JPH09228138A - Production of thermoplastic fiber and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic fiber having excellent boiling water shrinkage and peak thermal stress and useful for clothes, etc., by melt-spinning a thermoplastic polymer at or below a prescribed speed and drawing and heat- treating the product under specific condition. SOLUTION: The objective thermoplastic fiber is produced by melt-spinning a thermoplastic polymer such as polyethylene terephthalate at a spinning speed of <=3,000m/min, drawing the obtained undrawn yarn 7 under heating between a take-off and feeding godet roll 10 and a drawing and heat-setting godet roll 12 and subjecting the obtained drawn yarn to stretching heat-treatment with a temperature-gradient drawing and heat-setting godet roll 12 having a roll surface temperature maintained at a definite temperature between 110 and 160 deg.C near the yarn-introducing part at the base of the roll and a roll surface temperature maintained at a definite temperature below 80 deg.C near the yarn delivery part at the tip end of the roll. The drawing and heat-setting roll is preferably a tapered roll having diameter larger at the yarn-introducing part than at the yarn-delivery part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a thermoplastic fiber having highly versatile physical properties by a direct spinning drawing method which is a highly economical and continuous process. More specifically, a manufacturing method and apparatus capable of providing a thermoplastic fiber having a heat shrinkage property which is the same as that of a conventional thermoplastic fiber obtained by a two-step process of spinning-spreading at a low cost in the form of a large volume package. Regarding

[0002]

2. Description of the Related Art A fiber yarn made of a thermoplastic polymer such as polyester or nylon is produced by a melt spinning process as shown in FIG. 3 to produce an undrawn yarn, which is then stretched or drawn several times. It has been manufactured through a two-step twisting process. In recent years, direct spinning and drawing method (also called spin draw take-up method), which is a continuous two-step process
Has appeared, and now it has become widely used industrially. As shown in Fig. 2, there are 2 fiber yarns for clothing.
Stepwise uniform heating godet roll process (for example, JP-A-6-
No. 57532) is common.

The advantage of the direct spinning drawing method over the conventional two-step process is that the cost is reduced by the continuous process and the winding form is changed from the pan (FIG. 5) to the cheese-like package (FIG. 6) capable of mass winding. Is the cost reduction in the post-processing step. When a large number of reels are used, the number of creels (the number of times of yarn preparation) is reduced and the manpower is reduced, which leads to cost reduction in the post-processing step. However, the physical properties of the thermoplastic fiber obtained by this conventional direct spinning drawing method and the thermoplastic fiber obtained by the conventional two-step process are clearly different. That is, the former has a smaller boiling water shrinkage rate and thermal stress extreme value than the latter. For this reason, although the yarn obtained by the former direct spinning drawing method is very advantageous in terms of cost, there are restrictions on the application field of use.

That is, in the field of twisted yarn fabric, "texturing" is insufficient, and in the field of spandex interlacing, "laughing",
In the outer field, defects such as "fluffiness" generally occur, and in general, there is a lack of swelling and the like, and there is a problem that it cannot be used in a considerably general field covered by the two-step process yarn. In the recent era of “strong yen” or “price destruction”, it has become urgent to reduce the cost of clothing in the textile industry. Therefore, there has been a great demand for a process conversion from the two-step process to a direct spinning drawing method and for expanding the field of application of the thermoplastic fiber obtained by the direct spinning drawing method.

The second grade godet roll of the present invention, that is, the kind similar to the temperature gradient type godet roll used for the stretching and heat treatment godet roll is described in JP-A-6-330404 and JP-A-6-330405.
In both of these known techniques, a temperature gradient type godet roll is used as a first godet roll for multi-stage drawing of a yarn for material, that is, as a take-up / supply godet roll,
The purpose is to prevent the generation of fluff during stretching. The publication describes that a temperature grading type godet roll is used for the first godet roll, that is, the take-up / supply godet roll, but a conventional godet roll is arranged for the second godet roll, that is, the drawing / heat treatment godet roll. This is a direct spinning and drawing device. Therefore, the resulting thermoplastic fiber has a small thermal stress extreme value.
There are many prior arts in which a so-called taper type godet roll in which the diameter of the yarn outlet on the tip side of the goded roll is larger than the diameter of the yarn introduction portion on the root side of the goded roll in the direct spinning and drawing method is used.

Japanese Unexamined Patent Publication (Kokai) No. 50-83516 describes an example in which a taper type godet roll is used as a take-up and supply roll in the direct spinning draw winding method. The technique described in the publication is to arrange a taper type godet roll as a first goded roll, that is, a take-up and supply godet roll, to prevent yarn swaying on the goded roll. However, in this publication also, as a second goded roll, that is, a stretching / heat treatment goded roll, a known uniform temperature type goded roll is arranged in the entire inside of the known roll, so that the obtained thermoplastic fiber has a small thermal stress extreme value. Is.

Japanese Patent Laid-Open No. 55-27171 discloses about 5
A method is described in which an undrawn yarn is taken up by a heating type taper type godet roll at a spinning speed of 000 m / min, and drawing is performed by utilizing the taper on the godet roll. This is taken with a single-stage godet roll, stretched,
The purpose is to subject the high-speed spun fibers of 5000 m / min or more to a draw ratio of about 1.2 times by the method of performing heat treatment. However, since the tapered godet roll described in this publication is a uniform temperature godet roll, the extreme value of thermal stress of the resulting thermoplastic fiber is small. Thus, there is a prior art in which each of the gradient temperature type godet roll and the taper type godet roll is used independently for the purpose different from the present invention, but none is used for the tension heat treatment after stretching as in the present invention. Further, of course, there is no prior art using a godet roll that doubles as both.

[0008]

An object of the present invention is to improve the physical properties of thermoplastic fibers obtained by the conventional direct spinning and drawing method. That is, while maintaining the basic physical properties of the fiber yarn, the thermal shrinkage (boiling water shrinkage) and the thermal stress extreme value are made equal to those of the thermoplastic fiber obtained by the conventional two-step process method, and the cost-effective direct It is an object of the present invention to expand the field of application of the yarn obtained by the spinning and drawing method. The object of the present invention is to solve the above-mentioned problems and to have a heat shrinkage property equivalent to that of the conventional two-step process method, that is, a thermoplastic resin having a boiling water shrinkage ratio of 5% or more and a thermal stress extreme value of 0.28 g / d or more. It is an object of the present invention to provide a method and an apparatus for producing fibers by a direct spinning drawing method without increasing the number of stages of godet rolls.

[0009]

[Means for Solving the Problems]
In the stepwise process, the yarn is heat-treated in a tension state on the hot plate (24 in FIG. 3) of the twisting machine, whereas in the conventional direct spinning drawing method, the yarn is heat-treated in a relaxed state on a drawing and heat treatment godet roll, As a result, we have conducted intensive research focusing on the fact that relaxation shrinkage of the yarn occurs. As a result, they have found that providing the surface temperature of the stretched / heat-treated godet roll with a distribution is effective in avoiding heat treatment in a relaxed state, and completed the present invention.

The first aspect of the present invention comprises a thermoplastic polymer, 300
When the thermoplastic fiber is produced by melt spinning at a speed of 0 m / min or less, and the obtained undrawn yarn is drawn by using a two-stage heating type godet roll, the undrawn yarn is taken up. The film is heated and drawn between the godet roll that also serves as the feed and the godet roll that also serves as the drawing process to form a drawn yarn, and then the roll surface temperature near the yarn introducing portion on the roll root side is maintained at a constant temperature of 110 to 160 ° C. A method for producing a thermoplastic fiber, characterized in that a tension heat treatment is performed on a gradient temperature type drawing / heat treatment godet roll in which the roll surface temperature near the yarn outlet on the tip side of the roll is kept at a constant temperature of 80 ° C. or less. is there.

On the other hand, in the second aspect of the present invention, in a thermoplastic fiber manufacturing apparatus having a two-stage heating type godet roll of a take-up / supply godet roll and a drawing / heat treatment godet roll, the take-up / supply godet roll is entirely inside the roll. An apparatus for producing thermoplastic fibers, characterized in that it is a uniform temperature type with a built-in heater, and that the drawing / heat treatment godet roll is an inclined temperature type with a built-in heater on one side inside the roll. The undrawn yarn obtained by melt spinning at a speed of 3000 m / min or less has a draw ratio of 1.5 times or more in the drawing step, and therefore it is necessary to draw using the peripheral speed ratio of the two-stage godet roll. Melt-spin at a speed of 5000 m / min or more, and 1.3 on a single-stage tapered godet roll.
This is different from the technical object described in JP-A-55-27171, in which the following stretching is performed.

The device of the present invention will be described with reference to FIG. The apparatus of the present invention must have a take-off and supply godet roll 10 as shown in FIG. 1, and it must be of uniform temperature type with a heater built into the entire roll as shown in FIG. On this godet roll, it is necessary to heat the undrawn yarn containing the water and the finishing agent to the glass transition temperature of the thermoplastic polymer or higher, for example, to 70 ° C. or higher for polyethylene terephthalate, for which sufficient heat supply is required, It cannot be achieved unless it is of uniform temperature type.

Next, the apparatus of the present invention has a stretching and heat treating godet roll 12, which must be of the gradient temperature type with a heater on one side inside the roll as shown in FIG. This type must be used in order to obtain a fiber yarn having a boiling water shrinkage of 5% or more and a thermal stress extreme value of 0.28 g / d or more by heat-treating the drawn yarn on the godet roll in a tension state. If it is a uniform temperature type, no matter what the surface temperature is set, the heat treatment is performed in a relaxed state, and the extreme value of the thermal stress of the fiber yarn decreases. Since it is necessary to keep the winding tension at 0.20 g / d or less, the peripheral speed of the godet roll for stretching and heat treatment is set to be several percent higher than the winding speed, so that the relaxation of the as-heated fiber yarn is relaxed. This is because contraction occurs.

As shown in FIG. 9, the stretch / heat treatment godet roll is of a gradient temperature type and has different diameters at both ends of the roll. That is, it is preferable to use a taper type in which the diameter of the yarn outlet portion on the roll tip side is larger than the diameter of the yarn introducing portion on the roll base side. This is because the fiber yarn becomes strained as it goes from the yarn introduction portion to the yarn outlet portion, and the temperature decreases, so that the tension heat treatment action becomes more remarkable and the thermal stress extreme value is increased. The heater incorporated in the above two kinds of godet rolls may be a known heater such as a jacket heater type or an induction heating type. In the production method of the present invention, the undrawn fiber drawn by the take-up / supply godet roll 10 must be heated on a take-up / heating roll and drawn with the drawing / heat treatment godet roll 12 to form a drawn yarn.

In order to obtain a drawn yarn having good physical properties, it is usually preferable to heat the thermoplastic polymer to a temperature near the glass transition temperature of the thermoplastic polymer. The drawn yarn obtained by this heat drawing is mechanically imparted with excellent physical properties and is suitable as a fiber yarn for clothing. In the production method of the present invention, the drawn yarn obtained by heat drawing continues to keep the roll surface temperature in the vicinity of the yarn introducing portion at a constant temperature of 110 to 160 ° C, and the roll surface temperature in the vicinity of the yarn outlet portion to 80 ° C or less. It is necessary to perform heat treatment with a gradient temperature type godet roll maintained at a constant temperature. As a result, the drawn yarn is subjected only to the heat treatment in the substantially tensioned state near the yarn introduction portion, and relaxation shrinkage is avoided near the yarn outlet portion due to the low temperature.

If the temperature in the vicinity of the yarn introducing portion is less than 110 ° C., the heat treatment is insufficient and the boiling water shrinkage ratio becomes 15% or more.
Changes in the physical properties of the yarn after winding occur. Also 160
When the temperature is higher than 0 ° C, although it is a tension heat treatment, the boiling water shrinkage of the obtained yarn is less than 5% and the thermal stress extreme value is less than 0.28 g / d, and the object of the present invention cannot be achieved. A preferable range of the temperature near the yarn introducing portion is 120 to 150 ° C. The temperature near the yarn outlet should be below 80 ° C. 80
If the temperature exceeds ℃, relaxation shrinkage near the outlet of the yarn cannot be avoided. The preferred temperature range near the yarn outlet is 60 to 3
0 ° C. Further, in order to make the avoidance of relaxation shrinkage on the gradient temperature type godet roll more clear and to make the tension heat treatment effect more conspicuous, the stretching / heat treatment godet roll is of the gradient temperature type and the yarn is larger than the diameter of the yarn introduction portion. It is preferable to use a taper type (FIG. 9) in which the diameter of the outlet portion of the is large.
The taper angle is preferably 1.0 to 4.0 degrees.

The apparatus and manufacturing method of the present invention will be described below with reference to FIG.
Will be described in more detail. The pellets of the thermoplastic polymer are put into the hopper 1, melted by the extruder 2, and the molten polymer is supplied to the spin head 4 through the bend 3.
Further, the molten polymer is spun from the spinneret 6 through the pack 5, and is stretched according to the take-up speed and is cooled and solidified by the cooling air 8 to become the undrawn yarn 7. Undrawn yarn 7
The finishing agent is applied by the finishing agent applying device 9.
After that, the undrawn yarn 7 is collected and supplied by the godet roll 1
After being heated by 0, the drawn yarn 11 is drawn by utilizing the peripheral speed ratio of both godet rolls. The drawn yarn 11 is subsequently subjected to a tension heat treatment by a gradient temperature type drawing / heat treatment godet roll 12, is entangled by an interlacer 13, and then wound into a cheese-like package by a winder 14.

The thermoplastic polymer in the present invention includes polyethylene terephthalate and its copolymers, polycapramide and its copolymers, other polyesters, polyamides, and polyolefins such as polypropylene. Matting agents, antistatic agents, It may contain an additive such as a stabilizer. Hereinafter, the present invention will be described with reference to examples.

In the examples, the thermal stress extreme value and the intrinsic viscosity were measured by the following methods. (1) Thermal stress extreme value The thermal stress is measured using a thermal stress measuring device (for example, Kanebo Engineering Co., Ltd., trade name KE-2). A thread (multifilament) is cut into a length of 20 cm, and both ends of the thread are tied to form a ring, which is then loaded into a measuring machine. Initial load 0.05
The measurement is performed under the conditions of g / d and a temperature rising rate of 100 ° C./min, and the temperature change of thermal stress is drawn on the chart. Read the peak value of the thermal stress curve. That value is the extreme value of thermal stress. (2) Intrinsic viscosity [η] Intrinsic viscosity [η] in orthochlorophenol at 35 ° C
It is measured at a polymer concentration of 1 g / dl. (3) After measuring the sample length L ₀ under a load of 100 mg / d in boiling water shrinkage percentage (BWS) yarns (multifilaments), the sample with the no load 3
A boiling water treatment is performed for 0 minutes, a load of 100 mg / d is applied again, the sample length L1 is measured, and BWS is calculated by the following formula. BWS = {(L ₁ −L ₀ ) / L ₀ } × 100 (%)

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

[0021]

[Examples 1 to 3],

Comparative Examples 1-2 Polyethylene terephthalate having an intrinsic viscosity of 0.65 was spun and stretched using the direct spinning and stretching apparatus shown in FIG. In melt spinning, the temperature of the spin head 4 is set to 29
At 0 ° C., a spinneret 6 with 3 round holes of 0.25 mmφ
After spinning at a discharge rate of 41.0 g / min from a die having 6 holes, cooling air 8 was set to 0.65 m / sec for cooling and solidification, and a finishing agent was applied by a finishing agent applying device 9. Next, the undrawn yarn 7 is taken up by the take-up / supply godet roll 10, and drawn and heat-treated under the following conditions,
A substantially non-twisted cheese-like package 14 having a winding amount of 6 kg at 75 d / 36 f was obtained. In this example, the temperature of the yarn introduction part of the gradient temperature type drawing / heat treatment godet roll 12 is shown in Table 1.
Was changed as shown in FIG.

Pulling and supplying godet roll diameter 220 mmφ (FIG. 7) Length 250 mm Winding number 7 times Speed 2200 m / min Temperature 88 ° C. Stretching and heat treating godet roll diameter 220 mmφ (FIG. 8) Length 250 mm Winding number 7 times Speed 5038 m / min Yarn introduction part temperature Table 1 Drawing ratio 2.29 times Winding speed 4990 m / min

The physical properties of the drawn yarn thus obtained are shown in Table 1. Table 1
As is clear from the above, in Examples 1 to 3 in which the temperature of the godet roll stretched and heat-treated was within the range specified in the present invention, the ones in which the extreme value of thermal stress and the shrinkage rate of boiling water were improved were obtained. In Comparative Example 1, since the temperature near the yarn introducing portion was low, the thermal stress extreme value was improved, but the boiling water shrinkage rate was high and it was not practically applicable. Further, in Comparative Example 2, the temperature at the yarn outlet was out of the range specified in the present invention, so that the thermal stress extreme value was lowered.

[0024]

Examples 4 to 6 Melt spinning conditions were the same as in Example 1, and stretching and heat treatment were carried out under the following conditions. Pulling and supplying godet roll diameter 220 mmφ (Fig. 7) Length 250 mm Wrapping number 7 times Speed 2200 m / min Temperature 88 ° C Stretching and heat treatment Godet roll Yarn inlet diameter 220 mmφ (Fig. 9) Yarn outlet diameter 226 mmφ ( Taper angle 1.4 degree) Length 250 mm Winding number 7 times Yarn introducing speed 5038 m / min Yarn introducing temperature Table 2 Drawing ratio 2.29 times Winding speed 5058 m / min Physical properties of the obtained drawn yarn Is shown in Table 2. As is clear from Table 2, Examples 4 to 6 using the stretched / heat-treated godet rolls in which the inclined temperature godet rolls and the taper type were combined had high thermal stress extreme values and favorable boiling water shrinkage rates.

[0025]

Comparative Examples 3 to 5 Melt spinning conditions were the same as in Example 1, and stretching and heat treatment were performed under the following conditions using the apparatus shown in FIG. Pulling and supplying godet roll Diameter 220 mmφ (Fig. 7) Length 300 mm Winding number 7 times Speed 2200 m / min Temperature 88 ° C Stretching and heat treatment Godet roll type Uniform temperature type (Fig. 7) Diameter 220 mmφ Length 300 mm winding Number of times 7 times Speed 5038 m / min Temperature Table 3 Stretching ratio 2.29 times Winding speed 4990 m / min Physical properties of the obtained drawn yarn are shown in Table 3. As is apparent from Table 3, when a conventionally known uniform temperature type stretch / heat treatment godet roll is used, no matter how the temperature condition is changed,
Only a yarn having a low thermal stress extreme value was obtained.

[0026]

As in the case of the thermoplastic polymer fiber yarn obtained in the two-step process of spinning-spreading, heat having a boiling water shrinkage of 5% or more and a thermal stress extreme value of 0.28 g / d or more is used. Plastic polymer fiber yarns can now be obtained by direct spinning and drawing. As a result, the thermoplastic polymer fiber yarn produced by the direct spinning and drawing method is a twisted product, spandex interwoven,
The field of application has been expanded to include outerwear. This has led to the economic effects of the direct spinning drawing method, which is low in the cost of manufacturing the raw yarn and low in the cost of post-processing, to be utilized in a wide range of fields of application, which in turn led to a reduction in the cost of clothing.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[Brief description of drawings]

FIG. 1 is a schematic view showing the principle of a direct spinning and drawing apparatus of the present invention.

FIG. 2 is a conventional direct spinning and drawing apparatus (for example, Japanese Patent Laid-Open No. 6-5).
7532).

FIG. 3 is a schematic view showing the principle of a conventional two-step process apparatus.

FIG. 4 is a graph showing an example of thermal stress of the present invention and a conventional direct spinning drawing method.

FIG. 5 is a schematic view showing a pan.

FIG. 6 is a schematic view showing a cheese-like package.

FIG. 7 is a schematic view showing a uniform temperature godet roll.

FIG. 8 is a schematic diagram showing an inclined temperature type godet roll.

FIG. 9 is a schematic view showing a taper-inclined temperature type godet roll.

FIG. 10 is a schematic diagram showing an example of a surface temperature distribution of a gradient temperature godet roll.

[Explanation of Codes] 1 Hopper 2 Extruder 3 Bend 4 Spin head 5 Pack 6 Spinneret 7 Undrawn yarn 8 Cooling air 9 Finishing agent applying device 10 Taking-off and supplying godet roll 11 Drawing yarn 12 Drawing-heat treatment godet roll (gradient temperature Type) 13 interlacer 14 winder (and drawn yarn cheese package) 15 drawing and heat treatment godet roll (uniform temperature type) 16 spin head 17 spinneret 18 unstretched yarn 19 finisher application device 20 take-up godet roll 21 unstretched Yarn 22 Winder (and undrawn yarn cheese-like package) 23 Supply godet roll (non-heated type) 24 Hot plate 25 Stretched godet roll (non-heated type) 26 Winder (and drawn yarn pun) 27 Pawn bobbin 28 For cheese Bobbin 29 Built-in heater (uniform temperature type) (For godet rolls) 30 Built-in heater (for inclined temperature type godet rolls) 31 Built-in heater (for taper inclined temperature type godet rolls)

Claims (4)

[Claims] 1. A thermoplastic fiber is produced by a direct spinning drawing method in which a thermoplastic polymer is melt-spun at a speed of 3000 m / min or less, and the obtained undrawn yarn is drawn using a two-stage heating godet roll. At this time, the undrawn yarn is heated and drawn between a take-up / supply godet roll and a drawing / heat treatment godet roll to form a drawn yarn, and the roll surface temperature near the yarn introducing portion on the roll root side in the length direction of the roll is 1
Tensile heat treatment is performed with a gradient temperature type drawing / heat treatment godet roll that is maintained at a constant temperature of 10 to 160 ° C. and the roll surface temperature near the yarn outlet on the roll tip side is maintained at a constant temperature of 80 ° C. or less. A method for producing a thermoplastic fiber. 2. The method for producing a thermoplastic fiber according to claim 1, wherein the drawing / heat treatment roll is a taper type in which the diameter of the yarn outlet is larger than the diameter of the yarn introducing portion. 3. A thermoplastic fiber manufacturing apparatus having a two-stage heating type godet roll of a take-up / supply godet roll and a drawing / heat treatment godet roll, wherein the take-up / supply godet roll is a uniform temperature type godet roll having a heater inside the roll. An apparatus for producing a thermoplastic fiber, characterized in that the godet roll for drawing and heat treatment is an inclined temperature type godet roll having a heater built in on one side inside the roll. 4. The apparatus for producing a thermoplastic fiber according to claim 3, wherein the stretched / heat-treated godet roll is a taper type having different diameters at both ends of the roll.