maintain the strength, but in the woven or knitted fabric, adjacent yarns are interlaced, so that even if the spun yarn itself is untwisted and the strength is extremely low, Woven knitted fabric can retain strength.

Various production methods have been proposed as a method for producing a woven or knitted fabric made of such untwisted spun yarn. These are common in that a twisted yarn composed of a hardly soluble fiber and a readily soluble fiber is first prepared, and after weaving and knitting, the easily soluble fiber is dissolved and removed to obtain a woven or knitted fabric, and the kind of the easily soluble fiber is different. For example, in Patent Document 1, after spinning a cotton spun yarn and a polylactic acid filament yarn in a direction opposite to the twisted direction of the cotton spun yarn, weaving so that the obtained twisted yarn becomes a pile yarn, A method for producing a toweling fabric by dissolving and removing the polylactic acid filament yarn by alkali treatment is described. Further, in Patent Document 2, a cotton / water-soluble vinylon mixed roving yarn and a cotton spun yarn are finely spun and twisted in a direction opposite to the twisted direction of the cotton spun yarn, and then the obtained twisted yarn becomes a pile yarn. A method for producing a toweling fabric is described in which the water-soluble vinylon fibers are dissolved and removed.
Japanese Patent Laying-Open No. 2005-213661 (Example 1) JP 2003-306840 A (Example 1)

  The twisted yarn described in the above patent document (synonymous with the twisted yarn) is obtained by twisting in the direction opposite to the twisted direction of the cotton spun yarn. Therefore, the obtained twisted yarn is an untwisted spun yarn. It can be said that it is comprised from the twisted yarn which consists of an easily soluble fiber.

  Since the twisted yarn has a structure in which two yarns are entangled in a double spiral shape, when the twisted yarns are arranged, the distance between the untwisted spun yarns in each twisted yarn changes periodically in the longitudinal direction. Therefore, in the woven or knitted fabric obtained by dissolving and removing the twisted yarn from the woven or knitted fabric using the above-mentioned twisted yarn, the arrangement of the untwisted spun yarns constituting the woven or knitted fabric is not orderly. There is a problem that arises.

  Further, since the untwisted spun yarn has a remarkably low tensile strength, the tensile strength of the twisted yarn is substantially equal to the tensile strength of the single twisted yarn. Therefore, in order to increase the tensile strength of the twisted yarn, it is necessary to increase the content ratio of the twisted yarn. However, when obtaining a woven or knitted fabric having a high density, since the yarn tension at the time of weaving and knitting is set higher, the twisted yarn There is a problem that it is necessary to extremely increase the ratio of the twisted yarn in the inside, and further disadvantages such as flickering and cracking occur.

  From the above, the conventional woven and knitted fabrics using untwisted spun yarns used gauze-like woven or knitted fabrics having a high density as the uses, and the untwisted spun yarns as pile yarns as described in the above-mentioned patent documents. The situation is limited to such towels.

  The present invention solves such problems, a multi-layer yarn having a tensile strength capable of withstanding weaving and knitting while the mass ratio of the sheath portion is suppressed, and a method for producing the multi-layer yarn at a low cost, Another object of the present invention is to provide a woven or knitted fabric having a soft texture and a good surface feeling by dissolving and removing easily soluble short fibers from the woven or knitted fabric including the multilayer yarn.

  As a result of intensive studies to solve the above problems, the present inventor obtained a twisted state in which the spun yarn and the fiber bundle that can form the core portion and the sheath portion, respectively, are twisted in an entangled state in the spinning process. However, the present inventors have found that a multi-layer yarn having a two-layer structure can be obtained, and have reached the present invention.

That is, the gist of the present invention is as follows.
(1) A core-sheath type two-layer structure in which a hardly soluble short fiber is arranged in the core part and an easily soluble short fiber is arranged in the sheath part, the core part is made of untwisted spun yarn, and the sheath part is wrapped around it. A method for producing a multi-layered yarn by simultaneously supplying a spun yarn composed of hardly soluble short fibers and a short fiber bundle composed of easily soluble short fibers to a front roller of a ring spinning machine The draft ratio (D) between the second roller and the front roller is set to 0.960 <D <1.000 and the short fiber bundle is supplied to the front roller while the spun yarn is fed to the same front A method for producing a multi-layer yarn, characterized in that the yarn is supplied to a roller and superposed on a front roller, and then twisted in the opposite direction to the spun yarn.

  The multi-layer yarn of the present invention has excellent tensile strength without increasing the mass ratio of the sheath, and also has excellent weaving and knitting properties. Moreover, according to the manufacturing method of the multilayer yarn of this invention, manufacturing cost can be held down. The woven or knitted fabric of the present invention has a soft texture and a well-equipped surface feeling, and can be used for various purposes.

  Hereinafter, the present invention will be described in detail.

  The multi-layer yarn of the present invention has a core-sheath type two-layer structure in which a hardly soluble short fiber is arranged in a core part and an easily soluble short fiber is arranged in a sheath part. Here, “slightly soluble” means that it is difficult to decompose or dissolve in water, an alkaline solution, or various solvents, and “easy-soluble” means the opposite. “Short fiber” refers to a short fiber (staple) that is not a continuous fiber, and “untwisted spun yarn” refers to a spun yarn that is untwisted and untwisted or has a form like a fiber bundle. Point to.

  Examples of the hardly soluble short fiber in the present invention include natural fibers such as cotton, wool, hemp and bamboo, synthetic fibers such as aromatic polyester, polyamide, polyolefin and polyacrylonitrile, viscose rayon and solvent-spun cellulose fibers. Examples thereof include semisynthetic fibers such as fibers, diacetates, and triacetates. In the present invention, these are used alone or in combination, and among these, cotton, solvent-spun cellulose fibers, wool, and bamboo are preferably used. The single yarn fineness and fiber length of the short fiber are not particularly limited, but in the case of cotton and solvent-spun cellulose fiber, the single yarn fineness is preferably 0.6 to 4.2 dtex, and the fiber length is preferably 10 to 50 mm. In this case, the average diameter is preferably 15 to 30 μm and the fiber length is preferably 64 to 102 mm.

  On the other hand, the easily soluble short fibers are not particularly limited as long as they can be dissolved and removed in post-processing, and examples thereof include short fibers made of alkali-soluble polyester, polylactic acid, water-soluble polyvinyl alcohol, water-soluble vinylon, and the like. . Among them, short fibers made of water-soluble vinylon that can be easily removed by washing in hot water and are inexpensive are preferable.

  In the multi-layer yarn of the present invention, the sheath portion is wound around the untwisted spun yarn as the core portion.

  The untwisted spun yarn has a form like a fiber bundle and thus has a low tensile strength, and cannot be subjected to weaving or knitting alone. Therefore, a sheath is provided to form a multi-layer yarn including untwisted spun yarn, and this multi-layer yarn is provided with a tensile strength that can withstand weaving and knitting. Based on the conventional technical idea, untwisted spun yarn does not contribute to the tensile strength of the multi-layered yarn, and the tensile strength of the multi-layered yarn should be almost equal to the tensile strength of the sheath alone, but surprisingly In the multi-layer yarn of the present invention, the untwisted spun yarn partially contributes to the tensile strength of the multi-layer yarn. That is, in the present invention, the easily soluble short fibers are wound around the non-twisted spun yarn as if they are uniformly stacked one by one. Therefore, at the interface between the core portion and the sheath portion and in the vicinity thereof, the core The short fibers constituting the part (slightly soluble short fibers) and the short fibers constituting the sheath part (easily soluble short fibers) are strongly entangled, and the outer layer part of the untwisted spun yarn can contribute to the tensile strength of the multi-layer yarn. It is.

  Therefore, the multi-layer yarn of the present invention can have excellent tensile strength without increasing the content ratio of the easily soluble short fibers unlike the conventional twisted yarn described above. Specifically, the core-sheath mass ratio in the multi-layer yarn is preferably core / sheath = 50/50 to 90/10.

Further, the multi-layer yarn of the present invention is excellent in covering properties, and is very similar to a spun yarn consisting only of short fibers (easily soluble short fibers) arranged in the sheath portion in appearance. As a result, two large effects can be obtained. First, the shape of the untwisted spun yarn at the core portion is straightened, and can be arranged in an orderly manner in the woven or knitted fabric. Secondly, weaving and knitting can be improved. This is because the yarn surface tends to fluff more easily when it is beaten, so if the untwisted spun yarn at the core is exposed on the yarn surface, the portion is fluffed intensively, leading to poor weaving and knitting. Because it does.

  Next, the manufacturing method of the multilayer yarn of this invention is demonstrated.

  In the method for producing a multi-layer yarn of the present invention (hereinafter referred to as “the production method of the present invention”), first, a spun yarn and a coarse yarn obtained by a known method are prepared. Among these, the spun yarn is made of a hardly soluble short fiber to form a core portion of a multi-layer yarn. As a matter of course, this spun yarn is twisted, and the twist coefficient α calculated by the following formula (1) is preferably 2.5 to 5.4.

  On the other hand, the roving is made of easily soluble short fibers for forming a sheath.

  After preparing the two yarns, the roving yarn is introduced into the spinning machine, the draft ratio between the second roller and the front roller is set to a specific range, and the obtained fiber bundle is supplied to the front roller while Are fed to the same front roller, overlapped with each other, and twisted in the opposite direction to the spun yarn to obtain the multilayer yarn of the present invention.

  Furthermore, the manufacturing method of the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a schematic explanatory view showing one embodiment of the production method of the present invention.

  The roving 1 supplied to the ring spinning machine shown in FIG. 1 is drafted through back rollers 2, 2 ′, aprons 3, 3 ′ and second rollers 4, 4 ′ to form a short fiber bundle 8. In order to supply the short fiber bundle 8 to the front rollers 5 and 5 'in a relaxed state, the draft ratio (D) between the second roller and the front roller is set to 0.960 <D <1.000. As a result, the short fiber bundle is opened at the same time as the yarn path of the short fiber bundle is swung from side to side. Then, the short fibers are wound around the spun yarn as if they are stacked one by one uniformly.

  Here, the draft ratio (D) between the second roller and the front roller indicates a so-called mechanical draft, and is calculated by the following equation (2).

  If the draft ratio is 0.960 or less, the yarn path of the short fiber bundle is greatly swung left and right, and not only the coverage of the multi-layer yarn is lowered, but in some cases, the spun yarn and the short fiber bundle may be combined. It becomes impossible to superimpose. On the other hand, if it is 1.000 or more, the short fiber bundle is stretched without being loosened, so that the entanglement between the spun yarn and the short fiber bundle is not promoted. The upper limit of the draft ratio is preferably 0.990 considering the degree of entanglement between the spun yarn and the short fiber bundle.

  On the other hand, the spun yarn 6 is supplied to the front rollers 5, 5 'via the press rollers 7, 7'. The supply tension of the spun yarn 6 is not particularly limited as long as the yarn path can be formed. However, if the tension is set too low, the core portion and the sheath portion may be reversed or may be twisted. On the other hand, if it is too high, thread breakage may occur.

  Thereafter, the front rollers 5 and 5 'are overlapped with each other so that the spun yarn 6 is arranged on the inner side and the short fiber bundle 8 is arranged on the outer side. When the spun yarn 6 and the short fiber bundle 8 are overlapped, no special means is required, and the short fiber bundle 8 is in a relaxed state, whereas the spun yarn 6 is in a stretched state, so that the core is inevitably cored. The spun yarn 6 is arranged in the part, and the short fiber bundle 8 is arranged in the sheath part.

  After the spun yarn 6 and the short fiber bundle 8 are superposed, the snell wire guide 9 is passed through and twisted by the spindle 11 and the ring traveler 10 to obtain the multilayer yarn 12 of the present invention. Since this twisting is performed to untwist the spun yarn, it must be performed in the direction opposite to the twisted direction of the spun yarn 6. If it goes to the same direction, the spun yarn 6 will be twisted, and even if it dissolves and removes easily soluble short fiber by post-processing, a non-twisted spun yarn cannot be obtained. And as twist number at the time of twist, what is necessary is just the twist number that spun yarn 6 turns into untwisted spun yarn by the above-mentioned twist, and specifically, the untwisting rate calculated by the following formula (3) A twist number such that K is 60% or more is adopted.

  Here, “twisted twist number” means the twisted number of twists performed after the spun yarn 6 and the short fiber bundle 8 are overlapped, and “spun yarn twist number” means the twisted number of the spun yarn 6. Point to each.

  In addition to being able to use an existing ring spinning machine as described above, the manufacturing method of the present invention only requires twisting in a specific direction by employing a simple yarn path and a specific draft ratio. Can be suppressed.

  The multi-layer yarn of the present invention thus obtained is subjected to weaving and knitting to obtain a woven or knitted fabric. In the weaving and knitting, a yarn other than the multi-layer yarn of the present invention may be used in combination. However, from the viewpoint of obtaining a woven or knitted fabric having a soft texture, the multi-layer yarn is 60% by mass or more, more preferably 80% by mass. It is preferable that the knitting and knitting is performed so as to be contained by at least%. As a method of weaving and knitting, a known method of weaving and knitting through warping and sizing may be employed.

  And the woven or knitted fabric of the present invention can be obtained by dissolving and removing easily soluble short fibers from the obtained woven or knitted fabric. The process of dissolving and removing the easily soluble short fibers differs depending on the easily soluble short fibers to be used, but in the case of alkali-soluble polyester or polylactic acid, an alkaline aqueous solution is used, and in the case of water-soluble polyvinyl alcohol or water-soluble vinylon, water or hot water is used. Can be used. In addition, what is necessary is just to set suitably as processing temperature and time in consideration of content of an easily soluble short fiber.

  The woven or knitted fabric of the present invention can be obtained as described above, and the non-twisted spun yarn arranged in the core portion of the multilayer yarn constitutes the woven or knitted fabric. Therefore, the woven or knitted fabric of the present invention has a soft texture and a smooth surface feeling, and can be used for various purposes.

  Next, the present invention will be described specifically by way of examples.

Example 1
As the roving yarn 1, a roving yarn 50 gr / 30 yd composed of water-soluble vinylon short fibers having a single yarn fineness of 1.75 dtex is supplied to the ring spinning machine shown in FIG. 1, and the roving yarn 1 is back rollers 2, 2 ′, an apron 3, After being drafted 50.8 times through 3 'and second rollers 4 and 4' to form short fiber bundle 8, the short fiber bundle 8 was supplied to front rollers 5 and 5 'in a relaxed state. The surface speed of the second rollers 4 and 4 ′ is 9.95 m / min, and the surface speed of the front rollers 5 and 5 ′ is 0 in the draft ratio between the second rollers 4 and 4 ′ and the front rollers 5 and 5 ′. It was set to 9.83 m / min to be .988.

  On the other hand, as the spun yarn 6, a cotton spun yarn having a single yarn fineness of 1.15 dtex and having a twist direction of Z direction and a twist coefficient of 3.4 is passed through the press rollers 7 and 7 ′ as front rollers. 5 and 5 '. Then, after the spun yarn 6 and the short fiber bundle 8 are overlapped with each other at the front roller, the yarn is twisted at a spindle rotation speed of 10,000 rpm with a twisting direction S direction and a twisting factor 3.34 (untwisting rate = 85%). 60 (English cotton count) of the present invention was obtained. In addition, the core-sheath mass ratio of the obtained multilayer yarn was core / sheath = 75/25, and the tensile strength measured according to JIS L-1095 was 180.5 cN.

Next, a 2/2 twill fabric is woven using this multi-layered yarn as the background, and the fabric obtained with a liquid dyeing machine is treated with hot water at 90 ° C. for 30 minutes, and then the reactive dye is also used with the liquid dyeing machine. Was used for dyeing at 60 ° C. for 30 minutes, and final setting was performed at 170 ° C. for 1 minute using a pin tenter to obtain a woven or knitted fabric of the present invention. As the specifications of the obtained woven fabric, the warp density was 190 / 2.54 cm, the weft density was 120 / 2.54 cm, and the basis weight was 156 g / m ² . In this woven fabric, the arrangement of the untwisted spun yarn was orderly, and as a result of inspection (50 m), there were no defects such as chica and ground cracking, and the fabric had a soft texture.

( Comparative Example 1)
The same as in Example 1 except that the draft ratio between the second roller and the front roller is set to 0.960 by setting the surface speed of the front roller to 9.55 m / min instead of 9.83 m / min. Thus, a multi-layer yarn was obtained. In addition, the tensile strength of this multi-layer yarn was 168.5 cN. In addition, the core portion of this multi-layered yarn is exposed on the yarn surface everywhere in the longitudinal direction, and the yarn path of the short fiber bundle is likely to come off from the nip point of the front roller even during the production. There were many times.

  Next, a woven fabric was obtained in the same manner as in Example 1 using this multi-layer yarn. In this woven fabric, the stoppage due to the generation of fluff frequently occurred during weaving. As a result of the inspection (50 m), the arrangement of the untwisted spun yarn was somewhat cluttered, so some defects such as ticks and ground cracks were observed, and a stop due to the stop was also observed.

( Comparative Example 2)
The same as in Example 1 except that the draft speed between the second roller and the front roller is set to 1.000 by setting the surface speed of the front roller to 9.95 m / min instead of 9.83 m / min. Thus, a multi-layer yarn was obtained. In this multi-layered yarn, the tensile strength decreased to 102.7 cN because the entanglement between the cotton fibers and the water-soluble vinylon short fibers was insufficient at and near the interface between the core and the sheath.

  Next, a woven fabric was obtained in the same manner as in Example 1 using this multi-layer yarn. In this woven fabric, the arrangement of untwisted spun yarn was orderly, and as a result of inspection (50 m), there were no defects such as chica and ground cracking, but there were a number of stops due to warp breakage and stopping at that time. Admitted.

It is a schematic explanatory drawing which shows one embodiment of the manufacturing method of the multilayer yarn of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coarse yarn 2, 2 'Back roller 3, 3' Apron 4, 4 'Second roller 5, 5' Front roller 6 Spinning yarn 7, 7 'Press roller 8 Short fiber bundle 9 Snell wire guide 10 Ring traveler 11 Spindle 12 Duplex Layered yarn

Claims (1)

A core-sheath type two-layer structure in which a slightly soluble short fiber is arranged in the core part and an easily soluble short fiber is arranged in the sheath part, the core part is made of untwisted spun yarn, and the sheath part is wound around it. In the method for producing a multi-layer yarn, a method for producing a multi-layer yarn by simultaneously supplying a spun yarn composed of hardly soluble short fibers and a short fiber bundle composed of easily soluble short fibers to a front roller of a ring spinning machine. The draft ratio (D) between the second roller and the front roller is set to 0.960 <D <1.000, and the staple yarn is supplied to the same front roller while supplying the short fiber bundle to the front roller. A method for producing a multi-layer yarn, wherein the two are superposed on a front roller and then twisted in the opposite direction to the spun yarn.