JPH0345734A - Sheath-core structure elastic yarn - Google Patents

Abstract

PURPOSE:To provide a sheath-core structure elastic yarn having the touch of a spun yarn excellent in stretchability and binding force, and suitable for the neck portions, etc., of underwears, etc., by employing a specific elastic fiber as a core and a non-elastic fiber bundle as a sheath to form a sheath-core structure. CONSTITUTION:An elastic fiber (e.g. polyurethane elastic fiber) 2 having fineness of >=40 denier and an attached oil amount of <=4.0wt.% is fed to front rollers 12 while being drafted. Non-elastic fibers (e.g. acrylic fibers) 3 are also fed to the non-twisting front rollers 12. Two kinds of the fibers are fed into air jet nozzles N1 and N2 and bound with each other with revolving air flows A and B produced by the air jet nozzles N1 and N2 to prepare a sheath-core structure elastic yarn 1 comprising the elastic fiber 2 as a core and the bundle of the non-elastic fibers 3 as a sheath, the non-elastic fibers being employed in an amount of 60-90% based on the total amount of the elastic fiber and the non-elastic fibers.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention provides a core that has elasticity and power (stretch strength, also referred to as binding force) due to elastic fibers, and has the texture of spun yarn. Regarding sheath structure elastic yarn.

[Conventional technology]

Knitted fabrics for underwear, socks, sportswear, etc. (1. Because they come into direct contact with the skin, they are required not only to have elasticity and power, but also to have a texture similar to that of spun yarn.) Bare elastic fiber threads are rarely used as they are in areas that have elasticity, such as sleeve openings and waistbands. This is because there is a problem with it coming out.

Conventionally, elastic yarns with a core-sheath structure, in which polyurethane elastic fibers are arranged in the core and short cotton fibers are arranged in the sheath, or outer periphery, have been used for the stretchable parts of knitted fabrics. There is. This elastic yarn with a core-sheath structure has elasticity and power, and has a texture similar to that of a spun yarn. This core-sheath structure elastic yarn is manufactured by spinning with a ring spinning machine. That is, the polyurethane elastic fibers are fed into a ring spinning machine while being stretched, and the cotton slivers are fed around the polyurethane elastic fibers along their length, thereby simultaneously twisting the cotton slivers and the polyurethane elastic fibers. It is spun out over a long period of time.

The core-sheath elastic yarn thus obtained has inelastic fibers wound around the outer periphery of the core polyurethane elastic fiber, and twisting torque remains in the core polyurethane elastic fiber.

On the other hand, as a yarn that has elasticity and power and has the feel of a spun yarn, there is a covering yarn that has an elastic fiber core and a spun yarn made of inelastic fibers wound around the core in a coil shape.

In addition, while drawing the polyurethane elastic fibers, they are supplied to a binding spinning machine, and a stable fiber bundle is supplied around the elastic fibers, and a part of the stable fiber bundles is heated and untwisted to make the elastic fibers. An elastic yarn with a core-sheath structure was considered, in which a part of the stable fiber bundle is wound and bound from the outside of the stable fiber bundle wrapped around the core-sheath structure.

[Problem to be solved by the invention]

Conventional elastic yarns with a core-sheath structure produced by a ring spinning machine have a drawback of low power because they use elastic fibers with a fine denier (for example, thinner than 140 denier) as a core. The disadvantage of this is that thick elastic fibers (e.g. 2
It was thought that this could be improved by using a core of about 10 denier. However, core-sheath elastic yarns using thick elastic fibers as cores have not been produced conventionally for the following reasons.

When a core-sheath elastic yarn is manufactured using a ring spinning machine, the thicker the core polyurethane elastic fiber is, the more the twisting torque remaining in the polyurethane elastic fiber tends to be significantly larger. If stress torque remains in the elastic fibers, snarls will occur frequently when handling the core-sheath elastic yarns, making knitting and weaving difficult.

For this reason, it is generally necessary to take steps to prevent snarls by means of anti-twist sets.

On the other hand, covering yarn is generally made by winding twisted yarn around elastic fibers. Therefore, two processes are required: a process for manufacturing a yarn (spun yarn) to be wrapped, and a covering process for wrapping the elastic fiber. In particular, since the production speed of the covering process is slow, productivity is low, causing problems in cost, quick delivery, etc.

Moreover, there is a strong tendency for the texture of the wound yarn (spun yarn) to be damaged.

Since the elastic yarn with a core-sheath structure made by the above-mentioned binding spinning is only bound together by a portion of the inelastic fibers forming the sheath, a problem arises in that the sheath easily peels off. This problem becomes more serious as the elastic fiber becomes thicker. Further, since the sheath suppresses the expansion and contraction of the elastic fibers, there is a problem that the power of the core-sheath elastic yarn is low.

Therefore, the present invention provides an elastic yarn with a core-sheath structure that is low in cost, has high elasticity and power, has a texture like a spun yarn, and has a sheath that is difficult to peel off (that is, has good peeling resistance). That is the issue.

[Means to solve the problem]

In order to solve the above problems, the elastic yarn with a core-sheath structure according to the present invention has a fineness of 140 deniers or more and a fineness of at most 4 deniers.
．． The core is an elastic fiber with an oil adhesion of 0% by weight, and this core has 1. It is wrapped in a sheath consisting of a bundle of inelastic fibers and inelastic fibers binding the bundle, and the ratio of the inelastic fibers to the total weight of the elastic fibers and the inelastic fibers is 60 to 90.
%.

As mentioned above, the elastic yarn with a core-sheath structure exhibits almost no elasticity because the elastic fibers are bundled (bound) together with the inelastic fibers. However, in the research conducted by the inventors, it was found that, contrary to this prediction, when the ratio of the sheath was set within a certain range, the material had an elasticity of +9 minutes. It has also been found that sufficient peeling resistance can be achieved by setting the amount of oil applied to the core elastic fiber within a certain range. This invention was completed based on these findings.

FIG. 1 schematically shows the appearance of one embodiment of the core-sheath elastic yarn according to the present invention. As shown in FIG. 1, this core-sheath structure elastic yarn 1 has an elastic fiber 2 as a core, and this core has
A bundle of inelastic fibers 3... and inelastic fibers 4 that bind this bundle
It is wrapped in a sheath consisting of.

The elastic fiber used in this invention has rubber-like elasticity, such as polyurethane elastic fiber. The elastic fiber used in this invention has a fineness of 140 denier or more and an oil adhesion amount of at most 4.0% by weight (preferably 3.0% by weight or less). In this way, the power of the yarn is increased by using elastic fibers with a larger fineness than conventional ones.

Note that the thinner the elastic fibers, the weaker the power. If the amount of oil applied to the elastic fibers is more than 4.0% by weight, peeling between the core and sheath tends to occur.

Examples of the non-elastic fibers used in this invention include natural non-elastic fibers such as cotton, and synthetic non-elastic fibers such as acrylic and polyester. These may be used alone or in combination.

The sheath ratio of the core-sheath elastic yarn of the present invention is expressed by the following formula.

The range of sheath ratio of the core-sheath elastic yarn of this invention is 60~
It is 90%. When the sheath ratio exceeds 90%, the elastic fibers in the core are prevented from expanding and contracting, and the power of the core-sheath elastic yarn becomes low. Moreover, when it is less than 60%, the sheath becomes easy to peel off.

Although the core-sheath elastic yarn may be manufactured in any manner, it is preferable to manufacture it using, for example, knot spinning.

If a core-sheath elastic yarn is produced by knot spinning, the core elastic fibers will have virtually no twist, and the problem of snarls can be solved. Further, according to the binding method, elastic fibers can be covered with inelastic fibers during spinning, and the number of steps can be reduced. Moreover, the spinning speed of binding spinning is
It is possible to increase the covering speed by about 10 times. As a result, costs can be reduced and delivery times can be shortened.

The binding spinning is performed using, for example, a binding spinning machine schematically shown in FIG. 2, but is not limited thereto. As shown in FIG. 2, this binding spinning machine 11 performs binding spinning using swirling fluid, especially air. Along the travel path C of the elastic fibers 2 and inelastic fibers 3, a front roller 12, air injection nozzles Nl and N8, and a delivery roller 13 are arranged in this order. Air injection nozzles Nl and N□ generate swirling airflows A and B in opposite directions, with the supplied elastic fibers as virtual axes.
It is something that causes Elastic fibers 2 are always supplied to the front roller 12 at a constant speed from an elastic fiber supply source (not shown). A certain amount of draft is applied to the elastic fibers 2 between the elastic fiber supply source and the front roller 12.

In addition, the inelastic fibers 3 are always supplied to the front roller 12 at a constant speed from an inelastic fiber supply source (not shown). These supplies are made without twisting. On the front roller 12, inelastic fibers 3 are placed around the elastic fibers 2.
... will be arranged. The elastic fibers 2 and inelastic fibers 3 that have passed through the front roller 12 are supplied to air injection nozzles NI and N. The swirling airflow B generated by the air injection nozzle N8 on the downstream side of the traveling route C twists some of the inelastic fibers 3 around the elastic fibers 2.

Then, untwisting and binding are performed by the swirling airflow A generated by the air injection nozzle Nl on the upstream side, and the delivery roller 13
It is spun from. The obtained yarn is an elastic yarn 1 with a core-sheath structure, in which a core of elastic fibers 2 is wrapped in a sheath consisting of a bundle of inelastic fibers 3 and an inelastic fiber 4 that binds the bundle.

The draft given to the elastic fibers 2 is not particularly limited, but it is preferably a draft magnification of 3.5 to 5. If the elastic fiber is below this range, the elasticity and power will decrease, and the advantage of increasing the fineness of the elastic fibers may be lost. Moreover, if it exceeds this range, there is a risk that the elastic fibers will break. In addition, in this invention, since the amount of oil agent attached to the elastic fibers 2 is lower than that of the conventional one, it was thought that the elastic fibers would be difficult to unravel. However, by applying a draft within the above range, it can be easily Let me explain.

It is preferable to overfeed the elastic fibers 2 and the inelastic fibers 3 between the front roller 12 and the delivery roller 13. The feed ratio, the injection speed of the air injection nozzle, and the fleece width may be selected as appropriate depending on the conditions of the spun yarn.The core-sheath elastic yarn according to the present invention has a structure in which the elastic fibers constituting the core are substantially Because it does not have twist, snarl will occur and it will not be knitted! ! Weaving can be done easily. Since the elastic fibers are thick and have a fineness of 140 deniers or more, they have great elasticity and power. Since these elastic fibers are wrapped in a sheath made of inelastic fibers, the yarn has a texture similar to that of spun yarn. Moreover, since the elastic fiber has an oil adhesion amount of at most 4.0% by weight, the sheath is difficult to separate from the core. Therefore, by using the core-sheath elastic yarn according to the present invention, it is possible to efficiently produce a knitted fabric that has high elasticity and power and has a feel similar to that made from spun yarn.

In addition, since this elastic yarn with a core-sheath structure is hardly twisted, a knitted fabric that is less prone to skewing can be obtained by using this elastic yarn.

When the core-sheath elastic yarn according to the present invention is used in a stretchable part of a knitted fabric, it has a strong binding feeling, has the feel of a spun yarn, and the elastic fibers are less likely to come off.

A knitted fabric using the core-sheath elastic yarn according to the present invention is knitted or woven in the same manner as a knitted fabric using a normal elastic yarn. For example, only the core-sheath elastic yarn may be used around the neck, waist, sleeve openings, etc. of knitted fabrics such as underwear, socks, and sportswear, or for the entire knitted fabric or article; Interlacing or interweaving yarn with other yarns.

The core-sheath elastic yarn of the present invention can be used not only as a material for knitted fabrics and textiles, but also as a material for threads. For example, it is possible to form a thread by combining it with other types of threads or fibers, or to make threads with different physical properties by applying appropriate treatments.

[For production]

The elastic yarn with a core-sheath structure according to the present invention has a substantially untwisted elastic fiber as a core, so that snarl is less likely to occur, and the thickness of the elastic fiber is 140 deniers or more, which increases power. be able to. The core is wrapped in a sheath consisting of a bundle of inelastic fibers and inelastic fibers binding the bundle, and the ratio of the inelastic fibers to the total weight of the elastic fibers and the inelastic fibers is 60 to 90%. Therefore, it has a texture similar to that of spun yarn. Furthermore, by setting the amount of oil applied to the elastic fibers to be at most 4.0% by weight, the sheath becomes difficult to peel off from the core (that is, the sheath peeling strength is improved).

〔Example〕

Specific examples and comparative examples of the present invention are shown below, but the present invention is not limited to the following examples.

Examples 1 to 13 and Comparative Examples 1 to 3 - Using the elastic fibers and inelastic fibers shown in Table 1, using the binding spinning machine (No. 802MJS manufactured by Murata Machinery Co., Ltd.) shown in FIG. Binding spinning was performed at the draft magnification shown in the table to produce core-sheath structured elastic yarn. The spinning speed is 120 m/min, and the air injection speed of air injection nozzles N and N8 is 3.0~
The fleece width was 3 to 5 nm, and the feed ratio was 0.90 to 0.98. Fineness of inelastic fiber
The fiber length and mixing ratio (in the case of A/C blend) were as follows.

American Pima cotton has an average fineness of 1.35 denier and an average fiber length of 36.
．． 9 v*, the average fineness of the final fiber is 1.6 denier and the average fiber length is 30.5u, and the A/C blend has a mixing ratio of acrylic fiber/fiber fiber of 30/70, and the fineness of the acrylic fiber is 1.5 denier and the fiber length is 38 m. The average fineness of the final tightening is 1.6 denier and the average fiber length is 28.2 In, and the FD ester has a fineness of 0.7 denier.
It is a polyester fiber with an average fiber length of 32 m1m.

Regarding each core-sheath structured elastic yarn of Examples 1 to 13 and Comparative Examples 1 to 3, the count, sheath ratio, yarn unevenness, number of nep, power, covering strength, sheath peeling strength, covering property,
Spinnability and snarlability were examined. The results are shown in Table 1.

The yarn unevenness (NU%) and the number of neps were examined using a measuring machine (UT-3) manufactured by Zellweger Worcester Co., Ltd.

The power was determined by collecting 80 turns using a 1.5-yard frame circumference checking machine while applying the same tension as the elastic fiber tension during spinning. The strength when the above-mentioned material was stretched to 35 cm using CATV200BH (manufactured by CATV200BH) was expressed as the value divided by the fineness (denier) of the elastic fiber of the core thread.

The cover strength was measured using the electronic universal testing machine mentioned above.
-S curves (see Figure 3) were measured and shown in terms of strength at the first cutting point P.

The sheath peeling strength was determined by visually observing the rotational speed at which the sheath began to peel when the sheath was rubbed at 30 rpm with the same tension as the tension of the elastic fiber during spinning using a Hiruta Hiro 6 model conjugation force tester. I investigated and showed the number of revolutions.

Covering properties were determined by visual inspection after visual dyeing and tubular knitting dyeing, and were evaluated as: ○: practically satisfactory level; △: practically usable level for specific purposes.

Spinnability was determined by determining whether or not it could be mass-produced by spinning under general spinning conditioning, and was expressed as: O: No problem, ×: Problem.

The snarl property was determined by unwinding the spun cheese strand for about 1 m, and then visually inspecting the occurrence of snarl when the unwinding tension was relaxed. ○: No practical problem; ×: Practical problem.

In addition, the overall evaluation was shown as ■: No practical problem in terms of spinnability and quality, ○: Practically satisfactory level, ×: Impossible for practical use.

From Table 1, the following ■~■ can be seen.

■ As the amount of oil adhered increases, the sheath fraying strength decreases (Comparative Example 3).

■ When the sheath ratio is about 50%, the sheath peeling strength becomes low (Comparative Example 2) and the covering property becomes poor (Comparative Example 2), and when the sheath ratio exceeds 90%, the power becomes weak. At the same time, since elastic fibers with a large denier (large fineness) are used, the spinning count becomes thick, and spinnability deteriorates due to nozzle clogging, etc. (Comparative Example 1).

■ When the draft of elastic fibers becomes smaller, the power of the obtained yarn tends to become weaker (Example 1).

〔Effect of the invention〕

As described above, the core-sheath structured elastic yarn according to the present invention has a fineness of 140 deniers or more and an oil adhesion amount of at most 4. The core is made of an elastic fiber with an amount of OM%, and this core is wrapped in a sheath consisting of a bundle of inelastic fibers and an inelastic fiber that binds the bundle, and the total amount M of the elastic fibers and inelastic fibers is The ratio of inelastic fibers to the total amount of fibers is 60 to 90%. Therefore, the core-sheath structured elastic yarn of the present invention has high elasticity and power, has a feel like a spun yarn, and has good peeling resistance.

A knitted fabric using the core-sheath elastic yarn of the present invention has the feel of a spun yarn and has excellent elasticity.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing the appearance of one embodiment of a core-sheath structure elastic yarn according to the present invention, and FIG. Figure 3 is a schematic explanatory diagram of the single yarn S for examining the cover strength.
-8 curve.

Claims (1)

[Claims] 1 The core is an elastic fiber having a fineness of 140 denier or more and an oil coating amount of at most 4.0% by weight, and this core is wrapped with a sheath consisting of a bundle of inelastic fibers and an inelastic fiber that binds the bundles. An elastic yarn with a core-sheath structure, wherein the ratio of the inelastic fibers to the total weight of the elastic fibers and the inelastic fibers is 60 to 90%.