JPH0694607B2 - Double-covered elastic yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a double-covered covered elastic yarn in which a thermoplastic synthetic long fiber yarn such as polyamide is wound around an elastic system such as polyurethane type in a double manner. Regarding improvement.

In particular, the present invention relates to a covered elastic yarn which is useful as a material for socks such as socks and stockings.

[Prior art]

On the other hand, polyurethane-based elastic yarns, which have excellent elastic properties, have drawbacks such as dyeing properties, mechanical strength, and abrasion resistance. Therefore, thermoplastic synthetic fibers such as polyamide filaments are wound in double layers. It is widely used as a covered elastic yarn that is attached and double-covered. For example, JP-A-47-19146
Japanese Patent Laid-Open Publication No. 2003-242242 discloses that a polyurethane elastic yarn is wound and covered with a covering yarn while being stretched. In such an example, the combination of the denier of the covering yarn and the corresponding lower twist number and upper twist number is such that the lower cover twist number of the double cover is 2600 twists / m and the upper twist number is 1800 twists / m. Therefore, it is common to improve the coatability. However, in such a method, there are problems such as a manufacturing cost increase and a decrease in elasticity due to the high number of twists. The covering property can be improved by increasing the denier of the covering yarn, but the double covering becomes thicker, which is a limitation in applications where the transparency of the obtained product is strongly required, such as when used for stocking. It is what is done.

Also, Japanese Patent Publication No. 4518063/1985 describes a method of covering a false elastic stretch processed yarn on a polyurethane elastic yarn. The yarn obtained by this is stretchable from the false twist elastic processed yarn which is a covering yarn. The present invention relates to an improvement of a so-called single covering yarn, which is a covering yarn having an appearance like a stretched yarn and a soft appearance, which makes full use of original properties such as bulkiness. Therefore, such covering yarn is still unfavorable in the field where the transparency of the obtained product is strongly required such as for stocking.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION The main object of the present invention is to provide a double-covered covered elastic yarn which solves the above problems and has a compact yarn form with good covering properties and good productivity. Is. Even in the state of excellent covering property, the torque of the covering elastic yarn is reduced,
The purpose of the present invention is to provide a double-covered covering yarn that is easy to knit and can obtain a knitted fabric with a beautiful knitting surface.

[Means for solving problems]

 In order to achieve the above object, the present invention has the following configuration.

That is, in a coated elastic yarn formed by doubly wrapping a coating yarn made of long filaments of a thermoplastic polymer around a core yarn made of an elastic yarn, the coating yarn wound inward is A double-covered coating comprising crimped multifilament yarns having an average cross-sectional shape factor K of 1.2 to 1.6, and the coating yarns wound on the outside are non-crimped yarns. It is an elastic thread. More preferably, the covering yarn wound on the outer side is a non-crimped multifilament yarn having a cross-sectional shape factor K of 1.2 to 1.6 as an average value of each constituent single fiber in the same yarn cross section.

The cross-sectional shape factor K is a value of K = L / Lc, where L means the outer circumference of the fiber cross section, and Lc means the outer circumference of a circle having the same cross-sectional area as the fiber. To do.

[Action]

 Hereinafter, the present invention will be described in more detail.

In order to reduce the number of winding twists of the covering yarn, improve the covering property, and reduce the torque of the yarn, the type of the covering yarn, its characteristics, and the cross-sectional shape of the single yarn are important. This is the point, and as a result of intensive studies in view of this point, the present inventors have found that the object of the present invention can be achieved by using a crimped yarn having a deformed cross section as the covering yarn. That is, first, as the covering yarn to be wound inside, a crimped multi-filament yarn having a cross-sectional shape factor K of 1.2 to 1.6 as an average value of each constituent single fiber in the same yarn cross section is used.
The crimped yarn wound on the inner side originally improves the covering property due to the bending of the fiber, but it further improves the covering property by making the cross-sectional shape of the fiber non-circular. is there. The non-circularization of the fibers is achieved by twisting and heating the fibers even if they are false-twisted with a circular cross-section fiber, but to obtain a greater effect, they are used for false-twisting. It is preferable to make the cross-sectional shape of the fiber non-circular so that the obtained crimped yarn has a cross-sectional shape factor K of 1.2 to 1.6 as an average value of each constituent single fiber in the same yarn cross section.

Although the crimped yarn wound on the inside in this way exhibits a covering effect, it is not preferable in terms of the bulkiness of the covered elastic yarn, but the non-crimped yarn wound on the outside next It is intended to regulate the bulkiness of the covered elastic yarn in the diameter direction.

By making the inside bulky and shrinking it from the outside in this way, not only the appearance covering property is further improved, but also the stability against external force such as seawater is improved and the substantial covering property is improved. The compactness of the thread form is improved. As a result, it is possible to reduce the number of winding twists and improve productivity. When a stocking is made using the coated elastic yarn thus double-covered, a clean product with good transparency can be obtained, and its durability in actual wearing is also greatly improved.

If the cross-sectional shape factor K of the crimped yarn is less than 1.2, a sufficient covering effect cannot be obtained. On the other hand, the cross-sectional shape factor K is 1.6
If it exceeds the range, the abrasion resistance of the obtained coated elastic yarn is lowered, and further the dyeing fastness and the texture are lowered, which is not suitable for practical use. That is, in general, a non-circular cross-section fiber has lower mechanical strength than a round cross-section fiber, but a coated elastic yarn obtained by using a non-circular cross-section fiber having the above-mentioned specific cross-sectional shape as a coating yarn is substantially There is no problem at all. The cross-sectional shape of this non-circular cross-section fiber may be any of Y-shape, T-shape, X-shape, etc.
Further deformation. For example, if you use a Y-shape to perform false twisting, it will have a flat cross-sectional shape with bent legs.
The cross-sectional shape factor K is satisfied to improve the coverage of the coated elastic yarn. An example of a fiber cross-sectional shape obtained by false twisting a Y-shaped cross-section fiber yarn according to FIG. 1 is shown as a model.

As a processing method for obtaining the crimped yarn to be wound on the inside, false twisting, indenting, or the like may be used, but false twisting with good coverage may be used. The false twisted yarn is preferably obtained by performing twisting, heat setting and untwisting in the direction opposite to the twisting direction to be wound inside, from the viewpoints of torque balance, stretchability and the like.

Next, the covering yarn wound on the outside suppresses the bulkiness of the crimped yarn wound on the inside and creates a uniform yarn surface morphology.
Must be non-crimped yarn. Although this non-crimped yarn has a circular cross-section yarn, the desired effect can be obtained, and in addition, in order to improve the holding property, stability, and abrasion resistance of the covering yarn wound inside, It is preferable to have a cross section having a cross-sectional shape factor K of 1.2 to 1.6 similar to. In consideration of the torque of the covered elastic yarn, it is preferable to use a torque type non-crimped yarn that cancels the torque generated by winding the crimped yarn inside.

The elastic fiber used in the present invention is preferably a polyurethane-based elastic fiber generally called a spandex fiber, but may be another type of elastic fiber. On the other hand, polyamide, polyester, polyolefin, polyacrylic fiber, etc. are used as the filaments of the thermoplastic polymer forming the covering yarn, but polyamides having excellent dyeing properties, mechanical strength, abrasion resistance properties, etc. are preferable. Further, among polyamides, nylon 6 and nylon 66 fibers, which are particularly excellent in these properties, are preferable.

〔The invention's effect〕

According to the present invention as described above, a coated elastic yarn is provided which simultaneously satisfies many factors such as covering property, stretchability and manufacturing cost, which have been problems in the past. INDUSTRIAL APPLICABILITY In the present invention, since the crimped yarn having a non-circular cross section and the non-crimped yarn having a non-circular cross section are coated, the effect of significantly improving the covering property is effectively utilized. It was made possible by improving problems that could not be realized and putting them into practical use.

Hereinafter, the present invention will be described in more detail with reference to examples.

〔Example〕

20 denier, 3 filaments of spandex fiber yarn 3.
While being doubled in length, double covering (twisting Z direction 2800 times / m, twisting S direction 2300 times / m) was performed with an ordinary covering machine. The covering yarn used at this time and the covering conditions are as shown in Table 1. The covering yarn is 15D inside.
A crimped yarn obtained by false-twisting a thread made of nylon 6 having a round cross section of -5F and a trilobal section is used with a thread made of nylon 6 having a round cross section of 15D-5F and a trilobal section on the outside. , The type of yarn and the cross-sectional shape factor K were variously changed.

The covering property of the obtained coated elastic yarn was visually evaluated using a magnifying glass, and the judgment was made in four stages of ⊚➝➝➝Δ➝.
◎ and ○ are practical, but △ and × are serious problems and deteriorate the stocking quality. The stretchability of the coated elastic yarn is defined as the stretchability of the elastic yarn after the coated elastic yarn is treated with boiling water until the loosened portion of the coated yarn is fully stretched.

As can be seen from the above results, as the covering yarn, by covering the inside with the crimped yarn having a non-circular cross section and further covering the outside with the non-crimped yarn, it is possible to obtain a covering with good coverage and stretch ratio. An elastic thread is obtained. More preferably, it is effective for improving the covering property that the non-crimped yarn to be coated on the outside also has a non-circular cross section. If the degree of the non-circular shape becomes too large, the texture becomes coarse and hard, and a rough feeling occurs, which is not preferable.

[Brief description of drawings]

FIG. 1 shows an example of a non-circular cross section of the covering yarn of the present invention, and shows one example of a fiber cross sectional shape obtained by false twisting a Y-shaped cross section fiber yarn as a model. .

Claims (2)

[Claims] 1. A coated elastic yarn formed by double-wrapping a core yarn made of an elastic yarn with a covering yarn made of a long fiber of a thermoplastic polymer, wherein the covering yarn wound inside is the same yarn. A crimped multifilament yarn having a cross-sectional shape factor K of 1.2 to 1.6 as an average value of each constituent single fiber in the cross section,
A covered elastic yarn having a double covering, wherein the covering yarn wound on the outer side is a non-crimped yarn. The cross-sectional shape factor K is a value of K = L / Lc, where L means the outer circumference of the fiber cross section, and Lc means the outer circumference of a circle having the same cross-sectional area as the fiber. To do. 2. A patent characterized in that the covering yarn wound on the outer side is a non-crimped multifilament yarn having a cross-sectional shape factor K of 1.2 to 1.6 as an average value of each constituent single fiber in the same yarn cross section. The double-covered covered elastic yarn according to claim (1).