JPS6136098B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing spun yarn from undrawn polyester yarn. Polyester continuous multifilament yarn is widely used in the clothing field due to its excellent fiber properties, but compared to spun yarn, it has a cold feel or a unique slimy feel, and fabrics woven and knitted with it have a It has the disadvantage of poor heat retention and lacks warmth in both texture and appearance. To this end, various attempts have been made to produce fluffed yarns that have the appearance, feel, and heat retention properties of spun yarns and have a high degree of uniformity by intermittently cutting the constituent filaments of continuous multifilament yarns. There is. For example, a method of intermittently cutting a part of the constituent filaments of a continuous multifilament yarn in a twisted state or in the process of being twisted using a scraper or cutter (edge, etc.), or physical properties such as breaking strength and elongation. A method is known in which a plurality of multifilament yarns with different values are mixed and processed under conditions such that some or all of the multifilament yarns that are easy to break are cut. However, according to these methods, the condition of the fluff varies due to changes over time due to wear of the abrasive body for cutting the filament and differences in the abrasive body between the spindles, and it is extremely difficult to constantly control these factors. . In addition, when using multiple multifilament yarns with different physical properties such as breaking strength and elongation, there is a problem that the yarn cost increases due to the processing of foreign material yarns. Because of this difference in yarn structure, the spun yarns do not come close to the natural unevenness, appearance, and feel of spun yarns. As a result of intensive studies on these problems, the inventors of the present invention have arrived at the present invention and have overcome the drawbacks of the conventional methods. The present invention has the following configuration to achieve the above object. That is, in the present invention, an undrawn polyester yarn composed of at least 50 monofilaments is drawn and false-twisted, then subjected to a secondary heat treatment without substantial relaxation, and then continuously or discontinuously placed in a draft zone. This method of producing a spun yarn is characterized by supplying the yarn, pulling and cutting it, and then converging and entangling it. The present invention will be explained below with reference to the drawings. The drawings are for illustrative purposes only, and changes may be made without departing from the spirit of the invention. In FIG. 1, an undrawn polyester yarn Y consisting of at least 50 monofilaments is unrolled from a package 1 and fed through a guide 2 to a first feed roller 3. Here, the reason why the number of monofilaments constituting the undrawn polyester yarn Y is set to be at least 50 is that more than 50% of the filaments in the inner layer are covered by the outer filaments and are not damaged at all in the yarn after drawing and false twisting. In addition, the filaments in the outer periphery undergo large elongation and are locally severely damaged by making use of the large number of filaments. This is to facilitate cutting in the draft zone, and to make the number of fibers constituting any cross section of the yarn after drafting to be 20, preferably 25 or more. In addition, the use of undrawn yarn is aimed at reducing costs by omitting the drawing process by drawing and false-twisting the yarn, and also because it creates a denier difference due to the arrangement of the monofilaments in the false-twisting state (the more the outer periphery is This is because the fibers at the outer periphery are flattened (the higher the magnification is, the thinner the fibers become), thereby simultaneously giving a cross-sectional deformation effect similar to the shape unevenness in the longitudinal direction of individual single fibers that ordinary natural fibers have. Further, the fineness of the monofilament may be appropriately selected depending on the intended use.For example, 1.4 denier is generally used, but 3 denier or more is preferable in order to maintain the stiffness of the fabric. Furthermore, the polyester component forming the polyester fiber used in the present invention is one having ethylene terephthalate units as a main constituent unit, and usually includes copolyesters or homopolyesters containing 85 mol% or more of ethylene terephthalate units, or copolyesters or homopolyesters thereof. It is a polyester mixture. Copolymer components other than terephthalic acid and ethylene glycol include isophthalic acid,
Examples include 2,6 naphthalene dicarboxylic acid, adipic acid, sepacic acid, oxalic acid, diethylene glycol, propylene glycol, cyclohexanedimethanol, P-oxybenzoic acid, or derivatives thereof. Further, in the present invention, it is preferable that the monofilament has an intrinsic viscosity (a value measured at 30° C. of a mixed solution of phenol:tetrachloroethane=6:4, hereinafter referred to as "IVf") smaller than 0.48. This is to give the obtained spun yarn anti-pilling properties, and to easily cause a decrease in strength by false twisting using a friction false twisting device, so that it can be draft cut in a normal draft zone. In other words, the IVf of ordinary polyester filament is generally 0.58 to 0.63;
When a fluffed yarn is produced using a polyester filament with a high filament strength, the filament may be cut unevenly in the draft zone due to its high filament strength and elongation, or even if the filament is cut, the fluffed end will become a pill when rubbed against a cloth. It is easy to do so. To prevent this, for example, it is possible to use a friction false-twisting device that has a special rough surface with extremely uneven friction surfaces, which is used in the false-twisting process described later, but it is still insufficient, and such Those with a rough surface have a problem in that the surface condition changes greatly over time, so differences between weights and differences over time are likely to occur. On the other hand, undrawn monofilament polyester yarn with an IVf of less than 0.48 is easily cut when pulled even by a friction false twisting device that has a smooth contact surface with ordinary yarn, and has poor pill resistance. This makes excellent spun yarn. However, if the IVf is extremely low, such as less than 0.30, there will be more winding due to filament breakage in the spinning process and yarn breakage in the false twisting process, so it is better to have an IVf of 0.30 or more and 0.35 or more. By the way, the undrawn polyester yarn Y is fed to the second feed roller 6 through the first feed roller 3, during which time it is false twisted and simultaneously stretched by the friction false twisting device 5. The undrawn polyester yarn is false-twisted by the friction false-twisting device 5, so that each monofilament is given crimps, swirlability and damage. The monofilament of the skin also suffers some damage due to the migration effect and ends up being cut by traction. The portion of the rotary plate 5' that comes into contact with the undrawn polyester yarn must be considered to cause moderate damage. If possible, the strength of the false twisted yarn is preferably 0.8 g/denier or less, more preferably 0.6 g/denier or less. In the present invention, a friction false twisting device is used as a false twisting means, and the figure shows a disk type device as an example. Next, the false twisted yarn _Y2 is subjected to a secondary heat treatment by the heater 7 without being substantially relaxed between the feed roller 6 and the third feed roller 8. This suppresses the excessive crimp of the monofilament that makes up the false twisted yarn Y ₂ , leaving a suitable degree of turning ability, and reducing the unevenness of strong elongation in the longitudinal direction, allowing for draft cutting in the next draft zone. In addition, the quality is suitable for further focusing and entangling. In other words, if there is excessive crimp, the parallelism of the fibers after draft cutting is disturbed and the yarn quality deteriorates, and the draft cutting action in the draft zone is unstable and local traction spots are likely to occur. , furthermore, the focusing and entanglement is not performed sufficiently. In other words, the binding effect of the fluff fibers that bind the main bundle fibers of spun yarn Y ₃ is low, and the binding angle, binding interval, number of bundles, etc. of the fluff fibers with respect to the main bundle fibers are irregular. , the strength of the spun yarn is low and it becomes partly transparent. In addition, it is necessary to have appropriate swirlability in order to provide convergence without causing excessive fuzz. In other words, if the constituent monofilaments have swirling properties, the monofilaments become intertwined with each other to improve convergence, and the fluff ends protruding from the surface are also wound around the yarn body due to the swirling properties of the monofilaments. It will start to stick. The false twisted yarn _Y1 is then supplied to a draft zone A that includes a back roller 9, an apron roller 10, and a front roller 11, and almost all of the constituent monofilaments are draft-cut in the longitudinal direction. Therefore, in order for the monofilament to be smoothly drafted and cut in the draft zone, the monofilament must have few irregularities in strong elongation, and the converging portion where the monofilaments are not separated and the entire monofilament must be highly twisted. It is preferable that there is no twisted untwisted portion. Of course, the false twisted yarn Y ₁ supplied to the draft zone A may be substantially untwisted or twisted so as not to hinder drafting. In draft zone A, the false twisted yarn Y ₁ is given a draft greater than its elongation at break, causing its constituent monofilaments to break. Apron roller 10 as shown in the diagram
It is preferable to adopt this method from the viewpoint of controlling stray fibers. The draft cut yarn is then collected and entangled in the entanglement zone B by the collection and entanglement device 12. It is preferable that the focusing and entangling device 12 has suction and rotation functions. The spun yarn Y ₃ is then formed into a package 14 by means of a drum 15 . 16 and 17 are guides. Figure 2 shows false twisted yarn that has undergone secondary heat treatment.
This figure shows a device that aligns Y ₁ ′ and Y ₁ ′, drafts cuts them, and converges and entangles them. The description of the process is the same as in the case of FIG. 1' and 1'' are the package, 14' is the package, 15' is the drum, and 18, 19 are the guides.As described above, according to the method of the present invention, polyester undrawn yarn can be made from undrawn polyester yarn with bulky properties, excellent texture, and moderate A spun yarn with excellent fluff and excellent strength is produced at high speed.Example 1 An undrawn polyester yarn (1380 denier/313f) with an IVf of 0.38 was processed under the following conditions.Conditions: Friction false twisting device ; Three ceramic discs with a rough surface of 3S are attached to each axis of a three-axis type, for a total of nine discs Heater 4: 0.3m x 115℃ Processing speed: 75.7m/min False twist feed ratio: (V ₁ -V ₂ ) x 100/V ₁ = 3.25 where V ₁ is the surface speed of the first feed roller, V ₂ is the surface speed of the second feed roller. Speed of disk periphery/yarn speed: 1.8 Secondary heat treatment; 0.5 m x 170 °C Feed ratio; V ₃ - V ₂ /V ₃ ×100 = -4% However, V ₃ is the third feed roller. Draft in draft zone A: 2.8 times the distance between the crawler 9 and the front roller 11;
300m/m Feed ratio in entanglement zone B: +5% Focusing and entanglement device: Nozzle with suction and swirling ability Air pressure: 3.0Kg/cm ² G Strength of the false twisted yarn obtained under these conditions is 298g, the average breaking strength and elongation of the monofilament is 0.7g/denier, 6%, and the spun yarn is 35′ ^S
(English style), almost all of the constituent monofilaments are draft cut, and the average cut length is 125 m/
It was m. This spun yarn has fluffy ends tightly bound to the yarn body, and the yarn strength is 210g.
There were no problems in post-processes such as turning, and the fabric knitted and woven with this spun yarn had a moderate amount of fluff, was bulky, and had an excellent texture. Furthermore, in terms of pilling resistance, this fabric exhibited much better properties than ordinary ester cotton blended spun yarns. Example 2 The false twisted yarn (425 denier/313f) obtained in Example 1 was wound around a paper tube to form a package 1′,
1" was formed. The false twisted processed yarns Y ₁ ', Y ₁ " unwound from the packages 1', 1" were aligned and draft cut using the apparatus shown in Fig. 2, and then converged and entangled to be spun. Yarn was manufactured. In this case, the back roller 9 and the front roller 1
The distance to No. 1 was 300 mm, and the draft was 5.0 times. The yarn quality was as follows, and was softer and more bulky than ordinary spun yarn.

[Table] Here, U% is measured using an Evenes Tester Type B head manufactured by Zwelvega.

[Brief explanation of the drawing]

The figures relate to the present invention; FIG. 1 is a side view showing one example of an apparatus for carrying out the invention, and FIG. 2 is a side view showing another example. 3...First feed roller, 4...Heater,
5...Friction false twisting device, 7...Heater, 12...
Focusing entanglement device.

Claims (1)

[Claims] 1. An undrawn polyester yarn composed of at least 50 monofilaments is drawn and false-twisted, then subjected to a secondary heat treatment without substantial relaxation, and then continuously or discontinuously subjected to a draft zone. A method for producing a spun yarn, which comprises supplying the yarn to a spun yarn, draft cutting it, and then converging and entangling it. 2. The method for producing a spun yarn according to claim 1, wherein the monofilament has an intrinsic viscosity of less than 0.48.