JPH0655990B2 - Method of sizing polyamide yarn - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for sizing a polyamide yarn.

<Prior Art> When a woven fabric made of synthetic fibers such as polyamide and polyester is manufactured, it is sewn on a plain weaving machine WJL (water jet loom) after being pasted with a sizing machine as shown in FIG. In this sizing machine, a large number of raw yarns set on a creel 1 are passed through a reed 2 to be gathered at an equal pitch, and glue is attached by a glue bath 3. Squeeze roll 4
After squeezing, the thread after sizing is squeezed to the required amount of sizing. First drying chamber 5, second drying chamber 6 and drying cylinder 7
The yarn is dried by and is wound up on the beam 8. The stretch S% in sizing is represented by the speed ratio between the squeeze roll 4 and the drying cylinder 7. That is, the speed of squeeze roll 4 1.
When the speed of the drying cylinder 7 is 0.997 with respect to 0, "-
0.3% (overfeed of 0.3%) ", and when the speed of the drying cylinder 7 is 1.003," + 0.3% (0.3
% Underfeed) ”. That is, "+" is underfeed and "-" is overfeed.

<Problems to be Solved by the Invention> In recent years, the practical application of high-speed spinning (spinning speed of 4000 m / min or more) has attracted attention as an innovative technology for manufacturing polyamide yarn. However, high-speed spinning yarns that do not undergo the drawing process have characteristics different from conventional yarns, and therefore, applying the same woven fabric manufacturing conditions as conventional yarns causes troubles in process performance and product quality. In many cases, it has not been put to practical use industrially.

If the high-speed spinning yarn is carried out under the same conditions as the conventional yarn sizing conditions, the winding of the yarn or roller breakage of the yarn is likely to occur, or the operating rate of the loom during weaving is reduced as a result. Further, there is a problem that the quality of the woven fabric is deteriorated.

The present invention solves such a problem and provides a sizing method capable of performing good sizing, maintaining a high sizing step and an operating rate during weaving, and improving the quality of a woven fabric after weaving. The purpose is to provide.

<Means for Solving Problems> An object of the present invention is to spin at a high speed of 4000 m / min or more,
When sizing a polyamide yarn having a maximum dry heat shrinkage stress Fmax of 0.15 to 0.30 g / d and using it for warp to produce a woven fabric, the stretch S% between the squeeze roll and the drying cylinder is 15 Fmax. It is achieved by a method for sizing polyamide yarn, which comprises underfeeding a yarn from a squeeze roll to a drying cylinder so as to maintain the range of ≦ S ≦ 20Fmax and drying.

Fmax referred to here is the length at which the yarn is gripped by the thermal stress measuring machine at 50c.
It is fixed at m, heated at a rising rate of 10 ° C./min, and a heat shrinkage stress curve as shown in FIG. 2 is drawn to obtain the stress Fmax at the maximum temperature Tmax.

Incidentally, for example, a yarn spun at a high speed of 4000 m / min or more can have a Fmax of 0.15 to 0.30 g / d. On the other hand, the conventional polyamide yarn has Fmax of 0.7 to 0.8 g / d.

The number of twists of the yarn is OT /
It is M. However, there is a method of imparting 5 to 15 / m of entanglement by an air jet in order to improve the process performance, and such a yarn is preferable in terms of fabric production. But 1
When sizing a yarn having an entanglement of 5 or more / m, the entanglement point is fixed and the quality of the fabric is deteriorated, which is not preferable.

Conventionally, among the sizing conditions of polyamide yarn, stretch S% is practically −0.5 to −3.0% (that is, overfeed), for example, when sizing 70 ^d / 34 ^f SW warp, −2 It is done at 0.4%. Except when sizing processed yarns and special yarns having greatly different properties, the sizing of polyamide yarn is carried out under the above conditions. On the other hand, when a yarn with different properties such as a yarn spun by high speed spinning of 4000 m / min or more is set under the same conditions as the conventional yarn, that is, the stretch S% is set to around -2.4%, the heat shrinkage stress of the original yarn becomes that of the conventional yarn. Since it is lower than the above, the yarns in the drying chambers 5 and 6 are slackened, and the squeeze roll 4 is wound up, so that the operation cannot be performed.

In the present invention, as a result of studying various sizing conditions in order to solve these problems of sizing by high-speed spinning, the range described in the scope of the claims of the present invention, that is, 15 times to 20 times the Fmax of the yarn to be sized is underexposed. It was found that good results can be obtained by carrying out feeding.
If the underfeed is 15 times or less, the above trouble occurs, and if it is 20 times or more, over tension drying occurs and the quality of the woven fabric deteriorates. In particular, since the yarns produced by high-speed spinning are completely untwisted yarns without original twist, single yarn breakage and winding problems easily occur,
It is effective in the area of the present invention. Needless to say, the effect is not hindered even with a yarn having entanglement due to air pressure for improving process performance.

Moreover, since the conventional polyamide yarn is sized under the overfeed condition, the polyamide yarn is contracted in the drying chambers 5 and 6. Therefore, the denier with sizing yarn after sizing is made thicker than the denier before sizing. On the other hand, since the sizing method in the present invention is under-feed conditions, the polyamide yarns fed from the squeeze roll 4 into the drying chambers 5, 6 are pulled by the drying cylinder 7 to a length not less than the yarn length fed therein. Therefore, the sized denier yarn after sizing is made into a fine denier. When a woven fabric is woven with the fine denier sized yarn, the woven fabric feels like paper and the volume tends to be insufficient. For this reason, the denier of the warp original yarn for sizing may be set to a thick denier by correcting the amount of fine denier caused by underfeed.
Due to this thick denier, the denier of the sizing yarn after sizing becomes an appropriate value.

Further, when carrying out the sizing method of the present invention, other preferable sizing conditions include a chamber drying temperature of 115 ° C. to 130 ° C. and a cylinder drying temperature of 95 ° C.
˜110 ° C., the sizing tension (tension between the second drying chamber 6 and the drying cylinder 7) is preferably 0.20 to 0.25 g / d, and the adhesive adhesion rate is 4 to 5%.

<Example> Hereinafter, the result of studying the example of the sizing method according to the present invention in the sizing of the high-speed spun yarn of 6-6 nylon fiber will be shown. Extruder and winder are 7000-800 in terms of performance
It is possible up to 0 m / min, but it is 45 of 6-6 nylon fiber.
The sizing for high speed spun yarns of 00 m / min and 5500 m / min was examined.

The set denier of the warp raw yarn is set to 75 denier, which is about 1.07 times as much as it is necessary to set the stretch to underfeed by several%.

Therefore, the warp speed is 4500 m / min and 5500 m / min.
Of 6-6 nylon fiber 75 ^d / 20 ^f , weft is 6-6 nylon fiber 70 ^d / 20 ^f 70/70 nylon taffeta using yarn, sizing stretch S% condition of warp and sizing process performance and water jet room Of the weavability and the quality of the fabric were evaluated.

Spinning speeds are 4500 m / min and 5500 m / min, and the maximum values Fmax of dry heat shrinkage stress are 0.20 g / d and 0.2, respectively.
Sizing 5g / d yarn under various stretch conditions,
Woven as 70/70 nylon taffeta warp. The results are shown in Table 3 in comparison with the case of sizing a conventional yarn. Table 1 shows the main sizing conditions other than the sizing stretch conditions, and Table 2 shows the weaving conditions.

The sizing stretch S% setting on the sizing machine cannot be set arbitrarily, and it is a general sizing machine that is set to an integer multiple of 0.3%.
As shown in the table, the test was conducted within the range of +1.8 to + 5.4%. The weaving quality after weaving was evaluated according to the following criteria.

Quality evaluation A: Passed anti-class B: Semi-passed anti-class C: Semi-downgraded anti-class D: Downgraded anti-class S% of experiments No. 5, 6 and 12 were stable with no sizing during running Although it was in a running state, the quality of the raw fabric woven under the weaving conditions shown in Table 2 was a grade of degrading anti-class because of significant cracking defects in the ground. This is due to over-tension drying due to excessive underfeed of sizing.

Experiments with S% of 15 Fmax or less were conducted in Experiment Nos. 1, 2, 7, 8,
It is 9. In Experiment Nos. 2, 8 and 9, due to insufficient sizing underfeed, the sizing tension was low and roller winding, sticking of the running yarn, etc. were likely to occur, and the yarn was broken 1 to 5 times per 10 ⁶ m of the sizing running yarn. Occurred. Regarding the weaving property of this sizing yarn by WJL, the number of warp stops per day per loom is 1.5 to 3.0 times / day. The weaving property is poor, and the quality of the weaving machine is poor There has occurred.

In Experiment Nos. 1 and 7, the sizing tension was not applied because the underfeed was further insufficient, and the yarn was wound around the squeeze roll 4 and the sizing travel was impossible.

On the other hand, an experiment satisfying the conditions of the sizing method according to the present invention
Nos. 3, 4, 10 and 11 were applied with appropriate sizing tension, and there was no sizing yarn breakage.

The weavability by WJL is such that the number of warp cause stop is 0.1 to 0.2 times /
The weaving condition was good on both day and stand, and there were no defects such as cracks in the ground and hitting lines in the quality of the raw fabric, and the quality was good.

In particular, Experiment No. 4 and 10 sizing runnability, WJL weaving
The quality of the greige was extremely good and was the best among the present examples.

<Effect of the invention> When sizing a polyamide yarn spun at a high speed of 4000 m / min or more, the main stretch S% is set to 15 Fma.
By drying underfeed in the range of x ≦ S ≦ 5Fmax, good results can be obtained in sizing running property, weaving property, woven fabric quality and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic front view showing an example of a commonly used sizing machine for polyamide yarn, and FIG. 2 shows an example of heat shrinkage stress curve of the yarn. It is a graph. 1 ... creel, 2 ... reed, 3 ... paste bath, 4 ... squeeze roll, 5 ... first drying chamber, 6 ... second drying chamber, 7
… Drying cylinder, 8… Winding beam.

Claims (2)

[Claims] A polyamide yarn having a maximum dry heat shrinkage stress Fmax of 0.15 to 0.30 g / d is spun at a high speed of 4000 m / min or more, and is used as a warp to produce a woven fabric. In this case, a polyamide yarn characterized by under-feeding and drying the yarn from the squeeze roll to the drying cylinder so that the stretch S% between the squeeze roll and the drying cylinder is maintained in the range of 15Fmax ≦ S ≦ 20Fmax. Sizing method. 2. The sizing method according to claim 1, wherein a yarn in which the number of twists of the warp is OT / M and the number of entanglements by fluid treatment is 5 to 15 / m is used.