JPH0787880B2 - Manufacturing method of polyester raw cotton for wadding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a polyester raw cotton for batting having excellent bulkiness.

[Prior Art] Conventionally, hollow fibers are usually used for raw cotton for stuffed cotton, and in order to increase the bulge as stuffed cotton, it is inevitable to adopt a three-dimensional crimped form. It is said that.

In order to give this three-dimensional crimp, it is usual to have an asymmetric structure in the cross-sectional direction of the fiber, but in order to give a good three-dimensional crimp, for example, composite spinning of polymers with different intrinsic viscosity, or spinning There is a means of imparting an orientation difference by quenching immediately below the die.

Conventional raw cotton for wadding has adopted severe conditions in the spinning process in order to give good crimping, which tends to make the operation in the spinning process unstable. In other words, the raw cotton for stuffed cotton is finely controlled and changed mainly in the crimping state by changing the spinning conditions, and not only the work for changing the conditions is complicated, but also the production itself is greatly stabilized. Labor was required.

In order to solve such a problem, for example, JP-A-63-282315 proposes to improve the crimping method after stretching, but the bulkiness under a high load is insufficient, etc. , It has not been solved yet in terms of practicality.

[Problems to be Solved by the Invention] The problem to be solved by the present invention is to provide polyester raw cotton for batting which enables delicate control and change of the crimped state of the raw cotton without harsh conditions in the spinning process as described above. To provide a manufacturing method of. Another object of the present invention is to provide a method for producing a polyester raw cotton which is excellent in bulkiness when used as a stuffed cotton, especially under high load.

[Means for Solving the Problems] The above-mentioned problems of the present invention are as follows: in the production of a polyester raw cotton for wadding having a hollowness of 20 to 40% and a three-dimensional crimp expression ability, After drawing at ~ 100 ° C, guide the drawn yarn to a crimper to impart mechanical crimping with a crimp number of 3 to 5 threads / 25 mm, b. After cutting the yarn drawn out from the crimper The method for producing a polyester raw cotton for wadding, characterized by: opening the fibers in a range of 30 to 50% in opening degree, c. Applying heat treatment to the opened yarns by heating steam at 170 to 250 ° C. Can be resolved.

The configuration of the present invention will be specifically described below.

As the hollow fiber in the present invention, first, the hollow ratio is 20-40
%, And hollow fibers having the ability to develop three-dimensional crimp are used.

At this time, the higher the hollow ratio, the higher the bulkiness of the fiber. However, if it is too high, the hollow part is cracked due to impact due to carding during cotton making, and the bulkiness is substantially increased. Disappear. Therefore, the hollowness of the raw cotton for wadding is
It is generally in the range of 20 to 40%.

The hollow ratio here means the ratio (%) of the cross-sectional area of the hollow portion to the apparent cross-sectional area of the fiber, that is, It is a value represented by.

Generally, in order to give an asymmetric structure to the hollow fiber, for example, two kinds of polymers having different intrinsic viscosities are spun into a hollow bimetal structure, or the fiber yarn is cooled by chimney cooling just below the spinneret. There is a method of giving an orientation difference between the side and the non-cooling side, and by these, an undrawn yarn having latent crimping properties can be obtained.

After this undrawn yarn is drawn, it is subjected to a heat treatment in order to more highly develop the latent crimp expression ability of the fiber itself.

In this case, the stretching should be carried out at a temperature of not lower than the glass transition point (Tg, about 70 ° C for ordinary polyester) and not higher than 100 ° C, preferably 80 to 90 ° C. The stretching temperature is the glass transition point (T
If it does not reach g), the smooth flow of molecules will be hindered during stretching, and the asymmetric structure formed during spinning will not exhibit sufficient crimping ability. On the other hand, when the temperature exceeds 100 ° C., the amount of heat during stretching causes insufficient development of structural crimping due to subsequent heat treatment.

In addition, the stretched fiber is allowed to develop its structural crimp while maintaining a state in which crimp having the highest three-dimensionality can be revealed. That is, in the present invention, the fiber tow immediately after drawing is guided to the crimper. In particular, it is important to impart mechanical crimping with a crimping number of 3 to 5 peaks / 25 mm, which is substantially free from buckling of fibers. According to such means, three-dimensional crimping is easily obtained if the hollow fiber after drawing is crimped by heat setting and the fiber axis method is set to plural instead of the straight shape, Based on the present inventors' new knowledge, when the crimping with the crimper is accompanied by buckling, since the crimping itself is two-dimensional, the structural crimping revealed by the heat treatment has a three-dimensional effect. Without holding it, the bulk of the web will be low. The number of crimps is 3
If it is less than / 25 mm, the number of crimps after expression becomes too large and the texture becomes too hard, and the bulkiness when made into a web becomes low.

If it exceeds 5 peaks / 25 mm, buckling crimps in the crimper tend to remain, and the crimping property after heat treatment will be weak, and the bulkiness under a high load will be low, which causes problems such as not being practical.

The tow obtained here is cut into a predetermined length (usually about 50 to 100 mm) with a cutter in the next step, and then the degree of openness is 30 to 5
It is opened to 0%, preferably 35 to 45%, and cut cotton.

The cut cotton obtained here is a fiber with a three-dimensional effect, and although it itself has good three-dimensional crimp expression,
By opening 30 to 50%, the constraint between the single fibers in the opened part is almost eliminated, and the expression of three-dimensional crimping is further improved.

Of course, the higher the degree of openness of the cut cotton is, the better the bulkiness is, and when actually looking at the bulkiness of the web, in the cut cotton, the open portion is 30 to 50% (that is, The degree of opening is 30 to 50%), and the best condition is that the remaining non-opening portion is composed of so-called chip-shaped or scallop-shaped fiber portions. An open degree of more than 50% means that the number of fibers having a relatively small crimp increases, which in turn reduces the apparent bulk.

Here, it is preferable that the cut cotton be subjected to a known fiber oil treatment prior to the fiber opening treatment.

Cut cotton after opening should be 170-250 ℃, preferably 19
Heat treatment by heating steam at 0 to 220 ° C. is performed. It was found that this steam treatment is extremely effective in developing crimp of the fiber as compared with the dry heat treatment found in the prior art, and that the dry heat treatment can give a three-dimensional crimped form with little settling, which was completely unexpected. It was

At this time, if the heating steam temperature is lower than 170 ° C, the heat treatment effect is low as in the dry heat treatment, and not only the latent crimp of the fiber itself does not appear but also the crimp set during cotton making or use is large. Not suitable for. On the other hand, 250
When the temperature exceeds ℃, the heat treatment effect is great, but there is a problem in the heat resistance of the treated oil agent, and the feeling is deteriorated.

Of course, it does not matter if the heating steam treatment is combined with a conventional tunnel type heat treatment machine using hot air circulation.

The cut cotton thus obtained has a crimp number of 6 to 9 threads / 2
It is desirable to have a crimping property of 5 mm and a crimping degree of 20 to 30%. Therefore, not only the above-mentioned stretching-heat treatment conditions are properly adjusted, but also polymer specifications (for example, intrinsic viscosity difference between polymers, different polymers) during spinning, asymmetric cooling conditions (chimney wind speed, temperature), etc. are appropriately controlled, and the three-dimensional shape of the fiber itself is controlled. It is desirable to increase the ability to develop crimps.

[Examples] Hereinafter, the present invention will be described more specifically with reference to Examples.

a. Initial bulk: Apply a load of 0.5 g / cm ² to 10 g of a carded sample cut into a size of 20 cm on each side, and apply 30
The initial height (cc / g) is calculated by calculating the height of the sample after the lapse of seconds
And

b. Compressed bulk: The load in the initial bulk measurement was changed to 10 g / cm ² and the height of the sample after 30 seconds passed was compressed bulk (cc / g)
And

c. Recovery bulk: After measuring the compression bulk, change the load to 0.5 g / cm ² ,
The height of the sample after 30 seconds has passed is defined as the recovered bulk (cc / g).

d. Repulsion: After measuring the recovery bulk, change the load to 20 g / cm ² and
After the lapse of time, the load was further changed to 0.5 g / cm ^2, and the height of the sample was measured after 30 seconds, and it was 95 mm or more; good 5 to 95 mm; rather good 85 mm or less;

Example 1, Comparative Example 1 In o-chlorophenol solution, the intrinsic viscosity determined at 25 ° C was
0.636 polyethylene terephthalate spinning temperature 275 ℃,
It was extruded from a spinneret with 200 hollow holes. Chimney-like 160 between 60 mm and 400 mm below the spinneret surface of the discharged yarn
Asymmetric cooling was carried out at m / min and collected at 1300 m / min.

The spun yarn (unstretched yarn) thus obtained was combined into a tow of 500,000 denier and stretched 3.0 times in a 90 ° C warm bath.

The drawn tow was subsequently guided into a 16 mm-wide push-in type crimper, and a crimp of about 4 threads / 25 mm was imparted.

After the crimping, the tow was cut into a length of about 70 mm and opened with an opening machine to a degree of opening of about 40%.

After opening, the cotton was further heated with steam at 200 ℃ for 5-10 seconds to develop the structural difference crimp.

The obtained cotton had a crimped shape with a three-dimensional effect, and was excellent in apparent bulkiness and repulsion bulkiness.

Futon cotton webs were prepared from this raw cotton by carding in the usual manner, and the bulkiness characteristics were evaluated using seeds. The results are shown in Table 1.

On the other hand, for comparison, the opened cotton was heat-treated for 10 minutes at 200 ° C. in dry heat instead of heating steam. The obtained cotton has an extremely weak three-dimensional effect and is inferior in bulkiness, and as shown in Table 1, the futon cotton web also has a low bulkiness especially under high load and is poor in resilience. It was

Examples 2-3, Comparative Examples 2-3 In Example 1, the mechanical crimp number in the push-in type crimper was changed. The bulk properties of futon cotton made from these raw cottons were investigated, and the results are shown in Table 2.

As shown by these results, it is understood that the raw cotton exhibits good crimping and exhibits excellent bulkiness as futon cotton when the number of mechanical crimps with the crimper is in the range of 3 to 5 threads / 25 mm.

Examples 4 to 5 and Comparative Examples 4 to 5 In Example 1, the opening degree of the cut cotton was changed. The bulkiness of the futon cotton made from these raw cottons was investigated, and the results are shown in Table 3.

As shown by these results, it is understood that the raw cotton exhibits a crimped shape with a three-dimensional effect in the opening degree range of 30 to 50%, and exhibits excellent bulkiness characteristics as futon cotton.

Examples 6 to 8 and Comparative Examples 6 to 7 In Example 1, the heat treatment temperature by heating steam after opening was changed. The bulk characteristics of futon cotton made from these raw cottons were investigated, and the results are shown in Table 4.

As shown by these results, it is understood that the raw cotton exhibits a crimped shape with a three-dimensional effect and exhibits excellent bulkiness as futon cotton when the heat treatment temperature by the heating steam after opening is in the range of 170 to 250 ° C.

[Advantages of the Invention] As described above, the method of the present invention has the point of the invention in that the conditions of the drawing to the heat treatment step of the structural crimped fiber having a hollow cross section as the polyester raw cotton are optimized, and thereby the three-dimensional tension is obtained. Since shrinkage can be easily expressed, both initial bulk and compressed bulk are filled simultaneously and sufficiently, especially when using a futon for hanging or flooring,
The effects of the present invention are remarkable, such as being light and having a sufficient thickness feeling and rich heat retention.

Claims (1)

[Claims] 1. In the production of a polyester raw cotton for wadding having a hollowness of 20 to 40% and the ability to develop three-dimensional crimp, a. The spun yarn is drawn at a glass transition point to 100 ° C., and then the drawn yarn is drawn. Guide the thread to the crimper and give it a mechanical crimp with a crimp number of 3 to 5 threads / 25 mm, b. After cutting the thread derived from the crimper, open it in the range of 30 to 50% openness. A method for producing a polyester raw cotton for wadding, which comprises: c. Applying heat treatment by applying heating steam of 170 to 250 ° C. to the opened yarn.