JPH0641654B2 - High shrink stress core yarn - Google Patents

Description

The present invention relates to a high shrinkage stress core yarn suitable for a high density spun yarn-like woven fabric.

Hitherto, high-density fabrics have been manufactured by weaving as high a density as possible in the weaving stage. However, by increasing the density,
Productivity is also low, and thus cost is high. In particular, when a fine count spun yarn having a good texture is used, the number of yarn breakages increases and the productivity remarkably decreases. The present inventor, as a result of intensive research to solve the above-mentioned drawbacks, produced a woven fabric by simply using a yarn having a high shrinkage ratio, and performed shrinkage treatment to achieve high density. It was found that the density could not be increased because it could not shrink due to the restraint force of. This tendency is particularly great in the case of spun yarn. Therefore, the present inventor has arrived at the present invention by studying a method of using a high shrinkage stress yarn for overcoming the constraint force of the tissue to shrink it in the width-drawing step.

An object of the present invention is to provide a high shrinkage stress core yarn which is suitable for obtaining a woven fabric having a spun yarn quality and a substantially high density.

The present invention has the following configurations in order to achieve such an object. That is, the present invention has a spinning speed of 40.
Stapling around one or more filaments obtained by stretching unstretched yarn spun at a rate of 00 m / min or more at a crystallization temperature near the second stage and at a higher draw ratio than the first stage. In a core yarn obtained by winding and twisting fibers, a filament having a heat shrinkage stress of 0.3 g / denier or more at any temperature under dry heat of 130 ° C. to 200 ° C. is 20% by weight to 60% in the core yarn. A high shrinkage stress core yarn characterized by being contained in a weight percentage.

The present invention will be described in detail below. In the present invention, the core yarn in which the staple fibers are wound around one or more filaments is used for producing a spun yarn tone. Here, the filament means both a monofilament and a multifilament. The heat shrinkage stress of the filament contained in the high shrinkage stress core yarn of the present invention has a particularly important meaning in the present invention, and the filament of 130 ° C. to 200 ° C., preferably 150 ° C. to 160 ° C., and further preferably 140 ℃ ~
The heat shrinkage stress at any temperature under dry heat of 150 ° C. should be 0.3 g / denier or more, preferably 0.4 g / denier or more. This is because the core yarn is densified without lowering the heat shrinkage stress of the core yarn. The heat shrinkage stress here is defined as follows, but the sample to be measured is a filament taken out from the composite yarn before shrinkage treatment. Needless to say,
When the core yarn contains one or more monofilaments, the monofilament, and when the core yarn contains one or more multifilaments, the filaments constituting the multifilaments are added to the filaments extracted from the composite yarn. Equivalent to.

The term "heat shrinkage stress" as used in the present invention means that when fibers are gripped at a constant length under a tension of 0.05 g / denier and heated and heated, the fibers try to heat shrink, but both ends are fixed. Therefore, the actual shrinkage does not occur, and instead, the internal stress that causes the shrinkage occurs in the fiber. This stress is called heat shrinkage stress. To measure the heat shrinkage stress, a commercially available non-adhesive metal resistance wire strain meter is used, and the change of the stress with time is recorded and measured by an automatic XY recorder linked with this to increase the radiation. The sample is a loop with a fixed length, one end of which is directly connected to the strain gauge and the other end is also hooked.
/ Adjust and fix the length between the sample and the hook so that it becomes denier. (At this time, tension is applied with care so that there is no tarmi.) The sample fixed in this way is a cylindrical quartz glass tube with an inner diameter of 8 mm, and a nichrome wire is wound on the outside. Place the sample in the heater so that the sample is located at the center of the double-tube heater (20 cm in length) surrounded by, and install the detection end and the heater installed at the center 3 mm away from the sample and the integrated circuit with a program. The shrinkage force due to heat shrinkage, which was directly connected to the temperature controller, was heated at a heating rate of 20 ° C./min to continuously heat up the atmosphere and melted, was divided by the denier of the fiber. The value is the heat shrinkage stress.

The content of the filament in the high shrinkage stress core yarn according to the present invention is 20% by weight or more and 60% or more.
It is not more than 30% by weight, preferably not less than 30% by weight and not more than 60% by weight. If it is less than 20% by weight, the heat shrinkage stress of the core yarn decreases, and the dimensional stability of the cloth and the strength of the cloth also decrease. On the other hand, if the content exceeds 60% by weight,
When such a core yarn is used to form a high-density woven fabric, the high-density woven fabric is unlikely to have a spun yarn tone. And, as the material of the filament in the core yarn of the present invention,
Synthetic fibers are preferable, and examples thereof include polyester fibers and nylon fibers. The staple fiber may be synthetic fiber, semi-synthetic fiber, natural fiber or a mixed spun fiber thereof, but it should be selected according to the desired spun yarn feel.

Next, the twist coefficient (inch type) of the number of twists applied to the core yarn of the present invention is preferably 2.5 or more and 5.0 or less, more preferably 3.0 or more and 4.5 or less.
If it is less than 2.5, the entanglement between the staple fiber and filament becomes worse, and the anti-ironing property is lowered, which is not preferable. When it exceeds 5.0, the feel of the core yarn of the present invention becomes hard and spun yarn wind is impaired, which is not preferable. Here, the twist coefficient K is It is calculated from the formula. In the formula, T is the twist number (t / in), Ne
Is an English cotton count.

Further, the high shrinkage stress core yarn of 130 ° C. to 20 ° C.
Heat shrinkage stress at any temperature under dry heat of 0 ° C.
It is preferably 15 g / denier or more. this is,
This is because after the shrinking treatment, the binding force of the tissue is overcome and the shrinkage is performed to increase the density. The definition of the heat shrinkage stress here is also as described above.

Now, an example of the method for producing the high shrinkage stress core yarn of the present invention will be described. First, oriented crystallization, for example, a yarn spun at a spinning speed of 4000 m / min or more is stretched at a high ratio near the crystallization temperature to produce a multifilament having high heat shrinkage stress. Then, when drafting a roving yarn composed of staple fibers and spinning it from a front roller, the multifilament is supplied immediately before the front roller and is superposed on the drafted roving yarn, that is, the fleece. The product spun from the front roller is wound by applying a predetermined number of twists. At this time, it is important that the ratio of the multifilament in the core yarn is 20% by weight or more.

As described above, the high shrinkage stress core yarn of the present invention can achieve higher densification than that using a spun yarn of 100% staple fibers when it is made into a high density woven fabric, and also has the characteristics of spun yarn tone. The effect is that a woven fabric having higher strength can be obtained. Further, it is possible to woven at a lower density than that using spun yarn, to increase the density in the post-treatment stage, and to achieve cost reduction.

Examples 1-2 Polyethylene terephthalate having an intrinsic viscosity of 1.0 is 310
Spinning was performed at a discharge rate of 1.5 g / min per single hole from a nozzle having 16 orifice holes of φ0.3 mm at ℃, and the undrawn yarn was wound at a take-up speed of 4000 m / min.

Then, a multifilament obtained by drawing at a drawing speed of 100 m / min under a temperature condition of 85 ° C. for the first step and 110 ° C. for the second step and a roving yarn made of cotton fibers having an average fiber length of 30 mm were used to obtain a high-strength fiber of the present invention. A shrink stress core yarn and a high density fabric using the same were produced (Example 1). Also, polyethylene terephthalate having an intrinsic viscosity of 0.65 was spun at 300 ° C. from a nozzle having 24 orifice holes of 0.23 mmφ at a discharge rate of 2.1 g / min per hole and a take-up speed of 50.
The undrawn yarn was collected at 00 m / min. Then, a core yarn was made under the same conditions as in Example 1 using the drawn yarn produced at a drawing speed of 300 m / min under the temperature conditions of the first stage 85 ° C. and the second stage 110 ° C. to obtain a plain woven fabric (Example) 2). In addition,
For comparison, an undrawn yarn obtained by winding polyethylene terephthalate having an intrinsic viscosity of 0.63 at 285 ° C. at a take-up speed of 1300 m / min was drawn under the temperature conditions of the first stage 75 ° C. and the second stage 115 ° C. and the drawing in the table. A core yarn using a multifilament obtained under the same conditions as in Example except for stretching at a draw ratio and a roving composed of cotton fibers having an average fiber length of 30 mm and a woven fabric using the core yarn (Comparative Example 1), and a cotton having an average fiber length of 30 mm. A similar woven fabric was produced using a 60/1 cotton yarn made of fibers (Comparative Example 2). The results are shown in the table. The heat shrinkage stress (g / denier) in the examples was measured by the Toyo Baldwin Corporation T.S. I
-550-360 type, PRE-AMPL-IFIER SS-PR manufactured by Toyo Baldwin Co., Ltd.
Type, as an automatic XY recorder by Yokogawa Electric Corp.
PRO-11A type, AGN manufactured by Vacuum Riko Co., Ltd. as a temperature controller
E HPC-1500 and AGNE SCR-BOX
Was measured using. The toughness was measured using Tensilon manufactured by Toyo Baldwin. For the filaments taken out from the core yarns in the table, for reference, the boiling water shrinkage rate at 98 ° C. for 30 minutes was measured with a strain gauge at a clearance of 20 cm and an initial load of 5 mg / d.

As is clear from the results in the table, the high-density fabric using the high shrinkage stress core yarn of the present invention has the same density as that of Comparative Examples 1 and 2 before the treatment, but is 30 minutes in boiling water at 100 ° C. It was found that after the shrinking treatment, the density became considerably high. Moreover, it has the distinctive character of a very high-quality spun yarn-like product. In order to make the density of Comparative Example 2 the same as that of the Example, 95 wefts / in and 2 warps before the treatment.
It is considered that the weaving density of 75 yarns / in is required, and in this respect also, the product of the present invention shows high productivity.

Claims (2)

[Claims] 1. A filament obtained by drawing an undrawn yarn spun at a spinning speed of 4000 m / min or more at a drawing temperature near the crystallization temperature and a drawing condition higher than those of the first step. In a core yarn in which one or more staple fibers are wrapped around and twisted,
20% by weight to 60% by weight of filaments having a thermal shrinkage stress of 0.3 g / denier or more at any temperature under dry heat of 200 ° C., and high shrinkage stress characteristics Core yarn. 2. The core yarn has a heat shrinkage stress of 0.15 g / at any temperature under dry heat of 130 ° C. to 200 ° C.
The high shrinkage stress core yarn according to claim 1, which is a denier or higher core yarn.