JPH0627390B2 - Method for producing thick and thin polyester crimped yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention has an extremely large fineness difference and crimp in the longitudinal direction of the yarn, and moreover, a difference in thermal shrinkage between the large fineness portion and the fineness portion. Polyester that can produce a bulky and soft woven / knitted fabric with a high degree of unevenness even on a plain white fabric with less creases and a clean surface without wrinkle-like wrinkles between the concave and convex portions. The present invention relates to a method for producing crimped yarn.

<Prior Art> Conventionally, a method for producing a polyester yarn having a large-fineness portion and a fine-fineness portion along the longitudinal direction of the yarn has been already known, for example, a birefringence (Δn) of 0.5 × 10 ^−3. A method has been proposed in which an undrawn yarn of about 10 × 10 ^-3 is used as a supply yarn and the yarn is incompletely drawn. However, the polyester yarn having a fineness thus obtained has a large outer diameter ratio (thickness ratio) between the large fineness portion and the fineness portion, but on the other hand, the degree of orientation of the large fineness portion is too low. It has a drawback that it is easily embrittled by heat processing such as false twisting process and dyeing process.

For this reason, there is also known a method of producing a polyester yarn having a large thinness by using a highly oriented undrawn yarn having a birefringence (Δn) of about 15 × 10 ⁻³ to 80 × 10 ⁻³ as a supply yarn. However,
Such highly oriented undrawn yarn is modified as described in, for example, Japanese Patent Publication No. 38-2018, Japanese Patent Publication No. 38-2019, Japanese Patent Publication No. 39-9175, and Japanese Patent Publication No. 42-27563. The mechanical method of periodically deforming using rollers and notch rollers and the method of manufacturing by stretching at a draw ratio less than the natural draw ratio eliminate the problem of thermal embrittlement during processing, but Since the diameter cannot exceed the outer diameter of the supplied yarn, only a yarn having a small thick / thin ratio can be obtained, and there is a drawback that the thick and thin effect of the yarn cannot be exhibited in the white plain fabric before dyeing.

<Problems to be Solved by the Invention> The present invention solves the drawbacks of the conventional manufacturing method as described above, and its purpose is to provide a clear plain cloth with a plain white cloth. It is possible to obtain a bulky woven or knitted fabric that is visually and tactilely rich in unevenness, and manufactures a crimped polyester yarn with a clean product surface by approximating the difference in heat shrinkage between the large fineness and the fineness. To do.

<Means for Solving Problems> That is, in the present invention, the birefringence (Δn) is 15 × 10 ⁻³ to 80 ×.
A 10 ^-3 polyester highly oriented undrawn yarn is subjected to a relaxation heat treatment, and then water or an aqueous liquid is intermittently attached to the yarn, followed by continuous hot drawing in a heating device in a non-contact state, and then false twisting. The gist is a method for producing a thick and thin polyester crimped yarn, which is characterized by being processed.

Hereinafter, the present invention will be described in detail.

First, in the method of the present invention, the birefringence (Δn) is 15 × 10 5.
^-3 to 80 × 10 relaxes heat treated polyester highly oriented undrawn yarn of ^-3. In this case, if the birefringence (Δn) of the polyester highly oriented undrawn yarn is less than 15 × 10 ^−3, it may be fused during the relaxation heat treatment, or the large fineness portion of the yarn may become brittle during post-processing such as dyeing processing. Not preferable. On the other hand, the birefringence (Δn) is 80 × 10
^If it exceeds ^-3 , the degree of orientation becomes close to that of the drawn yarn, the shrinkage amount during relaxation heat treatment becomes extremely small, and the thickness ratio of the yarn cannot be increased, which is not suitable.

The relaxation rate when the polyester highly oriented undrawn yarn is subjected to relaxation heat treatment is such that the difference between the yield stress at room temperature drawing of the yarn subjected to relaxation heat treatment and the yield stress at high temperature heating drawing becomes larger than that of the supplied yarn. The relaxation ratio may be such a value, and the larger the ratio, the larger the thickness ratio can be made. However, it is preferably 30 to 150% for practical use in connection with the heat shrinkage performance of the supplied yarn. Here, the relaxation rate is a percentage of the ratio of the difference between the supply speed and the take-up speed to the take-up speed.

The relaxation heat treatment temperature depends on the relaxation rate and the yarn speed, but in the range of the relaxation rate of 30 to 150% and the yarn speed of 80 to 200 m / min,
The temperature is preferably 20 to 230 ° C.

The relaxation heat treatment of the highly oriented polyester unstretched yarn is preferably performed in a state of non-contact with a heating device. When the yarn is run while the relaxation heat treatment is in contact with the heating device, the tension of the single yarn filament is given by the contact resistance, and the single yarn filament cannot freely shrink, and the orientation degree of the yarn is increased. This is because unevenness in crystallinity occurs.

Next, in the method of the present invention, water or an aqueous liquid is intermittently adhered to the yarn subjected to the relaxation heat treatment. Here, the aqueous liquid contains 50% by weight or more of water, and examples of substances other than water include surfactants, dyeing aids, and rust preventives.

To intermittently attach water or an aqueous liquid (hereinafter referred to as a liquid) to the relaxation heat treated yarn, a method of attaching using a gear type deformable rotating roller having a protrusion on the roller surface, an electromagnetic solenoid intermittent Any method can be used as long as it can intermittently attach the liquid to the yarn at an appropriate length, such as a method of contacting and adhering to the liquid attached to the roller surface by reciprocating motion. In particular, a micro-computer and random pulse generation The method of using the unit together can deposit liquid at random intervals and lengths.
It is particularly suitable.

Then, as described above, the yarn to which the liquid is intermittently adhered is continuously subjected to hot drawing in a non-contact state with the heating device. In this case, when the yarn is brought into contact with the heating device and hot drawing is performed, the liquid evaporates, and the part to which the liquid adheres receives the same thermal action as the part to which the liquid does not adhere, and the same drawing results. However, it is not possible to obtain a yarn having a large thick-fineness ratio, which is the object of the present invention. Although the temperature of the heating device in this case depends on the yarn speed, for example, in the range of 80 to 200 m / min,
It is preferably set to 140 ° C to 230 ° C.

Further, the draw ratio Dr in the hot drawing is preferably (1 + S / 100) to 1.5 (1 + S / 100) with respect to the relaxation rate S (%) of the relaxation heat treatment. That is, the draw ratio Dr is (1+
If it is less than S / 100), stretching of the liquid non-adhesive part is insufficient, the fineness / fineness ratio becomes small, and the draw ratio Dr is 1.5.
This is because if it exceeds (1 + S / 100), the large fineness portion becomes thin.

Thus, the part to which the liquid adheres is not subjected to the heat action during the hot drawing, and has resistance to the drawing, so that the part having no liquid adheres to the large fineness part, while the part to which the liquid does not adhere is subjected to the heat effect and is sufficiently stretched to be fine. It becomes the fineness part.

Furthermore, in the method of the present invention, false stretching is performed after the hot drawing as described above. The false twisting here imparts crimp to the yarn and at the same time reduces the difference in heat shrinkage performance between the large fineness portion and the fineness fine portion, which is an important object of the present invention. For this reason,
In false twisting, a higher heat effect is required than the heat receiving effect received during hot drawing. Therefore, the heating device in the false twisting process is made to have a higher temperature than that in the hot drawing, or when the temperature is about the same, the yarn is brought into contact with the heating device to run. For example, in the range of the yarn speed of 80 to 200 m / min, 160 ° C to 240 ° C in the non-contact state and 150 ° C to 240 ° C in the contact state are suitable.

The number of false twists T (times / m) in false twisting is (D is the denier of the supplied yarn) or less,
False twist number T (times / m) If it exceeds the range, yarn breakage will occur, which is not preferable for operation. On the other hand, if the false twist number is too low, the number of crimps is reduced and the bulkiness is reduced. Therefore, the false twist number T (times / m) is The above is preferable.

The overfeed rate at the time of false twisting may be appropriately selected within the range in which the large fineness portion is not stretched more than necessary and the yarn breakage does not occur in the overfeed state. The overfeed rate is preferably around 0%. Is.

FIG. 1 is a process schematic diagram showing an example of the manufacturing process of the method of the present invention. In FIG. 1, the polyester highly oriented undrawn yarn F drawn from the spool 1 passes through a guide 2 and a feed roller 3 and then enters a first heating device 4, where a predetermined relaxation occurs between the feed roller 3 and the first delivery roller 5. The heat is shrunk at a rate, and the liquid is intermittently applied to the liquid applying device 6 through the first delivery roller 5 by a random signal from the micro computer. Subsequently, the first delivery roller 5 and the second delivery roller 8 are heat-stretched at a predetermined stretching ratio in a non-contact state with the second heating device 7, and then passed through the second delivery roller 8 and twisted by the false twisting and twisting device 10. At the same time, it is heat-fixed by the third heating device 9, passed through the third delivery roller 11, and taken up by the take-up roller 12 into the package 13 as crimped yarn having a thin and thin shape.

The polyester in the present invention is a generic name for polyesters having an ester bond in the molecular chain represented by polyethylene terephthalate, and also includes modified polyesters containing a third component such as isophthalic acid and paraoxyethoxybenzoic acid.

The birefringence (Δn) is a value measured by an interference fringe measuring method using a polarization microscope compensator.

<Operation> As described above, in the method of the present invention, it is possible to make the large fineness portion larger than the fineness of the supplied yarn by the relaxation heat treatment. Then, since the liquid is intermittently adhered and heat-stretched, the portion to which the liquid is adhered is not subjected to the heat action during the heat-stretching and is not deformed by stretching as shown in FIG. The thick fineness portion becomes a thick fineness portion, while the portion to which the liquid does not adhere becomes a fineness fineness portion as shown in FIG. 2b. In the present invention, as described above, the large fineness portion and the fineness fine portion are alternately formed in the longitudinal direction of the yarn, so that the yarn can be made into a large yarn with an extremely large fineness / fineness ratio.

Further, crimping is applied by subjecting the thick and thin yarns to false twisting, which results in high bulkiness. In this case, it is considered that the crimping of the fineness portion becomes stronger because the twist is preferentially introduced into the fineness portion. In addition, since the difference in heat shrinkage performance between the large-fineness portion and the fine-fineness portion is reduced during false twisting, it is possible to obtain a crimped yarn that can be a product having a clean surface.

<Examples> Hereinafter, the method of the present invention will be specifically described with reference to Examples. In the following examples, the thread diameter ratio of the large fineness portion and the fineness fine portion is
The thread diameter of the fine and fine parts is 300 under a load of 0.3 g / d.
(Twice / m) twist and measure with a graduated microscope,
It represents the ratio of the yarn diameter of the large fineness portion to the yarn diameter of the fineness portion.

Example A polyester highly oriented undrawn yarn 110d / 36f having a birefringence (Δn) of 51 × 10 ⁻³ obtained as high speed spinning was processed according to the present invention under the processing conditions shown in Table 1 according to the process shown in FIG. A crimped yarn having a thickness according to At this time, as the false twisting and twisting device, a false twisting and twisting binder was used.

The obtained crimped yarn was a crimped yarn having a large fineness portion and a fineness fine portion at predetermined intervals in the longitudinal direction. When the yarn diameter ratio between the fine and fine portions was examined, the yarn diameter ratio was 1.3.

This thick crimped yarn has a warp density of 67 threads / 2.54 cm, weft density
When weaved into a plain woven fabric with 64 pieces / 2.54 cm and refined it into a white plain product, the thick fineness part has convex parts and it has a slab-like appearance. The product has a bulky and soft touch that is peculiar to the yarn, and the product surface has a clean appearance with no unnatural marks.

<Effects of the Invention> As described above, according to the method of the present invention, a specific polyester highly oriented undrawn yarn is subjected to relaxation heat treatment, then liquid is intermittently adhered thereto, followed by hot drawing and then false twisting. Therefore, the fineness portion can be made larger than the fineness of the supplied yarn by the relaxation heat treatment, and the fineness portion is further stretched and finer than the fineness of the supplied yarn by hot drawing.
Therefore, the woven or knitted product obtained from the crimped yarn according to the method of the present invention can be a product having an extremely uneven feeling visually and tactilely in the plain white cloth before dyeing. Moreover, since the method of the present invention employs a structure in which false twisting is performed on a yarn that has been made thick and thin by hot drawing, the effect of crimping can be sufficiently reflected in the product, and during false twisting. By heating, it is possible to reduce the difference in heat shrinkage performance between the large fineness portion and the fineness portion, and it is possible to obtain a product that is bulky and has a clean surface.

Further, since the method of the present invention reveals the fineness unevenness of the yarn by intermittent liquid adhesion, the liquid adhesion can be adjusted arbitrarily by using a micro computer, and the pattern and wind of the woven or knitted fabric can be adjusted. It is possible to easily manufacture a crimped yarn that can be changed in a desired manner. Furthermore, in the method of the present invention, since highly oriented undrawn yarn having a birefringence (Δn) of 15 × 10 ⁻³ or more is used as the supply yarn, the obtained crimped yarn has a high orientation even in the large fineness portion. It has the advantage that it does not become brittle due to thermal processing such as false twisting.

[Brief description of drawings]

FIG. 1 is a schematic process diagram showing an example of the manufacturing process of the method of the present invention, and FIG. 2 is a schematic view of the appearance of crimped yarn having a thickness according to the method of the present invention. 1 ... Spool, 3 ... Feed roller 4 ... First heating device, 5 ... First delivery device, 6 ... Liquid applying device, 7 ... Second heating device 8 ... Second delivery device, 9 ... … Third heating device 10 …… False twisting and twisting device, 11 …… Third delivery roller, 12 …… Winding roller, 13 …… Package F …… Polyester highly oriented undrawn yarn a …… Large fineness part, b ...... Fineness part

Claims (2)

[Claims] 1. A polyester highly oriented undrawn yarn having a birefringence (Δn) of 15 × 10 ⁻³ to 80 × 10 ⁻³ is subjected to relaxation heat treatment, and then water or an aqueous liquid is intermittently adhered to the yarn, A method for producing a polyester crimped yarn having a large and thin thickness, which is characterized by continuously hot drawing in a non-contact state with a heating device, and then false twisting. 2. The method for producing a thick and thin polyester crimped yarn according to claim 1, wherein the draw ratio Dr in the hot drawing satisfies the following formula. (1 + S / 100) ≦ Dr ≦ 1.5 (1 + S / 100) where S is the relaxation rate (%) during relaxation heat treatment