JPH05321132A - Production of woven fabric for industrial material - Google Patents

Abstract

PURPOSE:To obtain woven fabric for industrial material, having high tensile strength, tear strength, flexibility and airtightness. CONSTITUTION:Polyester multifilament yarn having >=0.8 intrinsic viscosity, 1-3 denier fineness of single yarn, >=8g/de strength and 11-25% dry heat shrinkage percentage at 150 deg.C is woven, subjected to relaxing heat treatment dividedly two or more times at s 120 deg.C so as to give >=8% total relaxing ratio and then heat-set under 2-5% tension ratio at >=150 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a woven fabric for industrial materials which is required to have high strength, flexibility and airtightness. More specifically, it relates to a method for producing a woven fabric for industrial materials, which is suitable as a filter cloth for fine particles, an air mat, a water mat and the like.

[0002]

2. Description of the Related Art It is well known that synthetic fibers and woven fabrics made of the fibers are used in all industrial material fields. In particular, polyester fibers are relatively inexpensive and strong, and also have excellent dimensional stability, so sheet-like membrane structures such as canvas, tents, tarpaulins, and curing sheets,
Used as a reinforcing material for food belts, hoses, V-belts, conveyor belts, tires, etc. in a wide range of industrial material fields.

[0003]

However, as described above, the polyester fiber material, which exhibits excellent performance as a composite material of resin and rubber, is also poor in flexibility due to its rigidity due to its molecular skeleton, It has the disadvantage of low tensile and tear strength when woven at a high density. For this reason, its use has been restricted to industrial materials such as air mats and water mats, which are required to have flexibility and impact strength after enclosing a fluid.

The present invention has been made in view of such problems, and an object thereof is to provide a method for inexpensively producing a polyester-based industrial material woven fabric having high strength, flexibility and airtightness. ..

[0005]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have conducted a relaxation heat treatment in two or more stages after weaving those having a dry heat shrinkage ratio within a specific range. According to the method, it was found that a woven fabric excellent in airtightness and flexibility can be easily obtained without deteriorating the weaving property at the time of weaving, and the present invention was reached as a result of further studies based on such findings.

That is, according to the present invention, the polyester has an intrinsic viscosity of 0.8 or more, and the single yarn fineness is 1 to 3.
Denier, maximum tensile strength of 8 g / de or more, 150 ° C dry heat shrinkage of 11 to 25% Using polyester multifilament yarn with a cover factor of 1500 or more, after weaving, the total relaxation rate is 8 at a temperature of 120 ° C or more. %, And the relaxation heat treatment is performed twice or more in multiple stages, and then the tension heat treatment is performed at a tension ratio of 2 to 5% at a temperature of 150 ° C. or more.

The polyester referred to in the present invention is intended mainly for a polyester whose main repeating unit is ethylene terephthalate, but contains a copolymerization component within a range that does not impair the object of the present invention (for example, 10 mol% or less). Good.

It is important that the intrinsic viscosity of the polyester in the present invention is 0.8 or more. When it is less than 0.8, not only is it difficult to obtain fibers having a maximum tensile strength of 8 g / de or more, but also the mechanical properties such as tensile strength and tear strength of the finally obtained woven fabric are remarkably deteriorated, which is for industrial materials. It is not preferable because the level required for the woven fabric cannot be achieved.
Further, since there is a positive correlation between the abrasion resistance of the woven fabric and the intrinsic viscosity, it is necessary to be 0.8 or more also from this point.

On the other hand, it is not necessary to set the upper limit of the intrinsic viscosity, but 1.1 or less is preferable from the viewpoint of the spinnability of the polyester multifilament yarn, and 1.0 or less is particularly preferable from the spinnability of the fineness (single yarn) fiber. ..

Next, the maximum tensile strength of the polyester multifilament yarn is 8 g / de or more, preferably 9 g / de.
Above, it is necessary to be 10 g / de or more particularly preferably. When the tensile strength is less than 8 g / de, the strength is largely decreased during heat treatment, particularly relaxation heat treatment, and the tensile strength and tear strength of the resulting woven fabric are insufficient, which is not preferable.

Further, it is important that the dry heat shrinkage ratio at 150 ° C. is 11% or more and 25% or less in order to obtain a fabric excellent in strength, flexibility and airtightness by performing a relaxation heat treatment after weaving. If it is less than 11%, the effect of increasing the elongation by the relaxation heat treatment is insufficient, and the mechanical properties such as tear strength and toughness of the resulting woven fabric are insufficient, which is not preferable. On the other hand, when the 150 ° C. dry heat shrinkage exceeds 25%, only the maximum tensile strength of about 7 g / de can be obtained, so that the mechanical properties of the finally obtained woven fabric are insufficient.

The fineness of the monofilament constituting the multifilament yarn is 1 to 3 in terms of flexibility, airtightness, durability and the like.
It is important to set the range of denier, and if it exceeds 3 denier, the flexibility and airtightness of the obtained woven fabric decrease and the tenacity retention of the woven fabric also decreases, which is not preferable. On the other hand, when it is less than 1 denier, durability such as abrasion resistance is lowered and only a woven fabric for industrial materials is insufficient, which is not preferable.

In the present invention, since the above-mentioned polyester multifilament yarn is woven at a high density, the multifilament yarn is entangled with about 20 to 50 t / m or 50 to 100 T / m. It is preferable to apply a slight amount of sweet twist from the viewpoint of improving the weavability and the airtightness of the obtained woven fabric. The weaving method is not particularly limited, and the weaving can be performed by a known method using a known loom (rapia, water jet loom, etc.). At this time, in the present invention, since it is often applied to a field requiring airtightness (air mat, water mat, etc.), it is important to weave into a high-density woven fabric, and the cover factor is 150.
It is preferably 0 or more, and particularly preferably 1800 or more.

The cover factor referred to here is, for example, the warp density is Ny (books / inch) and the denier is Dy.
When the weft density is Nx (threads / inch) and the denier is Dx, the cover factor is Ny × √Dy + Nx × √Dx. When the woven fabric has multiple axes, it is represented by the sum of N × √D calculated for each direction.

In the present invention, the woven fabric woven as described above is subjected to relaxation heat treatment in two or more stages so that the total relaxation rate becomes 8% or more at a temperature of 120 ° C. or more. It is characterized by

A temperature of 120 ° C. or higher is required to develop a sufficient shrinkage stress during relaxation heat treatment.
When the temperature is lower than 0 ° C, sufficient shrinkage stress is not expressed and the relaxation rate of the woven fabric cannot be 8% or more, which is not preferable. On the other hand, if the treatment temperature is too high, the strength of the polyester multifilament yarn will be greatly deteriorated.

When the total relaxation rate is less than 8%, the toughness of the fibers constituting the woven fabric is not sufficiently improved, and therefore the tear strength can be low and the object of the present invention can be achieved. If the relaxation heat treatment is carried out in one step, it becomes difficult to uniformly shrink the entire woven fabric and the flatness of the obtained woven fabric is deteriorated, which is not preferable. On the other hand, the upper limit of the total relaxation rate varies depending on the physical properties of the polyester multifilament yarn used, but if it is too large, the tear strength of the obtained woven fabric does not improve so much, and the tensile strength decreases remarkably. Is 16%
The following is preferable.

It is not necessary to limit the number of divisions if the relaxation heat treatment is performed twice or more. However, in practical use, if the number is too large, the production efficiency decreases, so it is usually preferable to keep the number of stages to two or three. ..

In the present invention, the relaxation heat treatment is followed by a heat treatment at a temperature of 150 ° C. or higher under a tension of 2 to 5%. By doing so, the tensile strength of the polyester fiber reduced by the relaxation heat treatment is improved, and the structure of the polyester fiber in the woven structure is fixed to improve the tear strength. When the tension ratio is less than 2%, the improvement ratio of tensile strength and tear strength is small, and when it exceeds 5%, the strain due to the stretching of the woven structure becomes large and both tensile strength and tear strength decrease, which is not preferable. ..

The polyester multifilament yarn used in the method of the present invention described above can be manufactured, for example, as follows.

That is, a polyester having an intrinsic viscosity of 0.8 or more, preferably 0.8 to 1.2 is used at 290 to 300 ° C.
And then extruded through a discharge hole having a hole diameter within a range that does not cause discharge unevenness and discharge yarn wobbling.
Approximately 200 mm is heated and held, and delayed cooling is performed, and then cooling air is blown to rapidly cool. The purpose of this heating and holding just below the mouthpiece is to adjust the viscosity in the vicinity of the nozzle outlet, and it is most preferable to use a structure such as a ceramic heater in which radiant heat is transferred toward the cap surface.

The cooled and solidified yarn is taken up at a predetermined speed, and after being applied with oil, it is once wound or subsequently drawn. The stretching is preferably performed in two or more stages separately from the viewpoint of high strength. The stretching temperature is not particularly limited as long as the tensile strength is in the range of 8 g / de or more, but the heat setting for fixing the fiber structure is 1
It is desirable to carry out at a temperature lower than usual under a constant length or relaxation of 1 to 2% so that the dry heat shrinkage ratio at 50 ° C. is in the range of 11 to 25%.

To obtain a polyester multifilament yarn having a maximum tensile strength of 9.5 g / de or more, 2
The method of separately stretching at a speed of 00 to 400 m / min is preferable because the deformation speed is small and the yarn can be more stably formed.

[0024]

In order to produce a woven fabric for industrial materials, it has been conventionally required to use a polyester fiber having high tensile strength and low shrinkage in order to obtain a woven fabric having good dimensional stability.

On the other hand, according to the method of the present invention, since the polyester fiber having the dry heat shrinkage ratio in the specific range is used, even if the relaxation heat treatment is performed after the weaving, the tensile strength of the yarn is not lowered so much and the elongation is reduced. Can increase the degree
The toughness and tear strength of the woven fabric can be improved. Further, since the density of the woven fabric obtained by the heat treatment is also improved, the airtightness can be improved.

Therefore, the woven fabric obtained by the method of the present invention has flexibility, high tensile strength, high tear strength, and excellent airtightness as compared with the conventional woven fabrics for industrial materials, and therefore, it is fine particles. It can be applied to a wide range of applications such as air mats, water mats, sleeping bags, pillows, life-saving belts, life-saving boards, etc. by processing the filter cloth for resin and, if necessary, resin processing.

[0027]

EXAMPLES The present invention will be described in detail below with reference to examples. The intrinsic viscosity, physical properties of raw yarn, and physical properties of textiles in the examples were measured according to the following methods.

Intrinsic viscosity: Measured at 35 ° C. in an orthochlorophenol solvent.

Strength and elongation of multifilament yarn Using a tensile load measuring device (manufactured by Shimadzu, Autograph), JI
It was measured according to SL-1074-64.

Degree of Entanglement of Stretched Yarn Hanging with a load of 1/30 of the denier number of the yarn, 50
Mark at cm intervals and measure the number of entangled parts between them by the hook-drop method with a load of 1/10 of the denier of the yarn.
It was multiplied and expressed as ke / m.

Dry heat shrinkage ratio According to JIS L1013, the sample was heat-treated at 150 ° C. for 30 minutes under no tension and measured.

Stiffness of woven fabric: Measured with a sample width of 2 cm according to JIS L-1096 (45 ° cantilever method).

Aeration rate of woven fabric It was measured by the Frazier method of JIS L-1096.

Tensile Strength of Woven Fabric Measured by the strip method of JIS L-1096.

Tear strength of woven fabric Measured according to JIS L-1079A1 method (single tongue method).

Fabric Flatness The base fabric was placed on a horizontal plate and visually evaluated.

[0037]

Example 1 A polyethylene terephthalate chip having an intrinsic viscosity of 0.64 was solid-state polymerized at 230 ° C. under a vacuum of 1 mmHg until an intrinsic viscosity of 0.98, and then melted at a temperature of 300 ° C. and then 216 g / min. Discharge rate is 0.30mm, 2
Discharge from the 50-hole base, 200 mm directly under the base, 34
After passing through the zone heated and maintained at 0 ° C, a cooling air having a wind velocity of 0.3m / sec at 25 ° C was blown over the blowing length of 330mm to cool, and an oil agent was applied at a speed of 900m / min. I wound it up.

The undrawn yarn thus obtained was heated by a preheating roller at 85 ° C. to draw it in the first stage 3.0 times, and subsequently 260 ° C.
After being stretched 1.73 times in the dry heat bath of No. 1 and then relaxed by 1% in the dry heat bath of 220 ° C., it was wound at a speed of 300 m / min through an interlace nozzle having a compressed air pressure of 3 kg / cm ² .

Table 1 shows the physical properties of the obtained multifilament yarn.

Then, the obtained multifilament yarn was woven in a water jet loom at a woven density shown in Table 1, and thereafter subjected to a relaxation heat treatment and a tension heat treatment under the conditions shown in Table 1. The results are shown in Table 1.

[0041]

Example 2 The same procedure as in Example 1 was carried out except that the intrinsic viscosity after solid-state polymerization was 0.93, and the multifilament yarn shown in Table 1 was adjusted by changing the discharge rate, the draw ratio, and the heat setting temperature. did.

[0042]

Example 3 The intrinsic viscosity after solid state polymerization was 1.03, the discharge rate and the draw ratio were changed, the relaxation heat treatment (third step) was set to room temperature, and the multifilament yarns shown in Table 1 were used. It carried out like Example 1 except having adjusted.

[0043]

[Example 4] The intrinsic viscosity after solid-state polymerization was set to 0.87, the number of spinneret holes was changed to 500, and the discharge rate, the draw ratio, and the heat setting temperature (third stage dry heat bath temperature) were adjusted. Example 1 was repeated except that the multifilament yarn described in 1 was prepared.

[0044]

[Comparative Example 1] The same procedure as in Example 1 was carried out except that the intrinsic viscosity after solid state polymerization was 0.84, and the multifilament yarn shown in Table 1 was adjusted by adjusting the discharge rate, the draw ratio, and the heat setting temperature. did.

[0045]

[Comparative Example 2] The intrinsic viscosity after solid phase polymerization was changed to 0.95, the number of spinneret holes was changed to 120 holes, and the discharge rate, draw ratio and heat setting temperature were adjusted to adjust the multifilament yarns shown in Table 1. Except for this, the same procedure as in Example 1 was performed.

[0046]

Comparative Example 3 The procedure of Example 2 was repeated except that the multifilament yarn shown in Table 1 was adjusted by adjusting the draw ratio.

[0047]

Comparative Example 4 Example except that the multifilament yarn shown in Table 1 was adjusted by adjusting the drawing temperature in the dry heat bath to 200 ° C., the third-stage dry heat bath to room temperature, and adjusting the discharge rate and the draw ratio. The same procedure as 3 was carried out.

[0048]

Comparative Examples 5 to 11 Using the raw yarn of Example 1, fabric treatment was performed under the conditions of Table 1.

[0049]

[Comparative Example 12] Intrinsic viscosity after solid phase polymerization was set to 0.90,
Example 1 was carried out in the same manner as in Example 1 except that the multifilament yarn shown in Table 1 was prepared by adjusting the discharge rate, the draw ratio and the heat setting temperature.

[0050]

[Comparative Example 13] The intrinsic viscosity after solid-state polymerization was set to 0.91,
The multifilament yarn shown in Table 1 was obtained by adjusting the discharge rate, the draw ratio, and the heat setting temperature, and the same procedure as in Example 1 was performed except that the relaxation heat treatment of the woven fabric was not performed.

[0051]

Comparative Example 14 The procedure of Example 4 was repeated except that the raw yarn of Example 4 was used and the woven fabric was treated under the treatment conditions shown in Table 1.

[0052]

Comparative Examples 15 to 16 The same procedure as in Example 3 was carried out except that the raw yarn of Example 3 was used and the woven fabric was treated under the treatment conditions shown in Table 1.

The results obtained above are summarized in Table 1.

[0054]

[Table 1]

[0055]

[Table 2]

[0056]

[Table 3]

Claims (1)

[Claims] 1. A polyester having an intrinsic viscosity of 0.8 or more, a single yarn fineness of 1 to 3 denier, and a maximum tensile strength of 8.
After weaving with a cover factor of 1500 or more using polyester multifilament yarn having g / de or more and 150 ° C dry heat shrinkage of 11 to 25%, the total relaxation rate becomes 8% or more at a temperature of 120 ° C or more. A method for producing a woven fabric for industrial materials, comprising relaxing heat treatment in multiple stages two or more times, and then performing tension heat treatment at a tension rate of 2 to 5% at a temperature of 150 ° C or higher.