JPH10251913A - Direct spinning and drawing of synthetic yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for direct spinning and drawing capable of drawing eight or more yarns, slight in end breakage and singe yarn breakage and capable of producing a synthetic yarn excellent in yield and quality. SOLUTION: In this direct spinning and drawing process for a synthetic yarn capable of cooling and solidifying a yarn obtained by melt spinning, oiling the yarn, taking-off the yarn at >=500m/minute speed, successively drawing the yarn at a multiple stage by using plural roller groups, heat-treating and taking-up the yarn at >=3,000m/minute, feed yarn roller groups C and C' before a first-stage drawing comprise plural rollers having a mirror finished surface of <=1μm surface roughness (Rmax), first-stage drawing roller groups D and E comprise at least two rollers having a matte finish of 0.3-3.0μm surface roughness (RMS) and the yarn is successively hung on each of the feed yarn roller groups and the drawing roller groups, continuously drawn and heat-treated at stages on and after the second stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for directly spinning and drawing synthetic fibers. More specifically, the present invention relates to a method for directly spinning and drawing synthetic fibers capable of efficiently producing high-strength, relatively fine-fiber synthetic fibers suitable for industrial materials, particularly for textiles for industrial materials.

[0002]

2. Description of the Related Art JP-A-63-165513 discloses that
In the direct spinning and drawing method of a synthetic fiber, a method of using a Nelson roller, winding a plurality of yarns a plurality of times around two or more Nelson rollers, and performing drawing and heat treatment to increase the production efficiency is disclosed. ing.

[0003] This method is excellent as a method for drawing and heat-treating a yarn having a large fineness, since heat transfer at the time of drawing and heat treatment is good. When the yarns are to be simultaneously drawn, there is a problem that the roller length becomes long. That is, when multiple yarns are to be simultaneously drawn, the roller length becomes longer as the yarn width, the yarn pitch, the number of turns of the yarn, and the number of yarns increase. When the length of the roller is increased in this way, it is difficult to secure stability during high-speed rotation of the roller, especially in the case of a heating roller, as the weight increases.

Further, in order to simultaneously stretch the multiple yarns, if the yarn width, the pitch between the yarns and the number of windings of the yarns are appropriately secured, the twist between the Nelson rollers is increased. It is necessary to take a large angle. However, as the twist angle between the rollers increases, the yarn is stretched while being twisted with the next process stretching roller, so that it is difficult to perform smooth stretching, and yarn breakage or single yarn breakage occurs. They tended to be cut, causing a reduction in yield and quality.

Further, Japanese Patent Publication No. 42-8727 discloses that
Using a combination of a fixed pin whose surface is matte and heated by flowing steam or a heat medium into it, a separation roller whose surface is matte, and a stretching roller whose end face is matte and the other is mirror-finished, after stretching A method is disclosed in which a yarn is wound on a separating roller once or twice from a mating surface of a drawing roller and then wound.

According to this method, the frictional resistance between the yarn and the roller is reduced in the section which is the satin surface of the drawing roller, and since the heat is applied, the strain caused by the drawing is released and the obtained yarn remains. Shrinkage decreases.

However, in this method, stretching and heat treatment are continuously performed using a Nelson roller. Therefore, as in the case of the above-mentioned Japanese Patent Application Laid-Open No. 63-165513, enlargement of the roller, breakage of a single yarn, breakage of a single yarn, and the like occur. Have a problem.

Therefore, Japanese Patent Application Laid-Open No. Hei 4-245909 discloses a method suitable for stretching and heat-treating multi-filament yarns of eight or more yarns in a method of performing multi-stage drawing using a plurality of roller groups and performing heat treatment. The first-stage stretching roller is constituted by a mirror-finished roller having a surface roughness of 1S or less and a satin-finished roller having a surface roughness of 4 to 8S,
Subsequently, a method of performing stretching and heat treatment in the second and subsequent stages is disclosed.

[0009]

However, in this method, since the degree of improvement in the actual frequency of yarn breakage is small, there is a problem that the drawing yield is reduced by the increase in the number of yarns. In addition, by this method, relatively fine fineness, for example, 21
When high strength yarns of 0d, 315d and 420d are obtained and used for fabrics such as base fabrics for airbags and tarpaulins and bags, fluffs that affect the fabric quality strongly required in those applications are, for example, It has been difficult to stably reduce the number to a low level of several or less per 10 million m.

Therefore, a main object of the present invention is to solve the above-mentioned problems in the prior art, and it is possible to stretch eight or more yarns without using a long stretching roller.
Another object of the present invention is to provide a direct spinning and drawing method capable of producing a synthetic fiber excellent in yield and quality, with few yarn breaks and single yarn breaks.

[0011]

In order to achieve the above object, a direct spinning and drawing method for synthetic fibers according to the present invention comprises cooling and solidifying a melt-spun yarn to feed oil at a speed of 500 m / min or more. In the method of direct spinning and drawing of synthetic fibers that are taken up, subsequently subjected to multi-stage drawing using a plurality of roller groups, heat-treated, and wound at a speed of 3000 m / min or more, the yarn feeding roller group before the first-stage drawing has a surface A plurality of rollers having a mirror surface with a roughness (Rmax) of 1 μm or less, and a first-stage stretching roller group includes at least two rollers having a matte surface with a surface roughness (RMS) of 0.3 to 3.0 μm. , And the yarn is sequentially wrapped around each of the yarn supplying roller group and the drawing roller group, and then is drawn and heat-treated in the second and subsequent stages.

The method of the present invention is suitable for the case where eight or more multifilaments are simultaneously stretched and heat-treated, and the temperature of the first-stage stretching roller is preferably 100 to 180 ° C.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of a method for directly spinning and drawing synthetic fibers of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing a portion after a take-off roller in an example of a direct spinning and drawing process to which the method of the present invention is applied. In this drawing, eight yarns are simultaneously subjected to direct spinning and drawing. .

In practicing the method of the present invention, first, a plurality of yarns K composed of a plurality of synthetic fibers spun from a spinneret attached to a plurality of spinning sections provided in a melt spinning machine are formed. Then, it is cooled and solidified by passing through a cooling section, and then is supplied to each yarn at an oil supply section, and is hung one by one on take-off rollers A and B, and is taken up at a predetermined speed of 500 m / min or more.

The taken yarn K is drawn by a plurality of yarn feed rollers C and C 'shown in the drawing, drawn in a first-stage drawing region a and a second-stage drawing region b, and then heat-treated. Thereafter, it is wound on a cheese-like package I by a winder J at a high speed of 3000 m / min or more by turn guide rollers H and H '.

In the present invention, the yarn feed roller groups C, C ',
The stretching roller groups D, E, F, F 'and the heat treatment roller groups G, G' are each formed by two or more rollers. Among the rollers forming these groups, the yarn supplying roller groups C and C 'and the first-stage stretching roller groups D and E are of a single-hanging type. The remaining stretching roller groups F and F 'and the heat treatment roller groups G and G' may be of the Nelson type.

Here, the rotation speed of the former one-shot type roller group may be the same, or may be different if the speed difference between the rollers is 50% or less. on the other hand,
The rotational speeds of the Nelson-type rollers are synchronized and the same.

Then, the yarn K picked up by being picked up by the picking-up roller groups A and B sequentially has a surface roughness (Rma).
x) The yarns are sequentially hung on yarn supply roller groups C and C 'each composed of a plurality of mirror-finished rollers of 1 μm or less. The contact angle between the yarn K and each of the rollers A, B, C, C 'in this single hooking method is generally about 120 to 240 degrees, but the roller diameter, the yarn speed, the yarn fineness, etc. Considering this, it is sufficient to select the optimum contact length necessary for grasping the yarn.

Since the yarn supplying roller groups C and C 'are mirror-finished rollers having a surface roughness (Rmax) of 1 μm or less, the yarn K can be sufficiently gripped even in a single-rolling roller system. A multi-thread simultaneous drawing process of eight or more yarns by the one-sided roller system becomes possible. On the other hand, if a satin roller is used as the yarn supplying roller group C or C ', a large number of rollers or rollers having a long diameter are required to secure a sufficient gripping force. It becomes difficult to make the yarn simultaneous drawing process.

Next, the yarn K is sequentially hooked to a first-stage drawing roller group C, D comprising at least two rollers having a matte surface having a surface roughness (RMS) of 0.3 to 3.0 μm. Immediately before reaching the roller group, the first-stage stretching is performed.

In the process of simultaneously drawing multiple yarns of eight or more yarns, it is necessary to simultaneously hook one of the yarn feed rollers C and C 'and at least one of the first-stage drawing rollers. On the other hand, if a Nelson roller is used as the first-stage stretching roller, a long and heavy roller is required, which not only raises a problem in terms of securing safety at a high price, but also increases the twist angle of the thread between the rollers. It is not suitable because it causes a decrease in stretchability and an increase in fluff caused by the increase in size.

Further, the single-stage first-stretching roller group D, E of the present invention comprises two or more roller groups, and usually comprises a combination of two rollers D, E as shown in the figure. . For both of the two rollers D and E, it is essential to use a roller having a matte surface with a surface roughness (RMS) of 0.3 to 3.0 mμ. The first roller D in the first-stage drawing roller group grips the yarn K on the surface of the roller, and completes the first-stage drawing performed between the yarn supplying roller groups C and C ′. Perform the function.

Each of the first-stage stretching roller groups D and E needs to have a surface roughness (RMS) in the range of 0.3 to 3.0 μm. The first-stage stretching can be reliably completed on the roller D, and the stress is not concentrated at the stretching start point of the second-stage stretching (immediately downstream of the outlet of the first roller D). Eye stretching can be performed. As a result,
The fluff due to filament breakage can be greatly reduced, and at the same time, the yarn breakage is also significantly reduced, so that a high-quality raw yarn can be manufactured with high yield.

The RMS 0.3 to 3.0 μm of the surface roughness of the first-stage stretching roller groups D and E corresponds to a surface roughness of 4 to 8S. The roller surface temperature is 100 to 180.
It is preferable to set the temperature in the range of ° C.

On the other hand, in the method described in JP-A-4-245909 in which the first-stage stretching roller group is constituted by a mirror-finished roller (with a surface roughness of 1 S or less) and a satin finish roller,
It is excellent in that the yarn is securely gripped and the first-stage drawing is reliably completed on the first roller to stably perform the first-stage drawing, but the first mirror surface of the first-stage drawing roller group is excellent. Since a stretching point at the time of second-stage stretching is generated at a position immediately downstream of the outlet of the roller and that portion becomes a stress concentration point, filament breakage tends to occur there. The filament breakage causes fluff of the product yarn, and also causes the cut filament to be wound on the mirror-finished single-hanging roller having high friction to cause the entire yarn breakage.

The stress concentration at the stretching start point in the second stage stretching is caused by the surface temperature of the subsequent roller E of the first stage stretching roller group and the subsequent second stage stretching roller group, and the second stage stretching ratio. No matter how appropriate such conditions are selected, it is difficult to avoid as long as the first roller D of the first-stage stretching roller group is a mirror surface.

Next, the subsequent roller E of the first-stage stretching roller group is subjected to substantial second-stage stretching on this roller, but usually has the same speed and the same diameter as the first roller D. Although a method of changing only the roller surface temperature is employed, another stretching pattern can be selected by changing the roller speed and / or the speed of 1.5 times or less.

Subsequently, as the second-stage stretching roller group F, F 'for completing the second-stage stretching, a single-sided roller group similar to the above-described first-stage stretching can be used.
Since the first-stage stretching requires a higher temperature than the first-stage stretching and requires heat treatment in many cases, when a single-sided roller is used, the roller E and the second-stage stretching roller in the first-stage stretching roller group are used. It is preferable to install a heating element such as a steam heater or a dry heat heater between the stretching roller groups F and F '.

On the other hand, the second-stage stretching roller groups F and F '
Since the above-mentioned drawbacks of the Nelson roller are alleviated in this step, it is also practical to employ a Nelson roller for performing a strong heat treatment. That is, at the time of the second-stage drawing, the yarn width has been narrowed because the drawing has already been advanced, and all the rollers before the second-stage roller are single-sided rollers, so that the final stage of the second-stage drawing is performed. This is because the torsion angle of the second-stage stretching roller has no effect on the part that is shown.

The method of the present invention is generally applied to the production of synthetic fibers from a high molecular weight polymer capable of being melt-spun, and is particularly suitable for textiles for industrial materials and has high strength and relatively fine fineness. It is effective when trying to manufacture.

The method of the present invention is preferably applied to the production of high-strength synthetic fibers having a strength of 8 g / d or more, particularly 9 g / d or more, such as polyamide fibers and polyester fibers, which are suitable for industrial materials.

The method of the present invention has the above effects in the direct spin drawing method in which the drawing is performed at a high speed of 3000 m / min or more, especially when a plurality of, especially 8 or more multifilaments are simultaneously drawn and heat-treated. Is remarkably exhibited.

[0034]

EXAMPLES The present invention will be further described below with reference to examples. In addition, each physical property in this invention is the value measured by the following method.

(1) Surface roughness (RMS): The following formula (I)
Is expressed by the root mean square roughness. That is, the square of the deviation from the center line to the roughness curve f (x) is calculated as the measured length L
Is the square root of the value integrated over the interval and averaged over that interval. Here, the center line means a straight line in which, when a straight line parallel to the average line of the roughness curve is drawn, the area surrounded by the curve and the roughness curve is equal on both sides of the straight line.

[0036]

(Equation 1)

(2) Surface roughness (Rmax): JISB0
601 was measured.

(3) Number of yarn breaks: The number of yarn breaks per 10,000 km of fiber length. In the following examples of simultaneous production of eight yarns, one cut was converted into eight yarns, that is, eight times multiplied and displayed as eight times.

(4) Number of fluffs: After stretching heat treatment, a laser fluff detector was installed and counted immediately after a turn guide roller installed before winding by a winder, and the number was counted per 10,000 km.

(5) Strength and elongation characteristics: Measured according to the measuring method of JIS L1017.

Examples 1-6 and Comparative Examples 1-2 Nylon 66 chips containing 98 ppm copper acetate and 0.1 wt% potassium iodide (98% sulfuric acid relative viscosity 3.
6) was melt spun with an extruder type spinning machine. The extruder had four spinning packs, and the spinneret holes were arranged such that 1/4 of the total yarns were spun from each spinneret attached to each spinning pack.

The spinning temperature was 290 ° C., and a metal filter having a pore size of 20 μm was used as a filter.

A heating cylinder having a length of 20 cm is installed immediately below the base, and the atmospheric temperature at a position 15 cm below the base is set to 300 mm.
C. was controlled. Cold air was blown from the lateral direction onto the yarn exiting the high-temperature atmosphere in the heating cylinder and solidified by cooling. Cold air temperature is 20
C., the wind speed of the cold air was 40 m / min, and the air was blown straight from a 120 cm cold air box.

To the cooled and solidified yarn, an ordinary oil emulsion containing a smoothing agent, an emulsifier, an activator, an antistatic agent and the like as main components is applied so that the amount becomes 0.9% by weight based on the weight of the product original yarn. The amount was adjusted. The application of the oil agent was performed using an oil supply roller for each yarn.

After refueling, all the yarns were arranged at equal intervals, and were hung on take-off rollers A and B. The take-up speed (ie, spinning speed) was 864 m / min. Subsequently,
After stretching by 5% between the yarn supplying rollers C-C ', the yarns are sequentially threaded on the stretching roller groups D, E, F, and F', and the yarns are stretched by 8%.
The yarn was simultaneously stretched in two stages and heat-treated, and a half of the entire yarn was wound separately on a winder J.

Experiments were carried out by changing the number of yarns, the take-up roller group, the yarn supply roller group, the surface roughness of each roller in the first-stage drawing roller group, and the like as shown in Table 1, and performing experiments. The results of measuring the physical properties of the strip are also shown in Table 1.

As is evident from the results in Table 1, according to the method of the present invention (Examples 1 to 6), a high-quality raw yarn with less yarn breakage and less fluff could be efficiently obtained. .

[0048]

[Table 1]

Examples 7 to 12 and Comparative Examples 3 and 4 The polymer to be spun was changed to nylon 6 chips having 98% sulfuric acid relative viscosity of 3.3, the spinning temperature was set to 280 ° C.
Using a metal filter with a μ gap, 15c below the base
except that the ambient temperature at the m position was 290 ° C., the wind speed of the cool air at the time of cooling and solidification was 35 m / min, the amount of the oil agent was 0.7% by weight per the weight of the product raw yarn, and the spinning speed was 844 m / min. In the same manner as in Example 1, melt spinning, two-stage drawing and heat treatment were performed.

At this time, the number of yarns, the take-up roller group, the yarn supply roller group, and the surface roughness of each roller in the first-stage drawing roller group were variously changed as shown in Table 1, and experiments were performed. The results of measuring the physical properties of the obtained yarns are also shown in Table 1.

As is clear from the results shown in Table 2, according to the method of the present invention (Examples 7 to 12), it is possible to efficiently obtain a high-quality raw yarn with less yarn breakage and less fluff. Was.

[Table 2]

[0052]

According to the present invention, when synthetic fibers such as polyamide fibers are produced by the method of the present invention, multiple yarns of eight or more yarns can be simultaneously drawn without increasing the length and weight of the rollers used for drawing or heat-treating the synthetic fibers. In addition, yarn breakage and single yarn breakage are remarkably reduced, high-yield and efficient production can be performed, and high-quality fibers with less fluff can be obtained.

The high-quality, high-strength yarn obtained by the method of the present invention is particularly suitable for textile use for industrial materials.

[Brief description of the drawings]

FIG. 1 is a schematic process diagram showing a portion after a take-off roller in an example of a direct spinning and stretching process to which the method of the present invention is applied;

[Explanation of symbols]

A, B: take-up roller, C, C ': yarn feed roller,
D, E: First-stage stretching roller, F, F ': Second-stage stretching roller, G, G': Heat treatment roller, I: Cheese-like package, J: Winder, K: Thread, a: First-stage stretching Region, b: second stage stretching region

Claims (3)

[Claims] Claims 1. A melt-spun yarn is cooled, solidified, and refueled, taken up at a speed of 500 m / min or more, and subsequently multi-stage stretched and heat-treated using a plurality of roller groups.
In the direct spinning / drawing method for synthetic fibers wound at a speed of at least one minute, the yarn feeding rollers before the first-stage drawing have a surface roughness (R
max) is composed of a plurality of rollers having a mirror surface of 1 μm or less, and the first-stage stretching roller group has a surface roughness (RMS) of 0.
It is composed of at least two rollers having a pear surface of 3 to 3.0 μm, and the yarn is wrapped around each of the yarn feeding roller group and the drawing roller group sequentially. And spin-treating the synthetic fiber. 2. The method according to claim 1, wherein eight or more yarns are simultaneously drawn and heat-treated. 3. The temperature of the first-stage stretching roller is 100 to
The method according to claim 1 or 2, wherein the temperature is 180 ° C.