JPS59199810A - Production of polyamide fiber - Google Patents

Abstract

PURPOSE:To obtain the titled fibers for knitted and woven fabrics, etc. having a high strength, heat stability and improved dyeability, by quenching filaments melt extruded through spinneret extrusion holes to the solidifying point or below, passing the quenched filaments through a heated atmosphere, adjusting the spinning tension of the resultant filament yarn just after passing through the atmosphere, oiling the filament yarn, and winding the resultant oiled filament yarn at a high speed. CONSTITUTION:Filaments of a thermoplastic polyamide, e.g. nylon 6, melt extruded through spinneret extrusion holes are quenched to the solidifying point of the polyamide, passed through an atmosphere at a temperature (T deg.C) within the range satisfying formula I [T is the temperature ( deg.C); Tm is the melting point of the polyamide ( deg.C)] and formula II [D is the fineness per filament of the wound filament yarn (deniers); V is the winding speed (m/min)] at the same time for 0.01-0.03sec, adjusting the spinning tension (Gg) of the resultant filament yarn just after passing through the atmosphere within the range expressed by formula III [G is the spinning tension (g); F is the number of filaments in the wound filament yarn (filaments)], oiling the fialment yarn, and winding the oiled filament yarn at 4,500-5,500m/min speed to give the aimed fibers.

Description

[Detailed description of the invention] The mechanical properties of the present invention are improved by high-speed spinning method.

The present invention relates to a method for producing polyamide fibers having excellent thermal stability and dyeing properties and suitable for use in knitted fabrics.

Conventional methods for direct spinning and drawing of polyamide fibers are disclosed, for example, in Japanese Patent Publication No. 48-20268 and Japanese Patent Publication No. 46-22886.
As shown in the publication, the first pair of take-up rollers and the second
A common method is to draw the yarn with a pair of take-up rollers, and heat-set the yarn with a heated second pair of take-up rollers. Although the physical properties of the fibers obtained by this method are favorable, it is preferable to
When the speed is set to 0'%, the yarn sways greatly, and especially when the pair of rollers rotates a large number of yarns of 8 to 16 yarns, overlapping occurs between the yarns, causing the yarn to sway. If an attempt was made to increase the yarn spacing to avoid breakage, the length of the roller would become longer, making it impossible to rotate the roller at high speed.

On the other hand, a so-called high-speed spinning method is known in which the yarn is taken up at a high speed of 6,000 to 8,000'' without drawing between take-up rollers like the above-mentioned direct spinning and drawing method. 40%, which is a preferable level for yarn physical properties.
In order to obtain a certain degree of residual elongation, it was necessary to take it off at a high speed of s, ooor 4+ or higher, which resulted in frequent yarn breakage and decreased strength, making it unsuitable for industrial production. .

As an improvement on this method, a method has been proposed in Japanese Patent Publication No. 57-25644, etc. in which the polyamide thread is passed through a heated atmosphere after solidification. Although this method is quite effective in reducing the residual elongation and improving the thermal stability of polyamide fibers, B, 00-4.
Fibers obtained by high-speed spinning at a winding speed of about 00Or4 undergo a large amount of hot stretching in a heated atmosphere, causing uneven stretching between filaments, resulting in noticeable uneven yarn structure such as uneven fineness and uneven dyeing. A condyle was formed.

In order to reduce this yarn unevenness, the winding speed should be increased to 4.50.
It has been found that setting the winding speed to 0 to 5,500 mm is effective, but at such a high winding speed, it is difficult to perform sufficient heat treatment in the heating atmosphere, and the effect of improving mechanical properties is insufficient. New questions arose, such as sufficiency.

Therefore, as a result of studying how to solve this problem, we found that if the spinning tension immediately after passing through the heating atmosphere is set within a specific range shown by the following equation (3), the above problem is solved by ``, and this spinning tension is 3) When the heating atmosphere temperature is within the range of formula (1) and (2) below, the heating atmosphere temperature is within the range that satisfies the following formulas (1) and (2) at the same time, and the passing time is 0.01 to 0.
It has been found that setting the time to 0.03 seconds is most effective, and the present invention has been completed.

That is, the main objects of the present invention are to reduce uneven dyeing and uneven fineness of polyamide fibers obtained, and to sufficiently perform heat treatment in a heated atmosphere without causing yarn breakage. In order to achieve the purpose of
The thermoplastic polyamide spun yarn melted and discharged from the 40-karat gold discharge hole of the present invention is cooled to below the solidification point temperature of the polyamide, and then heated to a temperature ( 0.01-00 in an atmosphere heated to T °C)
After passing for 3 seconds, the spinning tension (CG%) immediately after passing was within the range shown in the 3-ton formula, and after oiling, 4,500
~Tm-10.0≦T≦Tm+60
(1) 20D+0.07V+Tm-500≦T≦10
D+0.04V+Tm-170 (2) 5J≦G≦17
, /T (3) According to the present invention, the disorder in the orientation of the amorphous portion in the fiber axis direction caused by high-speed winding at 4,500 to 5,500% is expressed by the above equations (1) and (2). This can be sufficiently resolved by passing it through a heated atmosphere under the temperature conditions of , the spinning tension conditions of equation (3) above, and the passing time conditions of above, so that the resulting polyamide fibers have good mechanical properties. It has excellent thermal properties and dyeing properties, and is suitable for knitted fabrics for clothing.

The method of the present invention will be explained in detail below.

The yarn immediately after spinning obtained by melting and discharging thermoplastic polyamide from the nozzle discharge hole in a conventional manner is once cooled to below the solidifying point temperature of the polyamide using a conventional cooling device such as cooling air blowing or air cooling. Ru. It is not preferable to pass the spun yarn before cooling through a heating range at a high temperature higher than the melting point of the polyamide because it causes unevenness in the thickness of the fibers. It is then focused by an upper focusing guide and passed through a heated atmosphere.

The position of the inlet of the heating atmosphere may be below the position where the yarn reaches the solidification point, but it is preferably closer to the solidification point in order to reduce air resistance to the yarn.

The spinning tension (G) immediately after passing through the heating atmosphere is 5F≦G≦1
5. /”F (F is the number of filaments in the yarn).

If the spinning tension is less than 5J, the effect of hot stretching on the yarn is small, and therefore the mechanical properties of the fiber cannot be sufficiently improved. Furthermore, if the spinning tension is (15σ)9 or more, the residual elongation of the yarn becomes too low, leading to frequent yarn breakage.

Preferably, it is in the range of (8F to 12 games).

In order to set the spinning tension (09) to (5 J″f to 15 J″), this can be done by adjusting the opening state of the yarn in the heating atmosphere using a focusing guide provided at the front of the heating atmosphere.

For example, in order to increase the spinning tension, the contact angle between the yarn and the guide may be increased, or the guide sound of a material with a high contact friction coefficient may be used. In addition, in order to lower the spinning tension 2, it is possible to use a guide containing a conductive material in the upper guide, to use a guide that minimizes contact with the yarn, or to use a guide that has a low contact friction coefficient and high wear resistance. It is sufficient to use a material with high quality.

Further, since the smaller the single yarn fineness of the yarn, the more sufficient the heat treatment effect can be, the single yarn fineness is preferably 6 denier or less.

Note that it is not preferable to supply oil above the inlet of the heated atmosphere because heating energy is consumed by the latent heat of vaporization of the oil agent.

As the device for forming the heating atmosphere, any device may be used as long as it is a non-contact heating device for yarn, but a heating tube with a circular cross section is particularly preferred. The inner diameter of the heating tube must be large enough to allow the yarn to pass through the tube without contacting it, and preferably has an inner diameter of between 5 and 20 mm per yarn. The length of the tube must be such that the thread passes through the tube for 0.01 to 0.03 seconds. Preferably it is 50-800 cm. More preferably, the length is 150 to 250 cm.

The temperature of the heating atmosphere needs to be within the range of equations (1) and (2) below.

□l Tm-100≦T≦Tm+60 (
1) 20D+0.07V+Tm-500≦T≦10D+
0.04V+TTm-170 (2) T: Melting point of polyamide (°C) D: Single yarn fineness of wound yarn (denier) ■: Winding speed ()) Less than (Tm-100)'O or (20D + 0.
At temperatures below 07V +Tm -500) 'C, the heat treatment effect is not sufficient, so the mechanical properties of the resulting fibers are not sufficiently improved, and the dyeing properties are also not sufficiently improved.

Furthermore, at temperatures exceeding (Tm+60)°C, fusion occurs between running yarns, making stable winding impossible. Or (10D
At temperatures exceeding +0.04V+Tm-170)'C, the residual elongation of the fiber becomes too low, leading to frequent yarn breakage.

Air is preferred as the heating atmosphere, but nitrogen may also be used. Further, the heated atmosphere inside the tube may be a static atmosphere except for the accompanying air flow caused by the yarn and the accompanying turbulence, but it is preferable to actively introduce the heated gas from upstream of the yarn.

“ After passing through the heated atmosphere, a refueling guide focuses the
After refueling, winding is performed at a speed of 4,500-5,500 mph.

The oil to be supplied may be an emulsion type oil having a concentration of 2 to 15% by weight, or may be a non-hydrous oil containing a mixture of mineral oil and a surfactant.

After refueling, processing such as interlacing may be performed.

The winding tension during winding is preferably within the range of 0.05 to 0.03. If it is less than 0.05%, the yarn may be wound up on a take-up roller or the like, or the yarn may come off from a traverse device, making it difficult to wind it onto a drum or bobbin.

Furthermore, if it exceeds 0.3%, the residual strain of the fibers becomes too large, making it difficult to obtain a good package form, or the difference in fiber properties between the center and end surfaces of the package becomes too large, resulting in problems such as product defects. There is. Further, 0.1 to 02% is preferable.

Furthermore, the winding bobbin used for winding the yarn is preferably a bobbin whose interior is reinforced with metal such as aluminum. In the fiber obtained by the present invention, the strain caused by hot drawing in a heated atmosphere is relaxed during winding, so when the fiber is wound on a winding bobbin made only of paper, the shrinkage of the winding yarn causes the thin tube bobbin to collapse. It collapses in the diameter direction, making stable winding difficult. If all bobbins are used that are internally reinforced with metal such as aluminum, the bobbin will not shrink and stable winding will be possible. The surface layer of the bobbin is preferably made of paper or synthetic resin such as ABS resin.

In order to obtain fibers with sufficient orientation of the crystalline portions, minimal yarn unevenness, and excellent thermal stability and dyeing properties, the winding speed must be 4,500 r'4 or higher;
0% or more is preferable. On the other hand, the winding speed is 5,500
If it exceeds %, spun yarn breakage will occur frequently,
Further, the thermal stretching in the heating region is small, and the improvement in mechanical properties is small, which makes it unsuitable.

The term "polyamide" used in the present invention mainly refers to nylon 6 or nylon 66, but it may also be a copolyamide obtained by copolymerizing these with a small amount of other polyamide-forming components. In addition, these polyamides are matting agents, 2 colorants, and heat stabilizers.

It may contain ultraviolet absorbers, fillers, moisture absorbers, and other additives. In the case of nylon 6, the melting point (Tm
) is approximately 215°C.

According to the method of the present invention, excellent polyamide fibers can be obtained in which the orientation of the crystalline portions is sufficiently advanced and the disordered orientation of the amorphous portions is sufficiently eliminated. This makes it possible to obtain fibers that have excellent properties and dyeing properties and are suitable for use as clothing fibers.

The polyamide fibers obtained by the method of the present invention are useful for, for example, trichomes, textiles, textured yarns, and the like.

The following examples illustrate the invention in detail.

- Example 1 After melting a nylon 6 chip (relative viscosity of sulfuric acid ηr-2,6) at a melting temperature of 265°C,
4=+) was discharged from the discharge hole. The discharge amount was adjusted so that the winding system fineness increased by 70D at each winding speed. The total temperature of the spun yarn was 18°C.

After cooling with a cooling cross-wind at a wind speed of 30), it passes through an upper focusing guide and is heated to a heating tube (temperature 2
00℃, tube length 120cm.

The entire yarn was guided through a tube with an inner diameter of 1.5 cm. The heating tube is filled with 50N% air heated to 200℃ from the upstream.

It flowed at a flow rate. The spinning tension immediately after passing through the heating tube was the value shown in Table 1. Thereafter, 5% of an emulsion-type oil agent having a concentration of 10% was applied using a refueling guide, and then the material was wound up through a godet roll at each winding speed shown in Table 1 with a winding tension of 7.

A comparative example was prepared by spinning yarn under the same conditions as above, except that the spinning tension was changed by adjusting the focusing guides provided before and after the heating tube.

The fibers obtained by the method of the present invention (Flats 1 to 3, 5, and 6) had excellent mechanical properties and dyeing properties, and also had good spinning properties. On the other hand, if the spinning tension is too low (A4) l”i
, mechanical properties and dyeing properties were unsatisfactory due to insufficient heat treatment effect. When the spinning tension was too high (A7), there were many spun yarn breakages, resulting in poor spinning properties and uneven dyeing.

The mechanical properties and birefringence of the fibers were measured according to the JIS method, and the color fastness was measured using 320 needles.
This is a value measured by the J Engineering S method for washing color fading of an item dyed at 98° C. and So for minutes at f, and the best grade is 5th grade, which is the normally usable level TFI 8th grade. To avoid uneven dyeing, use Paratine Fast Black W for the tube knit above.
Visual judgment was made on those stained with 0.2% OWF of AN at 60°C for 30 minutes. The spinning property was evaluated by the number of spun yarn breaks.

Fist Comparison Example Silk spinning was carried out under the same conditions as in Example 1, except that the winding speed was changed, the heating tube was not heated, and heated air was not flown. The results are shown in Table 2. Indicated.

If the winding speed is too low (flat 8), there will be uneven dyeing.
Moreover, the mechanical properties and dyeing properties were unsatisfactory.On the other hand, when it was too high (flat 9), the spinning properties were poor and the mechanical properties were unsatisfactory. Also, if heating is not completed (
Aio~12) has too high residual elongation and poor strength.

The modulus and orientation were too low, and the dyeing properties were also poor and unsatisfactory.

・( ・ Example 2 Silk spinning was carried out under the same conditions as in Example 1, except that the temperature of the heating tube, the temperature of the heated air, and the flow rate of the heated air were changed to the conditions shown in Table 3. The results are shown in Table 3. It was shown to.

As can be seen from the above table, the heating atmosphere temperature range is 5. ooor4+ winding place. , 150-2
50'O was good. That is, when the heating temperature was too low (Nos. 13 and 14), the characteristics of the obtained fibers were unsatisfactory, while when it was too high, single filament fusion occurred and the fiber could not be wound.

Example 3 Nylon 66 chips (sulfuric acid relative viscosity ηr-26) were melted at a melting temperature of 290°C and discharged from 24 discharge holes.The subsequent cooling, heating and winding conditions were the same as in Example 1. Ta.

The results are shown in Table 4.

As shown in Table 4, the method of the present invention was found to be effective for nylon 66 as well as nylon 6.

- Example 4 Nylon 6 chip (sulfuric acid relative viscosity ηr-2,6) after melting at a total melting temperature of 265°C, diameter 0.2 am (number of holes 68
It was discharged from a discharge hole with a diameter of 0.4 mm (number of holes: 2). The discharge amount was adjusted so that the winding system fineness was 70 ct at each winding speed. The subsequent cooling, heating atmosphere, etc. were the same conditions as in Example 1, and the results are shown in Table 5. As shown in Table 5, it was found that the smaller the single yarn fineness, the greater the heat treatment effect.

Patent applicant Higashishi Co., Ltd.

Claims (1)

[Claims] After cooling the thermoplastic boronamide spun yarn melt-spun from the nozzle discharge hole to below the solidification and selling temperature of the polyamide, the following formulas (1) and (2) are applied. At the same time, in an atmosphere heated to a temperature (T'O) within a satisfactory range of 0.01 to 0.
After passing for 08 seconds, the spinning tension (G9) immediately after passing was within the range shown by the following formula (3), and after refueling, 4,500
A method for producing polyamide fibers, characterized by winding at a speed of ~5,500%. Tm-100≦T≦Tm+60
(1) 20D+0.0TV+Tm-500≦T≦10D
+0.04V+Tm-170 (2) 5σ≦G≦17σ
(3)