JPH0787878B2 - Manufacturing method of polyester raw cotton for wadding with excellent bulkiness - 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 characteristics.

[Prior Art] Conventionally, a hollow fiber is usually used in the raw cotton for the wadding in order to increase the bulkiness, and a three-dimensional crimped form is used in order to increase the bulge as the wadding. Hiring is unavoidable.

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 a polymer having a difference in intrinsic viscosity, There is a means of imparting an orientation difference by quenching immediately below the die.

Conventional raw cotton for wadding has adopted harsh conditions in the spinning process in order to give a good crimp, and thus the operation in the spinning process tends to be unstable. In other words, the raw cotton for wadding is made by finely controlling and changing the crimped state mainly by changing the spinning conditions, which not only complicates the work for changing the conditions but also greatly stabilizes the production itself. Labor was required.

[Problems to be Solved by the Invention] An object of the present invention is to enable delicate control and change of the crimped state of raw cotton without taking the harsh conditions in the spinning process as described above. To provide an excellent method for producing raw cotton for wadding.

[Means for Solving Problems] The above object of the present invention is to produce a polyester raw cotton for wadding having a hollowness of 20 to 40% and a three-dimensional crimp expression ability. After drawing at a point (Tg) to 100 ° C, apply hot liquid treatment at 40 to 70 ° C, b. Guide the drawn yarn after the hot liquid treatment to a crimper, and crimp 1.5 under the condition shown by the following formula. Apply 3 ~ 25mm / 25mm crimp, D / W = 2-4 (10 ⁴ denier / cm) where D: Toe denier W; Crimper width c. Cut the yarn derived from the crimper And then opened to a range of 10 to 30% in opening ratio, and d. Heat-setting the opened yarn at 120 to 170 ° C., which has excellent bulkiness characteristics. This can be achieved by a method for producing a polyester raw cotton for use.

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

That is, as the hollow fiber in the present invention, first, a hollow fiber having a hollow ratio of 20 to 40% and a three-dimensional crimping ability is used.

At this time, the higher the hollow ratio, the higher the bulkiness of the fiber. However, if the hollowness is too high, the hollow part is cracked due to impact when hitting the carding during cotton making, and the bulkiness is substantially increased. Have no. Therefore, as a raw cotton for batting, the hollow ratio of hollow fibers is generally in the range of 20 to 40%.

The hollow ratio here is expressed by the ratio (%) of the cross-sectional area of the hollow part to the apparent cross-sectional area of the fiber, It is the value obtained by.

Generally, in order to give an asymmetric structure to the hollow fibers, 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 directly under 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 crimp characteristics can be obtained.

This unstretched yarn is stretched and then subjected to a heat treatment for more highly developing the latent crimping ability of the fiber itself.

Stretching in this case should be performed at a temperature above the glass transition point (Tg) (about 70 ° C for ordinary polyester) and below 100 ° C. If the stretching temperature does not reach the glass transition point (Tg), the smooth flow of molecules is hindered during stretching, and the asymmetric structure formed during spinning does not exhibit sufficient crimp expression performance. On the other hand, when the temperature exceeds 100 ° C., the amount of heat during stretching causes insufficient expression of structural crimps due to subsequent heat treatment.

Further, the stretched fiber is allowed to develop its structural crimp while maintaining the state in which the crimp having the highest three-dimensionality can be revealed.

That is, in the stretched hollow fiber, three-dimensional crimps are easily obtained if the shape of the yarn is not straight but the fiber axis direction is plural before the crimp development by heat setting. . Therefore, in the present invention, the fiber tow immediately after drawing is first heat-treated at a liquid temperature of 40 to 70 ° C., and then introduced into a crimper and crimped.

At this time, even if the warm liquid temperature is 40 ° C. or lower, or 70 ° C. or higher, the crimping in the next step cannot impart a three-dimensional effect to the fiber.

In addition, it is common to use a liquid bath of hot (hot) water or showering for the hot liquid treatment here.

Further, in the above crimper, it is important to impart a mechanical crimp having a crimp number of about 1.5 to 3 peaks / 25 mm, which is substantially free from buckling with respect to the fiber. At this time, if the crimps with the crimps are accompanied by buckling, the crimps themselves are two-dimensional, so the structural crimps revealed by the heat treatment do not have a three-dimensional effect and are low in bulk when made into a web. It becomes a thing.

Therefore, it is indispensable for crimps with a crimper to have a three-dimensional crimp without buckling. To do this, the relationship between the crimper roller width and the toe denier is D /
It is necessary to maintain in the range of W = 2-4 (10,000 denier / cm). Usually, considering the productivity, higher D / W is preferable, but when D / W exceeds 40,000 denier / cm, two-dimensional crimp with buckling like that seen in cotton for clothing is mainly used. As a result, the bulk properties of the stuffed cotton do not improve as expected. For this reason, the D / W should be kept small so that the tow does not receive too much force from the crimper roller. At this time, in order to prevent the crimps in the crimps from buckling, it is necessary to keep the number of crimps at about 1.5 to 3 peaks / 25 mm by appropriately adjusting the stuffing pressure.

The tow obtained here is cut to the required length (usually about 50 to 100 mm) with a cutter in the next step, and then the spread rate is 10 to 3
Open to 0%.

The cut cotton obtained here is a fiber with a three-dimensional appearance, and although it itself has good three-dimensional crimp expression,
By opening ~ 30%, the restraint between the single fibers in the opened part is almost disappeared, and the expression of three-dimensional crimp is further improved.

Of course, the higher the opening rate of the cut cotton, the better the bulkiness characteristic. Actually, when looking at the bulkiness of the web, in the cut cotton, the opened portion is 10 to 30%.
It is the best condition (that is, the opening ratio is 10 to 30%) and the remaining unopened part is composed of so-called chip-shaped or scalloped fiber parts. An open area of more than 30% means an increase in fibers having a relatively small crimp, which in turn results in a significant reduction in apparent bulk.

At this time, the opening means used include a spike roller and a cotton opening machine.

It is preferable to apply a known fiber oil to the cut cotton prior to the fiber-spreading process.

After opening, the cut cotton should be 120-170 ℃, preferably about
Heat set at 125-160 ℃.

At this time, if the heat-setting temperature is lower than 120 ° C, the heat-setting effect is low, the latent crimp of the fiber itself is not sufficiently expressed, and the crimp at the time of cotton making or use is large, which is suitable for practical use. Absent. On the other hand, when the temperature exceeds 170 ° C, the heat-setting effect is great, but not only the heat resistance problem of the treating oil agent and oligomers frequently occur, but also the cotton becomes rough to the touch, which is not suitable for practical use.

The heat treatment means used at this time includes, for example, a tunnel type heat treatment machine by circulating hot air and a method of performing heat treatment simultaneously with opening with hot air.

The cut cotton thus obtained has a crimp number of about 7 to 13 threads / 25 mm, a crimp degree of about 25 to 40% in the opened portion, and a crimp number of about 3 to 7 in the unopened portion. Mountain / 25 mm, crimp degree 15 to 24
It is desirable to have a crimp characteristic of%. Therefore, not only the above-mentioned stretching-heat setting conditions are optimized, but also the polymer specifications (for example, the difference in intrinsic viscosity between polymers, different polymers) during spinning, asymmetric cooling conditions (chimney wind speed, temperature), etc. are appropriately controlled, and the fiber itself is controlled. It is desirable to increase the three-dimensional crimp development ability of the above.

[Advantages of the Invention] As described above, the present invention has the point of the invention in that the conditions of the drawing or heat setting process of the structural crimped fiber having a hollow cross section are optimized as the polyester raw cotton for batting. Since a three-dimensional crimped state can be easily developed, especially when using a cotton quilt for hanging, both the initial bulk and the compressed bulk are simultaneously and sufficiently filled, and are light and have a sufficient sense of thickness. The effects of the present invention are remarkable, such as being rich in heat retention and drape.

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

The initial bulkiness, compression bulkiness, recovery bulkiness and repulsion property in this example were measured according to the following measuring methods.

Initial bulk: Apply a load of 5 g / cm ² on 10 g of a carded sample cut into a size of 10 cm on each side, find the height of the sample after 30 seconds, and calculate the initial bulk (cc / g). To do.

b. Compressed bulk: The load is changed to 10 g / cm ² and the height of the sample after 30 seconds is taken as the compressed bulk (cc / g).

c. Recovery bulk: After measuring the compression bulk, change the load to 5 g / cm ² and
The height of the sample after the lapse of seconds 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 5 g / cm ^2, and the height of the sample was measured after 30 seconds, and 90 mm or more; good, 80 to 90 mm; somewhat good, 80 mm or less;

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.636 determined in an ocp solvent at 25 ° C. was extruded at a spinning temperature of 275 ° C. from a spinneret having 100 holes. The cotton thread under the spout 11
Asymmetrical cooling of chimney style 100m / min between ~ 400mm,
It was collected at 1650 m / min.

The obtained spun yarn (unstretched yarn) was combined into a 50,000 denier tow and stretched 2.5 times in a 90 ° C. hot bath.

The drawn tow is then subjected to a hot water shower treatment at 50 ° C., and then the yarn is guided into a 20 mm width push-in type crimper, and approximately 3 threads / 25 m
A crimp of m was applied.

After crimping, the tow is cut into 70 mm length, and the
The fiber was opened to a spread rate of 20%.

The cotton after opening is further heated at about 130 ° C with a hot air circulation heat treatment machine,
Heat crimping was performed for 5 minutes to develop structural crimps.

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

Futon cotton webs were prepared from this raw cotton by carding in the usual manner, and the bulk properties were mainly evaluated. The results are shown in Table 1.

Example 2 In Example 1, the hot water shower temperature after stretching was changed. The bulk properties of futon cotton prepared from these raw cottons were investigated, and the results are shown in Table 2.

As the results show, the hot water shower temperature after stretching is 40
It can be seen that in the range of up to 70 ° C, the raw cotton exhibits a crimped shape with a three-dimensional effect and exhibits excellent bulk characteristics as futon cotton.

Example 3 In Example 1, the D / W of the push-in type crimper was changed. The bulk characteristics of the futon cotton prepared from these raw cottons were investigated, and the results are shown in Table 3.

As the result shows, when the D / W of the crimper is in the range of 2 to 4 (10,000 denier / cm), the raw cotton exhibits a crimped shape with a three-dimensional effect, and exhibits excellent bulk properties as futon cotton. Recognize.

Example 4 In Example 1, the opening ratio of the cut cotton was changed. The bulk properties of the futon cotton prepared 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 shows a crimped shape with a three-dimensional effect and exhibits excellent bulk characteristics as futon cotton when the opening ratio of the cut cotton is in the range of 10 to 30%.

Example 5 In Example 1, the heat setting temperature after opening was changed.
The bulk characteristics of the futon cotton prepared from these raw cottons were investigated, and the results are shown in Table 5.

As this result shows, the heat setting temperature after opening is 120 ~ 1
It can be seen that within the range of 70 ° C, the raw cotton exhibits a crimped shape with a three-dimensional effect and exhibits excellent bulk properties as futon cotton.

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. A spun yarn is drawn at a glass transition point (Tg) to 100 ° C., Hot-liquid treatment at 40-70 ° C, b. Guide the drawn yarn after the hot-liquid treatment to a crimper, and apply crimps with a crimp number of 1.5-3 threads / 25 mm under the conditions shown by the following formula. , D / W = 2 to 4 (10 ⁴ denier / cm) where D: tow denier W; crimper width c. After cutting the yarn derived from the crimper, the opening rate is in the range of 10 to 30% A method for producing a polyester raw cotton for wadding having excellent bulkiness characteristics, which comprises the steps of: d. Opening, and d. Heat setting the opened yarn at 120 to 170 ° C.