JPS6141319A - Manufacture of polyester multifilament - Google Patents

Abstract

PURPOSE:To obtain the titled multifilament yarn free from drawing unevenness, fluff, and slack, and having fine size suitable for high-quality fabric, by drawing an undrawn polyester multifilament yarn in two stages under respective specific heating condition and draw ratio. CONSTITUTION:An undrawn polyester multifilament yarn Y composed of >=40 filaments is heated with a revolving hot roller 3 having a surface temperature T1 satisfying the formula I (Tg is glass transition temperature of the polyester), and is subjected to the first-stage drawing at a draw ratio DR1 satisfying the formula II (NDR is natural draw ratio of the undrawn yarn; TDR is upper optimum draw ratio of the undrawn yarn). The drawn yarn is heated with a hot drawing roller 4 having a surface temperature T2 satisfying the formula Tg< T2<Tg+50 and subjected to the second-stage drawing at a draw ratio DR2 satisfying the formula DR2<TDR<DR1. The product is wound in the form of a drawn yarn cheese 7 to obtain the objective yarn having a filament size of <=1.5 denier.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for producing polyester multifilament. More specifically, the total number of filaments (hereinafter referred to as single yarn) that make up the multifilament yarn is 4.
The present invention relates to a method for stably producing multifilaments for high-quality textiles with a fineness called fine denier yarn, which has 0 or more fibers and a single filament fineness of 1.5d or less.

[Prior art and its problems]

In the past, much research has been done on raw yarn for high-grade textiles, and it has been known that bottle-drawn yarn is the most suitable.

However, when fine denier yarn, in which the total number of single yarns constituting a multifilament yarn is 40 or more and the single yarn fineness is 1.5 d or less, is drawn in a bin, the single yarns overlap on the drawing bin, and the drawing The temperature of the outer single yarn, which is not in direct contact with the bottle surface, did not reach the specified temperature, causing uneven stretching, fuzz, and walnuts.

Therefore, the present inventors attempted to draw a fine denier yarn using a heated rotating roller without using a drawing bin.

For example, Japanese Patent Publication No. Sho 43-1M09 proposes a method of pressing a using a heated rotating roller. In this method, [when polyester fibers are drawn between a heating supply roller and a drawing roller, a pre-tension of 10 to 90 inches of the neck drawing start tension is applied before drawing, and then the surface temperature T of the heating supply roller is adjusted to that level. The temperature is set to be 10 to 55°C higher than the secondary transition temperature (Tg) of the yarn, and the time t during which the yarn contacts the heating supply roller is t≧-o, o O7 (T
-T g) +0.4 a s When pressing the elastic roller onto the heating supply roller, connect the point where the elastic roller contacts the heating supply roller and the point where the yarn separates from the axis. A stretching method characterized in that the angle (ct) formed by the curve is in the range of 0 to 20 degrees.
It is.

This method is more effective than the method using a drawing bin to obtain uniformly drawn yarn with less drawing unevenness, but since the elastic roller pressed onto the heating supply roller gradually undergoes thermal deterioration and hardens. In order to achieve the initial goal, maintaining the functionality of the elastic rollers is complicated and very expensive as an industrial production process.

In addition, when drawing fine denier yarn, it is practically impossible for individual filaments to completely open on the heated supply roller and come into direct contact with the surface of the heated supply roller, so they overlap on the heated supply roller. The temperature of the outer filament that is not directly fused to the roller surface is lower than that of the inner filament that is in direct contact with the roller surface, and therefore the drawing point varies slightly between individual filaments. However, when dyed, some of the individual filaments constituting the multifilament yarn are dyed darkly, causing minute drawing irregularities, fuzz, and walnuts.

In addition, findanil yarn is often used as yarn for high-grade textiles, but for example, high-quality textiles such as Fuji Silk 1, Den/N, and Yangyanagi have minute irregularities called grains on the surface of the textile. This gives the fabric a fluffy, warm, deep luster, and gives it a high-class image. In order to express it uniformly, the heat shrinkage stress of the yarn is preferably 0.48 g/4 or more, and 0.50 g
/d or more is said to be more preferable.

However, the multi-filament degree is obtained by preheating and drawing with a heating supply roller without using the entire drawing bin, and thus it is impossible to obtain a drawn yarn that is desirable as a raw yarn for high-grade textiles.

[Objective of the Invention] The object of the present invention is to improve the drawbacks of the prior art, and to create a single yarn fineness of 1.5 that is substantially free from drawing unevenness, fluff, and walnuts.
The present invention provides a method for extremely stably producing fine denier yarn having a filament count of d or less and a filament count of 40 or more.

[Structure of the invention]

In order to achieve the above object, the present invention has the following configuration. That is, a polyester multifilament undrawn yarn consisting of 40 or more filaments is fully drawn,
When making a drawn yarn with a filament fineness of 1.5d or less, the undrawn yarn is heated with a heated rotating roller heated to the range of formula (1) below, and drawn at a drawing ratio within the range of formula (2) below. A method for producing a non-rolled sheet after carrying out one-stage stretching, followed by heating with a heated stretching roller heated to the range of the following formula (3), and performing a second-stage stretching at a stretching ratio within the range of the following formula (4). It is.

Tg+5 (T+<7g+30 ・・・・・・−・
・・・・・・－・・・(1) NDR≦DR, (0,95T
DR・・・・・・・・・・・・(2) Tg<72
<Tg+50 ・・・・・・・・・・・・−・・・・
−・・−・・・・(3) DR2≦TD R/DR+
・・・・・・・・・・・・・・・・・・・・・・・・
- (4) The present invention will be explained using drawings.

FIG. 1 is a schematic diagram of a manufacturing process showing one embodiment of the present invention. In FIG. 1, an undrawn yarn Y is pulled out from an undrawn yarn drum, fed at a constant speed by a nip roller 1 for suppression and a feed roller 2, and wound around a heated rotary roller 3 heated to a range expressed by equation (1) above. After being sufficiently preheated, it is guided to the heating stretching roller 4, and the heated rotating row 25 and the heating stretching roller 4
The first stage of stretching is carried out within the range of formula (2) above. Subsequently, it is wound around the heated stretching roller 4 heated to the range of formula (3) above, and after being sufficiently preheated, it is led to the stretching roller 25 and between the heated stretching roller 4 and the stretching roller 5. 4) A second stage of drawing is carried out within the range of the formula, and the drawn yarn is wound into a cheese 7 using a drive roller 6. The stretching roller 5 may be at room temperature, or may be heated for heat treatment if necessary. When using the drawing roller 5 at a temperature below 5iTg, a fluid turbulence nozzle (
It is preferable to perform an interlacing process (not shown) and then wind it up.

On the other hand, when the drawing roller 5 is used at a temperature higher than Tg, after the yarn exiting the drawing roller 5 is subjected to an entangling process using a fluid turbulence nozzle, a cooling roller (not shown) is used for the purpose of cooling the yarn. It is preferable to wind it up and run it, and then wind it up.

Further, as a winding method, as shown in FIG. 1, it can be wound around a drawn yarn cheese 7 using a drive roller 6, or it can be wound in a burn shape using a twister that makes full use of the spindle rotation.

In the present invention, 77 [I thermal rotation roller 30 surface temperature T
1 must satisfy Tg+5<T+(T:)<7g+30. If the temperature of the heated rotating roller is less than (Tg + 5°C), the preheating effect of the undrawn yarn will be insufficient, resulting in a stretched floor, fluff, walnuts + rawness, and on the other hand, (7g + 30) r
In this case, when the undrawn yarn is wound around a heated rotating roller and preheated, the undrawn yarn softens and the yarn tension on the roller decreases, resulting in increased yarn wobbling on the roller. Furthermore, the yarn tangle phenomenon occurs at the point where the yarn separates from the roller welding running section, and the drawing floor, fuzz, and walnuts increase, so that the surface temperature of the heating rotating roller decreases to the level described in (1) 2, T g+ 5 (T + < T g, +50
must be within the range.

Moreover, if the first stage drawing ratio DR becomes less than the natural drawing ratio NDR, an unstretched portion remains in the yarn after the first stage drawing, and the second stage drawing ratio
Even if stage stretching is carried out, the sufficient effect aimed at by the present invention cannot be obtained;
If it is more than double, the ratio of the first stage drawing ratio is too high, so the effect of the second stage drawing becomes insufficient, and it becomes difficult to obtain the drawing floor, yarn without fuzz or sag, which is the objective of the present invention. Therefore, the first stage stretching ratio DR+ must satisfy the above formula (2), that is, in the range of NDR≦DR+(0.95TDR).

In addition, in the conventional method of drawing the undrawn yarn to an appropriate ratio using only the first stage drawing ratio, it is possible to achieve extremely high quality and a heat shrinkage stress of 0.45g, which is the objective of the present invention. It was virtually impossible to obtain a drawn yarn with a diameter of /d or more.

However, after carrying out the first stage stretching under conditions that satisfy the above formulas (1) and (2), the second stage stretch ratio DR 2% heated stretching roller temperature T2 is adjusted to the above formulas (31 and (4), that is, Tg <
T2<Tg+50, DR2≦TDR/DR+
By carrying out the second-stage drawing under conditions that satisfy the following range, the drawn bed produced in the first-stage drawing is selectively re-stretched, making it possible to obtain a drawn yarn without a drawn bed, fuzz, or walnuts. can. At the same time, by further hot-drawing the drawn yarn that has been drawn to a ratio of NDR or higher in the first stage drawing and has undergone considerable crystallization and orientation, the crystallization is The growth of the drawn yarn is promoted, and the ability to develop heat shrinkage stress of the drawn yarn is increased, which is the objective of the present invention.
In terms of g/dv, Sarako produces drawn yarns with a heat shrinkage stress of 0.50 g/d or more.

When the heated stretching roller temperature T2 of the second stage stretching is below Tg, the growth of crystals becomes insufficient and the thermal shrinkage stress decreases.On the other hand, when it is above (Tg+50)°C, the growth of crystals increases rapidly. The heating stretching roller temperature T2 is set at the temperature T2 above (3.
) must be within the range of expression. If the product of the first-stage draw ratio DR+ and the second-stage draw ratio DR2 exceeds the upper limit TDR of the appropriate ratio range for undrawn yarn, the occurrence of fuzz due to single yarn breakage will increase. Stretching ratio D of rows
R2 must be within the range of the upper limit appropriate ratio TDR of the undrawn yarn together with the first stage drawing ratio DR+, that is, within the range of formula (4) above. The measurement method and calculation method for the natural draw ratio NDR and upper limit appropriate ratio TDR of the undrawn yarn shown below will be explained.

FIG. 2 is a graph showing the relationship between tensile strength and elongation when an undrawn yarn is subjected to a tensile test using a Tensilon type universal tensile tester.

In Figure 2, the a-line S is the tension-elongation curve when unstretched 7v+ is pulled to the breaking point, point A is the tension starting point, and point B
Point C indicates the elongation corresponding to the natural stretching ratio of the undrawn yarn, point C indicates the elongation corresponding to the upper limit appropriate magnification of the undrawn yarn, and point C indicates the elongation corresponding to the breaking point of the undrawn yarn. , natural draw ratio (NDR) and upper limit appropriate ratio* (TDR) of undrawn yarn
is the value calculated using the following formula (5) and formula (6). However, the range of appropriate magnification is when the elongation of the drawing system is 20 to 5.
The upper limit appropriate ratio (TDR) is a ratio where the elongation of the drawn yarn is 20%.

However, v is the tensile speed of the tensile testing machine (cIn/m1n) v
22 Chart speed of recorder (cm/min) to = undrawn yarn sample length (cm) l! B Distance from two points A to point B (am) lc Two points A
Distance from point C4 ((1)) Next, the polyester multifilament undrawn yarn used as the raw material of the present invention uses terephthalic acid as the main dibasic acid, and as the glycol, ethylene glycol or /chlorohexane dimetatool is the main dibasic acid. It is used as a glycol, or it uses ethylene oxy/benzoate, and it contains 6 to 15 moles of a third component such as oxalic acid, sebacic acid, fudaric acid, or isophthalic acid for the purpose of imparting high shrinkage. Polymerized and easily dyeable propylene oxide, polyethylene glycol, sodium m-phenol sulfonate, sodium m-(β-okineethquin)benzenesulfonate, 3,5
Sodium carboxybenzene sulfonate,
It may also be a product obtained by copolymerizing 1 to 10 mol of a fifth component such as dimethyl-5-sodium sulfoinphthalate or bis(β-hydroxyethyl)-5-sodium isophthalate, or it may have a matte effect or a silk-spinning effect. The multifilament may contain 0 to 5% titanium oxide for the purpose of improving properties, etc., and the cross-sectional shape of the multifilament may be circular,
Or, it is effective even if it has an irregular cross section (triangular, pentagonal, octagonal, etc.).

The heat shrinkage stress in the present invention was measured by the following method.

[Heat shrinkage stress measurement method]

Set the sample length 1001EI on the strain meter with an initial load of 30m9/d, and in a dry heat state, the temperature increase rate is 2.5℃/e:ec, and the normal power is high. 7) Record the bottling from conversion to -n using an X-Y recorder, read the MAX stress and peak temperature from the chart on the recorder, and use the value calculated by the following formula (7) as the heat shrinkage stress.

Heat shrinkage stress (g/a) = MAX stress (g)/drawn yarn denier (d) (7) [Effects of the invention] The present invention has the above structure. By adopting.

It is possible to stably obtain a uniform polyester multifilament drawn yarn having a heat shrinkage stress of o4sg/d or more and substantially free from drawing unevenness, fuzz, and walnuts.

The present invention will be explained below using examples.

Example 1 A polyester chip with an intrinsic viscosity of 0.65 (measured in orthochlorophenol at 25°C) was spun at a spinning temperature of 293°C and a spinning speed of 1480 m/min using a spinneret with 72 circular holes and a triangular hole. Spun, denier 2
18D, glass rolling g temperature 70℃, natural stretching ratio 2.41
An undrawn yarn with an upper limit appropriate magnification of 311 times and a breaking elongation of 345% was obtained.

The undrawn yarn was drawn at a drawing speed of 800 in the manufacturing process shown in Fig.
m,/min under the conditions shown in Table 1, measuring the heat shrinkage stress of the drawn yarn, measuring Worcester's unevenness, measuring fluff and sagging by warping test, and measuring the fine dark dyed filaments when weaving and dyeing. We carried out visual judgment using a magnifying glass, and visually judged the texture of the finished fabric when it was finished with a raised fabric.
Obtained the results in the table.

Note that T + defined by formulas (1) to (4) of the present invention,
The values of T2 and DR+ are 75<T+<10, respectively.
0, 70<T2<120 and 2,41≦DR+
<3.05.

DR2 is defined by DR+ as follows.

In Table 1, Jikkenya 1, 5, 6, 9, 10, 13 and 15 are comparative examples for clarifying the effects of the present invention.

Experimental shops 1 to 5 confirmed the effect of the surface temperature T1 of the heating rotating roller for drawing in the first stage, and in cases A2, 3, and 4, good drawn yarns, which are the object of the present invention, were obtained. On the other hand, since the temperature in flat 1 is low, stretching spots tend to occur due to insufficient preheating between the filaments, resulting in an increase in Worcester spotting, dark dyed filaments, and fuzz/walnuts. Due to the high temperature, yarn wobbling on the heated rotating roller and pixelation phenomenon of the yarn at the yarn separation point occur, resulting in stretching unevenness, an increase in Worcester unevenness, and the occurrence of dark dyed filaments, fuzz, and walnuts.1 This invention The desired drawn yarn could not be obtained.

Test shops 6 to 9 confirmed the effect of the surface temperature IRT2 of the heated drawing roller for drawing in the second stage, and test shops 7 and 8 were able to obtain good drawn yarns that are the object of the present invention. On the other hand, A6 has a low temperature, so the heat shrinkage stress level is low, and therefore the embossment of the fabric is insufficient. The yarn tended to be defective, and fluff increased, making it impossible to obtain the drawn yarn targeted by the present invention.

Experimental shops 10 to 13 confirmed the full effect of the drawing ratio in the first stage, but experimental shops 11 and 12 were able to obtain good drawn yarn, which is the object of the present invention, whereas experimental shops 10 Since the drawing ratio in the first stage is lower than the natural drawing ratio NDR of the undrawn yarn, drawing unevenness occurs, an increase in Worcester unevenness, dark dyed filaments, fuzz/walnuts, etc. Since the yarn is drawn at a magnification of 0.95 TDR or more in the first stage, the effect of two-stage stretching cannot be obtained, and therefore the heat shrinkage stress level is low, and the drawn yarn targeted by the present invention cannot be obtained. There wasn't.

Experimenters 14-15 have the upper limit appropriate magnification and the 1st and 2nd stage
This is to confirm the limit of the draw ratio of the stages, but A1
4H While the drawn yarn targeted by the present invention was obtained,
Since A15 was drawn at a combined draw ratio of the first stage and second stage exceeding the upper limit of the appropriate ratio range, fuzz and walnuts were generated. I couldn't.

Experimental flat plate 16 was stretched under the same conditions as flat plate 3, and then the effect of air entanglement treatment was performed for the purpose of imparting convergence and improving passage through higher-order processing steps. At 1%, the texture of the fabric was better than A3.

Flat 17 and A18 have a triangular cross-sectional shape system.
The drawn yarns were drawn under the same conditions as in Example 6, and good drawn yarns, which are the object of the present invention, were obtained in all cases.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a manufacturing process showing one embodiment of the present invention. FIG. 2 is a graph showing the relationship between tensile strength and elongation in order to explain NDR and TDR shown in the present invention.

Claims (1)

[Scope of Claims] When drawing an undrawn polyester multifilament yarn having a total number of 40 or more filaments to obtain a drawn yarn with a filament fineness of 1.5 d or less, the undrawn yarn is subjected to the following (1). The material is heated with a heated rotating roller heated to the range of formula (2), and the first stage stretching is performed at a draw ratio in the range of formula (2) below.Subsequently, the material is heated with a heated stretching roller heated to the range of formula (3) below. A method for producing a polyester multifilament, which is characterized in that the polyester multifilament is stretched in a second stage at a stretching ratio within the range of formula (4) below and then wound up. Tg+5<T_1<Tg+30……………………(1)
NDR≦DR_1<0.95TDR………………(2
)Tg<T_2<Tg+50………………………………(
3) DR_2≦TDR/DR_1…………………………
...(4) Tg: Glass transition temperature (°C) T_1: Surface temperature of heated rotating roller (°C) T_2: Surface temperature of heated drawing roller (°C) NDR: Natural draw ratio of undrawn yarn TDR: Upper limit of undrawn yarn Appropriate magnification DR_1: 1st stage stretching ratio DR_2: 2nd stage stretching ratio