JPH06346329A - Special latent-crimping polyester yarn and its production - Google Patents

Abstract

PURPOSE:To obtain a special latent-crimping yarn giving a woven or knit fabric having varied appearance by alternately forming thick parts and thin parts along the length of a filament and imparting the thick part with crimp- developing capability. CONSTITUTION:Thick parts and thin parts are alternately formed in the longitudinal direction of each filament of a polyester multifilament yarn and at least the thick part is imparted with a crimp-developing capability by relaxed heat- treatment. The yarn is produced by using a highly oriented undrawn polyester yarn having a birefringence DELTAn of 0.02-0.08 and a crystallinity of <=15% as a starting material, subjecting the yarn to a hot-fluid stuffing crimp processing at an over-feed ratio of >=30% and drawing the crimped yarn at or below Tg. The thick part and the thin part are different in dyeability caused by the difference of the orientation degree. A number of relatively coarse crimps are developed at the thick part (c) by the crimp-developing treatment such as boiling water treatment to develop remarkable shape difference and dyeability difference between the thick part (c) and the thin part (d).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a polyester special latent crimped yarn which is composed of filaments having thick portions and fine details alternately in the longitudinal direction of a yarn and which, when knitted or woven, becomes a cloth with a wide variety of appearances. And its manufacturing method.

[0002]

2. Description of the Related Art Various fancy yarns have been proposed in response to the trend of fashion in the market. Among them, many fancy yarns having crimps and alternating thick and small parts have been proposed. ing.

For example, a polyester undrawn yarn having a birefringence Δn of about 0.005 to 0.010 is non-uniformly drawn at a low draw ratio to form thick portions and details in the longitudinal direction of the yarn, and then false twisting is performed. The method of applying crimp to the yarn has been proposed. However, while the fancy yarn obtained by this method has the advantage that the diameter ratio (thickness ratio) between the thick part and the detail and the dyeing difference are large, the orientation of the thick part is too low, so false twisting and dyeing However, there is a drawback in that brittleness is liable to occur due to heat treatment during post-processing, and yarn breakage easily occurs.

In order to solve the above drawbacks,
Japanese Patent Publication No. 2-29773 discloses that a polyester highly oriented undrawn yarn having a birefringence Δn of 0.030 or more is heat-treated in a relaxed state,
Then, a method of performing false twisting after drawing is disclosed. However, in the yarn obtained by this method, the thick portion is stretched by false twisting, so that the difference in the thickness of the yarn becomes unclear, and the fabric has a poor change in appearance even after weaving or knitting. In addition, a compound external force such as tensile or torsional deformation is applied to the thick portion due to false twisting, and it is easily damaged by a decrease in strength. For this reason, a post-process such as twisting yarn or weaving after false twisting is performed. There was a problem such as inducing fluff and thread breakage.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art and has good process passability without causing fluff or yarn breakage in the weaving / knitting process and its preparation process. At the same time, the thick portions and details that are alternately formed in the longitudinal direction of the yarn have a remarkable morphological difference and dyeing property difference, and crimps are developed by the relaxation heat treatment such as the dyeing and finishing process, resulting in a soft texture. It is a technical subject to provide a polyester-based special latent crimped yarn and a method for producing the same, which has a woven or knitted fabric with a wide variety of appearances.

[0006]

The present inventors have arrived at the present invention as a result of intensive research to solve the above problems. That is, the present invention has the following configurations. (1) Thick portions and details are alternately formed in the longitudinal direction of the monofilaments constituting the polyester-based multifilament yarn, and at least the thick portions have a crimp-developing ability by relaxation heat treatment. Polyester special latent crimped yarn. (2) Highly oriented polyester unoriented yarn with a birefringence Δn of 0.02 to 0.08 and a crystallinity of 15% or less is supplied to a heating jet stuffer at an overfeed rate of 30% or more for heating fluid indentation crimping. A method for producing a polyester special latent crimped yarn, which comprises subjecting the yarn to a drawing and then drawing at a temperature not higher than the glass transition point of the yarn.

The present invention will be described in detail below.

First, in the polyester special latent crimped yarn of the present invention, thick portions and details are alternately formed at random lengths in the longitudinal direction of each single filament constituting the yarn,
The monofilament has an uneven shape in the longitudinal direction due to the presence of a thick portion and details. In addition, the thick part and the small part have a difference in dyeing property due to the difference in orientation degree, and the thick part shows a deep dyeing property and the small part shows a light dyeing property.

As for the arrangement state of the thick portion and the detail formed in the longitudinal direction of each single filament constituting the yarn, one in which the positions of the thick portion and the detail are almost aligned between the single filaments, There are those which are formed so as to be dispersed like this, or those which exhibit an intermediate arrangement between them.

In the yarn of the present invention composed of a plurality of monofilaments having such a thin and thin shape, the apparent form of the whole yarn is as follows: It depends on the length of the details (pitch) and the ratio of the diameter of the thick part / the diameter of the small parts (thickness ratio), but as described above, the positions of the thick parts and the details are almost aligned between the single filaments. The yarn has a slab-like appearance in which the thick, thin, thick and thin morphology is clear. In addition, the yarn formed so that the positions of the thick portion and the details are evenly distributed has a heather appearance having a natural contrast in which the thick and thin shapes are appropriately dispersed.
In any of these, as will be described later, since the density difference between the thickness and the density is emphasized by the relaxation heat treatment in the post-process such as dyeing, the woven or knitted fabric can have a wide variety of appearances.

As described above, the polyester special latent crimped yarn of the present invention has a thick and thin form, but almost no apparent crimp is imparted, and at least the thickened by the relaxation heat treatment in the post-process such as dyeing. A relatively coarse wavy crimp appears mainly in the part. Moreover, crimps do not appear in the details, or relatively fine crimps mainly appear.

As described above, the polyester special latent crimped yarn of the present invention, in addition to the difference in density dyeing property, is subjected to relaxation heat treatment to emphasize the form difference such as the difference in crimp, the difference in thickness, etc. The fabric thus obtained is bulky, has a soft texture, and exhibits a variety of new surface morphologies.

Since the polyester-based special latent crimped yarn of the present invention develops crimps by the relaxation heat treatment in the later step as described above, the thick portion like the conventional thick and thin crimped yarn is temporary. The strength is not affected by the external force during the twisting process, and thus it is possible to prevent the occurrence of fluff and yarn breakage in the weaving and knitting process and other preparation processes. In addition, since the crimp does not decrease or disappear during these subsequent steps, stable processing is possible.

The relaxation heat treatment for developing crimps in the polyester-based latent latent crimped yarn of the present invention is preferably performed in the dyeing step after weaving and weaving, but is performed in the yarn stage such as cheese dyeing. Good.

Next, the polyester special latent crimped yarn of the present invention will be described with reference to the drawings. 1 and 3 are schematic diagrams showing an embodiment of the yarn of the present invention, and FIGS.
FIG. 4 is a schematic view showing a yarn form after the yarn of FIG. 3 is treated with boiling water at 100 ° C. for 30 minutes in a free state. In the figure, (a) is the thick part of the monofilament, (b) is the detail of the monofilament, (c)
Shows the thick part where latent crimps appear, and (d) shows the details where latent crimps appear. The thick parts and details are alternately formed in the longitudinal direction of each monofilament.

FIG. 1 is a yarn in which the positions of the thick portions and the details are evenly distributed among the individual filaments, and the yarn as a whole has a moderate heathered appearance. The yarn is formed so that the positions of the thick part and the details are aligned, and the yarn as a whole has a slab-like thick thin morphology with a clear dark and light thick thin morphology. The yarns shown in Fig. 1 and Fig. 3 show latent crimps as shown in Fig. 2 and Fig. 4 respectively by relaxation heat treatment, and a large amount of relatively coarse crimps appear in the thick part,
The details are slightly crimped.

As described above, the latent latent crimp of the polyester-based special latent crimped yarn of the present invention is exposed by the relaxation heat treatment, so that the crimped form is emphasized in addition to the thick and thin form and the difference in dyeability. It is a yarn that has the potential for crimping that has never been seen before.

Next, the method for producing the special latent crimped yarn of the present invention will be described.

First, in the present invention, the birefringence Δn is 0.02 to
Highly oriented unoriented polyester yarn with a crystallinity of 0.08 and a crystallinity of 15% or less is used as the feed yarn, and is fed to a heating jet stuffer at an overfeed rate of 30% or more to perform crimping by heating fluid.

At this stage, the yarn is once crimped. This treatment is important to promote the occurrence of necking that occurs in each single filament in the subsequent drawing. The reason for this is that highly oriented undrawn yarn is likely to form oriented spots in the longitudinal direction of the filament during high-speed spinning, and its internal structure is not as stable as that of drawn yarn. It is considered that the nonuniformity of the internal structure is extremely promoted by the heating fluid indentation crimping treatment, and the necking phenomenon is promoted.

Here, in the highly oriented polyester unoriented yarn having a birefringence index Δn of less than 0.02, if heat treatment is performed with a heating fluid as in the present invention, a part of the filament is easily embrittled and the processing becomes unstable. Become. On the other hand, when the birefringence Δn becomes high or the degree of crystallinity becomes high, as described above, the unevenness in the orientation of the filament in the longitudinal direction is small and the internal structure is stabilized, so that a sufficient thick and thin forming effect can be obtained. I can't. Therefore, it is necessary to use yarns with Δn of 0.08 or less and crystallinity of 15% or less as the supply yarn.

In the present invention, the heating jet stuffer device used for crimping the highly oriented polyester unoriented yarn by heating fluid is a yarn, a jet nozzle portion for ejecting the heating fluid, and a yarn depositing device. And a cooling unit for stabilizing the crimps applied to the yarn, which has the function of discharging the heated fluid to the side of the accumulated yarn, A crimp having a combination of shrinkage characteristics and indentation characteristics can be provided.

In this heating fluid indentation crimping process, if the yarn is supplied in an overfeed state of 30% or more, the necking that occurs in each single filament during the subsequent stretching in the subsequent step is promoted and the thick filament is thickened. The positions of the parts and the details can be arbitrarily formed. This overfeed rate varies depending on the yarn supplied and the processing conditions, but it is 30 to 30
A range of 0% is preferable, and when the overfeed rate is less than 30%, the slack necessary for heat shrinkage and buckling is not given, so not only the crimp morphology becomes insufficient, but also the internal structure of each single filament. Cannot be sufficiently promoted, and therefore, even if a stretching process is performed in the next step, it is not possible to impart a thick and fine difference and a difference in shading dyeing property with excellent effects.

It is possible to control the state of origin of the thick portion and the details during stretching by the above-mentioned overfeed rate, and although it varies depending on the stretching conditions, when it is approximately 100% or less, the thick portion of each single filament is It has a form in which the positions of the details are dispersed, and when it exceeds 100%, it shows a form in which the positions of the thick parts and the details of each monofilament are aligned.

The temperature and fluid pressure of the heating fluid used in the heating fluid indentation crimping process are not particularly limited, and may be appropriately set according to the type and fineness of the supplied yarns. Temperature is 130-240 ℃, fluid pressure is 1.0-
It is preferably in the range of 5.0 kg / cm ² .

In the present invention, the yarn subjected to the heating fluid indentation crimping process is continuously supplied to the drawing step and drawn at a temperature below the glass transition point of the yarn to obtain the desired special latent crimp. Use as thread. This drawing not only eliminates the latent crimp characteristics of the yarn after the heating fluid indentation crimping process, but forms only the crimps that are visible on the surface, while forming a thick portion and details in the longitudinal direction of the yarn. It is for disappearing.

If the stretching temperature is higher than the glass transition point, the necking phenomenon is unlikely to occur, so that a clear thick and thin difference does not occur, and the latent crimp property is easily lost.

The draw ratio is appropriately selected in relation to the overfeed rate according to the desired yarn form. For example, although it is slightly different depending on Δn, the preferable draw ratio is 2 to 3 when the overfeed rate is 100%.
When the double feed rate and the overfeed rate are 300%, the preferable draw ratio is 4 to 5 times.

Next, the method for producing the polyester special latent crimped yarn of the present invention will be described with reference to the drawings.

FIG. 5 is a schematic process diagram showing one embodiment of the present invention. In FIG. 5, a highly oriented polyester unoriented yarn 1 having a Δn of 0.02 to 0.08 and a crystallinity of 15% or less has a heating jet stuffer composed of a feed roller 2, a jet nozzle portion 3, a deposition portion 4 and a cooling portion 5. After that, it is guided to the first delivery roller 6. In the meantime, the yarn is supplied to the heating jet stuffer by the feed roller 2 at an overfeed rate of 30% or more, and is subjected to the heating fluid pushing crimping process. Next, the crimped yarn is drawn between the first delivery roller 6 and the second delivery roller 7 at a temperature not higher than the glass transition point, and then wound up by the winding roller 8 into the package 9.

The polyester in the present invention is a polymer having an ester bond in the molecular chain, and includes homopolymers represented by polyethylene terephthalate and copolymers or blend polymers thereof.

The birefringence index Δn is a value measured by an interference fringe measurement method using a combination of a polarization microscope and a compensator. Furthermore, the crystallinity (%) is measured by the density method and calculated from the following equation. _{Xc = (ρ-ρ a)} × 100 / (ρ c -ρ a) However, Xc: degree of crystallinity [rho: the density of the sample [rho _c: density of crystal unit = 1.455 (in the case of polyethylene terephthalate) [rho _a: amorphous Part density = 1.335 (for polyethylene terephthalate)

The term "overfeed rate" as used herein means the ratio of the difference between the feed roller speed and the first delivery roller speed to the first delivery roller speed, expressed as a percentage.

[0034]

EXAMPLES Next, the present invention will be specifically described by way of examples.

Examples 1 and 2, birefringence Δn obtained by high-speed spinning was 0.05, and crystallinity was 8.5%.
Polyethylene terephthalate Highly oriented undrawn yarn 110d / 36
Using the f (glass transition point: 68 ° C) as the yarn to be fed, the heating fluid indentation crimping process and the drawing are continuously performed under the conditions shown in Table 1 according to the process shown in FIG. Got

[0036]

[Table 1]

The two special latent crimped yarns obtained above were each twisted in the S direction at 500 T / M, and then 2/2.
When weaving the twill, there was no trouble such as fluff or yarn breakage during weaving, and stable processing operability was obtained. Next, when the obtained woven fabric was subjected to a normal polyester dyeing process, the fabric using the yarn of Example 1 exhibited a natural heathered appearance in which thick and thin morphologies were uniformly dispersed, and The fabric using the yarn of Example 2 had a slab-like appearance with a clear dark and light thick and thin morphology, and was a product with a soft texture in which crimps were developed and which was rich in surface changes.

Example 3 Birefringence Δn obtained by high-speed spinning was 0.04 and crystallinity was 7.5%.
Polyethylene terephthalate highly oriented undrawn yarn 220d / 72
Using f (glass transition point: 68 ° C.) as the yarn to be fed, the heated latent fluid crimping process and the drawing are continuously performed under the conditions shown in Table 2 according to the process shown in FIG. Got

[0039]

[Table 2]

The special latent crimped yarn obtained above was knitted into a knit having a rib structure and subjected to a usual polyester dyeing process. As a result, it was excellent in the fancy effect due to the dark thick portion and the light details. Moreover, a knit product having a span-like soft texture was obtained.

[0041]

EFFECT OF THE INVENTION The polyester-based latent latent crimped yarn of the present invention does not cause fluff or yarn breakage during the weaving and weaving process and its preparatory process, has good processability, and has a longitudinal direction of the yarn. Since the thick portions and details that are alternately formed on the sheet have a remarkable morphological difference and a difference in shade dyeability, and crimps are developed by relaxation heat treatment such as a dyeing process, when the yarn of the present invention is used, It is possible to obtain a woven or knitted fabric which has a rich texture and a variety of appearances. Further, according to the production method of the present invention, it becomes possible to easily and stably produce the polyester-based special latent crimped yarn having the above advantages.

[Brief description of drawings]

FIG. 1 is a schematic view showing one embodiment of a polyester special latent crimped yarn of the present invention.

FIG. 2 is a schematic view showing a form after the yarn of FIG. 1 is treated with boiling water in a free state.

FIG. 3 is a schematic view showing another embodiment of the polyester special latent crimped yarn of the present invention.

FIG. 4 is a schematic diagram showing a form after the yarn of FIG. 3 is treated with boiling water in a free state.

FIG. 5 is a schematic process drawing showing one embodiment of a method for producing a polyester-based special latent crimped yarn of the present invention.

[Explanation of symbols]

 a thick part of monofilament b detail of monofilament c thick part where latent crimp was developed by boiling water treatment d detail where latent crimp was developed by boiling water treatment 1 polyester highly oriented undrawn yarn 2 feed roller 3 nozzle portion 4 deposition portion 5 Cooling part 6 1st delivery roller 7 2nd delivery roller 8 Winding roller 9 Package

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display area D02J 1/22 M

Claims (2)

[Claims] 1. A monofilament constituting a polyester-based multifilament yarn is alternately formed with a thick portion and a fine portion in the longitudinal direction, and at least the thick portion has a crimp-developing ability by relaxation heat treatment. Polyester special latent crimped yarn. 2. The birefringence Δn is 0.02 to 0.08 and the crystallinity is
Highly oriented polyester unoriented yarn of 15% or less is supplied to a heating jet stuffer at an overfeed rate of 30% or more to perform crimping with heated fluid and then drawn at a temperature below the glass transition point of the yarn. A method for producing a polyester special latent crimped yarn, which is characterized in that