JPS5818455B2 - Manufacturing method of textured yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a textured yarn by drawing and simultaneously false twisting undrawn polyester yarn.

Recently, several methods have been proposed for producing textured yarns having permanent crimps by subjecting undrawn polyester yarns obtained by high-speed spinning to simultaneous or sequential drawing and false twisting.

For example, U.S. Pat. No. 3,771,307 describes
Crystallinity 30 spun at high speed of 0-4000 yards/min
% polyester undrawn yarn at a stretching ratio of 1.3 to 2
．． It is described that stretching and false twisting is performed under the conditions of 0 times and a heat set temperature of 200° C. or higher.

According to this method, compared to the conventionally known method of drawing and false-twisting ordinary undrawn polyester yarn spun at a spinning speed of about 500 to 1,500 m/m, contact with the heater when threading the yarn to a draw-false-twisting machine is required. It has the advantage that there is less yarn breakage caused by the process, and the crimp properties of the resulting textured yarn are excellent. Changes in properties due to storage and transportation cannot be avoided, which may lead to uneven quality of the resulting textured yarn.

For example, if an undrawn yarn spun at 3000 yards/min is
If stored in an atmosphere of 'C for 20 days, yarn breakage and fuzz will occur more frequently than when undrawn yarn immediately after spinning is stretched and false-twisted, and when the resulting textured yarn is dyed, it becomes significantly darker. At the same time, the beam floor also increases.

Moreover, when the undrawn yarn is threaded into a drawing false twister, it sometimes undergoes significant shrinkage when it comes into contact with a heater, so special consideration must be taken in threading the thread.

Furthermore, if the above-mentioned undrawn yarn is used and subjected to stretching and false twisting, the single yarn will become flattened in the same way as when using ordinary undrawn yarn, resulting in a disadvantage that the feel and appearance of the resulting textured yarn will deteriorate. There is.

The present invention provides a method for producing textured yarn without the above-mentioned disadvantages, and in particular, it provides a method for producing a textured yarn, in which a polymer consisting essentially of polyethylene terephthalate is melt-spun at high speed.
The spun yarn is once cooled and then reheated to 140-210°C and wound up to give (a) elongation at break of 50-80% (b) initial modulus of 600-1100 kg7m1fL (c) i, 371 ? The polyester undrawn yarn having a density greater than /crii and (d) a flood shrinkage rate less than 8% is stretched at a draw ratio of 10.
This is a method for producing a textured yarn characterized by stretching and simultaneously false twisting at a processing temperature of 5 to 130 times and a processing temperature of 170 to 240°C.

The term "polyester" as used in the present invention refers to polyethylene terephthalate or copolyesters containing 85 mol% or more, preferably 95 mol% or more of ethylene terephthalate units.

These polyesters may contain known additives such as matting agents, pigments, dyes, flame retardants, stabilizers, and the like.

The intrinsic viscosity of these polyesters is preferably within the range of 0.3 to 1.0.

In the present invention, the undrawn yarn to be subjected to the drawing and false twisting process must be obtained by high-speed spinning the above-mentioned polyester using a special method and have the following physical properties.

Breaking elongation: 50-80%, preferably 60-70%
.

(b) Initial modulus: 600-1100kg/m
1fL1 preferably 700 to 900 kg/m4゜(e
) Density: 1.371? /Cvi, preferably from 1.372], 395?7'cvi0(b) Sumoto shrinkage less than 8%, preferably from 1 to 6%.

Elongation at break is less than 50% or initial modulus is 1
If it exceeds 100 kg/mn, a textured yarn with excellent crimpability cannot be obtained, and if the elongation at break exceeds 80% or the initial modulus is 600 kg/m! If the diameter is less than L, the cross section of the single yarn tends to be flattened by drawing and false twisting.

Also, the density is 1371? /cyilJJ tends to change over time and, for example, if left in an atmosphere at 35° C. for 20 days or more, yarn breakage and fuzz during the drawing and false twisting process will significantly increase.

On the other hand, if the flood shrinkage rate exceeds 8%, the yarn sometimes shrinks significantly when threaded into a drawing false twister, making threading work difficult.

Among the undrawn yarns having the above-mentioned physical properties, the birefringence is 0.09 to 0.14 and the breaking strength is 3 to 4 Si'/de.

It is preferable to have a primary yield point strength of 1.0 to 1.8 P/de and a dry heat shrinkage rate of less than 13% at 200°C.

The crystal size of such undrawn yarn is 30-45%, and the crystallinity is within the range of 40-65%.

In addition, the thickness of the undrawn yarn should be appropriately selected depending on the final use, but it is generally 2 to 7 de/fil, particularly 3 to 6 de/fil.
fil is preferred.

Next, the definition and measurement method of each physical property specified in the present invention will be explained in detail.

Elongation at break (TE) and strength at break (TS) Using an Instron tensile tester, the sample length was 20 CrrL.
A tensile test is conducted at a tensile rate of 100% per minute, and the load (f/de) and elongation rate (%) at which the fiber breaks are read and used as the breaking strength and breaking elongation, respectively.

Note that the breaking strength does not take into account a decrease of 5 denier due to elongation.

Initial modulus (Mi) Using an Instron tensile tester, the sample length was 20CrfL,
A tensile test is conducted at a tensile rate of 20% per minute, and the strength at an elongation rate of 1% within the elastic limit is read and calculated using the following formula.

Density (ρ) A sample dried under vacuum at 70°C for 2 hours is measured by the float-sink method.

That is, a sample is put into a pre-adjusted mixture of normal hemobutane and carbon tetrachloride at 20°C, the temperature is raised at a constant rate, the temperature at which the sample stops hanging is determined, and the density of the mixture at that temperature is determined at 20°C. It is calculated by converting it to the density of

Flood shrinkage rate and drying shrinkage rate samples were taken for 5 rotations using a measuring machine with a frame circumference of 1.125 m, and the samples were removed from the measuring machine and placed in a cassette with an initial load of 1/30P per tenier. Measure the length (lo).

Next, this sample was immersed in hot water for 30 minutes, then taken out and air-dried, the initial load was applied again, the skein length (11) was measured, and the flood shrinkage rate was determined using the following formula.

In addition, the sample was lowered into a drying mold at 200°C, left for 15 minutes, taken out, air-dried, and then the initial load was applied again.
) and calculate the dry heat shrinkage rate using the following formula.

Primary yield point strength (sy) Using an Instron tensile tester, measure the stress-strain curve under the conditions of a sample length of 20 degrees and a tensile rate of 100% per minute. The intensity at the inflection point of the strain curve is expressed as f/d.

Birefringence (Δn) and crystallinity according to the method described in US Pat. No. 2,931,068.

Crystal size (L) X-ray diffraction was performed under the following conditions using a DC-9 device manufactured by Rigaku Denki Co., Ltd., and the meridional diffraction intensity at the plug reflection angle 2θ = 17.70 was defined as Iam, (01-0) If the surface reflection peak intensity is It, then (It + Iam)/
Peak width B of the (010) plane reflection peak at an intensity of 2 (
(expressed in radians), and from this, the crystal size L (person) is calculated using Scherrer's formula.

(Here b=0.00204 radian, K=0.94λ
-1,542 people) [X-ray diffraction measurement conditions: VX20mA at 35, for Ni Mitsuitaru, divergence slit 0.1511tl
+! φ, scattering slit 1°, receiving slit 0.4 degrees] Intrinsic viscosity [η] - Calculated from the viscosity of a solution in which the sample is dissolved in ordichlorophenol # at 35°C.

The undrawn yarn, which has the above-mentioned physical properties, has extremely good stability over time, and even when left in an atmosphere at 35°C and 65% RH for 60 days, the processability and texture obtained are as good as those immediately after spinning. No substantial difference was observed in the properties of the yarns.

Therefore, it is possible to transport this package of undrawn yarn to a drawing and false-twisting factory that is far away from the spinning factory, and it is also possible to store it for a long period of time in a normal warehouse or the like.

Undrawn yarn having such special physical properties can be industrially produced by the following high-speed spinning method.

That is, the intrinsic viscosity is 0.3 to 1.0, preferably 0.
Chips of polyester in the range of 55 to 0.80 are extruded from a spinneret at a temperature 20 to 50 °C higher than the melting point to form a fiber, and the spun fiber is the glass transition point (Tg) of the polyester + 40 °C. 140-210°C, preferably 150-20°C.
After traveling 100 to 200 cm in a heated atmosphere at 0°C, 2600 to 5500 m/# preferably 3000 to
It can be produced from a rolled rucotoni at a speed of 5000 m/IruIL.

Here, the glass transition point (Tg) of polyester refers to the value measured by the method described in US Pat. No. 2,556,295, and Tg of undefined polyethylene terephthalate.
g is about 70°C.

Further, the temperature of the heating atmosphere refers to the ambient temperature near the yarn measured at a position 5 degrees away from the outside of the running fiber bundle.

When the present invention is carried out industrially, approximately 1
It is appropriate to heat the yarn running atmosphere to a temperature of 140 to 210°C by installing heating tubes, slit heaters, etc. with a cooling section of ~1.5 m apart.

Air is preferred as the atmosphere, but steam, nitrogen,
An inert gas such as carbon dioxide may also be used.

The temperature of the atmosphere does not need to be uniform over the entire section, and a temperature gradient may be created between the yarn entry side near the spinneret and the yarn exit side near the winding section.

At this time, it is preferable that the yarns introduced into the heating atmosphere be bundled to such an extent that the single yarns do not come into close contact with each other. It is preferable to provide a ring-shaped guide with a diameter of about 0.5 to 1.5 cfrL.

In this way, yarn breakage and denier unevenness in the spinning process can be significantly reduced.

After leaving the heated atmosphere, the yarn is coated with an appropriate finishing agent, taken up by a pair of godet rollers, and wound up by a winder to form a package.

Spinning winding speed is 2600-5500yt 7mltt,
Preferably 3000-5000m/IIu! If the spinning speed is outside this range, an undrawn yarn having the above-mentioned physical properties cannot be obtained.

When winding, the yarn may be directly taken up and wound by a winder without using a godet roller, or the yarn may be subjected to a turbulent flow or a swirling flow of gas to create interlace or alternate twisting. It is preferable to provide the yarn with a cohesive property.

In the present invention, as mentioned above, the undrawn yarn has excellent stability against changes over time, and there is no shrinkage when stretched after being hoisted to the pan gauge, so that the yarn can be wound up to 10 kg when wound up.
Even if the package is larger than a roll, there is no risk of it collapsing or causing unevenness on the inner and outer layers of the package.

The undrawn yarn as described above is then supplied to a drawing and false twisting process at a temperature of 170 to 240°C, preferably 180 to 230°C.
1.05 to 1.30 times, preferably 1.
By subjecting the yarn to a stretching ratio of 10 to 1.25 times and simultaneous false twisting, a textured yarn having excellent crimpability, dyeability, and texture is obtained.

"Processing temperature" is defined as the yarn temperature when it exits the heater, and this processing temperature is usually approximately the same as the set temperature of the heater.

The temperature is preferably 210 to 230°C when producing a textured yarn with high crimp properties, generally called "0-type", and when producing a textured yarn with low crimp properties and low torque properties, called "U-type". 180-210°C is preferred.

The undrawn yarn used in the present invention has the advantage that even if the processing temperature in the drawing and false twisting process becomes high, the physical properties (strength and elongation, etc.) of the textimard yarn are less affected by this. Processing at high temperatures such as , 220 to 240°C is also possible.

As the heater, a contact type heater such as a plate heater is preferred, but slit heaters, tube heaters, etc. may also be used.

Furthermore, although a spindle method is most preferred as the false twisting means, a friction method using a rotating hollow cylinder, a rotating disk, or the like may also be used.

The number of twists is preferably set so that the twist coefficient (α) defined by the following formula is 0.9 to 1.0 in order to obtain a textured yarn for ordinary use, but in the present invention, the twist coefficient (
By setting α) to 1.2 or more, it is also possible to obtain a textured yarn with extremely high crimpability, which has not been previously available.

[Here, K is the number of twists (T/m), and De is the fineness of the undrawn yarn before drawing and false twisting (de).The drawing ratio is much higher than that in the case of drawing and false twisting conventional undrawn polyester yarn. small, 1.05 to 1.30
(preferably 1.10 to 125).

Therefore, a conventionally widely used false twisting machine for drawn yarn can be used with almost no modification.

To produce a "U-type" textured yarn, the textured yarn obtained under the above-mentioned conditions is subjected to subsequent processing (in the range of 90 to 250 °C, preferably 200 to 240 °C and the processing adopted during the stretch false twisting). The heat treatment is carried out at a temperature 10°C or more higher than the temperature and under 8-30% overfeed.

In this heat treatment, a non-contact type heater such as a slit heater or a tube heater is preferably used as the heater.

According to the present invention as described above, since there is virtually no change in the undrawn yarn over time, the undrawn yarn can be stored and transported for a long period of time, and special consideration is not required for storage and transportation. For example, it is possible to load an undrawn yarn package wound at a spinning factory onto a bobbin truck, transport the entire truck to a distant stretch and false twist processing factory, and use it as it is as a creel part in the stretch and false twist process. becomes.

Furthermore, threading on the drawing false twisting machine is extremely easy because even if the undrawn thread comes into contact with the heater, it does not break or shrink, so threading is extremely easy. There is almost no occurrence of yarn breakage, fuzz, or untwisting during false twisting, and there is also extremely little flattening of the single yarn cross section.

Even more surprisingly, the dyeing rate of the textured yarn according to the present invention shows very little variation due to variations in processing temperature, and in the temperature range of 170 to 240°C, even if the processing temperature varies slightly, Shows uniform stainability.

The crimpability, dyeability, etc. are comparable to those of the textured yarn described in US Pat. No. 3,771,307, and it is extremely useful as a material for textiles and knitting.

□ Next, examples of the present invention will be described in detail.

Among the characteristics of the crimped yarn in the examples, the total crimp rate (TC)
, torque (Tq) and dyeing rate (L value) according to British Patent No. 13.
The value was measured by the method described in No. 33679, and the joints were determined visually by dyeing a stockinette knit sample.

In addition, the oblateness is defined as b, where b is the length of the longest inner diameter (diagonal line) in the single yarn cross section of the textured yarn, and a is the longest diameter perpendicular to the longest diameter.
/a, and is expressed as the average value of the values measured for 20 pieces.

The closer the oblateness is to 1, the closer to a perfect circle it is.

Example 1 [Manufacture of undrawn yarn] A chip of polyethylene terephthalate (melting point 261°C, Tg 68°C) having an intrinsic viscosity of 0.64 was heated at 288°C to a pore size of 0.
It is extruded from a spinneret with a diameter of 35 mm and 30 holes, and the spun fiber is about 2
After the fibers are cooled to 70°C by blowing air at 5°C from the side, they are focused by a ring-shaped guide with a diameter of ICrrL, and then introduced into a heating cylinder with a length of 140cm to be formed inside the cylinder. After passing through a heated atmosphere, a finishing agent was applied using an oiling roller, and the material was taken up by a pair of godet rollers and wound into a 10 kg package using a winder.

At this time, the atmospheric temperature inside the heating cylinder and the winding speed were varied as shown in Table 1.

Table 1 shows the physical properties of the undrawn yarns obtained under each condition.

[Manufacture of textured yarn]

Each undrawn yarn package was spun at 25℃65%.
After leaving it in the RH room for one day, SQUOG C312-6
00 type stretching false twisting machine, spindle rotation speed 29
．． 5X10'rpm, twist coefficient 0.99, heater length 10
0 cm, false twisting was performed at the same time as stretching at the optimum stretching ratio and processing temperature for each undrawn yarn, and winding was performed with an overfeed of 4%.

Table 1-2 shows the stretching ratio, processing temperature, and characteristics of the obtained "○-type" textured yarn.

Example 2 The undrawn yarn of Experiment 6 of Example 1 was drawn and false-twisted using the same drawing and false-twisting machine while changing the drawing ratio and processing temperature.

The results are shown in Table 2.

Example 3 Spinning was carried out under the same conditions as in Example 1, except that the distance from the spinneret to the heating cylinder was changed to change the yarn temperature before the spun yarn was introduced into the 170°C heating atmosphere. ,3
It was wound up at a speed of 500 m/min.

Next, each undrawn yarn was prepared in Example 1 Experiment 1.
, □1 'False twisting was carried out at the same time as stretching under the same conditions as A6, and 4%
It was wound under overfeed.

The yarn temperature immediately before being introduced into the heating atmosphere at this time,
The physical properties of the undrawn yarn are shown in Table 3-1, and the properties of the textured yarn are shown in Table 3-2.

Example 4 Spinning was carried out in exactly the same manner as in Example 1 except for changing the length of the heating cylinder (ambient temperature 170°C; 3500 rr
Roll up ivy with L/-.

Table 4-1 shows the physical properties of the undrawn yarns obtained in each experiment.

Next, each undrawn yarn was drawn and false-twisted under the same conditions as in Experiment 6 of Example 1, and wound up under 4% overfeed.

The properties of the textured yarn obtained are shown in Table 4-2.

Example 5 The undrawn yarn package from Example 1 Jikkenya 6 was mounted on a bobbin cart and allowed to age in a room at 40°C and 65% RH, and then subjected to stretching and twisting under the same conditions as Experiment A6. went.

Table 5 shows the processability and properties of the textured yarn over time.

Example 6 In Experiment A6 of Example 1, the processing temperature by the first heater was varied within the range of 170 to 210°C, and false twisting was performed at the same time as stretching, followed by 16% relaxation at a temperature of 230°C. A "U-type" textured yarn was produced by winding under 9% overfeed.

The results are shown in Table 6 below.

Claims (1)

[Scope of Claims] 1. A polymer consisting essentially of polyethylene terephthalate is melt-spun at high speed, the spun yarn is once cooled, and then reheated to 140 to 210°C and wound up, (a) 50°C. Elongation at break of ~80% (b) Initial modulus of 600-1100 kg/- (c
) An undrawn polyester yarn having a density greater than 1.371'iI/crA and (d) a submerged shrinkage ratio less than 8% was drawn at a draw ratio of 1.
False twisting is carried out at the same time as stretching at a processing temperature of 170 to 240°C. A method for producing textured yarn characterized by: