JPS5917222B2 - Pleating method for polyester fiber knitted fabric - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pleating method for pleating a knitted fabric using a two-layer structured yarn in which highly oriented undrawn polyester fibers are wound around a core yarn.

Generally, pleating of a knitted fabric is performed by pleating a knitted fabric using thermoplastic synthetic fiber filament yarn.

Conventionally, knitted fabrics for pleating have been made of thermoplastic synthetic fiber filament yarns and thin fabrics in order to maintain their pleatability and improve the setting effect.

However, thick fabrics made using bulky type yarns often do not have sufficient pleatability and lack retention.

This tendency is particularly strong in thick knitted fabrics.

In order to improve these drawbacks, it is strongly desired to develop a bulky type yarn with good pleat setting properties.

Knitted fabrics for bulky type pleats include:
Various methods have been tried to improve the pleatability, but there is no definitive method, and attempts have been made to improve the pleatability of knitted fabrics by changing the texture.

In order to improve the above drawbacks and improve the setting properties during pleating, the present invention provides at least two kinds of polyester filament yarns that have been subjected to false twist and crimping under false twist setting conditions at a temperature of less than 180°C. A two-layer structure yarn in which one of the filament yarns is used as a core yarn and the other filament yarn, which is a highly oriented undrawn polyester fiber, is wound around it is knitted and woven, and the knitted fabric is heated at a temperature higher than the temperature of the false twist setting conditions. This is a method for pleating a woven or knitted polyester fiber fabric, which is characterized by pleating a woven or knitted fabric using polyester fibers.

The present invention will be explained in detail below.

The polyester fiber knitted fabric used in the method of the present invention is made of a two-layer structured yarn that has been subjected to a false twist crimp process.

In other words, this two-layer structure yarn is a two-layer structure yarn in which one of at least two kinds of polyester filament yarns that has been subjected to a false twist and crimp process is used as a core yarn, and the other filament yarn is wound around it. be.

Although some of the filaments that make up the winding yarn are randomly mixed and intertwined with the filaments in the core, the winding system as a whole is wound around the core yarn in a continuous alternating manner. Particularly preferred.

In the above-mentioned continuous alternating reverse winding, the twisting effect is reduced compared to complete twisting (winding), but on the other hand, the winding yarn has a very short pitch, that is, the winding yarn alternately crosses the yarn axis in opposite directions. This is the structure obtained.

Further, a textured yarn having a S-shaped structure can be obtained by subjecting at least two yarns having different elongation differences in a mixed and intertwined state to a special drawing false twisting method.

In this case, it is necessary to first obtain a wound two-layer twisted yarn structure by intertwining two or more raw yarns with different elongations and then heating them with a false twister.

For this purpose, it is necessary that the yarn with lower elongation can be drawn and false-twisted, and at the same time, the difference in elongation between the yarns to be combined with this yarn is 1
It is necessary to have 00 sections or more.

Since the interlaced yarn is a mixture of two yarns with different elongation, it is difficult to form a two-layer structure even if it is heated as it is.

However, this problem can be solved by supplying a yarn that can be drawn and false-twisted to the yarn with lower elongation.

In other words, by false twisting and heating at the same time as drawing, yarns with different elongations that are integrated by interlacing treatment can be made into filaments with high tension due to the difference in the elongation characteristics of both yarns with respect to the false twisting tension. While the filaments are separated again into a filament group and a filament group with low tension, some of the fibers of both groups become yarns that are partially intertwined in the length direction, which is twisted by a false twisting device.

From this point of view, it is necessary that the filament yarn with lower elongation used as the core yarn described above can be drawn and false-twisted at least 1.2 times or more, but when the draw ratio is 1.4 times or more, the most Favorable results are obtained.

Furthermore, in order to obtain a wound two-layer twisted yarn structure at this time, the magnitude of the difference in elongation between the two yarns is relevant, and a larger difference in elongation than conventionally known is required.

That is, in the case of no entanglement, a difference in elongation of both yarns of about 50% is enough to obtain a two-layer structure, but in the case of interlacing treatment, a difference in elongation of 10% or more is required. In particular, more favorable results can be obtained if there is a difference in elongation of 150 modulus or more.

In this way, by providing a large elongation difference between the two yarns, the separation of the mixed fiber yarn into two layers due to drawing becomes apparent, and a two-layer heating structure is obtained for the first time in the heating region. As a result, by untwisting the heated yarn, a two-layer structured yarn with alternate twisting and winding can be obtained.

Furthermore, in the present invention, it is necessary to use highly oriented undrawn polyester fibers as filaments for winding the two-layered yarn, and the fibers can be obtained by spinning polyester at high speed using a known method. It is obtained by

Further, the above-mentioned two-layer structured yarn can be obtained by false twisting while being stretched, and the false twisting setting condition can be a low temperature of less than 180°C.

That is, normally, a bulky crimped yarn is obtained only by using a high temperature of 200°C or higher, but the two-layer structured yarn used in the present invention uses the above-mentioned polyester filament yarn. Even under false twist setting conditions at such low temperatures, a sufficiently bulky crimped yarn can be obtained.

The present invention is a method of knitting and weaving the bulky crimped yarn having a two-layer structure obtained in this manner and pleating the knitted fabric, wherein the pleating conditions include the following:
It may be carried out at a temperature higher than the temperature of the false twist setting conditions, and for example, a dry heat temperature of 160° C. to 200° C. is preferably used.

By the pleating process performed as described above, it is possible to obtain pleats with excellent setting properties and retention properties.

That is, in the method of the present invention, pleats in a more thermally stable state are obtained by making the temperature conditions for pleating higher than the temperature for the false twist setting conditions, and the above-mentioned specially wound yarn By using highly oriented undrawn yarns, it is possible to easily obtain a sheep pleat structure by taking advantage of its heat shrinkage stress rate.

Furthermore, in the method of the present invention, since the above-mentioned two-layer structured yarn is used for knitting and weaving, it is possible to produce a knitted fabric that is bulky and has a large basis weight. It is possible to obtain pleats with excellent setability and retention properties even when the pleats are made of plastic.

At this time, since the above-mentioned two-layer structure yarn constituting the polyester fiber knitted fabric used in the method of the present invention is processed at a relatively low temperature, the processing temperature of the pleats is also low in the method of the present invention. Therefore, it is possible to reduce the "shininess" and "hitting" of pleats, which were problems in the past.

Claims (1)

[Claims] 1 One of at least two types of polyester filament yarns that have been subjected to false twist and crimping under false twist setting conditions at a temperature of less than 180°C is used as a core yarn, and the other filament yarn, which is a highly oriented undrawn polyester yarn, is surrounded by the core yarn. A pleating force method for a polyester fiber knitted fabric, which comprises knitting and weaving a two-layer structured yarn formed by winding fibers, and pleating the knitted fabric at a temperature higher than the temperature of the false twist setting conditions.