JPS6218652B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a latent bulky multifilament yarn, and more particularly to a method for producing a latent bulky multifilament yarn that exhibits texture, luster, and depth of color comparable to natural silk. In the present invention, the term "potentially bulky multifilament yarn" refers to a thermoplastic multifilament yarn having extremely short pitches and irregular contractile portions within and between single fibers. It means something that develops silk-like texture and swelling through heat shrinkage treatment. Conventionally, thermoplastic multifilament yarn is brought into instant contact with a dry heat heating element under its dry heat shrinkage stress, specifically in an almost free state.
It is known that a certain number of filaments are intermittently contracted, and other filaments are accordingly stretched to create loops and slack, thereby giving yarn length differences and curling within the entire yarn. The yarn thus obtained is bulky and has a silk-like feel, but has the following drawbacks. (a) Since the filament yarn is subjected to random heat shrinkage treatment in the cross-sectional direction and longitudinal direction, scratch-like stripes occur in woven or knitted fabrics. This is due to the fact that since the yarn is subjected to contact heat treatment in an almost free state, the yarn itself does not run smoothly and the process itself is extremely unstable. Of course, in order to prevent the above-mentioned scratch-like stripes, it is sufficient to selectively heat-treat only a part of the filament at a constant rate, but in this way, for example, only half of the filament should be heat-treated at all times by instantaneous heat treatment. is very undesirable, and the proportion is constantly changing. Moreover, there is a natural limit to the processing speed due to the constraints of the almost free state of slight tension and instantaneous heat treatment. (b) As a result of partially shrinking the filament yarn,
Loops and slacks occur on the yarn surface, but these loops themselves cause a decrease in the handling properties of the yarn, and in particular, not only significantly impair the weaving and weaving properties, but also cause a deterioration in the appearance of the woven or knitted fabric. For this reason, it has been proposed to temporarily eliminate the loops by heat treatment, but in this case, since the entire yarn is heat treated, the difference in shrinkage between the high shrinkage part and the low shrinkage part is reduced, and the initial If this is the case, it cannot be expected to reproduce the tactile sensation. (c) Since the yarn is partially heat-shrinked under extremely low tension, a flow portion remains in the yarn, causing the yarn to be stretched irregularly during weaving, causing sink marks, and in woven and knitted fabrics, elbows may fall out. easy. (d) The yarn as a whole has a high shrinkage component and a low shrinkage component, but because it is made by heating on one side, the two exist separately (so-called not mixed).
Therefore, even if there is a difference in shrinkage due to heat during dyeing, etc., the threads will only appear to be pulling, and the effect of swelling and becoming silk-like as in the case of mixed threads will be reduced. As described above, the above-mentioned methods are always accompanied by problems such as dyeing spots, shedding, and poor weavability, and the silk-like properties of the yarn structure cannot be fully utilized. Therefore, the object of the present invention is to provide a latent bulky multifilament yarn that not only exhibits a silk-like texture and luster, but also has excellent weavability, and does not cause wrinkles or scratch-like stripes in woven or knitted fabrics. The object of the present invention is to provide a method and apparatus that can reproducibly produce . In the course of various studies aimed at achieving the above object, the present inventors came to the conclusion that it is essential to heat-treat the filament yarn evenly along the longitudinal direction in order to prevent scratch-like stripes. Based on the assumption that if the entire yarn could be subjected to periodic heat shrinkage treatment while being kept under tension, the drawbacks of the conventional method would be eliminated at once, and as a result of further study, the present invention was arrived at. . That is, according to the present invention, a thermoplastic multifilament yarn having substantially no Cournot loops on the yarn surface and only sagging and overhanging portions is used at a rate of 0.02 g/de.
With the above, the slack and overhanging parts are heat treated at a temperature of at least 130°C under tension that does not deform and eliminate them, and while the yarn as a whole is subjected to tension heat treatment, only the slack and overhanging parts are allowed to shrink freely and are eliminated. Provided are a method for producing a potentially bulky multifilament yarn characterized by forming it into a substantially straight state, and an apparatus for producing the same. To further describe this, the present invention subjects a multifilament yarn in which slack portions are formed intermittently along the longitudinal direction to tension heat treatment under tension, and exceptionally allows only the slack portions to freely contract, thereby reducing the slack portions. The main feature is that the difference in shrinkage within the fibers and between single fibers is maintained to the maximum extent possible, and the differential shrinkage portions with regularity are obtained by mixing the fibers. FIG. 1 is an external view of the multifilament yarn before heat shrinkage treatment according to the present invention, and numeral 1 indicates a slack portion due to the constituent single fibers, which is composed of slack of various sizes. Reference numeral 2 denotes a base yarn portion, which exists continuously along the longitudinal direction of the yarn. Therefore, this thread is placed under a certain tension (i.e., tension in a range that does not eliminate slack).
If the fabric is placed in a heat-treated state, all the tension will be concentrated in the ground thread, and the slack will not be eliminated.If heat treatment is performed in this condition, the slack will shrink extremely smoothly, resulting in a so-called free heat shrinkage treatment, and the setting effect will greatly reduce the shrinkage rate. decreases dramatically. On the other hand, since the ground yarn portion 2 is maintained under a tension of 0.02 g/de or more, it is subjected to so-called tension heat treatment, and therefore the heat setting effect is less than that of free heat treatment. As a result, a difference in setting effect, that is, a larger difference in shrinkage ratio occurs between the two. Figure 2 shows the relationship between tension and shrinkage rate during heat setting.The horizontal axis shows the slack, the tension applied to the overhanging part 1 is represented as A, the tension applied to the ground thread part 2 is represented as B, and on the other hand The vertical axis shows the heat shrinkage rate of each part after heat treatment, A′ (sag, overhang),
It is expressed as B' (base thread part). As can be seen from this figure, the lower the tension is used to set the yarn, the greater the setting effect (because the amorphous portion is more likely to relax and assume a stable shape), and the shrinkage rate tends to be lower. In other words, the ground thread part set under high tension has approximately the shrinkage rate B' before setting, and the slack when set under low tension,
That of the overhanging part is extremely reduced to A′,
In this way, the maximum shrinkage difference of ΔS can be obtained even with the same yarn portion. FIG. 3 shows the appearance of the yarn after heat shrinkage treatment, and it appears to be in a substantially straight line, no different from that of a normal filament yarn, that is, a flat yarn. However, as shown in FIG. 4, when looking at each single fiber, it consists of a low shrinkage part Pl, which is formed by shrinkage of slack along the longitudinal direction, and a high shrinkage part Ph, where no shrinkage occurs substantially. As is clear from the above explanation, the low-shrinkage area Pl is where the single fibers that had been forming slack around the high-shrinkage ground yarn have shrunk and become aligned. . The most important thing to achieve this aligned state is that the slack is formed as an overhang (half-arc shape) of each single fiber, as shown in Figure 1, and this is the first time that smooth contraction is induced. . In this respect, similar to sagging or overhanging, there is a Cournoud loop (a so-called taslan-specific loop as shown in Figure 5, where the thread is wrapped around the thread axis).
However, such loops are substantially eliminated in the present invention. This is because, even when this Cournoud loop is subjected to heat shrinkage treatment, the single fibers do not shrink linearly as shown in FIG. 5, and protrusions remain on the yarn surface. This is because not only does this form a crimped portion, but it also gives the entire thread a rough and hard feel, which is far from the texture of silk. In addition, even if the single fibers do not become loops but simply sag or overhang, if the heat treatment is insufficient and the sag or overhang is not removed sufficiently and remains, the fabric will still have an uneven feel. occurs, resulting in a so-called twisted thread-like fabric. In other words, the slack and overhanging portions are sufficiently removed to create a nearly straight filament, and when this is woven into a textile and finished with dyeing, the yarn is swollen by causing a difference in heat shrinkage. As a result, it has a unique, fluffy silk texture. For this purpose, it goes without saying that loops should not be mixed in the original yarn (Fig. 3), but it is also necessary to eliminate slack and overhanging portions by sufficiently relaxing and heat-shrinking them during heat treatment. Furthermore, by forming the filament yarn into a substantially straight filament yarn in this way, it is effective in the sense that the yarn can be easily handled like a normal filament yarn and can be woven without any problems. In addition, if the original yarn (Figure 3) contains loops, even if they are removed by heat shrinkage, the fibers will remain twisted, giving off a unique sparkling luster that is unique to silk. In this sense as well, the original thread (Figure 3) should not have any loops mixed in, as the result will be completely different from the mild luster of the thread. When the thus obtained heat-treated yarn shown in FIG. 3 is relaxed in, for example, boiling water, the ground yarn portion 2 existing as a core along the longitudinal direction of the yarn and the high shrinkage portions Ph ₁ to Phn in FIG. As the fibers contract, the voids between the single fibers increase, and the yarn as a whole exhibits a high degree of swelling, flexibility, and suppleness, as shown in FIG. In the present invention, the thermoplastic multifilament yarn used as the starting yarn is made of a thermoplastic synthetic polymer such as polyester, polyamide, polypropylene, etc., and has a total denier of 15 to 15.
250de, single fiber denier 1.7de or less boiling water shrinkage
15% or less is preferably used. Furthermore, since the present invention is originally intended to provide a silk-like material, the cross section of the filament is also important, and an irregular cross section, preferably a triangular cross section, is used rather than a circular cross section. In order to give such multifilament yarn slack as shown in Fig. 1, a known interlace nozzle (for example, Japanese Patent Publication No. 36-12230,
(Refer to Special Publication No. 37-1175)
Kg/cm ³ , under 1-5% overfeed, yarn speed
It is sufficient to pass at a speed of 200 m/min or more, preferably 500 m/min or more. However, in order to obtain a material with a silk-like texture, which is the object of the present invention, the slack in the filament yarn does not necessarily need to exist over the entire surface of the yarn, and as shown in FIG. It has been found that the effect is sufficiently exerted even if it exists intermittently. In this case, the number of intersecting points 4 between the slack parts may be 50 points/m or more. When using the above-mentioned turbulent nozzle, such yarn has a pneumatic pressure of 1 to 3 kg/cm ² and an overfeed rate of 1 to 3 kg/cm 2 .
Under 5%, there is an advantage that can be obtained at high speeds of 750 m/min or more. Hereinafter, one embodiment of the present invention will be explained with reference to FIG. 8. After the undrawn polyester filament yarn 5 is taken out from the package 6, it is passed through a tensor 7 and drawn between a supply roller system 8 and a drawing roller system 9. A post-drawn yarn 10 is obtained. The drawn yarn 10 is passed from the roller 9 through the turbulent flow nozzle 11, the yarn bending guide group 12, 12', 12'', and the buffer 13, then runs on the plate heater 14 under constant tension, and then from the draw-out roller system 15. The drawn yarn 10 is fed to a winding device 16, where the surface speed of the intermediate roller system 9 is adjusted to rotate at a higher speed than that of the drawing roller system 15, so that the drawn yarn 10 is kept under a constant overfeed. On the other hand, the guide groups 12, 12', 12'' (a three-stage guide is shown in the figure, but this may also be a two-stage guide) are treated with the turbulent flow nozzle 11 to form a slack.
It plays the role of keeping the air under overfeed when it passes through the turbulent nozzle 11, and at the same time keeping it under tension on the plate heater. Moreover, since this guide group bends and presses the yarn that has been given slack and overhanging portions, the yarn does not jump on the plate heater, and a uniform heat treatment effect can be obtained. Of course, rotating rollers can be used instead of the guide groups 12, 12', 12'', but in this case, there will be significant disadvantages in terms of equipment costs and workability. It has a function of preventing the yarn from shaking (on the heater) due to the fluid ejected from 11. Another embodiment will be explained with reference to FIG.
After the undrawn filament 17 is removed from the package 18, it is passed through a pretension roller system 19,
20, the yarn is drawn between a supply roller system 21 and a large diameter portion of a take-up roller 22 constituted by a stepped roller, and becomes a drawn yarn 23. This drawn yarn 23
is the turbulent flow nozzle 2 from the large diameter part of the take-up roller 22.
4. After passing through the yarn bending guide 25 and the buffer 26, the yarn 29 runs in a fixed length through the slit heater 27 and is turned around the yarn path by the guides 28 and 28'.
is supplied to the winding device 30 from the small diameter portion of the take-up roller 22. Here, since the large diameter portion of the take-up roller 22 has a higher circumferential speed than the small diameter portion, the drawn yarn 23 is processed by the turbulence nozzle 24 under a constant overfeed to form a slack. Furthermore, even one stage of the bending guide can maintain the target slit heater 27 under tension. In the above example, an undrawn yarn is used as a starting yarn, which is stretched, and the yarn is successively subjected to turbulence treatment and heat shrinkage treatment to achieve a boiling water shrinkage rate of 15% or less. Instead of the yarn, a drawn yarn having a boiling water shrinkage rate of 15% or less is used in the intermediate roller system 9 or 9 of FIG.
It may also be fed directly to the processing zone from the take-off roller system 22 shown. Furthermore, the multifilament yarn, which has been given slack in advance, may be subjected to heat shrinkage treatment under constant tension on the plate heater 14 of FIG. 8 or in the slit heater 27 of FIG. 9. In short, it is important to give the filament yarn as much slack as possible while preventing the occurrence of Cournode loops (3 in Figure 5) as much as possible. It is necessary to maintain the air pressure, overfeed amount, and processing speed within a certain range. At the same time, the thread tension during heat shrinkage treatment to eliminate this slack is also critical. In other words, the tension of the yarn on a plate heater or in a slit heater is less than the stress of dry heat shrinkage (when the entire yarn is subjected to free heat shrinkage).
If treated under these conditions, the yarn as a whole will shrink, and the desired swelling will not occur even in subsequent boiling water treatment. Therefore, in the present invention, this yarn tension (the tension between the plate heater and the pull-out roller or the tension between the slit heater and the first yarn guide) is maintained at at least 0.02 g/de or more. It is desirable to do so. On the other hand, the thickness and number of slacks are also quite important, and this can be explained using Figure 10.
When a load of g/de is applied, the apparent length _L1 of sag is 1 to 15 mm, and the height H is 0.5 to 3.5 mm, and it is appropriate that there be at least 3 sag per 1 cm. It is. Furthermore, from the viewpoint of uniformly dispersing slack, it is preferable that at least 20% or more of the single fibers constituting the multifilament yarn have slack. Among these requirements, the apparent length L is particularly important; if this is less than 1 mm, fine crimp, for example, a woolly odor will appear, and a sufficient swelling effect cannot be expected. In addition, in order to shrink and eliminate sag, it is necessary to maintain the temperature and processing time of the plate heater or slit heater within an appropriate range; the former is generally 130 to 250℃, and the latter is 0.01 to 0.1℃.
You can choose from a range of seconds. In this way, the heat-treated yarn with the slack removed is supplied to a winding device and wound up. As the winding device, in addition to the ring twisting machine shown in the figure, a friction-driven bobbin may be used and there are no particular restrictions. . As mentioned at the beginning, the latent bulky multifilament yarn produced by the present invention has an appearance that is no different from ordinary unprocessed filament yarn, but due to the action of heat, the yarn's cross section and longitudinal direction change. It is characterized by partial shrinkage, swelling of the thread as a whole, and a squeaky feeling. Therefore, the stage at which such characteristics are obtained can be arbitrarily determined during the process of obtaining the final product. For example, the yarn may be passed through boiling water with overfeeding at the yarn stage, or treated with boiling water in the skein state, or may be subjected to shrinkage treatment at the scouring and dyeing finishing stages after being knitted or woven.
Furthermore, when the filament yarn is made of polyester, it is also useful to subject it to a known alkali weight loss treatment to further increase the interfiber voids. As described above, according to the present invention, it is possible to make the single fibers constituting the multifilament yarn more distinct and between the single fibers, thereby imparting a uniform heat shrinkage difference. Moreover, in the manufacturing process, it is essential to heat-shrink the filament yarn with slack under tension, so the yarn runs smoothly and is well suited for high-speed processing that requires high tension. In addition to improving the yarn's primary yield point, there is a trend toward improving the yarn's primary yield point. Further, since such yarns are apparently straight and have a smooth surface, there is an advantage that there is no concern that any trouble will occur when handling the yarns during the process from winding to knitting. Moreover, finishing and dyeing and scouring treatments are essential for knitted fabrics, but by simply shrinking the threads during these treatments, a smooth, supple, and full silk-like product can be provided. Example 1 Using the process shown in FIG. 8, processing is carried out under the conditions shown in Table 1, and the obtained latent bulky yarn is used to manufacture a palace fabric under the design conditions shown in Table 2. Table 3 shows the evaluation results for fabric quality and other aspects when this palace fabric was dyed using Dayanix Yellow GR-E (Cl Dispers Yellow 60) dye. Table 1 (Processing conditions) (1) Undrawn yarn 5 Polyethylene terephthalate undrawn yarn 143de/36fil (triangular cross section) (2) Supply roller system 8 surface speed 170m/min (3) Stretching roller system 9 surface speed 500m/min min (4) Stretching magnification 2.933 times (5) Boiling water shrinkage rate of drawn yarn 6.7% (6) Pull-out roller system 15 surface speed 465 m/min (7) Turbulent flow nozzle Figure 3 of Japanese Patent Publication No. 1175/1975 (Pneumatic pressure 1Kg/cm ² ) (8) Overfeed rate of yarn when passing through turbulent nozzle
7% (9) Plate heater 14 A Temperature 200℃ B Effective heating length 36cm (10) Yarn tension between plate heater 14 and pull-out roller system 15 0.06 g/de (11) Winding device Ring twisting machine (A) Spindle rotation speed 7000rpm (b) Tension 0.16g/de (12) Appearance of drawn yarn after passing through turbulence nozzle 11
Only sagging is observed (a) Size of sagging (average)
H=0.7mm, L=6mm (b) Density of slack (average) 5 pieces/cm Table 2 (fabric design and finishing conditions) (1) Thread used _Warp S300t/m, Weft ^SZ 2000t/m (2 ) Two reeds with a density of 19.8 birds/cm (3) Latitude Density 39.6 birds/cm (4) Relax Continuous scouring machine at 95℃ x 10 minutes (5) Preset 180℃ x 45 seconds (6) Alkali weight loss 35g /, 100℃ Weight loss rate 20.7% (7) Dyeing Uniace (Nippon Dyeing Machinery)
(manufactured) at 130℃ x 45 minutes (8) Final set 160℃ x 45 seconds (9) Finishing density Warp 67.5 lines/cm, Weft 40 lines/cm

[Table] Comparative Example 1 In Example 1, the turbulent flow nozzle 11, guide group 12, 12', 12'', buffer 13, and plate heater 14 were removed, and instead, a 4.0 cm diameter
A 180°C heating roll was installed to subject the drawn yarn to instant heat treatment. In addition, the roll and pull-out roller system 15
The thread tension between the two was 0.001 g/de. Table 4 shows the process stability, the appearance of the heat-treated yarn, and the properties of the fabric obtained from the heat-treated yarn in the same manner as in Example 1.

[Table] As is clear from the above table, the weavability of the fibers obtained by stretching the single fibers during heat treatment to form loops and slacks and having a good feel and texture is poor in weavability. On the other hand, those with few loops and sagging have good weavability but poor process stability and texture. In order to improve this weavability, 20g/de of filament yarn after heat treatment was used.
The yarn was run at 60 m/min on a plate heater (effective contact length: 4 cm) heated to 210° C. under the tension of 100° C. to eliminate slack and loops, thereby obtaining a substantially straight filament yarn, from which a woven fabric was obtained. In this case, the weavability was improved as well as that of ordinary filaments, but the woven fabric treated with boiling water had poor swelling, and it was observed that the squeak, stiffness, etc. characteristic of silk were rapidly reduced. Comparative Example 2 The same operation as in Example 1 was carried out except that the overfeed rate of the drawn filament yarn when passing through the turbulent flow nozzle 11 in Figure 8 of Japanese Patent Publication No. 34-8969 was changed to 15% and the compressed air was changed to 5 kg/cm ² . I went. The yarn taken out from the turbulent flow nozzle 11 contained a mixture of Cournoud loops and slack or overhang, with the former at a rate of 40% and the latter at a rate of 60%. The surface of the yarn heat-treated on the plate heater 14 has 10 protrusions/cm.
The texture and feel were rough and hard. Example 2 Using the process shown in Figure 9, processing was carried out under the conditions shown in Table 5, and using the obtained latent bulky yarn,
Table 6 shows the evaluation results when the palace fabric was manufactured under the conditions shown in Example 1 and Table 2. Table 5 (1) Undrawn 17 Polyethylene terephthalate undrawn yarn 143de/36fil (triangular cross section) (2) Surface speed of supply roller system 21 271 m/min (3) Surface speed of large diameter part of drawing roller system 22
800m/min (4) Stretching ratio 2.95 (5) Boiling water shrinkage rate of drawn yarn 13% (6) Surface speed of small diameter part of drawing roller system 22
784m/min (7) Turbulent nozzle 24 The one shown in Figure 3 of Japanese Patent Publication No. 37-1175 Pneumatic pressure 2Kg/cm ² (8) Overfeed rate of yarn when passing through turbulent nozzle
2% (9) Slit heater 27 Temperature 180℃ Effective heating length 30cm (10) Yarn tension between slit heater 27 and first guide 28 0.07g/de (11) Winding device 30 Ring twisting machine Spindle rotation speed 10000rpm Tension 0.4g/de (12) Appearance of drawn yarn after passing through turbulence nozzle 24
Only sag is observed Sag size (average) H = 0.9 mm, L = 11 mm Density of sag (average) 8 pieces/cm Table 6 Process stability Breakage rate 0.3% (n = 1000) Winding yarn Primary yield Strength 2.6g/de Appearance Almost straight yarn Weavability Good Fabric No staining spots (warp lines) Touch, feel Large bulge, soft Drapability Good Creep test 0.3%

[Brief explanation of the drawing]

Figure 1 is an external view of a thermoplastic multifilament yarn with slack and overhanging parts. Figure 2 is a graph to explain the difference in shrinkage that occurs within the same yarn. Figure 3 is a tension heat treatment of the yarn in Figure 1. External view after
Figure 4 is an enlarged view of the single fibers that make up the yarn in Figure 3;
Figure 5 is an external view of thermoplastic multifilament yarn with Courno loops after tension heat treatment;
Figure 6 is an external view of the yarn shown in Figure 3 after being relaxed in boiling water, Figure 7 is an external view of a thermoplastic multifilament yarn with intermittent slack and overhanging parts, and Figures 8 and 9 are FIG. 10, which is a schematic diagram showing an embodiment of the present invention, is an explanatory diagram of the size of slack and overhang of the thread in FIG. 1 or FIG. 7.

Claims (1)

[Claims] 1. There are substantially no Cournoud loops on the yarn surface,
By heat-treating the intertwined yarn of thermoplastic multifilament having only sagging and overhanging parts at a rate of 0.02 g/de or more at a temperature of at least 130°C under a tension that does not deform and erase the sagging and overhanging parts, the entire yarn is A method for producing a potentially bulky multifilament yarn is characterized in that, while performing tension heat treatment, only the slack and overhanging portions are freely contracted and eliminated to make them into a substantially straight state. 2. A method for producing a potentially bulky multifilament yarn according to claim 1, wherein the slack and overhanging portions are obtained by fluid entanglement treatment. 3. A method for producing a latent bulky multifilament yarn according to claim 1, wherein the interlaced yarn has 50 or more entangled points/m. 4. A fluid entangling nozzle and a heat treatment heater are provided in this order between a delivery roller and a take-up roller that rotates at a speed lower than the surface speed of the roller, and between the nozzle and the heat treatment heater, a bending roller is provided while pressing the yarn. A running guide is installed, and in the treatment zone by the fluid entanglement treatment nozzle, the yarn is relaxed and virtually no Cournoud loops occur.
Only sagging and overhanging parts are formed on the yarn surface,
1. An apparatus for producing latent bulky multifilament yarn, characterized in that the yarn is kept under tension in a treatment zone using a heat treatment heater. 5. An apparatus for producing a latent bulky multifilament yarn according to claim 4, wherein the sending roller and the take-up roller are stepped rollers. 6. The apparatus for producing a latent bulky multifilament yarn according to claim 4, wherein the heat treatment heater is a non-contact heater.