JPS6366932B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a special bulky yarn that has a difference in heat shrinkage rate in the fiber axis direction, does not have a slimy feel, and can impart a spun-like appearance and bulkiness. Conventionally, thermoplastic filament yarns such as polyester fibers and polyamide fibers exhibit the metallic luster, slimy feel, and paper-like texture characteristic of synthetic fibers when used in stretched yarns for fabrics. It is hardly used as it is for clothing, and is only used for special purposes, and is generally used by adding bulk to it through bulky processing such as false twisting or by using different shrinkage blend yarns. However, these fabrics fail to meet the modern demands for fancy and varied fabrics with a more uniform appearance. On the other hand, the design twisting method has been known as a means of changing the appearance of fabrics, but this method
Because the process is complicated and the processing speed is slow,
It was disadvantageous in terms of cost. The obtained decorative yarn also has problems in yarn passing ability, unwinding ability, etc. in the fabric-making process because the yarn diameter and yarn structure differ in the yarn longitudinal direction and the unevenness is strong. An object of the present invention is to provide a special bulky yarn that does not have the drawbacks of the conventional design yarns and is suitable for manufacturing fancy and varied fabrics.
To this end, the present invention has the following configuration. That is, in the present invention, two types of thermoplastic multifilament yarns having different average heat shrinkage rates are mixed,
It is a special bulky yarn characterized in that the average thermal shrinkage rate of one thermoplastic multifilament yarn is at least 5% higher than that of the other, and the shrinkage rate of the former varies randomly in the fiber axis direction. The present invention will be explained below with reference to the drawings. Note that the drawings are for illustration purposes only, and as long as the spirit of the invention is not lost,
Changes are allowed. In the present invention, the two types of thermoplastic multifilament yarns have different average heat shrinkage rates.
In other words, the average heat shrinkage rate of one thermoplastic multifilament yarn (hereinafter referred to as "high shrinkage yarn") is:
It should be at least 5% higher than the average heat shrinkage of the other thermoplastic multifilament yarn (hereinafter referred to as "low shrinkage yarn"), preferably in the range of 5 to 30%. This is because if the special bulky yarn according to the present invention is heat-treated when the amount of bulge is less than 5%, the difference in yarn length between the high shrinkage yarn and the low shrinkage yarn will be small and the bulk of the entire yarn will be insufficient. If the yarn length exceeds , the difference in yarn length between the two becomes extremely large, and when the special bulky yarn according to the present invention is used to make a fabric and then heat-treated, loops of filaments constituting the low-shrinkage yarn will occur on the surface of the fabric. This is because the appearance is impaired. Note that the average heat shrinkage rate of the high shrinkage yarn is preferably 35% or less in order to facilitate fabric design. Next, the heat shrinkage rate of the high shrinkage yarn must vary randomly within an appropriate range in the fiber axis direction. This is to make the special bulky yarn according to the present invention potentially have random bulkiness spots in the fiber axis direction. In addition, the heat shrinkage rate as referred to in the present invention refers to a yarn having a length of 5 cm under a load of 0.1 g/d, treated in hot water at 95°C for 20 seconds under a load of 5 mg/g, and then 0.1 g/d. Dry under a load of g/d and then dry again.
The yarn length l (cm) under a load of 0.1 g/d is determined, and the value is calculated from the formula: heat shrinkage rate (%) = 5 (cm) - l (cm)/5 (cm) x 100. Moreover, the average heat shrinkage rate refers to the value obtained by calculating the heat shrinkage rate for each 5 cm of a yarn having a length of 1.5 m using the above method and averaging the results. Furthermore, in order to vary the heat shrinkage rate of a high shrinkage yarn randomly in an appropriate range in the fiber axis direction, for example, if the structural integrity parameter of the undrawn yarn is ε, then the stretching ratio is DR, ε
It is preferable to draw the undrawn yarn at a drawing ratio DR in the range of +0.8≦DR≦ε+1.2. Here DR is ε+
If DR exceeds 1.2, the heat shrinkage rate will not change much in the fiber axis direction, and if DR is less than ε+0.8, the heat shrinkage rate will change too much in the fiber axis direction, so the above range is preferable. Here, ε is measured as follows (Japanese Unexamined Patent Publication No. 35112/1983). That is, a load of 0.2 g/d is applied to the undrawn yarn, and the length l ₀ of the undrawn yarn at that time is measured. Then, the undrawn yarn
Immerse it in hot water at 80°C for 30 seconds, then take it out, leave it to cool, and then measure its length l. All of these operations are carried out while the undrawn yarn is under a load generated by a weight. ε is then calculated by the following equation. ε=l ₀ −l/l ₀ Also, an arbitrary cross-section of at least one part of the filament constituting the low shrinkage yarn has 2 parts on the outer periphery.
It is preferable that the shape has at least three convex portions and a void in the center. For example, as shown in FIG. 1, a cross-section 1 of a filament of a low-shrink yarn has protrusions 2, 2', 2'' on the outer periphery, and a void 3 in the center of the cross-section 1. A cross section 4 is shown, and there is a gap 5 in the center, and convex parts 6, 6', and
6". The protrusions give a dry feel, and the voids give a bulky feel. When the void size is 0.2D≦d≦0.4D,
It is preferable to set it within this range if possible, since it can provide good bulk. Here, d
is the diameter of the inscribed circle of the void, and D is the diameter of the circumscribed circle of the cross section. 3 and 4 show the caps corresponding to FIGS. 1 and 2, and FIG. 4 shows an example in which cooling air is blowing from the direction of arrow A. Incidentally, by employing a filament having the above-mentioned cross-section for the filament constituting the high-shrinkage yarn, it is possible to impart a good feel, so it is preferable to employ such a cross-section. Furthermore, it is preferable to impart latent crimp ability to the low-shrinkage yarn in the sense that it imparts fine crimps, increases bulkiness, and imparts a soft feel. The following method can be considered as a means of imparting potential crimp ability. Examples include a method of manufacturing a conjugate yarn by joining and spinning different types of polymers with different heat shrinkage abilities, an asymmetric cooling method, a nonuniform heat treatment method, and a method using edge abrasion. In terms of cost, it is preferable to use asymmetric cooling during spinning to give internal structure differences in the cross-sectional direction.In particular, it is more effective to make the cross-section of the filament have a void in its center as described above. This is preferable in the sense that it imparts a latent crimp ability. In general, regarding latent crimp ability, the restraining force in the fiber axis direction at the time of crimp development has a large influence on the crimp development ability, and it is important to mix high-shrinkage yarn and low-shrinkage yarn as in the present invention. Accordingly, the stress during heat treatment is concentrated mainly on the high shrinkage yarns, while the low shrinkage yarns are heat treated under extremely low stress, thereby achieving effective crimp development. Next, the material used in the present invention may be any thermoplastic multifilament yarn, and it is also possible to use different materials for high-shrinkage yarn and low-shrinkage yarn, and in particular, to combine different dyeing yarns. By this,
A more varied effect can be obtained. Furthermore, thermoplastic multifilament yarns made of polyester fibers are preferred because they provide a firm and elastic feel. Furthermore, high shrinkage yarns and low shrinkage yarns are mixed, and in this case, the mixed fibers are heat treated by regulating the filaments of high shrinkage yarn and filaments of low shrinkage yarn at their intertwining points. Necessary to increase bulk later. This effect is not achieved by mere alignment. Examples of the means for mixing fibers include a fluid method and an electricity application method, but the fluid method is preferable in terms of cost and effectiveness. Next, a method for implementing the present invention will be described. In FIG. 5, the undrawn yarn F is the package P
is unwound from the feed roller 2 through the guide 1.
Then, it passes through a hot roller 3, a hot plate 4, and a stretching roller 5, and is stretched at a predetermined stretching ratio, passes through a guide 6, and is twisted by a ring and a traveler (not shown) to form a drawn yarn F' in a package P. ’ is wound up. In this case, the stretching ratio DR
is within the range of ε+0.8 to ε+1.2 to appropriately change the heat shrinkage rate in the fiber axis direction. Note that a slight tension is applied between the feed roller 2 and the hot roller 3 in order to control tension unevenness. On the other hand, a drawn yarn having a heat shrinkage rate that changes randomly in the fiber axis direction is obtained by manufacturing a drawn yarn with a draw ratio DR larger than ε+1.2 and hardly changing the heat shrinkage rate. A special bulky yarn before heat treatment is produced by mixing the fibers with a fiber mixing device (not shown). Figure 6 shows undrawn yarns with different structural integrity parameters.
This is a front view of an apparatus that simultaneously draws and mixes F ₁ and F ₂ at once to produce special bulky yarn Y.
The undrawn yarns F ₁ and F ₂ are unwound from the package P ₁ and P ₂ , pass through guides 7 and 8, respectively, guide 9, feeder 10, hot roller 11, hot plate 12, and drawing roller 13. The fibers are stretched at a predetermined stretching ratio, then mixed in a fiber mixing device 14, passed through a delivery roller 15 and a guide 16, and then wound into a package _P3 as a special bulky yarn Y by a ring and a traveler (not shown). In this case, it is necessary to appropriately determine the relationship between the structural integrity parameter ε of the undrawn yarns F ₁ and F ₂ and the drawing ratio DR. Thus, according to the present invention, the high shrinkage yarn and the low shrinkage yarn are mixed, the average heat shrinkage rate of the former is at least 5% higher than that of the latter, and the average heat shrinkage rate of the former is higher than that of the fiber. A special bulky yarn with random changes in the axial direction is obtained, and this special bulky yarn is a uniform yarn with no change in appearance, so it has excellent process passability, and after heat treatment, the high shrinkage filaments randomly change. The filament shrinks with the amount of vine, creating a yarn length difference between it and the low-shrinkage filament, resulting in a spun-like yarn with random bulkiness in the fiber axis direction.
After fabric production, heat treatment such as relaxation treatment creates a spun-like appearance with yarn length differences and fabric density unevenness due to shrinkage unevenness in the fiber axis direction, as well as crimps on the fabric surface and cross-sectional shape of low-shrinkage yarns. This has the remarkable effect of producing a fabric with a dry touch and bulky texture. Example 1 First, polyethylene terephthalate chips were
It was melted at 282℃ and discharged at a rate of 12.1g per minute from a nozzle with pores with the cross-sectional shape shown in Figure 4.
The yarn was wound at a speed of m/min to produce an undrawn yarn of 42 d/15 f. The cross section of the filament had the shape shown in FIG. When the ε of the undrawn yarn was measured using an Epsilon meter (manufactured by Toyobo Co., Ltd.) by the method described above, ε=0.5. The undrawn yarn was drawn using the apparatus shown in FIG. 5 under the following conditions. Conditions Circumferential speed of stretching roller 5: 900 m/min, temperature of hot roller 3: 40°C, temperature of hot plate 4;
105℃, stretching ratio DR; 1.45 In this case, when calculating the range of DR from ε, the lower limit is
0.5 + 0.8 = 1.3, the upper limit is 0.5 + 1.2 = 1.7, and the above DR of 1.45 is within this range, and the obtained drawn yarn has heat shrinkage that changes randomly in the fiber axis direction. rate. In fact, when we measured the heat shrinkage rate of this drawn yarn for a yarn length of 1.5 m, we found that the heat shrinkage rate varied randomly in the fiber axis direction from a maximum of 35% to a minimum of 18%, and the average was
It was 25.6%. Next, in the same die, polyethylene terephthalate was wound at a rate of 1300 m/min at a discharge rate of 10.4 g/min to produce an undrawn yarn of 72d/20f. When ε of the undrawn yarn was similarly measured, it was found to be 1.1. The undrawn yarn was drawn using the apparatus shown in FIG. 5 under the following conditions. Circumferential speed of feed roller 2: 375 m/min, circumferential speed of stretching roller 5: 900 m/min, temperature of hot roller 3: 40°C, temperature of hot plate 4: 152°C, stretching ratio DR: 2.4 In this case, from ε to DR When determining the range, the lower limit is 1.1 + 0.8 = 1.9, the upper limit is 1.1 + 1.2 = 2.3, and the DR of 2.4 is outside this range, and the obtained drawn yarn is heated in the fiber axis direction. The shrinkage rate remains almost unchanged. In fact, when the heat shrinkage rate of this drawn yarn was measured every 5 cm for a yarn length of 1.5 m, the heat shrinkage rate only varied from 8% to 4% in the fiber axis direction, and the average was 5.3 It was %. Here, both drawn yarns were mixed with a blending device (not shown) at an overfeed of +1.5% and a winding speed of 300 m/min.
minutes, mixed fibers under the condition of air pressure 3Kg/cm ² G, 60d/
A special bulky yarn of 35 f was manufactured. using this thread
The knitted fabric was knitted using a 32-gauge interlock circular knitting machine, relaxed in hot water at 90°C for 30 minutes, dyed using a jet dyeing machine at 130°C, dried, and set using a pin tenter. This knitted fabric had spun-like irregularities, and was dry and full of bulge. Example 2 Two types of undrawn polyester yarns F ₁ and F ₂ were spun under the following conditions.

【table】

[Table] However, when spinning the undrawn yarn _F2 , air was blown at 3.0 m/min at a temperature of 20° C. from the direction of arrow A in FIG. 4 for cooling. Next, the undrawn yarns F ₁ and F ₂ were drawn and mixed using the drawing and twisting machine shown in Fig. 6 under the following conditions.
Obtained special bulky yarn of 125d/60f. Conditions Feed roller 10 peripheral speed: 500 m/min, stretching roller 13 peripheral speed: 900 m/min, hot roller 1
Temperature of 1: 40℃, temperature of hot plate 12;
115℃, stretching ratio DR: 1.8, overfeed in fiber mixing device: +2%, air pressure: 3Kg/cm ² G,
Winding speed: 900 m/min. When the heat shrinkage rates after drawing the undrawn yarns F ₁ and F ₂ were measured, the heat shrinkage rates were 20 to 41.5% and 5%, respectively.
It varied in the fiber axis direction within a range of ~12%, and the average values were 32% and 8.2%, respectively. A knitted fabric with a double pique structure was made using a 24-gauge circular knitting machine using the obtained special bulky yarn, dyed and dried in the same manner as in Example 1, and the fabric was full and had density irregularities on its surface. A knitted fabric with a dry texture and yarn length unevenness was obtained. When the surface of this knitted fabric was closely observed, it was found that the filaments in the large part of the yarn length had a delicate crimp, which had a subtle effect on the fullness and texture.

[Brief explanation of drawings]

The figures relate to the present invention, and FIGS. 1 and 2 show the cross-sectional shape of the filament, FIGS. 3 and 4 show the corresponding cross-sections of the base, and FIG. 5 is a front view of the twisting machine.
FIG. 6 is a front view of an apparatus for drawing and mixing fibers. 2, 10... Feed roller, 3, 11... Hot roller, 5, 13... Stretching roller, 14... Mixing device, 15... Winding roller, Y... Special bulky yarn.

Claims (1)

[Claims] 1. Two types of thermoplastic multifilament yarns having different average heat shrinkage rates are mixed, and the average heat shrinkage rate of one thermoplastic multifilament yarn is at least 5% higher than that of the other thermoplastic multifilament yarn, The special bulky yarn is characterized in that the heat shrinkage rate of the former varies randomly in the fiber axis direction. 2. An arbitrary cross section of at least one part of the filament constituting the thermoplastic multifilament yarn with a low average thermal shrinkage rate has two or more convex portions on the outer periphery,
The special bulky yarn according to claim 1, which has a shape with a void in the center. 3 Claim 1 in which the thermoplastic multifilament yarn with a low average thermal shrinkage rate has latent crimp ability
The special bulky yarn described in item 1 or 2.