JPS5847488B2 - Multifilament yarn for knitting and weaving - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvement of polyamide filament yarns, and an object thereof is to provide polyamide filament yarns for knitting and weaving, which can yield woven and knitted fabrics with excellent level dyeing properties and quality.

Conventionally, polyamide multifilament yarns for woven or knitted fabrics have a birefringence of 50×, which is obtained by melt-spinning polyamide, stretching it to about 3 to 4 times without winding it up, or heat-treating it if necessary. 10-3 or higher is used.

However, at present, woven or knitted fabrics made from such polyamide multifilament yarns lack flexibility, are prone to dyeing spots, and have poor quality, so their uses are naturally limited.

The present inventor has previously proposed a method of using low-orientation yarn (birefringence 30×10-3 to 45×10-3) obtained by high-speed spinning as a multifilament yarn for woven and knitted fabrics that does not have such drawbacks. .

When such a low degree of orientation yarn is used for woven or knitted fabrics, products with extremely excellent level dyeing properties and excellent flexibility can be obtained.

Such low-orientation yarns are practically obtained by spinning at a high speed of over 3000 m/m, and are wound with substantially no twist.

For this reason, there are disadvantages in that the winding stability of the package, the winding form, the unwinding property of the yarn from the package, the weaving, knitting and weaving of the yarn, and the convergence of the yarn are affected.

For this purpose, it is conceivable to wind the untwisted yarn after interlacing the filaments (so-called interlacing).

Therefore, the present inventor investigated a method of subjecting such low-orientation yarns to the above-described entanglement treatment, and found that (1) In order to improve the cohesiveness of low-orientation yarns spun at high speed for the above-mentioned purpose, it was found that (2) The interlacing applied to the low-orientation yarn is
Unlike the case of drawn yarn, the interlacing is extremely strong, and it hardly disappears even when the yarn is subjected to tension in the weaving and weaving process or when it is rubbed with guides, and the interlacing remains even after it is made into a woven or knitted fabric. (3) It has been found that interlacing remaining in woven or knitted fabrics significantly impairs the quality of the woven or knitted fabrics.

A polyamide multifilament yarn for knitting and weaving that provides good knitting and weaving properties and product quality has been discovered.

That is, in the present invention, the birefringence obtained by high-speed spinning is 3.
0x10-3 to 45x10'' polyamide multifilament yarn, and the filaments surrounding the yarn have an entanglement coefficient (C.F.) of 2.0 or less. It is filament yarn.

The polyamide constituting the yarn of the present invention is polypropyramid, polyhexamethylene adipamide, or a copolyamide containing these as main components.

The polyamide may contain additives such as matting agents, pigments, dyes, stabilizers, and flame retardants.

The cross-sectional shape of the filament of the present invention is not only circular but also
It may also have an irregular shape such as a trilobal or a hollow cross section.

The multifilament yarn is produced by high-speed spinning and has a birefringence index higher than that of ordinary undrawn yarns and lower than that of drawn yarns, i.e., a birefringence of 30X10-3 to 45X10'' (preferably 35X10-3 to 40X10''). It has a refractive index.

The birefringence of the multifilament yarn is 30×10
If it is less than -3, molecular orientation within the fiber is insufficient, which not only results in poor strength and elongation, but also causes quality defects such as warp stripes when fabricated into a woven or knitted fabric, which is not preferable.

On the other hand, when the birefringence exceeds 45X10-3, the molecular orientation within the fiber increases and becomes similar to conventional drawn yarn.
The desired woven or knitted fabric with improved flexibility cannot be formed.

The spinning speed should be selected depending on the type and properties of the polyamide, the denier of the ejected multifilament yarn, the cooling conditions, etc. so that the birefringence after winding is within the above range.
Generally, a speed of 3000 to sooom/min is suitable.

The multifilament yarn of the present invention has entanglement between the structured filaments, but the degree of entanglement is 2
．． It needs to be extremely low compared to conventional interlacing, such as 0 or less, preferably 0.01 to 2.0, more preferably 0.1 to 1.5.

The confounding coefficients (C, F.) here refer to U.S. Pat.
It refers to the "Coherency Factor" measured by the hook-drop method described in No. 85995, and if this coherency factor exceeds 2.0, the quality of the woven or knitted fabric is poor.

That is, a completely drawn drawn yarn (birefringence 50×10
The strength is completely different between the interlace applied to yarns (above) and the interlace applied to low-orientation yarns, and in the present invention, extremely less interlace (entanglement between filaments) is applied compared to conventional interlaces. That's what I do.

This will be explained using drawings. Figure 1 shows a device for testing the strength of interlacing. 1 is a supply roller, 2 is a delivery roller, and between them, three titanium pins 3, 4, and 5 with a roughness of 2S and a diameter of 15φ are inserted at θ1. and θ2 is 135° and θ3 is 90°, and the speed of the feed roller 1 is constant (200 m/m
In), when the circumferential speed of the delivery roller 2 is variously changed, the yarn tension T when leaving the final bin 5 can be arbitrarily changed, and the degree of interlace disappearance with respect to the yarn tension T can be measured. It is a device.

Here, the interlaced Y is supplied to roller 1
It is wound 3 to 10 times around the delivery roller 2, brought into contact with the pins 3, 4, and 5 as shown in the figure, and wound 3 to 10 times around the delivery roller 2, and once wound up.

Next, the entanglement coefficient of the wound yarn is determined by the method described above.

Figure 2 shows the confounding coefficients (C, F,
), each yarn is 70 denier/16 filaments, and line a is a normal drawn yarn (birefringence 52
Line b is a high-speed spun yarn with a birefringence index of 36 x 10-3 and an interlace pattern.

Comparing the two, it can be seen that the interlace imparted to the high speed spun yarn is difficult to disappear even when tension or ironing is applied.

Therefore, compared to conventional methods, the confounding coefficient (
C. F. ), there will be a large amount of interlace remaining in the multifilament yarn after weaving and knitting, and the yarn will be wholly or partially bundled and intertwined, which will deteriorate the quality of the product.

Since the multifilament yarn of the present invention is supplied to the weaving and weaving process in the form of a so-called "flat yarn" without being subjected to drawing heat treatment or drawing crimping in the subsequent process, the structure of the multifilament yarn is The number of filaments, denier, etc. should be appropriately selected depending on the intended use of the knitted fabric, but in general, it is appropriate that the number of constituent filaments is 3 to 50 and the total denier is 20 to 300 de.

The multifilament yarn of the present invention is produced by melting the polyamide described above and then extruding it through a spinneret.
This method is industrially advantageous by passing the yarn through an air agitation nozzle before winding to impart interfilament entanglement to a predetermined entanglement coefficient (C, F,). can be manufactured.

When interfilament entanglement is imparted in this way, the entanglement coefficients (C, F,) are mainly influenced by the tension of the yarn to be treated, the air pressure supplied to the nozzle, and the shape and dimensions of the nozzle. .

However, it also depends on the tenier of the filaments, the number of filaments, the frictional properties of the oil, the focusing properties, etc.

Therefore, in the present invention, various conditions may be selected so that the confounding coefficients (C, F,) fall within the above-mentioned specific range, taking these factors into consideration.

According to the research of the present invention, the methods of (a) lowering the pressure of the compressed air supplied to the air turbulence nozzle, and (b) increasing the tension (processing tension) of the multifilament yarn to be processed are generally available. It is effective to obtain a yarn with an entanglement coefficient (C, F,) of This is preferred because it is easy to increase the tension and the processing tension becomes stable.

The multifilament yarn of the present invention as described above has a relatively lower birefringence index than drawn yarns conventionally used for woven or knitted fabrics, and therefore has excellent level dyeing properties and good flexibility.

Furthermore, the entanglement coefficient (C,
F. ), it maintains sufficient cohesiveness, there are no troubles in the weaving and weaving process, and it can be made into knitted fabrics of good quality, among other advantages.

Next, Examples and Comparative Examples of the present invention will be described in detail.

Note that the warp stripes, dyed spots, and latitude spots shown in the examples were determined visually and ranked as follows.

Warp stripes: Ranked from 1 to 8, with 1st grade being the best.

Staining spots: Ranked from 1 to 5, with grade 5 being the best.

Latitude stripes...Wo is the best and ranked as Wo-W3.

Example 1 The intrinsic viscosity (measured with a metacresol solution at 35°C) is 1.
05 polypropyramid was melted at 250°C, and the pore size Q, 4
m+1! The yarn was discharged from a spinneret having 16 circular spinning holes at a constant rate so that the final wound yarn had a denier of 70.

Apply 15 crrL of cooling air at 25°C and 65% RH to the discharged yarn.
After applying the emulsion by spraying at a linear velocity of /see to cool and solidify, the emulsion was wound up in a winder via a first godet roller and a second godet roller.

At this time, an air turbulence nozzle was provided between the first godet roller and the second godet roller to provide interlacing between the filaments.

At this time, the yarn tension between the first godet roller and the second godet roller was set to 20P, and the pressure of the compressed air to the air turbulent flow nozzle was set to 1.5 kg/crAG.

The intertwining coefficient (C, F,) of the obtained yarn was 1.5.

When this thread was used as a warp to weave a plain weave, the weaving transfer rate was as good as 97%, and the warp stripes of the fabric were as good as 3.5 grade.

Further, as a result of staining with SupuranolCyanine G, the staining was very good with grade 5 staining.

When the warp threads were extracted from the obtained woven fabric and the entanglement coefficient was measured, it was found to be 0.5.

Furthermore, when the fabric structure was observed under a microscope, the shape of one multifilament appeared as a spread of 10 single threads (six overlapping), and the spacing between the warp threads was as small as less than % of the multifilament width.

Further, when a similar woven fabric was produced using the above yarn as the weft, a high-quality woven fabric without weft irregularities was obtained.

Comparative Example 1 Using the same method as Example 1, the pressure of compressed air was reduced to 7 kg/c.
Changed to rAG.

The intertwining coefficient (C, F,) of the obtained yarn was 20.

As a result of weaving in the same manner as in Example 1, the weaving transfer rate was 9.
Although it was good at 7%, the warp stripes of the fabric were poor at grade 6.

When the warp threads were extracted from the woven fabric and the entanglement coefficient was measured, it was 6.

Furthermore, when observing the fabric structure under a microscope, the shape of a single multifilament is divided into two parts: one part that looks like 7 to 8 single filaments spread out (the remaining 8 to 9 threads overlap in double or triple layers), and the other part that looks like 10 single threads spread out. In the former, the distance between the warps was more than h of the multifilament width, and in the latter, it was less than %, so the warp stripes of the fabric appeared strong and the quality was poor. .

Comparative Example 2 An experiment was conducted in the same manner as in Example 1, but with the interlaced nozzle removed.

The confounding coefficient (C.F.) of the obtained yarn was O, but
The winding properties were extremely poor and winding was impossible for more than 30 minutes.

Comparative example 3 The yarn obtained in the same manner as in Comparative Example 1 was used as a weft for weaving.

It was defective with a latitude spot W2. When the fabric was observed under a microscope, it was found that there were differences in the spread of the multifilaments, which were found to be shiny latitude spots.

Comparative Example 4 A 30-minute winding yarn obtained in the same manner as Comparative Example 2 was woven as a weft, but there were frequent stoppages due to poor unwinding (1/1 time).
30 years old).

Comparative Example 5 A normal drawn yarn was woven with an interlace having an entanglement coefficient (C, F.) of 20 after drawing and before winding, as a warp.

The weaving transfer rate was good at 97%, and the warp stripes were also good at grade 4.0.

When the warp threads were extracted from the woven fabric and the entanglement coefficient was measured, it was 1.

However, the texture of the fabric was extremely hard compared to Examples 1 and 2 and Comparative Examples 1 to 4.

Moreover, as a result of dyeing with Supranol Cyanine G, it was grade 2.5, and Examples 1 to 2 and Comparative Examples 1 to 4 were all grade 5, so the level dyeing properties were poor.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating an apparatus for testing the strength of interfilament entanglement in a multifilament yarn, in which 1 is a supply roller, 2 is a delivery roller, and 3, 4, and 5 are titanium pins, respectively. FIG. 2 is a graph showing the relationship between yarn tension T(y) and the degree of interlacing remaining in the multifilament yarn (entanglement coefficient) when measured using the apparatus shown in FIG. Drawn yarn, line b shows data for high speed spun yarn.

Claims (1)

[Claims] 1. Birefringence obtained by high-speed spinning is 30×10−
A multifilament yarn for knitting and weaving, which is a polyamide multifilament yarn having a size of 3 to 45×10 −3 , wherein the filaments constituting the yarn have an entanglement coefficient (C, F,) of 2.0 or less. 2. The multifilament yarn for knitting and weaving according to claim 1, wherein the number of constituent filaments of the polyamide multifilament yarn is 3 to 50. 3. The multifilament yarn for knitting and weaving according to claim 1 or 2, wherein the polyamide multifilament yarn has a total denier of 20 to 300 de.