JPH0129589B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to staple cotton suitable for use in bedding such as futons and stuffing, and an object of the present invention is to provide a polyester fiber cotton that has superior versatility compared to conventionally commonly used polyester fiber cotton. It is something to do. Synthetic cotton fibers such as polyolefin fibers, polyacrylonitrile fibers, and polyester fibers have been widely used for bedding purposes due to their excellent bulk, and in recent years, composite spinning and asymmetric cooling spinning have been developed to further improve their performance. Synthetic fiber cotton with three-dimensional crimp has been developed and is becoming widely used. However, with synthetic cotton produced by forward three-dimensional crimp in only one direction, lowering the number of crimp improves the bulkiness of the product when no load is applied, but the entanglement between single fibers increases. This decreases so much that it becomes difficult to handle during cotton milling, and the volume decreases when a load is applied (so-called sagging). On the other hand, increasing the number of crimps improves the handling properties during cotton manufacturing and the resistance to settling, but the bulkiness under no load decreases. Ultimately, no matter which conditions are considered, staple cotton has not been obtained that satisfies both bulkiness under no load, resistance to settling, and ease of handling during cotton manufacturing. Although various attempts have been made to improve these drawbacks, such as making the fiber hollow, changing the single fiber fineness, fiber length, and changing the oil agent, the above-mentioned contradictions have not yet been resolved. The present invention was completed as a result of various studies in order to solve these problems, and is a polyester fiber having three-dimensional crimp performance. The present invention relates to staple cotton for bedding, which is characterized by homogeneously mixing crimped fibers having an inverted three-dimensional crimp of % to 90%, and a method for producing such staple cotton for bedding. For example, the fact that a wave-shaped crimp with three-dimensionality (inverted three-dimensional crimp) can be obtained by mechanically crimping the spun yarn of a synthetic fiber that potentially has three-dimensional crimp performance is known, for example, as reported by Tokko Sho. 51-48091. However, with staple cotton having only such inverted three-dimensional crimp, the product cotton has low bulk under no load, and is therefore difficult to put into practical use. As a result of thorough analysis and study of the technical background, the present inventors found that inversion crimp cannot necessarily be obtained only by mechanical crimp after stretching, and that a spinning material with three-dimensional latent crimp performance can be obtained. This can be obtained by applying pressure with a pressure roller under tension after drawing the yarn, and surprisingly, when no reverse pressure is applied from the stuff-in box of the crimper, the pressure roller It has been discovered that the mixing ratio of forward type three-dimensional crimp and reverse type three-dimensional crimp can be arbitrarily changed by changing the pressing force, and that both types of three-dimensional crimp can be mixed extremely homogeneously. Ta. Furthermore, if a crimping machine is used after drawing in the method described in Japanese Patent Publication No. 51-48091, almost all of the fibers will turn into inverted three-dimensionally crimped fibers under conditions of stable feed to the crimping machine and crimping. Although it is not possible to obtain a homogeneous mixture of forward type three-dimensional crimp and reverse type three-dimensional crimp because of the It may also be used as a substitute for a metal pressure roller. For example, a 1 million Dr spun yarn that has been given latent crimp performance by asymmetric cooling is stretched 2.5 times, passed through a metal roller with variable pressure, and then subjected to relaxation heat treatment at 160°C to develop crimp. The relationship between the ratio of the inverted three-dimensional crimped fibers and the pressing force of the metal roller is shown in Figure 1 (〇-〇). As can be easily understood from Figure 1, the rate of occurrence of inverted three-dimensional crimped fibers is 1 cm from the pressing length of the metal roller.
There is almost no contact pressure up to 80KG/cm, and from now on, it gradually increases as the pressure increases, and the pressure increases.
At 180KG/cm or more, it is almost 90% or more.
In the staple cotton produced in this way, as the proportion of inverted three-dimensionally crimped fibers increases, the ratio of decrease in the volume under load to the unloaded volume of the product cotton becomes smaller;
In other words, it has improved resistance to settling, and although there is a slight decrease in unloaded bulk, the unloaded bulk is far superior to that of forward type three-dimensional crimped staple cotton with an increased number of crimps. It shows. Among bedding applications, the blending ratio of inverted three-dimensional crimped fibers for fields that require bulkiness in no-load or low-load areas, such as for comforters, stuffed toys, and cotton filling applications, is 10% or more and 50%. The following is desirable, and on the other hand, the mixing ratio of inverted three-dimensional crimped fibers for fields that require bulk maintenance in heavy load areas, such as for futons, pillows, and cushions, is preferably 50% or more and 90% or less. As described above, by setting the mixing ratio of the inverted three-dimensionally crimped fibers to the optimum ratio, it is possible to supply staple cotton that is extremely suitable for each field. Furthermore, as can be seen from Figure 1, the proportion of the inverted three-dimensionally crimped fibers can be adjusted to any desired ratio by fixing the strength of the latent crimp performance of the spun yarn and the pressing force of the pressure roller. can get. Furthermore, the forward type three-dimensional crimp mentioned in the text refers to the spiral-like three-dimensional crimp as shown in Figure 2, and the inverted three-dimensional crimp refers to each crimp type as shown in Figure 3. It is a three-dimensional crimp in which the fiber is reversed to an omega shape (Ω), and since both fiber bundles exhibit one of the crimp forms, they can be easily counted visually, and the mixing ratio of the two can be calculated. . Furthermore, the fibers having the latent crimp performance targeted in this text may be those produced by composite spinning, those produced by asymmetric cooling spinning, or any other fibers, and the fiber fineness and fiber cross-sectional shape are not particularly limited. Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.60 was melted, melt-spun through a spinneret having a hollow discharge hole, and asymmetrically rapidly cooled. The obtained undrawn yarn was bundled into an undrawn tow and stretched 2.5 times.
After that, it is passed through a pair of metal pressure rolls and further
Relaxation heat treatment at 160°C was performed. It was further cut into 57 mm pieces to produce hollow staple cotton. Furthermore, the staple cotton was milled and the initial load (0.5
Table 1 shows the results of measuring the molded product specific volume under load (10 g/cm ² ) and under load (10 g/cm ² ). Comparative examples include one in which the pressurized metal roll is not passed through, one in which the number of crimps is increased without passing through the pressurized metal roll, and one in which the crimping machine staff inbox is activated to apply regular mechanical crimps. added.

[Table] The following can be seen from Table 1. That is, (1) No. 1 has sufficient initial bulk, but the bulk when loaded is too low and the sag is too large. (2) No. 2 and No. 3 have a large initial bulk, and the molded products are clumped together, so the bulk when loaded is also quite high. It is especially suitable for use in futons. (3) Although the initial bulk of No. 4 and No. 5 is slightly inferior, the bulk under load is sufficient, and although inferior to No. 2 and No. 3, they can be used for comforters. (4) No. 6, No. 8, and No. 9 all have sufficient bulk under load, but their initial bulk is too low, so they have no commercial value for futon use. Example 2 Polyethylene terephthalate having an intrinsic viscosity of 0.60 was melted and then melt-spun through a spinneret and asymmetrically cooled to produce a spun yarn having latent crimp performance and a protruding cross section (〓). After converging this to form an undrawn yarn tow, it is stretched 2.8 times.
It was immediately passed through a metal pressure roll. Thereafter, it was stapled in the same manner as in Example 1, and cotton manufacturing evaluation was performed. However, the initial load when evaluating the molded product is 0.5
g/cm ² , and the load weight was 35 g/cm ² , and the performance was evaluated focusing on the resistance to set. The results are shown in Table 2.

【table】

[Table] The following can be seen from Table 2. That is, when considering the use as a futon, (1) No. 1, No. 7, and No. 8 have no commercial value because their bulk under load is too low. (2) No. 2 and No. 3 have good initial bulk and bulk under load, and have sufficient commercial value. (3) No. 4 and No. 5 have poor initial bulk, especially when loaded, so they are not suitable for use in mattresses, etc.
Particularly suitable for fields that require bulkiness under high loads. (4) Although No. 6 and No. 9 have high bulk under load, their initial bulk is so poor that they lack marketability.

[Brief explanation of drawings]

Figure 1 shows the pressing force when a synthetic fiber with latent crimp performance is stretched and then pressed with a pressure roller under tension, and the amount of force in the three-dimensionally crimped fibers developed by the subsequent relaxation heat treatment. FIG. 3 is a diagram showing the ratio of inverted three-dimensional crimped fibers. Also, Figures 2 and 3
Each figure is a photograph for explaining a three-dimensionally crimped fiber or an inverted three-dimensionally crimped fiber.

Claims (1)

[Claims] 1. 10% polyester fiber having three-dimensional crimp performance in a crimped fiber having forward three-dimensional crimp.
A polyester fiber staple cotton for bedding made of a mixture of crimped fibers having an inverted three-dimensional crimp of 90% or less. 2. After stretching the spun yarn of polyester fiber potentially endowed with three-dimensional crimping performance, it is pressed under tension with a pressure roller, and then subjected to relaxation heat treatment to form a forward three-dimensional crimped fiber with 10 % or more 90%
A method of manufacturing polyester fiber staple cotton for bedding by mixing the following inverted three-dimensional crimped fibers.