JPH0147571B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Technical Field of the Invention The present invention relates to a composite intertwined crimped yarn comprising polyethylene terephthalate filaments and polybutylene terephthalate filaments.

B. Prior art and its problems Conventionally, it has been known to use a composite yarn of polyethylene terephthalate and polybutylene terephthalate as a yarn for woven or knitted fabrics having stretch properties.
For example, Japanese Patent Application Laid-Open No. 57-205536 discloses an alternately twisted two-layer structure yarn using polybutylene terephthalate as the core yarn and polyethylene terephthalate as the crimped yarn. This is because the winding state around the core thread is relatively gentle, so the elasticity of the polybutylene terephthalate core thread is not inhibited. However, since this yarn consists of only alternate twists, the yarn structure is unstable, such as the core yarn and wound yarn separating due to repeated expansion and contraction. For this reason, even if the yarn structure is stabilized by interlacing before and after the false twisting process, in order to obtain excellent stretch characteristics, it is necessary to remove the instability of the yarn structure as long as a two-layer structure yarn is created with light entanglement. It's difficult.

In addition, such threads have a heathered texture, but in woven and knitted fabrics, the heathered texture and luster are the most sensitive to the visual sense, and therefore, the thread manufacturing process and the thread structure after the product is made. Subtle changes in fiber tend to appear as spots or defects, so stabilizing the thread structure is extremely important.

C. Object of the present invention The object of the present invention is to provide a composite yarn consisting of polyethylene terephthalate and polybutylene terephthalate yarns, which is rich in cast stretch, has a stable yarn structure even through repeated expansion and contraction, and is suitable for use in woven or knitted fabrics. The object of the present invention is to provide a yarn for woven or knitted fabrics having surface effects and flexibility.

D. Structure of the present invention "(1) A crimped multifilament yarn composed of filament fibers made of polyethylene terephthalate and filament fibers made of polybutylene terephthalate, the total length of the intertwined portion being 1
polyester composite interlaced crimped fibers present in an amount of 20% or more per m, and most of the single fibers in the entangled and converged portion exhibit a wavy or coiled crimped structure in an integrated state. thread. In the present invention, since the multifilament yarn is made of polyethylene terephthalate and polybutylene terephthalate, polybutylene terephthalate has excellent elasticity and is highly stretchable, and has the effect of improving stretch properties. There are many advantages to using polybutylene terephthalate, such as polybutylene terephthalate yarn having an initial tensile resistance comparable to that of polyamide, and unlike composite yarns made of polyethylene terephthalate, it has a soft texture.

Here, the intertwined portions need to have a total length of 20% or more per 1 m of yarn length. The reason for this is that it is necessary to have structural stability during the crimping process, weaving, knitting, and products. For this purpose, it is preferable that the intertwined portion be strong or have a high ratio of intertwined portions. If the entanglement is weak, the intertwined portions will come undone during the crimping process, resulting in a yarn that is no different from a normal crimped yarn and will not be able to exhibit the surface effects described below. In addition, if the ratio of intertwined parts is high, the structure becomes an integrated crimped structure, which is rich in surface effects and flexibility, but conversely, if the ratio of intertwined parts is low, an integrated crimped structure cannot be obtained, and the single fiber becomes an open fiber. As a result, only spot-like unresolved portions remain, and a wavy or coiled crimped structure cannot be obtained.

In order to obtain the yarn of the present invention, the overfeed rate at the time of interlacing is 3%, preferably 5% or more, and the fluid pressure is ² to 7 kg/cm2. A yarn having a crimped structure as described above is produced. Further, the false twisting conditions may be the same as those for normal crimped yarn. If the number of false twists is small, the crimps will be coarse, and if the number of false twists is large, the crimps will be dense, resulting in a dense surface effect as described below. In addition, in order to further give the surface unevenness effect, 5000≦K≦15000
Additional twisting may be performed in the same direction as the false twisting with a twist coefficient (K) of .

The false twisting temperature is preferably about 120 to 220°C.

The intertwined portion ratio is the ratio of the total length of the intertwined portions to the yarn length, and is measured as follows.
First, the average number N of entangled parts per unit length under a tension of 0.1 g/D is counted in a non-tensioned state.
Subsequently, a pin is inserted into the unentangled portion under a tension of 0.1 g/D, and the pin is moved back and forth in the longitudinal direction of the thread under a tension of 0.02 g/D to determine the average length S of the unentangled portion. From N and S obtained in this way, the interlaced part ratio L
is calculated using the following formula.

L (%) = 1 (m) - N (ko/m) x S (m) / 1 (m
) x 100 e Effects of the present invention The effects of the present invention are that the yarns made of polyethylene terephthalate and polybutylene terephthalate are highly stretchable, and that the yarn structure is stabilized by repeated expansion and contraction, and that the surface effect and flexibility of woven and knitted fabrics are improved. A yarn for woven or knitted fabrics with a Next, an example will be given and explained.

Example 1 Multifilament drawn yarns of polyethylene terephthalate and polybutylene terephthalate
75D-36f was subjected to intermittent entanglement treatment at an overfeed rate of 5% to obtain a strong entangled yarn, which was then continued. Processing temperature: 205℃ Processing speed: 100m/min Number of false twists: 2450T/M Processing feed: False twisting was performed under -3% conditions. The confounding ratio at this time was 22%. This yarn was woven into a fabric using polyethylene terephthalate 50D-36f as warp yarn, and dyed and finished. The resulting fabric had a uniform heathered texture, a stretch rate of 25%, and a rich uneven surface variation.

Example 2 Using the same yarn as Example 1, the entanglement feed rate was 7%.
False twisting was carried out under the same conditions as in Example 1. The confounding ratio at this time was 43.5%. This yarn was woven into a fabric using the same warp yarn as in Example 1, and dyed and finished. The results are in Example 1
became the same.

Comparative Example Using the same yarn as Example 1, the entanglement feed rate was 2%.
False twisting was carried out under the same processing conditions as in Example 1 except that the processing feed was -2%. The confounding ratio at this time was 7%. This yarn was woven into a fabric using the same warp yarn as in Example 1, and dyed and finished. The results showed that there were almost no surface effects.

[Brief explanation of drawings]

FIG. 1 shows an interlaced crimped yarn of the present invention. 1: Entangled portion, 2: Unentangled portion, 3: Polyethylene terephthalate, 4: Polybutylene terephthalate.

Claims (1)

[Claims] 1 A crimped multifilament yarn composed of filament fibers made of polyethylene terephthalate and filament fibers made of polybutylene terephthalate, with a total length of intertwined parts of 1 m.
A polyester composite interlaced crimped yarn, characterized in that the fibers are present at 20% or more in the interlaced and bundled part, and most of the single fibers in the interlaced and bundled part exhibit a wavy or coiled crimped structure in an integrated state. .