JP2003003340A - Polyamide multi-filament yarn for high density woven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide multi-filament yarn, suitable for a high density woven fabric, especially the high density woven fabric for an air bag, that is required to have the strength of the fabric, being a high strength yarn having >=7 cN/dtex stock yarn strength and a low single yarn fineness yarn having <=3.3 dtex single yarn fineness, excellent in weaving property and exhibiting a low strength reduction in its high density weaving. SOLUTION: This polyamide multi-filament having >=7 cN/dtex strength and <=3.3 dtex single yarn fineness is the polyamide multifilament for the high density woven fabric having >=2,100 covering factor, and characterized by having 10-30 positons/m interacting degree of its stock yarns.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention has a yarn strength of 7 cN /
High strength yarn of dtex or more and single yarn fineness of 3.3d
The present invention relates to a polyamide multi-filament yarn having a low single yarn fineness of tex or less, and is particularly suitable for a high-density woven fabric, particularly for a high-density woven fabric for airbags that require high strength, and has excellent weavability and high-density weaving. The present invention relates to a polyamide multifilament which is less likely to lose strength.

[0002]

2. Description of the Prior Art In order to increase the tensile strength of a high density woven fabric of polyamide, the strength of the polyamide filament itself is increased or the yarn density of the woven fabric is increased. However, there is a limit to increasing the density of the weave, and it becomes very difficult to increase the density when weaving reaches a certain high density. On the other hand, it is possible to increase the tenacity even with the same weaving density by increasing the tenacity of the raw yarn, but the higher the tenacity, the worse the yarn operability and the tendency to increase the fluff, resulting in the poor weaving operability. Especially 3.3d
When weaving at a high density with a low single yarn fineness of tex or less, it was difficult to maintain the same weaving operability and strength as a high density woven fabric with a single yarn fineness of 4 dtex or more.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polyamide filament for high density woven fabric, which can solve the above problems of the prior art.

[0004]

[Means for Solving the Problems] Means for solving the above problems, that is, the first aspect of the present invention, has a strength of 7 cN / dtex.
The polyamide multifilament having the above single filament fineness of 3.3 dtex or less and a cover factor of 210
A polyamide multifilament yarn for high-density woven fabrics having a density of 0 or more, wherein the degree of entanglement of the raw yarn is 10 to 30 filaments / m, and a cover factor = √ (warp fineness dtex) ×
(Warp yarn density / inch) + √ (weft yarn fineness dt
ex) × (weft density book / inch) The second is the polyamide multifilament yarn according to claim 1, wherein the polyamide is nylon 6.6.
The third is the polyamide multifilament yarn according to claim 1 or 2, which has a strength of 8 cN / dtex or more, and the fourth is the degree of entanglement of the raw yarn of 10 to 25 /
The polyamide multifilament yarn according to any one of claims 1 to 3, wherein the fifth is a polyamide multifilament yarn according to any one of claims 1 to 4, which has a residual entanglement index of 20 or less. The sixth is the polyamide multifilament yarn according to any one of claims 1 to 5, wherein the high-density fabric is for an airbag, and the high-density fabric is woven in a water jet loom. Item 10. The polyamide multifilament yarn according to any one of Items 1 to 6.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below. The polyamide in the present invention is polyamides such as polyamide 6, polyamide 6.6, polyamide 4.6, etc., or copolyamides. A cover factor (warp density (books / inch) with a high-density woven fabric that is a fiber made of these polyamides and has a low single-fiber fineness multifilament with a raw fiber strength of 7 cN / dtx or more and a single-fiber fineness of 3.3 dtex or less. × (Warp yarn fineness (dtex)) ^ (1/2)
+ Weft density (books / inch) x (warp yarn fineness (dtex))
^ (1/2)) relates to a high-density woven fabric of 2100 or more. In such a fabric, the warp is usually warped in the warping step,
Alternatively, after obtaining beaming or the like, it is adjusted and hung on a loom.

On the other hand, the weft is usually driven in at high speed as a weft of a woven fabric. In such a woven fabric, in particular, in a high-density woven fabric having a cover factor of 2100 or more, there is a problem that the strength of the base fabric is hard to sufficiently increase with respect to the strength of the raw yarn. Especially when the warp yarns are woven at a high speed and in a high density state, the entanglement itself becomes more restrictive to the yarns, so that the hardness of the yarns may damage the yarns due to the contact between the yarns during weaving. It has been found that the strength of the base fabric is lowered when the degree is too high.

Further, when the entanglement degree of the original yarn is as low as 10 pcs / m, the filament is broken and the weaving property is extremely deteriorated. From such examination results, when weaving a high-density fabric having a low single yarn fineness of 3.3 dtex or less and a cover factor of 2100 or more, the degree of entanglement of filaments is 10 to 30.
Weaving is good by using filaments of ke / m,
It has been found that damage during weaving is suppressed and deterioration of the base fabric strength is suppressed. Especially, the strength of the raw yarn such as airbag is 8 cN / dtex or more and the cover factor is 21.
In a high-density woven fabric base fabric of 00 or more, such damage during weaving due to the degree of entanglement of the raw yarns causes the strength of the base fabric to drop, and therefore the damage in the high-density fabric must be minimized. .

On the other hand, if the number of entanglement of the original yarn is too low, unwinding property is deteriorated and yarn cracking is caused, and a degree of entanglement of 10 pieces / m is at least necessary. The strong entanglement causes damage to the yarn in the high density weaving.The degree of entanglement of the decomposed yarn in the base cloth is examined to that extent, and the residual entanglement after disassembly of the base cloth and the weaving is examined to determine the relationship between the residual entanglement and the strength of the base cloth. The residual confounding index is 2
It was found that when the value is 0 or more, the strength of the base fabric is significantly reduced.

The residual entanglement index of the decomposed yarn of the base fabric was examined by a method of measuring the inter-entanglement distance using a needle because the yarn does not spread in a water bath like the original yarn. In the measurement, one point in the yarn length direction is fixed by the chuck 1 by the method shown in FIG. 1, and the chuck 2 is opened, and the load is applied to the yarn at the position of the load 2 (fineness (dtex) ×
0.045) (g). When the scale is installed, read the distance from 0 from the center position of the measurement to the point where load 2 starts moving by inserting the needle almost in the center of the thread and moving it slowly (the point at which the entanglement point stops the needle movement) A
(Cm). Next, the chuck 2 is tightened, the thread on the chuck 2 side is fixed, the load applied to the load 2 is applied to the position of the load 1, and the chuck 1 is released. Next, the point at which the load 1 starts to move by moving the piercing needle upward is set as reading B at a distance from 0. The inter-entanglement distance H is calculated by H = A + B. This is repeatedly measured for 20 sampled yarns, and the average value (cm) is determined and is designated as V. The residual entanglement index K is obtained by K = 100 / V, and it is necessary that the entanglement does not remain strong in order not to increase the damage in weaving, and the residual entanglement index in the woven fabric must be 20 or less. I came to the conclusion that there is.

Further, a low residual confounding index of 15 or less is preferable from the viewpoint of keeping the strength of the base fabric high. In order to efficiently weave a high-strength, high-density fabric for airbags, weaving with WJL is preferable to weaving with an AJL or rapier, and it is preferable to weave with WJL.

[0011]

EXAMPLES Next, the present invention will be specifically described by way of examples.

Examples 1 to 4 and Comparative Examples 1 to 2 Polyamide 66 having a sulfuric acid viscosity of 3.3 was melt-spun and spun,
Using a heating roller with a maximum temperature of 195 ° C, multi-stage direct drawing is performed using a group of rollers, and 350 dtex-108 filament has a strength of 8.
A multifilament with 4 cN / dTex and boiling water shrinkage of 9% was used as a winding package. Warp This multifilament was warped and beamed. Using this beam, the same package was used as the weft yarn in a water jet loom at 580 times / min for plain weaving.

Comparative Example 3 Polyamide 66 having a sulfuric acid viscosity of 3.3 was melt-spun and spun.
Using a heating roller with a maximum temperature of 195 ° C, multi-stage direct drawing is performed by a group of rollers, and 350dtex-72 filament has a strength of 8.4c.
A multi-filament with N / dTex and boiling water shrinkage of 9% was used as a winding package. Warp This multifilament was warped and beamed. Using this beam, the same package was used as a weft yarn in a water jet room at 580 times / min for plain weaving, refining, drying and heat setting to obtain a base fabric for an airbag. The degree of entanglement of the raw yarn was determined by counting the number of entangled portions while gently floating the yarn in a 100 cm water bath and setting the number of entanglements per 1 m of the raw yarn. The strength of the base cloth is measured, and the strength of the raw thread is used to determine the strength utilization ratio (= strength of base cloth / (strength of original thread x fineness x number / c
m)) was calculated. The results are shown in Table 1.

[0014]

[Table 1]

Examples 4 to 6 and Comparative Examples 4 to 6 Polyamide 66 having a sulfuric acid viscosity of 3.3 was melt-spun and after spinning,
Using a heating roller with a maximum temperature of 195 ° C., multi-stage direct drawing was carried out by a group of rollers to prepare 350 dTex-144 filament, and before winding the multifilament, the air pressure was changed by an interlacer to change the number of entanglement to form a package. As the warp, the multifilament was warped and beamed. Using this beam, as a weft yarn, the same package as the warp yarn was woven by plain weaving at 580 times / min in a water jet room, refined, dried and heat set to obtain a base fabric for an airbag. The warp yarn of the base fabric was disassembled from the base fabric, and the residual entanglement index of this yarn was determined. The results are shown in Table 2.

[0016]

[Table 2]

[0017]

EFFECTS OF THE INVENTION According to the present invention, a high-strength yarn having a yarn density of 7 cN / dtex or more, which is particularly suitable for a high-density woven fabric, especially for a high-density woven fabric for airbags which requires high strength. Moreover, a polyamide multifilament yarn having a single filament fineness of 3.3 dtex or less and a low single filament fineness can be provided, and a polyamide multifilament having excellent weaving properties and less reduction in strength in high-density weaving can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an apparatus for measuring the number of remaining confounding.

[Explanation of symbols]

1: Guide roller 2: Chuck 1 3: Chuck 2 4: Load 1 5: Load 2 6: Needle

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3D054 CC26 FF18                 4L036 MA06 MA24 MA33 PA01 PA03                       PA12 PA42 UA23                 4L048 AA24 AA34 AA48 AA50 AB08                       BA01 BA02 CA15 DA25 EA01

Claims (7)

[Claims] 1. A polyamide multifilament having a strength of 7 cN / dtex or more and a single yarn fineness of 3.3 dtex or less, a polyamide multifilament for a high-density fabric having a cover factor of 2100 or more, and a degree of entanglement of a raw yarn. Is 10 to 30 pieces / m, and is a polyamide multifilament yarn. Cover factor = √ (warp yarn fineness dtex) ×
(Warp yarn density / inch) + √ (weft yarn fineness dt
ex) × (weft density book / inch) 2. The polyamide multifilament yarn according to claim 1, wherein the polyamide is nylon 6.6. 3. The polyamide multifilament yarn according to claim 1, which has a strength of 8 cN / dtex or more. 4. The polyamide multifilament yarn according to claim 1, wherein the degree of entanglement of the raw yarn is 10 to 25 yarns / m. 5. The polyamide multifilament yarn according to claim 1, which has a residual entanglement index of 20 or less. 6. The high-density fabric is for an airbag.
6. The polyamide multifilament yarn according to any one of 1 to 5. 7. The polyamide multifilament yarn according to claim 1, wherein the high-density woven fabric is woven by a water jet loom.