JP2009062627A - Long-short composite twisted union yarn - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new long-short composite twisted union yarn whose long fiber groups and short fiber groups are approximately simultaneously broken without the breakage of the short fiber groups inferior in strength, when the union yarn is drawn out and broken. <P>SOLUTION: This long-short composite twisted union yarn 9 in which the rate of the long fiber groups to the total amount of the union yarn is 5 to 70 mass%, is obtained by twisting a plurality of long-short composite spun yarns in which core and sheath portions have the long fiber groups and the short fiber groups arranged, respectively. The breakage of the long-short composite twisted union yarn can be detected in good sensitivity, even when a vibration type yarn breakage detector, a pin dropper, or the like is used as yarn breakage detection means in a weaving or knitting process. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to long and short composite twisted yarns.

Conventionally, a long / short composite spun yarn in which a long fiber group is arranged in a sheath part and a short fiber group is arranged in a core part is known (for example, see Patent Documents 1 to 3). These are all invented for the purpose of improving the covering property.
Japanese Patent Publication No. 40-8743 Japanese Patent Laid-Open No. 10-195721 JP 2006-161227 A

  In general, in a process for obtaining a woven or knitted fabric, a tension is applied to the yarn for the purpose of improving process passability. Therefore, the process proceeds while paying attention to thread breakage. However, it is physically impossible to eliminate thread breakage at any given care. Therefore, in the process for obtaining knitted and knitted fabrics, it is naturally important to sufficiently reduce yarn breakage, but on the other hand, it is also very important to stop the machine base immediately when yarn breakage and repair the broken yarn portion quickly. That's it. In short, if the machine base does not stop when the yarn breaks, the process proceeds with a defect, and a warp beam or a raw machine including the defect is completed.

  The yarn includes a yarn made of long fibers and a yarn made of short fibers. Here, consider the case where both are stretched until the yarn breaks. In this case, considering both structures, in the former case, cutting the yarn and cutting the long fiber itself have substantially the same meaning. That is, in the former, the sum of the tensile strengths of the respective long fibers corresponds to the tensile strength of the yarn. On the other hand, in the latter case, cutting the yarn and causing slippage between the short fibers have substantially the same meaning. In other words, in the latter case, the conjugation force between the short fibers corresponds to the tensile strength of the yarn. From this, it can be said that the yarn made of long fibers tends to have a much higher tensile strength than the yarn made of short fibers.

  In turn, consider the case of long and short composite spun yarn. The long / short composite spun yarn is a spun yarn composed of long fibers and short fibers. Therefore, when the long and short composite spun yarn is stretched, first, the short fiber group inferior in strength is cut, and then the long fiber group is cut.

  When a yarn breaks in the process of obtaining a knitted or knitted fabric, for example, as a yarn breakage detecting means, a photoelectric fluff detector or the like is used in the Aramaki warp, and a vibration type thread trimming detector or a pin dropper is used in the weaving and knitting process. The machine stop signal is activated immediately after the cut part is detected. In the case of yarn breakage in the process of producing a woven or knitted fabric using long and short composite spun yarns, as described above, the yarn is first cut from a group of short fibers having inferior strength. Therefore, thread breakage detection that detects the thread breakage by detecting the breakage of the yarn when the guide drops down along with the thread breakage and contacts the terminal installed at the bottom, such as a vibration type thread breakage detector or pin dropper in the weaving and knitting process. In the means, unless the short fiber group as well as the long fiber group is cut, the guide does not fall down, so that only the short fiber group is cut, the yarn break cannot be detected, and the machine stop signal is activated. I can't. As a result, the process proceeds with a defect, and a living machine including the defect is completed.

  In order to solve this problem, if a yarn breakage detecting means that judges that the yarn breakage occurs when a change occurs in the photoelectric tube emission light blocked by the running yarn, such as a fluff detector in Aramaki Warping, short fiber Although it is considered that the yarn breakage can be detected even in a state where only the group is cut, in the weaving and knitting process, since the machine base vibrates strongly and the yarn swings up and down, such a yarn breakage detection means cannot be adopted structurally. .

  Therefore, new thread breakage detection means are being developed, but no detection means to replace the vibration type thread trimmer detector and pin dropper has been developed yet. Changes are necessary.

  The present invention eliminates the drawbacks of the prior art as described above. When the yarn is stretched and cut, the short fiber group having poor strength is not cut first, but the long fiber group and the short fiber group are cut. It is a technical problem to provide a novel long / short composite twisted yarn in which a fiber group is cut almost simultaneously.

  As a result of diligent research to solve the above-mentioned problems, the present inventor has found that, in a long and short composite spun yarn, if a plurality of long fiber groups are arranged in the core portion instead of one bundle, the short fiber groups are stretched when the spun yarn is stretched. And the long fiber group were cut at substantially the same time, and the present invention was reached.

  That is, the present invention is a long and short composite twisted yarn in which the ratio of the long fiber group to the entire yarn is 5 to 70% by mass, and is formed by arranging the long fiber group in the core part and the short fiber group in the sheath part. The gist of the present invention is a long / short composite twisted yarn characterized by being formed by twisting a plurality of composite spun yarns.

  In the long and short composite twisted yarn of the present invention, the long fiber group and the short fiber group are cut substantially simultaneously at the time of cutting. Even when a type thread trimming detector or a pin dropper is used, thread breakage can be detected with high sensitivity. Therefore, it becomes possible to quickly repair the yarn breakage part, and as a result, the area contributing to the improvement of the quality of the woven or knitted fabric becomes large.

  Hereinafter, the present invention will be described in detail.

  The long / short composite twisted yarn of the present invention is composed of a long fiber group and a short fiber group, and the ratio of the long fiber group to the entire yarn needs to be 5 to 70% by mass, and 10 to 50% by mass. % Is preferred. When the ratio of the long fiber group is less than 5% by mass, the characteristics unique to the long fiber group are not reflected in the characteristics of the entire twisted yarn. On the other hand, when it exceeds 70% by mass, not only yarn joining mistakes frequently occur in the finishing process after spinning, but the long fiber group is exposed on the surface of the twisted yarn, resulting in deterioration of the quality of the woven or knitted fabric. .

  As a measuring method of the ratio of the long fiber group to the whole yarn, it shall be in accordance with JIS L1030-2 Textile Mixed Rate Test Method-Part 2: Fiber Mixed Rate.

  Moreover, the long and short composite twisted yarn of the present invention is formed by twisting a plurality of long and short composite spun yarns. The long / short composite spun yarn refers to a spun yarn having a long fiber group at the core and a short fiber group at the sheath. In addition, the long fiber group refers to a plurality of long fibers combined to form a single bundle, and the core portion may include a plurality of long fiber groups, which is usually in terms of cost. Therefore, the long fiber group is preferably one bundle.

  The long fibers constituting the long fiber group in the present invention are not particularly limited as single yarn fineness, shape and material. For example, the single yarn fineness is preferably 0.1 to 5.0 dtex, and the shape is flat, crimped, thick, ring-shaped, spiral-shaped, etc. as the shape in the longitudinal direction. Examples of the shape include a round shape, a rhombus shape, a triangular shape, a hexagon shape, a cross shape, a hollow shape, and a C shape. Examples of the long fiber material include polyester, polylactic acid, nylon, polyurethane, polyacrylonitrile, rayon and the like. Of course, such a long fiber group may be composed of a single long fiber, or may be composed of a plurality of different long fibers. In addition, as discrimination | determination of a fiber raw material, it shall apply according to JIS L1030-1 mixed-use rate test method of fiber products-1st part: Fiber discrimination.

  On the other hand, the short fiber group is arranged in the sheath of the yarn so as to surround the periphery of the long fiber group. The short fibers constituting the short fiber group are not particularly limited, and the single yarn fineness, shape and the like are basically the same as those of the long fibers, but the materials are those exemplified for the long fibers. In addition, cotton, wool, bamboo, etc. can be used. The fiber length of the short fibers is preferably 10 to 60 mm from the viewpoint of spinnability.

  The long and short composite twisted yarn of the present invention is formed by twisting a plurality of such long and short composite twisted yarns. As a cross-sectional shape, an island made of long fiber groups floats in the sea made of short fiber groups. It will be close to the sea-island structure.

  The long and short composite twisted yarn of the present invention exhibits excellent effects that can never be achieved by a conventional long and short composite spun yarn having a bundle of long fibers arranged in the core due to such a shape. That is, when the yarn is stretched until it is cut, in the conventional long and short composite spun yarn, the long fiber group is cut after the short fiber group is cut, whereas in the long and short composite twisted yarn of the present invention, the long fiber group and The short fiber group is cut almost simultaneously. The reason for this is not clear, but the contact surface between the long fiber group and the short fiber group is increased by arranging a plurality of long fiber groups in the yarn, and as a result, slipping between the short fibers is suppressed and the conjugation force is increased. It can be inferred to be due to this.

  In the long and short composite twisted yarn of the present invention, the long fiber group and the short fiber group are cut substantially simultaneously at the time of cutting. Even when a type thread trimming detector or a pin dropper is used, thread breakage can be detected with high sensitivity. Therefore, it becomes possible to quickly repair the yarn breakage part, and as a result, the area contributing to the improvement of the quality of the woven or knitted fabric becomes large.

  Next, a method for obtaining the long and short composite twisted yarn of the present invention will be described.

  The long and short composite twisted yarns of the present invention can be obtained basically by a method by twisting or fine spinning twisting. The method by twisting is a method for obtaining the present invention by obtaining a plurality of long and short composite spun yarns and then twisting the obtained long and short composite spun yarns. Long fiber yarns (yarns composed of the above-mentioned long fibers) and short fiber bundles (rope-like aggregates composed of the above-mentioned short fibers) are overlapped, and the overlapped fiber bundles are joined and added. This is a method of twisting to obtain the present invention. The difference between the two is that in the former (method by twisting), it is difficult to entangle the short fibers located near the boundary between the long and short composite yarns in the long and short composite twisted yarn, whereas in the latter (method by fine spinning and twisting method) ), The short fibers can be sufficiently entangled with each other. As a result, the twisted yarn obtained by the former is rubbed with guides and wrinkles in the process of obtaining a woven or knitted fabric. As a result, slipping easily occurs between long and short composite spun yarns, whereas in the latter, such slipping occurs. It is hard to do. In this respect, since slipping between the long and short composite spun yarns may reduce the tangling force between the short fibers and thus reduce the tensile strength of the twisted yarns, the latter is preferably employed in the present invention.

  Here, FIGS. 1 and 2 illustrate a method using fine spinning and twisting. These drawings are plan views around the draft area of the ring spinning machine, but are merely illustrative of spinning and are not limited thereto.

  In order to carry out the method by fine spinning and twisting, first, a short fiber bundle 1 and a long fiber yarn 5 that can be obtained by applying a known technique mutatis mutandis are prepared. Then, as shown in FIG. 1, the short fiber bundle 1 supplied to the ring spinning machine is drafted to a predetermined magnification through the back roller 2, the apron 3 and the front roller 4. On the other hand, the long fiber yarn 5 is supplied to the front roller 4 while applying tension via a press roller or the like.

  And in the front roller 4, the long fiber yarn 5 and the short fiber bundle 1 are piled up. At this time, since the long fiber yarn 5 is in a tensioned state, the long fiber yarn 5 is necessarily arranged in the core portion and the short fiber bundle 1 is arranged in the sheath portion.

  In this way, the long fiber yarn 5 and the short fiber bundle 1 are overlapped to form one fiber bundle 7.

  Thereafter, a plurality of fiber bundles 7 are joined together by a snell wire guide 8 and twisted by a spindle and a ring traveler to form a long and short composite twisted yarn 9 of the present invention.

  The long and short composite twisted yarn of the present invention comprises a long fiber group and a short fiber group. As already stated, the short fiber group is inferior in tensile strength to the long fiber group. Therefore, it is preferable to improve the tensile strength of the short fiber group in order to improve the tensile strength of the long and short composite twisted yarn. Then, since the tensile strength of the short fiber group largely depends on the conjugation force between the short fibers, it is preferable to suppress slipping between the short fibers constituting the short fiber group as much as possible.

  In order to suppress slipping between the short fibers, for example, it is sufficient that the group of short fibers in the twisted yarn can be strongly gripped. For example, at the time of spinning, it can be realized by more entanglement between the long fiber yarn and the short fiber bundle. . FIG. 2 illustrates the case where the auxiliary roller 6 is installed in the downstream area of the front roller 4. If the surface speed of the auxiliary roller 6 is made faster than that of the front roller 4, the short fiber bundle 1 is substantially relaxed. It is possible to drive in the state. Then, if the long fiber yarn 5 and the short fiber bundle 1 are overlapped with each other in the auxiliary roller 6, the long fiber yarn 5 and the short fiber bundle 1 can be entangled more strongly.

  As described above, the long and short composite twisted yarn of the present invention can be easily obtained by using existing equipment or a slightly modified one, and the cost can be sufficiently suppressed.

  Next, an example explains the present invention. The tensile strength and elongation of the yarn were measured based on JIS L1095 9.5.1 at a grip interval of 25 cm and a tensile speed of 30 cm / min. The tensile strength is a graph of the relationship between tensile strength and elongation (hereinafter referred to as “SS curve”), and the highest point in the SS curve is defined as the tensile strength of the yarn. The number of tests was 60, and the average values were taken as the tensile strength and elongation.

Example 1
As the short fiber bundle 1, two cotton coarse yarns 130gr / 30yd made of short cotton fibers having a single yarn fineness of 1.15 dtex are simultaneously supplied to the ring spinning machine shown in FIG. 1, and the back roller 2, the apron 3 and the front roller 4 are supplied. The draft was 38.8 times.

  On the other hand, a nylon long fiber yarn 44dtex24f having a tensile strength of 4.5 cN / dtex and an elongation rate of 42% is supplied to the front roller 4 shown in FIG. did.

  And in the front roller 4, after superimposing both to make one fiber bundle 7, the two fiber bundles 7 are merged by the snell wire guide 8, and then at the spindle rotation speed of 8000 rpm, the twist direction Z direction, Twisting was performed at a number of twists of 18.0 times / 2.54 cm to obtain a long and short composite twisted yarn 9 of the present invention having 23 counts (English cotton count).

  The obtained long and short composite twisted yarn was excellent in covering property, and the exposure of the long fiber group to the yarn surface could not be confirmed visually. The ratio of the long fiber group to the entire yarn was 35% by mass. The tensile strength of the twisted yarn was 451 cN, and the elongation was 8.0%. Furthermore, when the twisted yarn was stretched, it was confirmed at the time of measurement of tensile strength and elongation that the long fiber group and the short fiber group were cut almost simultaneously.

(Example 2)
As the short fiber bundle 1, two cotton rovings used in Example 1 were simultaneously supplied to the ring spinning machine shown in FIG. 2 and drafted through three rollers in the same manner as in Example 1, and the draft ratio ( The surface speed of the auxiliary roller / the surface speed of the front roller) was supplied to the auxiliary roller 6 set to 0.98.

  On the other hand, as the long fiber yarn 5, the nylon long fiber yarn used in Example 1 was supplied to the auxiliary roller 6.

  And in the auxiliary roller 6, after superimposing both into one fiber bundle 7, the two fiber bundles 7 are merged and twisted in the same manner as in Example 1, and the 23rd (English cotton count) book The long and short composite twisted yarn 9 of the invention was obtained.

  The obtained long and short composite twisted yarn was excellent in covering property, and the exposure of the long fiber group to the yarn surface could not be confirmed visually. The ratio of the long fiber group to the entire yarn was 35% by mass. And the tensile strength of the twisted yarn was 460 cN, and the elongation was 9.4%. Furthermore, when the twisted yarn was stretched, it was confirmed at the time of measurement of tensile strength and elongation that the long fiber group and the short fiber group were cut almost simultaneously.

(Comparative Example 1)
As the long fiber yarn 5, two nylon long fiber yarns used in Example 1 are used by being aligned, and when the long fiber yarn 5 is supplied to the front roller 4, it is supplied to substantially the center of the two short fiber bundles. Except that, a 23-th (English cotton count) long and short composite spun yarn was obtained in the same manner as in Example 1.

  The obtained long / short composite spun yarn was excellent in covering property, and exposure of the long fiber group to the yarn surface could not be confirmed visually. The ratio of the long fiber group to the entire yarn was 35% by mass. And while tensile strength became lower than 381 cN and the twisted yarn concerning an Example, elongation rate became higher than the twisted yarn concerning an Example with 13.1%. Furthermore, when the spun yarn was stretched, it was confirmed at the time of measuring the tensile strength and the elongation rate that the short fiber group inferior in strength was first cut and then the long fiber group was cut.

(Comparative Example 2)
As the long fiber yarn 5, two nylon long fiber yarns used in Example 1 are used by being aligned, and when the long fiber yarn 5 is supplied to the auxiliary roller 6, it is supplied to substantially the center of the two short fiber bundles. Except for the above, in the same manner as in Example 2, a 23-th (English cotton count) long and short composite spun yarn was obtained.

  The obtained long and short composite twisted yarn was excellent in covering property, and the exposure of the long fiber group to the yarn surface could not be confirmed visually. The ratio of the long fiber group to the entire yarn was 35% by mass. And while tensile strength became 430cN lower than the twisted yarn concerning an Example, elongation rate became 12.7% and became higher than the twisted yarn concerning an Example. Furthermore, when the spun yarn was stretched, it was confirmed at the time of measuring the tensile strength and the elongation rate that the short fiber group inferior in strength was first cut and then the long fiber group was cut.

(Comparative Example 3)
The two nylon long fiber yarns used in Example 1 were aligned, and a single cotton covering of 30 cotton counts in the twist direction Z direction and 300 twists / m was added to the nylon long fiber yarns. No.) long and short composite spun yarn was obtained.

  The obtained long / short composite spun yarn was slightly inferior in covering property, and exposure of the long fiber group to the yarn surface could be observed occasionally. The ratio of the long fiber group to the entire yarn was 35% by mass. And tensile strength was 413cN and elongation rate was 7.8%, and both tensile strength and elongation rate became lower than the twisted yarn concerning an Example. Furthermore, when the spun yarn was stretched, it was confirmed at the time of measuring the tensile strength and the elongation rate that the short fiber group inferior in strength was first cut and then the long fiber group was cut.

  Here, the SS curve of the long / short composite twisted yarn according to Example 2 and the long / short composite spun yarn according to Comparative Examples 2 and 3 is shown in FIG.

  As is clear from FIG. 3, the SS curve of the long and short composite twisted yarn according to Example 2 suddenly falls at the peak (herein, the peak means the peak of the elastic region, the same applies hereinafter), and thereafter In contrast, although the SS curve of the long and short composite spun yarns according to Comparative Examples 2 and 3 falls at the peak, the rise and fall are repeated. From the above, in the long and short composite twisted yarn according to Example 2, the long fiber group and the short fiber group are cut substantially simultaneously, whereas in the long and short composite spun yarn according to Comparative Examples 2 and 3, the short fiber group has the short fiber group. It can be read that the long fiber group is cut stepwise first and then the long fiber group.

  When the long and short composite spun yarns according to Comparative Examples 2 and 3 are compared with each other, the former has a lower peak tensile strength than the latter, and the S-S curve is less depressed at the boundary. The rise and fall of the SS curve is remarkable. From this, it can be read that the number of long fibers cut simultaneously with the cutting of the short fiber group is smaller in the former than in the latter. The reason is that, since the latter uses spun yarn that has already been twisted in the production process, the conjugation force of the short fiber group is superior to the former.

It is a schematic plan view which shows one embodiment for obtaining the long and short composite twisted yarn of this invention. It is a schematic plan view which shows other one embodiment for obtaining the long and short composite twisted yarn of this invention. It is a graph which shows the relationship between the tensile strength and elongation rate of the long-short composite twisted yarn of this invention, and the conventional long-short composite spun yarn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Short fiber bundle 2 Back roller 3 Apron 4 Front roller 5 Long fiber yarn 6 Auxiliary roller 7 Fiber bundle 8 Snell wire guide 9 Long and short compound twisted yarn

Claims (1)

A plurality of long and short composite spun yarns in which the ratio of the long fiber group to the whole yarn is 5 to 70% by mass, and the long fiber group is arranged in the core part and the short fiber group is arranged in the sheath part. Long and short composite twisted yarn characterized by being twisted together.