JP2006161179A - Spun yarn of core-sheath two-layer structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide spun yarn of core-sheath two-layer structure, having enough strength and capable of preventing such a defect that fibers in a core part and a sheath part are slipped on each other and the fibers in the sheath part is exfoliated, even when the yarn is affected by friction, flexure, or elongation. <P>SOLUTION: This spun yarn of core-sheath two-layer structure is produced by forming spun yarn and then subjecting the spun yarn to twisting, wherein the spun yarn is formed so that a drawn and cut yarn thread which is formed by drawing and cutting a continuous long fiber bundle having no crimps, and then entangling the drawn and cut fibers with each other and/or twisting end parts of the fibers around each other, so as to together bundle the drawn and cut fibers, and has an average length of the drawn and cut fibers of 20-80cm is arranged in the core part, staple fiber is arranged in the sheath part, and the drawn and cut fibers composing the drawn and cut yarn thread and the staple fiber are entangled or crossed with each other in at least a part thereof. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a core-sheath type two-layer structure spun yarn. More specifically, the present invention relates to a core-sheath two-layer structure spun yarn that has high strength and does not peel off the fibers of the sheath portion even when it is rubbed, bent, stretched, or the like.

  Conventionally, cotton, wool, hemp, silk, and other natural fibers can be used for the spun yarn, so their own texture, appearance, feel, etc., hygroscopicity, heat resistance, dyeability, blendability, It has been used in various fields by utilizing other functions. Also, yarns such as fuzz, bulkiness, twist, and blend that are not found in filament yarns of chemical fibers such as rayon, acetate, polyester, acrylic, nylon, polypropylene, aramid, glass, metal, synthetic fibers, inorganic fibers, etc. By adding structure, its use has been expanded.

  However, from the viewpoint of strength, the spun yarn is composed of a collection of short fibers with respect to the filament yarn, the short fibers have a crimped shape, the fiber arrangement of the yarn is low, and the yarn is twisted. Since it has a form, the strength of the yarn is easily reduced compared to the strength of the single fiber constituting the yarn, and it has been difficult to develop into a field where strength is required.

  In addition, this decrease in strength tends to appear more prominently as the elongation of the fiber is lower, and even when high-strength fibers are developed, there are many that generally have low elongation, so the high strength is used for the spun yarn. It was difficult.

  Therefore, various methods for improving this have been studied so far, and as a typical example, a method of combining high-strength filament yarn is known. Among these, the core span method in which filament yarn is inserted in the spinning process is the most widely used (for example, Patent Documents 1 to 3).

  However, a core-sheath two-layer structure spun yarn in which the core part is a high-strength filament yarn and the sheath part is made of staple fibers is obtained, so-called core spun yarn, but there are few entanglements and bonds between the filament yarn and the staple fibers, When the side surface of the spun yarn is rubbed many times or is subjected to bending or stretching, there is a drawback that the filament yarn and the staple fiber are slipped, and nep or slab is easily generated.

Further, woven fabrics, knitted fabrics and cords using the present yarn also have drawbacks such that the staple fibers in the sheath portion are easily peeled off when the surface is rubbed many times or subjected to deformation distortion.
In particular, as the yarn becomes thicker, the number of twists needs to be lowered, so the coupling between the core and sheath tends to be lessened. In addition, the higher the twist rigidity of the yarn, the stronger the twist torque, so the number of twists needs to be lowered. Again, there is less coupling between the core and sheath.

Japanese Utility Model Publication No. 49-29247 Japanese Patent Publication No. 63-3777 Japanese Patent No. 3035894

  An object of the present invention is a core sheath 2 which has sufficient strength and does not cause the fibers of the core portion and the sheath portion to slip and the fibers of the sheath portion to peel off even when subjected to effects such as friction, bending, and elongation. It is to provide a layered spun yarn.

  As a result of studies to solve the above-mentioned problems, the present inventor has a very high strength in spun yarn in which a thread composed of checked fibers and a staple fiber are skillfully combined in a core sheath. It was also found that the binding of both fibers was strong and that the fibers in the sheath part were less peeled off.

  Thus, according to the present invention, an average fiber length in which continuous long fiber bundles without crimps are checked, and the checked fibers are entangled and / or the ends of the fibers are bound by winding. A check yarn of 20 to 80 cm is arranged in the core portion and a staple fiber is arranged in the sheath portion, and the checked fiber and the staple fiber constituting the check yarn are entangled or crossed at least partially. And a core-sheath two-layer structure spun yarn, wherein the spun yarn is twisted.

  According to the core-sheath two-layer structure spun yarn of the present invention, it is possible to achieve a high strength that cannot be obtained with a spun yarn composed only of staple fibers that are widely used in general, and the core with respect to actions such as friction, bending, and extension. Strong durability is obtained in which the portion and the sheath are unlikely to slip or peel off.

  The core-sheath two-layer structure spun yarn of the present invention has a check yarn arranged in the core portion and staple fibers arranged in the sheath portion, and the checked fibers and staple fibers constituting the check yarn are A spun yarn that is entangled or crossed at least partially, and the spun yarn is twisted.

  In the present invention, examples of the check yarn disposed on the core include polyester fiber, polyamide fiber, carbon fiber, aramid fiber, and glass fiber. Especially, in order to exhibit high intensity | strength as a spun yarn, it is preferable that the intensity | strength of a single fiber is 6 cN / dtex or more, and it is more preferable that it is 8 cN / dtex or more. From this viewpoint, among the fibers, aramid fibers (particularly para-type aramid fibers) and carbon fibers are preferable.

  In the present invention, the check yarn is a continuous long fiber bundle that does not have crimps, and the checked fibers are entangled and / or the ends of the fibers are bound by winding. It must be a yarn.

  A continuous long fiber bundle without crimps is checked if the continuous long fiber bundles have crimps like cotton used in normal spinning, and it becomes difficult to uniformly check. This is because, when the spun yarn is stretched, it is difficult for uniform tension to act on all of the constituent fibers, and sufficient strength cannot be exhibited.

  The check yarn of the core part has an average fiber length 20 in which the continuous long fiber bundle is checked and checked, and the checked fibers are entangled and / or the ends of the fibers are bundled by winding. Threads that are ~ 80 cm. By using such a yarn for the core part, it is possible to obtain a high strength that cannot be realized by a spun yarn made of staple fibers.

In addition, in the conventional spun yarn with the core-spun method in which the filament yarn is arranged in the core portion, the binding force between the filament yarn and the staple fiber arranged in the sheath portion is weak, and the staple fiber falls off due to friction or bending. There are drawbacks. On the other hand, in the spun yarn of the present invention, since the core portion is composed of check yarns, there are many end portions of single yarn, loops and slack, and these and staple fibers in the sheath portion are easy. The fibers can be prevented from falling off by crossing or entangled with each other.
Furthermore, since the spun yarn of the present invention is twisted, the fibers constituting the check yarn of the core part and the staple fibers of the sheath part are more strongly bound, and the above-mentioned dropping can be suppressed.

  When the average fiber length of the fibers constituting the check yarn of the core is less than 20 cm, the number of fibers contributing to the strength of the check yarn is reduced although fuzz and loops increase, which is sufficient as a spun yarn. Strength cannot be obtained. Conversely, if the average fiber length exceeds 80 cm, the number of fibers contributing to the strength increases, but the fluff and loops decrease, and the entangled or crossed with the staple fibers in the sheath when the spun yarn is formed, and / or the fiber ends. This is not preferable because the number of wrinkles and the like is reduced, and sufficient binding strength between the core and the sheath cannot be obtained. A preferable average fiber length is 30 to 60 cm.

On the other hand, as staple fibers constituting the sheath, natural fibers such as cotton, wool, hemp and silk, chemical fibers such as rayon, acetate, polyester, acrylic, nylon, polypropylene, aramid, glass and metal, synthetic fibers, Inorganic fibers can be used according to the purpose.
The average fiber length of the staple fibers is preferably from 15 to 100 mm, more preferably from 25 to 80 mm, from the viewpoint of ease of entanglement with fibers constituting the check yarn of the core part and prevention of dropping.

  In the present invention, when the core-sheath two-layer structure spun yarn of the present invention is subjected to actions such as rubbing, bending, and stretching, a large distortion occurs between the staple spun yarn in the core and the staple fiber in the sheath. The difference in elongation between the two is preferably as small as possible so that the bond between the two is not broken. The difference in elongation is preferably -5 to + 65%, more preferably 0 to 45%.

  Further, the weight ratio of the check yarn to the core-sheath two-layer structure spun yarn is preferably high in order to effectively use the strength, but if it is too high, the characteristics as the spun yarn cannot be exhibited. The bond with the core is weak, which is not preferable. Accordingly, the weight ratio of the check yarn is preferably 50 to 90%, more preferably 65 to 80%.

  In the present invention, in order to strengthen the binding between the core part and the sheath part and prevent the fibers of the sheath part from falling off, the twist coefficient K of the core-sheath two-layer structure spun yarn is T = K√n (where T is The number of twists between 1 inch, n is a count, and K is a twist coefficient), and is preferably 2.0 to 4.0, more preferably 2.5 to 3.5.

  In the case of a conventional core-sheath double-layer structure spun yarn in which filament yarn is inserted into the core, so-called core spun yarn, the weight ratio of the core increases as described above, and the amount of staple fibers in the sheath decreases. Or when the core-sheath two-layer structure spun yarn is thick and the number of twists is reduced, the binding force between the core and the sheath is likely to be greatly reduced, and resistance to external forces such as abrasion, bending, and extension is weak. In the case of the core-sheath two-layer structure spun yarn in which the check spun yarn according to the present invention is inserted into the core portion, the check yarn and the staple fiber are fluff or loop of the check yarn, Since it is firmly bonded by loosening or the like, there is an advantage that such a defect is difficult to occur, and it can be developed for a wider range of uses.

  The core-sheath two-layer structure spun yarn of the present invention described above can be manufactured by the following method. First, the check yarn of the core part will be described. The check yarn is manufactured by a process as shown in FIG. 1, for example. That is, the continuous long fiber bundle 1 is stretched between the nip roller 2 and the nip roller 4 so as to extend beyond the cutting elongation of the continuous long fiber bundle and checked, and the short fiber thus checked is sucked from the nip roller 4 with suction air. It is sucked by the nozzle 5 and taken up, and then the entangled air nozzle 6 gives a bundle by entanglement and / or winding of the check short fiber end, and is wound as a check yarn 8 through the nip roller 7. .

Here, if the continuous long fiber bundle has a crimp like cotton used for normal spinning, it becomes difficult to uniformly check, and when the check spun yarn is stretched, It is not preferable that uniform tension hardly acts on all of them, resulting in a disadvantage that sufficient strength cannot be exhibited.
The distance between the nip roller 2 and the nip roller 4, the so-called check length, is set to about 50 to 150 cm so that the average fiber length of the check short fibers is 20 to 80 cm.

In addition, the conjugation of the checked fibers by the conjugating air nozzle 6 is effective for binding by either entanglement of fibers by an interlaced air nozzle or winding by a fiber end portion by a swirling air nozzle. However, in the latter case, it is possible to reduce the torque of the spun yarn obtained and to set the core sheath so that the winding direction of the fiber end is set to be wound in the direction opposite to the twisting direction in which the fiber ends are subsequently twisted together with the staple fiber. Bonding is also strong, which is preferable.
Furthermore, when the conjugation is imparted, the tension of the check yarn is preferably increased to 0.09 cN / dtex or higher in order to improve the fiber arrangement of the check yarn and increase the strength.

  Thus, by producing the check yarn using the above-mentioned specific conditions, the ratio of the yarn strength to the strength of the single fibers constituting the yarn (hereinafter referred to as strength utilization rate) is composed only of normal staple fibers. In the case of spun yarn, it is about 30 to 70%, which can be increased to about 60 to 90%.

  This effect is more prominent with lower elongation fibers. For example, in the case of para-aramid fibers, the strength utilization rate is only about 35% at most with a spun yarn consisting only of ordinary staple fibers. On the other hand, in the check yarn, this reaches approximately 70% or more, which is almost twice as large, and a large effect is obtained and effective.

Next, the following method can be employed to obtain the core-sheath two-layer structure spun yarn of the present application in which the check yarn is used as a core and staple fibers are arranged in the sheath.
That is, for example, with the apparatus shown in FIG. 2, the roving yarn 11 made of staple fibers is thinned while being drafted between the nip rollers 12, 13, and 14, and the check yarn is fed from the nip roller 14 to the central portion of the staple fiber bundle. The strands are inserted and aligned, and the staple fibers are sheathed around the check yarn while the fibers constituting the check yarn 10 and the staple fibers are entangled or crossed by the ring twisting and winding device 15. The core-sheath two-layer structure spun yarn 16 of the present invention is obtained by twisting the yarns at the same time.

  Further, when the check spun yarn is inserted from the nip roller 14, the staple spun yarn may be fed in a tension state so that the check spun yarn is positioned at the core when twisted simultaneously with the staple fiber to be aligned. preferable.

Hereinafter, an example is given and the composition and effect of the present invention are explained in detail. In addition, each physical property in an Example is calculated | required by the following method.
(1) Average fiber length This is a value obtained by dividing the number obtained by multiplying the fiber length and the number of fibers in 150 staple diagrams arbitrarily sampled by the total number of fibers.
(2) Strength and elongation Measured according to JIS 1017.
(3) Friction test A tension of 0.07 cN / dtex is applied to the core-sheath two-layer structure spun yarn, and it is abraded at a speed of 300 m / min while being bent into a W shape using three guides made of cylindrical ceramic having a diameter of 5 mm. After imparting the action, Thin, Thick, and Nep were measured with an even tester.

[Example 1]
Using a check yarn production apparatus as shown in FIG. 1, the continuous fine fiber bundle 1 has a total fineness of 2220 dtex, a filament number of 2668, a single fiber fineness of 0.83 dtex, a strength of 26.0 cN / dtex, and an elongation. Using para-aramid (PA) fibers (Technola: manufactured by Teijin Techno Products Co., Ltd.) having no crimp of 4.5%, the continuous long fiber bundle is 8 times between the nip roller 2 and the nip roller 4 The check thread ratio (surface speed of the nip roller 4 / surface speed of the nip roller 2) is checked, and then the check yarn is sucked out by the suction air nozzle 5 from the nip roller 4 and the fiber bundle is removed. The fiber bundle is passed through a conjugated air nozzle 6 having a swirling flow in a direction in which Z twisting is applied, and the fiber bundle is bound and wound by an end of a check fiber, and then passed through a nip roller 7 to be checked. When the wound yarn 9 was wound as the spun yarn 8, it was 277 dtex, the average fiber length was 38 cm, the strength was 17.7 cN / dtex (measured by applying 350 T / M twisted yarn, the strength utilization rate ≈ 66%), the elongation 4 A very high-strength check yarn was obtained despite the use of 3% low elongation fiber. In addition, the distance (checking length) between the nip roller 2 and the nip roller 4 at this time was set to 100 cm.

  Next, using a spinning spinning machine as shown in FIG. 2, a coarsely composed polyethylene terephthalate (PET) staple fiber having a fineness of 1.7 dtex, a fiber length of 38 mm, a strength of 5.5 cN / dtex, and an elongation of 20%. The yarn 11 is drafted into a fiber bundle having an average of 93 dtex through nip rollers 12, 13, and 14, and the check yarn 10 is drawn and inserted into the fiber bundle upstream of the nip roller 14. A high-strength core-sheath two-layer spun yarn having a fineness of 371 dtex, a strength of 13.7 cN / dtex, and an elongation of 4.1% was obtained by twisting 433 T / M in the Z direction. The results are shown in Table 1.

  Although the core-sheath double-layer structure spun yarn is dyed with disperse dye as a woven fabric, the dyeability of the PET fiber in the sheath portion is good, and it becomes a fabric rich in high colorability that cannot be obtained with a woven fabric made only of PA fibers. It was. The dyed fabric was subjected to an exposure test with an ultraviolet fade meter for 50 hours. However, the fading and strength deterioration were extremely small.

[Example 2]
A core-sheath two-layer structured yarn was obtained in the same manner as in Example 1 except that the check yarn at the core was changed to a check yarn having an average fiber length of 60 cm shown in Table 1. The results are shown in Table 1.

[Example 3]
The core sheath in the same manner as in Example 1 except that the check yarn of the core is changed to a check yarn of 224 dtex shown in Table 1 and the weight ratio of the core / sheath is 60/40. A two-layer yarn was obtained. The results are shown in Table 1.

[Example 4]
A core-sheath two-layer structure yarn was obtained in the same manner as in Example 1 except that the number of twists was changed to 10 T / inch in the production of the core-sheath type two-layer structure spun yarn. The results are shown in Table 1.

[Example 5]
A core-sheath two-layer structured yarn was prepared in the same manner as in Example 1 except that the staple fibers in the sheath were changed to meta-type aramid (MA) staple fibers (Conex: manufactured by Teijin Techno Products Co., Ltd.) shown in Table 1. Obtained. The results are shown in Table 1.

[Example 6]
A core-sheath two-layer structured yarn was obtained in the same manner as in Example 1 except that the staple fibers in the sheath were changed to the cotton shown in Table 1. The results are shown in Table 1.

[Comparative Example 1]
Using the same spinning machine as in Example 1, instead of the check yarn used in Example 1, a para type having a fineness of 0.83 dtex, a fiber length of 38 mm, a strength of 23.1 cN / dtex, and an elongation of 4.1% Using a spun yarn of 283 dtex made of aramid staple fibers, a core-sheath two-layer spun yarn was produced in the same manner as in Example 1. The results are shown in Table 1.
As a result, the spun yarn of the para-type aramid fiber used here has a low strength utilization because the elongation of the para-type aramid fiber is extremely low, and the strength is 7.0 cN / dtex (strength utilization rate≈30%), The elongation was as low as 5.1%.

Further, since the core-sheath two-layer structure spun yarn obtained using the spun yarn has a lot of fluff in the spun yarn, the spun yarn has the effect of friction, bending, extension and the like as the core-sheath two-layer structure spun yarn of Example 1. Although it was durable, the strength was as low as 5.6 cN / dtex.
Moreover, since the spun yarn of the core is twisted twice, the number of twists tends to be high, and para-aramid fibers with a very high modulus are used, so the torque in the untwisting direction becomes strong and snare (yarn) Entanglement) was easy to occur and handling was also bad.

[Comparative Example 2]
Using the same spinning machine as in Example 1, instead of the check yarn used in Example 1, 277 dtex, 334 filament, single fiber fineness 0.83 dtex, strength 25.2 cN / dtex, elongation 4.7% A core-sheath two-layer spun yarn was produced in the same manner as in Example 1 except that the multi-filament yarn of para-type aramid fiber was used.

  As a result, the spun yarn has a strength of 18.8 cN / dtex and an elongation of 4.3% because the strength of the multi-filament yarn of para-aramid fiber is high, but the filament yarn and sheath portion of the core portion can be obtained. Since there are few joints due to entanglement or crossing with other staple fibers, the core part and the sheath part easily slip due to the action of friction, bending, extension, etc., and as shown in Table 1, Thin, Thick, Nep There were a lot of drawbacks and the handling was also poor.

  According to the present invention, it is possible to achieve high strength that cannot be obtained with a spun yarn composed only of staple fibers that are widely used in general, and the core portion and the sheath portion slip due to friction, bending, stretching, and the like. The core-sheath two-layer structure spun yarn having strong durability can be provided because the fibers of the sheath part are hardly peeled off. Moreover, in the core-sheath two-layer structure spun yarn, fibers having various sensitivities and functions can be used for the staple fibers in the sheath, thereby not only compensating for the defects of the fibers in the core. It enables the development of new materials and products that could not be obtained in the past.

It is the schematic which shows an example of the manufacturing apparatus of a check yarn. It is the schematic which shows an example of the manufacturing apparatus of a core sheath 2 layer structure yarn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Continuous long fiber bundle 2, 4, 7 Nip roller 3 Guide which prevents disorder of fiber bundle during check 5 Suction air nozzle 6 Conjugation imparting air nozzle 8 Check thread 9 Winding device 10 Check thread 11 Staple fiber Roving yarn 12, 13, 14 nip roller 15 ring twisting device 16 core-sheath two-layer structure spun yarn

Claims (3)

  A continuous yarn bundle having no crimps is checked, and the checked fibers are entangled and / or the ends of the fibers are bundled by winding, and a check yarn with an average fiber length of 20 to 80 cm Is a spun yarn in which staple fibers are respectively arranged in a core portion and a sheath portion, and the checked fibers constituting the checked yarn and the staple fibers are entangled or crossed at least partially. A core-sheath two-layer structure spun yarn, wherein the spun yarn is twisted.   The core-sheath two-layer structure spun yarn according to claim 1, wherein the fibers constituting the check yarn disposed in the core portion are para-type aramid fibers.   The core-sheath two-layer structure spinning according to claim 1 or 2, wherein the ratio of the core part to the sheath part (core part: sheath part) in the core-sheath two-layer structure spun yarn is 80:20 to 50:50 based on the weight. yarn.

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