JPS6211096B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a marbled yarn of a thermoplastic synthetic fiber multifilament having fine gaps and non-periodic spots in the fiber axis direction, and a method for producing the same. A number of methods for producing drawn uneven yarns have been provided in the past, such as a method in which drawing unevenness is generated by drawing an undrawn yarn using a cold drawing pin at a drawing ratio below its specific draw ratio, There is a method in which stretching is performed in a state in which a gear is pressed and a part of the material is stretched in a step to generate stretching unevenness. In these methods, the aim is to create a slab effect by creating stretching unevenness and taking advantage of the difference in dyeability between the stretched areas and the insufficiently stretched areas. On the other hand, the quality was not constant and the slab was long. In particular, from the standpoint of quality, the length of the darkly dyed spots is generally around 20 mm or longer, and even with conventional manufacturing methods, one cannot expect finer periods than this. Nakatsuta. It is an object of the present invention to provide a marbled yarn having extremely short deep dyed spots, which have never been seen before, and a method for producing the same. While conducting various studies to achieve the above object, the present inventors discovered that undrawn or semi-drawn yarn exhibits a peculiar behavior when drawn. When an undrawn yarn or a semi-drawn yarn is drawn, it is normal that the drawing starts from the stress-weaker parts and spreads in sequence. However, if there is a stress concentration point where stress is concentrated at one point, stretching will start from that point as well, and if many stress concentration points occur at a minute interval, they may occur at the same time or with a slight time lag. However, the present invention was achieved by obtaining the knowledge that stretching progresses in a finely dispersed state and by utilizing intertwined points as stress concentration points. Thus, according to the present invention, (1) dark-dyed spots and light-dyed ground threads that have 25 or more residual entanglement points per meter and are minutely spaced and aperiodic in the fiber axis direction; It consists of
The length of the darkly dyed spots is 12.0 mm or less, and the proportion of this total (length) to the entire yarn is 5% or more.
A marbled yarn characterized in that it is 80% is provided. To explain the present invention in more detail, it is important to give a large number of intertwining points to the undrawn yarn or semi-drawn yarn using a fluid jet nozzle in advance and then perform incomplete stretching. However, the state of stress concentration changes after the glass transition point of the thread. That is, when the preheating temperature is around or below the glass transition point, each interlacing point becomes a stress concentration point during stretching, and stretching starts reliably from the interlacing point, although the number is the same as the number of interlacing points or is slightly reduced. Here, along the yarn axis direction, these intertwined points are also in a completely entangled state, incompletely entangled points that tend to come undone, and furthermore, there are cases where the fibers are simply intertwined, which is not suitable to be called an intertwined point, and there are non-entangled states that are not entangled at all. Various parts such as intertwined parts coexist, but when the yarn is completely stretched, stretching starts from the completely intertwined part, progresses to the incomplete intertwining point, and then progresses to a mere degree of interlacing, and finally the non-entangled part is stretched. When the drawing is completed, a drawn yarn with only the interlacing points remaining is produced, but when the yarn is completely drawn in this way, the marbled yarn of the present invention cannot be obtained. The point of the present invention is to finish the stretching in the middle, so that the fully entangled part has already finished stretching, but the incompletely entangled part includes some parts that have finished stretching and some parts that have not finished, and non-entangled parts. , it remains as it is without being stretched at all. In this way, the stretched portion, semi-stretched portion, and unstretched portion can be freely selected by changing the degree of entanglement in the fluid treatment, and the marbled yarn of the present invention is thus obtained. On the other hand, if the temperature of the preheated heating roller is set to far exceed the glass transition temperature, the stretching from the completely entangled point mentioned above will not take place, but on the contrary, stretching will begin from the non-entangled point, and at the final stretching time, the fully entangled point will be stretched. In this case as well, if the stretching is stopped midway through, a yarn containing a mixture of fully stretched parts, semi-stretched parts, and unstretched parts will be produced. In this way, depending on the degree of temperature setting of the preheating heating roller, there is a difference whether the stretching starts from the interlaced points or vice versa, but in any case, the stretching is started from the pre-treatment fluid injection nozzle. The combination of entanglement treatment and incomplete stretching is important. The reason why stretching starts from the completely entangled point when the preheating temperature is lower than the glass transition temperature is considered to be as follows.
In other words, when the preheating temperature is low, stress concentration occurs at the intertwined points, and stretching proceeds back and forth from that point.When the stretching reaches a certain point and the stress becomes strong, stress concentration occurs at the half-interlaced points, and stretching occurs, and finally In this case, the unentangled portion where stress concentration is less likely to occur is stretched. On the other hand, in stretching when the preheating temperature greatly exceeds the glass transition temperature, the stretching stress is low and stress gradients are difficult to form.
The intertwined parts are tightly tightened due to heat shrinkage, making them stronger in terms of stress than non-intertwined parts. Therefore, the stretching proceeds from the unentangled portions where the stress is weaker. Although these are contradictory phenomena, by intertwining undrawn or semi-drawn yarns and subjecting them to incomplete stretching, it is possible to produce yarns with extremely fine irregularities. In addition, in terms of yarn structure, if the preheating temperature is below the glass transition temperature, the unentangled part a will be the unstretched part and the intertwined point b will be the stretched part, as shown in Figure 3A.
Above the glass transition temperature, as shown in FIG. 3B, the intertwined part b' becomes an unstretched part and the unentangled part a' becomes a stretched part, and the difference in dyeing between the two forms a frosted state. Next, a specific example for obtaining the marbled yarn of the present invention will be described. In the process shown in FIG. 1, the undrawn yarn or semi-drawn yarn 1 is supplied to the fluid jet nozzle 4 from the supply roller 3 via the guide 2, and after being entangled, it passes through the guide 5 to a pair of preheating rollers 6 and a separate roller 7. It is stretched unevenly between a pair of stretching rollers 8 and a separate roller 9, and then the heat-fixing plate 1 is stretched as necessary.
The film is heat-treated at 0, and then reaches a winding device 13 via a pair of take-up rollers 11 and a separate roller 12. Here, the fluid ejecting nozzle may be a taslan nozzle that generates a large number of loops, an interlace nozzle whose main function is interlacing, or any other fluid nozzle as long as it creates a large number of interlacing points. The degree of entanglement in the method of the present invention refers to the degree of complete entanglement, and is calculated by the following measurement method. After taking a sample of about 1 m and suspending it with a load of 0.1 g/d, mark a sample length of 25 cm and prepare a temperature of 50° ± 5°C.
After floating in hot water for 30 seconds, immediately calculate the number of completely entangled parts per reading meter. In addition, the following table shows the distinction between completely entangled areas, incompletely entangled areas, and non-entangled areas.

[Interlaced stretching conditions]

(B) Supply roller 3 speed 282m/min (B) Preheating roller 6 speed 273m/min (C) Stretching roller 8 speed 600m/min (D) Take-up roller 11 speed 660m/min (E) Fluid injection nozzle pressure 4
3Kg/cm ² (degree of entanglement 150 wires/meter) (F) Preheating roller surface temperature 70℃ (G) Shrink plate surface temperature 200℃ (H) Stretching ratio 2.1 (70% of the specific stretching ratio) The obtained yarn is 72 denier 36 filament, residual entanglement degree is 100 pieces/meter, boiling water shrinkage rate is
It was 12%. This was dyed in tube knitting and then unraveled, and the average length of the darkly dyed part was 1.4 mm, and the overall dyeing ratio was 30%, making it a good marbled yarn. Example 2 Using the same material and the same equipment as in Example 1, processing was performed under the same processing conditions by changing only the pressure of the fluid injection nozzle. The results are shown in the table below. , almost no marbling effect was obtained.

[Table] Example 3 Undrawn polyethylene terephthalate yarn as supply yarn
150 denier 36 filament (specific draw ratio 3
polyethylene terephthalate semi-drawn yarn 110 denier 36 filament (specific draw ratio 1.5
The marbled yarn obtained was processed using the apparatus shown in Figure 1 under the following processing conditions.
pieces/meter, the average length of the dark dyed part was 2.5 mm, and the ratio of the dark dyed part to the whole was 40%, resulting in a good marbled yarn. (B) Supply roller speed 378m/min (B) Preheating roller speed 363m/min (C) Stretching roller speed 600m/min (D) Take-up roller speed 600m/min (E) Fluid injection nozzle pressure
3.0Kg/cm ² (degree of entanglement 120 wires/meter) (F) Preheating roller surface temperature 70℃ (G) Shrink plate surface temperature 200℃ (H) Stretching ratio 1.58 (52.7% of specific stretching ratio)

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing one embodiment of the present invention, Fig. 2 is a graph showing the degree of residual entanglement and the average length of the darkly dyed part obtained by the fluid jet treatment, and Fig. 3 is a graph showing the average length of the darkly dyed part obtained by the present invention. It is an enlarged schematic diagram of a marbled thread. a... Unstretched part (unentangled part), b... Stretched part (entangled part), a'... Stretched part (unentangled part), b'... Unstretched part (entangled part), 1... Not yet Stretched yarn, 2... Guide, 3... Supply roller, 4... Fluid injection nozzle,
5...Guide, 6...Preheating roller, 7...Separate roller, 8...Stretching roller, 9...Separate roller, 10...Shrink plate, 11...Take-up roller, 12...Separate roller, 13... Winding device, 14...marbled yarn.

Claims (1)

[Scope of Claims] 1. It has 25 or more residual entanglement points per meter, and is composed of dark dyed spots and light dyed ground threads that are non-periodic and have minute gaps in the fiber axis direction. A marbled yarn characterized in that the length of the darkly dyed spotted portion is 12.0 mm or less, and the ratio of this total (length) to the entire yarn is 5% to 80%. 2. Production of marbled yarn characterized by subjecting an undrawn yarn or semi-drawn yarn made of thermoplastic synthetic fibers to a fluid treatment to impart inter-fiber entanglement, and then drawing the yarn at a stretching ratio that leaves an undrawn portion. Method.