JP2733301B2 - Method for producing low-shrink viscose rayon yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a low-shrink viscose rayon yarn.

<Conventional technology> Conventionally, viscose rayon yarns used in the flat knitting field by twisting and twisting with other kinds of yarns are 200-400 T / M of yarn having a boiling water shrinkage of about 2% called cake. Twist, (hereinafter,
It was twisted with other yarns of about 2.5% boiling water shrinkage.

In recent years, production of viscose rayon yarn by continuous spinning instead of cake has been considered due to innovation of the production process. In the continuous spinning method, there are many steps of continuously pulling the yarn during production, and the boiling water shrinkage tends to be as high as 5 to 10% as compared with the cake. This viscose rayon yarn is twisted by sweet twisting in the same manner as cake, and the viscose rayon yarn has a larger boiling water shrinkage ratio of the yarn than that of other kinds of yarns of around 2.5%. Compared with a normal yarn in which viscose rayon cake 1 and other yarns are alternately twisted as shown in FIG. 1, the other yarn 2 is entangled around this yarn 3 as shown in FIG. It becomes a problem.

Two methods are conceivable as means for reducing the shrinkage of the viscose rayon yarn. One method is a method in which the yarn is skeined and dyed after sweet twisting, the yarn is shrunk once, and then wound up on a bobbin with a skein reeling machine, and then twisted with another type of yarn. . However, in this method, since the skein is used, the yarn length is short, and the number of knots at the time of twisting increases. In addition, the process from sweet twisting to twist twisting is long, requires complicated work, takes time, and increases costs. There is also a problem that post-dyeing cannot be performed because of first-dying. Another method is
In this method, a sweet twist core having a winding amount of 700 to 1600 g is formed on the double twister core, and then subjected to wet heat treatment to shrink the yarn once and alternately twist it with another kind of yarn. In this method, the degree of treatment differs greatly between the innermost layer yarn and the middle to outer layer yarn, resulting in a large problem of a large difference in boiling water shrinkage. That is, the yarn after the sweet twisting becomes a yarn having a low boiling water shrinkage rate by the wet heat treatment, but the yarn in the innermost layer portion of the wound yarn is in contact with the winding core, so that the wet heat shrinkage of the yarn is inhibited. Therefore, the yarn in the innermost layer portion of the winding always shows a value whose boiling water shrinkage is 20 to 30% higher than that of the yarn in the middle layer to the outer layer portion. This physical property value has a bad influence on use, which is a problem.

<Problems to be Solved by the Invention> The present invention relates to a method for producing a low-shrink viscose rayon yarn which is advantageous for industrial production and implementation when lowering the boiling water shrinkage of a conventional viscose rayon yarn. To provide.

The present invention <Means for Solving the Problems> is a feature that the viscose rayon yarn, raising seeded in wound density 0.25~0.70g / cm ³ to coated winding core with cushioning material, and then wet heat treatment Is a method for producing a low-shrink viscose rayon yarn.

The present invention is particularly effective for viscose rayon yarns having a boiling water shrinkage of 6% or more.

 Hereinafter, the present invention will be described in detail.

In the present invention, the cushioning material refers to a material that is deformed by wet heat shrinkage stress (plane compressive stress) during wet heat treatment. When this buffer material is used, a wet heat shrinkage stress of the yarn is generated in the wet heat treatment, and the stress buckles the buffer material, so that the residual wet heat treatment stress of the yarn from the innermost layer to the outer layer portion of the wound yarn becomes uniform. Examples of such a cushioning material include an air cushion, an ester wooly material, and cardboard. Among them, cardboard is particularly preferred. As a more preferable corrugated cardboard, the wave height shown in FIG.
A 9/4 cm cardboard A tier 4 is preferred. FIG. 4 is a diagram in which a thread 9 is wound around a core 8 covered with a cushioning cardboard 4.

Next, the winding density is 0.62-0.70g /
cm ³ is preferred, and can be reduced to 0.25 g / cm ³ by soft winding. If it is less than 0.25 g / cm ³ , as shown in FIG. In addition, the filaments in the outer layer shown in FIG. If it exceeds 0.70 g / cm ³ , fluffing and cutting occur during twisting, which is a problem.

The wet heat treatment is usually performed by using a vacuum setter and setting a set temperature and a set time according to a required boiling water shrinkage. Usually, a set temperature of 65 to 90 ° C. and a set time of 30 to 50 minutes are preferably used.

 Next, the present invention will be specifically described with reference to examples.

Example 1 Viscose rayon yarn was subjected to wet heat treatment under the following conditions. The boiling water shrinkage was used as a means for evaluating low shrinkage yarns. The boiling water shrinkage was evaluated according to the JISL-1013-7.15- (1) -A method.

Thread type Rayon yarn 250B / 60f Twist type Double twister Number of twists 300T / M Winding density 0.67g / cm ³ Winding type 1600g Winding core diameter 90mmφ Setting temperature x time 80 ℃ × 40min 90 ℃ × 40min Twisting / wet The heat-treated yarn was stratified from the outer layer to the innermost layer of the wound yarn, and the boiling water shrinkage was measured. The results obtained are shown in FIG. In the figure, the reference numeral 11 indicates no wet heat treatment, 12 indicates a set temperature × time of 80 ° C. × 40 minutes, and 13 indicates a set temperature × time of 90 ° C. ×
40 minutes. As shown in the figure, by performing the wet heat treatment, the boiling water shrinkage rate is reduced, and a low heat shrinkage yarn is obtained at a higher wet heat treatment temperature.

Example 2 Wet heat treatment was performed using various types of buffer materials. Air cushion, ester wooly material, cardboard A as cushioning material
Four types of columns were examined.

The same conditions as in Example 1 were used except that the setting conditions were 90 ° C. × 40 minutes.

The boiling water shrinkage was measured by stratifying the yarn after the twisting / moist heat treatment from the outer layer to the innermost layer of the wound yarn. The result is shown in FIG. In the drawing, reference numeral 14 denotes no cushioning material, 15 denotes an air cushion, 16 denotes an ester wooly material, and 17 denotes a cardboard A step.

The twisted state was determined by layering the twisted yarn and the filament after the wet heat treatment from the outer layer to the innermost layer of the winding, and the outer layer, the middle layer, and the innermost layer were each twisted with another material, and the twisted state was evaluated by sensory evaluation. Table 1 shows the results. The sensory evaluation was performed by the following method.

…: Good twisted state.

C: The twisted state is poor.

The color difference is obtained by layering the yarn after the twisting / moist heat treatment from the outer layer to the innermost layer of the winding yarn, knitting the outer layer, the middle layer, the innermost layer, and the outer layer in a single knitting machine, dyeing the outer layer, the middle layer, and the outer layer. The color difference between the innermost layer, the middle layer and the innermost layer was determined. Table 2 shows the results. The color difference was evaluated by the following method.

…: Within 0.5 NBS ×: 1.0 NBS or more From FIG. 9, it was found that the buffer material had an effect of making the boiling water shrinkage rate uniform from the outer layer to the innermost layer of the wound yarn. In particular, the effect of cardboard is great.

In Tables 1 and 2, those using the cushioning material show good quality without any problem in the twisted state and color difference. When the cushioning material was not used, there was a problem in the twisted state and the color difference, and the quality was poor.

The effect of the cushioning material was examined by changing the winding density from 0.25 to 0.70 g / cm ^3, and within this range, FIG. 9, Table 1,
The results were the same as in Table 2.

<Effects> The present invention has the following remarkable effects.

* Low-shrink viscose rayon yarn can be easily manufactured.

* There is no difference in the boiling water shrinkage in the yarn length direction.

* The process is simplified.

* Large packaging is possible.

* Can be dyed.

[Brief description of the drawings]

Fig. 1 is a diagram of a normal twisted state, Fig. 2 is a diagram of a twisted state after a boiling water treatment using a yarn having a large difference in boiling water shrinkage, and Fig. 3 is a cross-sectional view of a corrugated cardboard used in the present invention. Fig. 4 is a diagram showing a state in which a corrugated cardboard is wound around a core and a filament is wound thereon, Fig. 5 is a diagram showing a state in which the winding layer is displaced from the core, Fig. 6 is a diagram showing a state in which outer layer disturbance has occurred, FIG. 7 is a diagram showing the relationship between the presence and absence of wet heat treatment and the boiling water shrinkage ratio, and FIG. 8 is a diagram showing the relationship between the yarn in each layer portion of the winding yarn and the boiling water shrinkage ratio for each buffer material. 1 ... rayon cake yarn, 2 ... other kind yarn, 3 ... rayon yarn with boiling water shrinkage of 5 to 10%, 4 ... corrugated cardboard paper, 6 ... thickness of corrugated paper (mm), 8 ... … Winding core, 9…
… Viscose rayon yarn, 10… Bound portion of the yarn.

Claims (1)

(57) [Claims] 1. A low-shrink viscose rayon yarn comprising: winding a viscose rayon yarn around a core coated with a cushioning material at a winding density of 0.25 to 0.70 g / cm ^3; Manufacturing method