JPH073564A - Slub-like multifilament yarn - Google Patents

Abstract

PURPOSE:To provide the yarns good in the process passability in its post- processing and capable of obtaining knitted fabrics of natural appearance. CONSTITUTION:The objective yarns are a kind of sheath-core type conjugated yarns with uneven finenesses in the longer direction produced by turbulent flow teratment of multifilament yarns with high-pressure fluid, having the following characteristics: (1) mean fineness ratio for the maximum fineness portions and minimum fineness portins is 1.1-1.6, (2) the slubs >=10% greater in mean fineness than the minimum fineness portions accounts for 20-60% of the whole yarns, and (3) nep parts large in apparent fineness are randomly distributed in said slub portions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slab-shaped multifilament yarn using multifilaments and having fineness unevenness in the longitudinal direction of the yarn.

[0002]

2. Description of the Related Art As a well-known means for producing a slab-shaped yarn using a multifilament yarn, it is possible to obtain two kinds of yarns having different supply amounts by temporarily twisting them. There are pongee-finished threads. This pongee-finished yarn has a good appearance, but since a strong twist is introduced into the entire yarn, the woven or knitted fabric obtained using this yarn has a hard texture. As a method that does not use temporary processing, for example, as shown in Japanese Patent Laid-Open No. 61-19829, one of two types of multifilaments is fed by a variable speed roller while changing the supply amount, and high-pressure fluid turbulent flow treatment is performed. It is also well known to squeeze two kinds of multifilaments into a slab-shaped thread. However, this method using high-pressure fluid turbulent flow also has problems that under the conventionally known conditions, the passability in the next process such as thread is poor and the slab portion is too uniform to give a natural appearance.

[0003]

DISCLOSURE OF THE INVENTION The present invention is a slab yarn produced by high-pressure fluid turbulent flow treatment, has a slab portion that is not uniform and has a natural appearance, and has good passability in the next step such as cotton thread. A slab-shaped multifilament yarn is provided.

[0004]

The present invention has the following constitution in order to solve the above problems. That is, the present invention is a core-sheath type composite yarn having fineness unevenness in the longitudinal direction of the yarn obtained by subjecting a multifilament yarn to turbulent high-pressure fluid treatment,
The average fineness ratio of the maximum fineness part and the minimum fineness part of the composite yarn is 1.
1 or more and 1.6 or less, the proportion of the slab portion having an average fineness of 10% or more and an average fineness larger than the average fineness of the minimum fineness portion of the composite yarn is 20% or more and 60% or less, and the slab portion of the slab portion It is a slab-shaped multifilament yarn characterized in that nep-shaped portions having an apparent fineness greater than 30% are randomly mixed.

The present invention will be described in more detail below.
The multifilament as referred to in the present invention may be made of polyester, nylon or the like, but polyester yarn is preferable because it has excellent mechanical stability. The method of producing slab-shaped multifilament yarns by high-pressure fluid turbulent flow processing is as follows: a multi-filament of core yarn is rotated from a roller that rotates at a constant speed, and a sheath yarn is rotated at a variable speed by an arbitrary random signal. It is manufactured by being simultaneously drawn into a high-pressure fluid turbulence treatment nozzle from a roller connected to a motor.

[0006] A yarn usually undergoes processes such as thread and warp, but in the case of a slab-shaped yarn, the process passability in these processes is poor. It is clear from the results of the study that the ratio of the slab portion to the non-slab portion is important for the process passability, and the process passability becomes extremely high when the average fineness ratio of the maximum fineness portion and the minimum fineness portion of the composite yarn exceeds 1.6. become worse. However, it was also found that if the ratio is less than 1.1, the slab-like effect cannot be obtained with the woven or knitted fabric. More preferably, it is 1.2 or more and 1.4 or less. The average fineness ratio here is determined from a U% chart measured with a Worcester-Ibnestestar at a chart speed of 25 cm / min and a yarn speed of 100 m / min for 5 minutes. It is calculated by the ratio of the average fineness of the maximum fineness portion and the average fineness of the minimum fineness portion.

When the slab-shaped multifilament yarn of the present invention is used as a woven or knitted fabric, the ratio of the slab-shaped portion and the shape of the slab portion become problems in order for the fabric to have a good appearance. Mechanically, the slab thickness can be changed within the average fineness ratio by arbitrarily changing the signal, but even if the slab thickness is changed within the average fineness ratio in consideration of the post-processing step passability, when the fabric is used. The degree of change of the cloth surface that can be seen becomes large,
It was found to look uniform and artificial. The present inventors have conducted investigations to improve the above-mentioned drawbacks, and by arranging a nep-like portion having a larger fineness but a shorter fineness in the slab portion, a natural appearance can be obtained when the cloth is formed and the post-processing step is passed. It turned out that the sex is also good.

Considering the effect of the cloth, the size of the nep-shaped portion occupying the slab portion is 3 from the apparent fineness of the slab portion.
It is necessary that the nep-like portions having an apparent fineness of 0% or more are randomly mixed. Nep-like parts having an apparent fineness of 200% or more larger than the apparent fineness of the slab and a length of 10 mm or more are not preferable in consideration of the post-processing step passability. The apparent fineness referred to here is the fineness based on the fineness of the non-slab portion obtained by taking a 25 times magnified photograph of the woven and knitted yarn. Furthermore, in order to have a natural appearance in which the slab portion is not abundant and not a little when made into a woven or knitted fabric, the average fineness of the minimum fineness portion of the composite yarn is 10%.
It is necessary that the proportion of the slab portion having a large average fineness is 20% or more and 60% or less.

An example of the method for producing the slab-shaped multifilament yarn of the present invention is shown in FIG. The multifilament 1 to be the core yarn is supplied to the high pressure fluid turbulent flow treatment nozzle 5 via the constant speed roller 2. Multifilament 3 that becomes a sheath thread
Is supplied to the high-pressure fluid turbulence treatment nozzle 5 via the speed change roller 4 which changes speed according to the signal received from the computer 10. The conditions for the high-pressure fluid turbulent flow treatment nozzle 5 are set by appropriately selecting the set pressure, the type of nozzle to be used, etc. so that the entanglement of the core-sheath multifilament is not increased. The slab-shaped multifilament yarn ironing guide 7 exiting the high-pressure fluid turbulence treatment nozzle 5 produces a fine nep-shaped portion in the slab portion. The yarn continues to pass through the confounding nozzle 8 and the package 9
To be wound up. 6 is a take-off roller.

[0010]

EXAMPLES Working was performed under the following conditions using the apparatus shown in FIG. (Used multifilament) Core yarn Polyester multifilament yarn 50 denier 36 filament Sheath yarn Polyester multifilament yarn 75 denier 36 filament (Processing speed) 150 m / min (Core yarn overfeed rate) 5% constant (Sheath yarn overfeed rate) Random changes are made every 0.1 second to 1.0 second in an overfeed amount range of 5% to 70%. The obtained yarn had the following characteristics.・ Average fineness ratio between maximum fineness and minimum fineness 1.3 1.3 ・ Average slab length 2.1 ・ Ratio of slabs having average fineness of 10 or more than minimum fineness 25% ・ Apparent fineness of nep-like portion 30% 130% -Nep-shaped part average length 7 mm When the following woven fabric was manufactured using the composite yarn, the woven fabric had an extremely good natural appearance. -Warp Polyester multifilament 75 denier 72 filaments Number of trails 1000 times / m Warp density 100 / in-Weft The slab-shaped multifilament yarn of the present invention Number of trails 1000 / m Weft density 80 / in

[0011]

Comparative Example Using the same core yarn and sheath yarn as in the example, only the range of overfeed rate of the sheath yarn was changed from 7% to 140% to obtain the following yarn. -Proportion of average fineness between maximum fineness and minimum fineness 1.8-Average slab length 2.8-Proportion of slabs with average fineness 10% or more greater than minimum-35% -Nep-like apparent fineness 50% From 30% ・ The average length of the nep-shaped portion is 13 mm. When the same woven fabric as in the example is produced by using the composite yarn,
There were many yarn breakages in the fabric manufacturing process, resulting in many defects.

[0012]

As described above, the slab-shaped multifilament yarn processed within the scope of the present invention has good post-process passability and has a nep-shaped portion in the slab portion. Woven fabrics have a natural appearance.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an apparatus used in the present invention.

[Explanation of symbols]

 1 multifilament 2 constant speed roller 3 multifilament 4 variable speed roller 5 high-pressure fluid turbulence treatment nozzle 6 guide 7 confounding nozzle 10 computer

Claims (1)

[Claims] 1. A core-sheath type composite yarn obtained by subjecting a multifilament yarn to turbulent high-pressure fluid treatment and having fineness unevenness in the longitudinal direction of the yarn, wherein the maximum fineness portion and the minimum fineness portion of the composite yarn are provided. Of the average fineness ratio of 1.1 or more and 1.6 or less, the proportion of the slab portion having an average fineness greater than 10% or more than the average fineness of the minimum fineness portion of the composite yarn is 20% or more and 60% or less, and A slab-shaped multifilament yarn, wherein nep-shaped parts having an apparent fineness of 30% or more larger than the apparent fineness of the slab are randomly mixed.