JPH0329900B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a method for producing a composite spun yarn in which sheath fibers are twisted and wound around a core fiber, particularly a strong spun yarn using an aromatic polyamide fiber as the core fiber. Specifically, by completely covering aromatic polyamide fibers with appropriate staple fibers selected from natural fibers and/or synthetic fibers, the disadvantages of aromatic polyamide fibers can be compensated for, and the range of applications thereof can be greatly expanded. The present invention relates to a method for producing a composite spun yarn with a core-sheath structure that can be realized. (Prior Art) Aromatic polyamide fibers have been highly evaluated as high-strength organic fibers suitable for various industrial applications such as ropes, cables, safety protection fabrics, and coating base fabrics. However, although the aromatic polyamide fiber has characteristics such as high strength, high cutting strength, and heat resistance, it also has disadvantages, which are a major hindrance to expanding its use. In other words, aromatic polyamide fibers are subject to severe discoloration and fading, and it is unavoidable that the discoloration occurs immediately when exposed to the outside air.For this reason, the development of applications tends to be limited to industrial and work use, making it difficult for the general public to accept it. That is the reality. Therefore, the idea was to cover the aromatic polyamide fibers with other fibers to solve the above-mentioned problem of discoloration and fading. However, even if one tries to manufacture this composite yarn by the usual ring traveler method, it is impossible to obtain the desired one completely covered with aromatic polyamide fibers, or even if it is possible, it is extremely difficult. Yes, it is accompanied by all kinds of problems in spinning. (Problems to be Solved by the Invention) In the above-mentioned composite spun yarn having a core-sheath structure, it is a fatal problem that the aromatic polyamide fiber in the core portion is not completely covered and a bare portion remains. That is,
When such a composite spun yarn is made into a woven fabric, the bare parts are exposed in some places and even if dyed, these bare parts remain undyed, resulting in a severe loss of commercial value. Therefore, in order to achieve good dyeing, it is necessary to use a two-bath dyeing method, but this requires troublesome labor and a large amount of time. Therefore, the present inventors have found that it is appropriate to adopt the DREF method as a means to completely and strongly cover the aromatic polyamide fiber in the core when spinning this composite spun yarn. Ta. this
The DREF method is described in Japanese Patent Application Laid-Open No. 56-53213, and it is certain that its mechanism is extremely effective in producing all kinds of composite spun yarns. It was extremely difficult to spin a composite yarn coated with aromatic polyamide fibers. That is, when the core fibers and the sheath fibers are supplied through their respective supply paths to between a pair of suction drums that are the yarn forming section, there is a deviation in the overlapping state of both the core and sheath fibers, as shown in FIG. If this happens, sufficient coverage becomes impossible, and the resultant product is a defective composite yarn with many bare parts. The present invention makes full use of the characteristics of aromatic polyamide fibers such as high strength and high cutting strength, and then completely and strongly uses staple fibers selected from natural fibers and/or synthetic fibers. The object of the present invention is to provide a manufacturing method for obtaining a composite spun yarn having a core-sheath structure that solves the problem of discoloration and fading by coating and can be dyed favorably by a one-bath dyeing method. (Means for Solving the Problems) In order to achieve the above object, the method for producing a composite spun yarn of the present invention has the following configuration.
That is, when manufacturing a composite spun yarn with a core-sheath structure in which a core made of aromatic polyamide fiber filaments or spun yarns is covered with staples of natural fibers and/or synthetic fibers, the sheath fibers are stretched for coating fibers. From the mechanism, the core fiber is moved from the core fiber supply path to the sheath fiber, at least one of which can be adjusted in position in a direction perpendicular to the thread running direction, and the overlapping state of both fibers is adjusted by adjusting the mutual position. The fibers are passed through the fiber guide and the core-sheath fiber guide, respectively, and then supplied to the merging guide disposed just before the front roller of the stretching mechanism, and then the two fibers rotate in the same direction in close contact with each other. JIS L 1095
7.10.2 This is a method for producing a composite spun yarn with a core-sheath structure, the gist of which is to produce a composite yarn with an abrasion strength of 110 or more in the B method. (Function) The composite spun yarn obtained by the above method of the present invention has a complete and strong coating with no bare parts, and its abrasion strength is remarkable, so that the sheath part is not exposed during weaving. It does not peel off, and the one-bath dyeing method allows for even and beautiful dyeing. In other words, by employing the above-mentioned DREF method and using the unique manufacturing method of the present invention, a composite spun yarn with a core-sheath structure that is excellent as a spun yarn can be obtained while taking advantage of the characteristics of aromatic polyamide fibers. Hereinafter, embodiments of the present invention will be described in detail based on the drawings. (Example) FIG. 1 is an explanatory diagram showing an example of a composite spun yarn having a core-sheath structure obtained by the method of the present invention. In the figure, 1 is an aromatic polyamide fiber as a core fiber, and 2 is a staple fiber of a sheath portion, which is appropriately selected from natural fibers and/or synthetic fibers. First, the method for producing composite spun yarn according to the present invention will be explained based on FIGS. 2 and 3, which show an example of an apparatus for carrying out the method. In these figures, reference numeral 3 denotes a sheath fiber, ie, a roving, drawing mechanism that is composed of a plurality of pairs of rolls having a circumferential speed that increases in the yarn running direction. A sheath fiber guide 4 is disposed immediately in front of each of the plurality of roll pairs of the stretching mechanism 3. The fiber bundle, such as a sliver, pulled out from the can C is stretched while passing through the stretching mechanism 3 and the sheath fiber guide 4, and is supplied to the merging guide 6 just before the front roller 5. On the other hand, the filament or spun yarn of aromatic polyamide fiber, which is the core fiber 1, passes through the core fiber supply path 7 and the core fiber guide 8, and then passes through the above-mentioned merging guide 6.
It is now being supplied to Two parallel suction drums 9 that are close to each other and rotate in the same direction are arranged in parallel on the extension line of the stretching mechanism 3, and the core fibers 1 and sheath fibers (rough Immediately after the yarn) 2 leaves the nip point of the front roller 5, it is transferred to the suction drum 9.
The fleece of the sheath fibers 2 is wound around the core fibers 1 while being twisted by the rotation of the suction drum 9. The yarn thus formed is passed through the yarn drawing roll 1
0 in parallel to the axis of the suction drum 9. Furthermore, for the above-mentioned device, the core fiber guide 8
The position of at least one of the sheath fiber guide 4 and the sheath fiber guide 4 can be adjusted in a direction perpendicular to the thread running direction. As shown in FIG. 6, this is to stack the core fibers 1 and sheath fibers 2 in an optimal shape in the merging guide 6 just before the front roller 5, and then send them out to the front roller 5. The configuration is as follows: A. By fixing the core fiber guide 8 and adjusting the sheath fiber guide 4, the sheath fibers 2 are moved to the merging guide 6 according to the position of the core fiber 1 supplied to the merging guide 6. B. By fixing the sheath fiber guide 4 and adjusting the core fiber guide 8, the position of the core fiber 1 on the merging guide 6 is adjusted according to the position of the supplied sheath fiber 2. C. By adjusting both the core fiber guide 8 and the sheath fiber guide 4, the position of the core fiber 1 in the merging guide 6 and the corresponding supply position of the sheath fiber 2 are adjusted. There are three options: , and choose from these as appropriate. After conducting and comparing the three configurations mentioned above,
It is easier and more reliable to adjust the supply position of the sheath fibers 2 by adjusting the position of the sheath fiber guide 4 in accordance with the position of the core fibers 1 supplied to the merging guide 6 than configuration B. It was hot. Furthermore, more delicate adjustment is of course possible by the configuration of C. That is, it is preferable to make the positions of both the core fiber guide 8 and the sheath fiber guide 4 adjustable, since all of them can be implemented and the best form can be selected depending on the situation. As described above, various known means may be used as a mechanism for attaching the guides 4, 8 in a position adjustable in a direction perpendicular to the thread running direction. For example, a method using bolts and nuts as shown in FIG. 4A and B, that is, a bolt 12 is provided in the hole for attaching the guides 4 and 8 to the machine base 11, and the bolt 12 is tightened appropriately with a nut 13. Accordingly, the position of the guides 4 and 8 can be adjusted in the direction perpendicular to the thread running direction (arrow A). Regarding the sheath fiber guide 4, the stretching mechanism 3
Although they are arranged at multiple locations in the area, three locations in this embodiment, it is not necessary for all of them to be adjustable in position as described above, and only the one in front of the merging guide 6 is adjustable in position. A sufficient effect can be obtained. In the present invention, the natural fibers of the sheath include cotton, wool, linen, etc., and the synthetic fibers include polyester, polyamide, acrylic fiber, rayon,
Indicates acetate etc. When selecting sheath fibers from among these, it is preferable to consider the purpose of the present invention and select those that do not have problems with discoloration or fading, and furthermore, those that have excellent dyeability. In addition, abrasion strength is in accordance with JIS L 1095 General Spun Yarn Test Method 7.10 Abrasion Strength 7.10.2B method, using a yarn abrasion tester as shown in Figure 7, and applying a sample (yarn) to the tester at 2 gf/. tex (0.0196N/tex) was applied under the following conditions, and the number of reciprocating wear until the sheath fibers wear out due to abrasion and the core fibers appear on the surface is measured. It is something that Friction speed 120 times/min Friction angle 110° Reciprocating distance 2.5cm Test length 20cm Friction element φ0.6mm hard steel Repeat the above test 10 times and take the average value. (Specific example 1) Core fiber...Aromatic polyamide fiber filament 200 ^d
30% Sheath fiber…ester staple fineness 1.3 fiber length 38
m/m 70% A composite spun yarn having the above structure was manufactured by the manufacturing method of the present invention, and the abrasion strength test described above was conducted. In addition, as a comparative example, a composite yarn having a similar two-layer structure was manufactured using the conventional manufacturing method using the DREF method, that is, without a means for adjusting the overlapping state of the core fiber and sheath fiber in the merging guide just before the front roller. It was manufactured using the manufacturing method described below. Samples were taken from each of the two locations and tested, and the results are shown in the table below.

[Table] (Example 2) Core fiber...Aromatic polyamide fiber spun yarn 20'35% Sheath fiber...Cotton staple fineness 4.5 fiber length 31m/m65
% The same test as in Example 1 was conducted on the composite spun yarn having the above structure. Incidentally, the spun yarn mentioned here refers to one made of staple fibers of aromatic polyamide fiber. The results are shown in the table below.

[Table] As is clear from the results shown in the above two specific examples, the composite spun yarn obtained by the unique manufacturing method of the present invention has an abrasion strength of 110 or more; Conventional composite yarns with an abrasion strength of less than 110 inevitably suffer from problems such as sheath fibers peeling off during weaving. In other words, there are no bare parts in the yarn, and there is no unevenness on the surface even when it is made into a woven fabric.1
Those that can be easily and beautifully dyed by the bath dyeing method are composite spun yarns obtained by the method of the present invention, that is, those having an abrasion strength of 110 or more, preferably 120 or more, and more preferably 130 or more. Furthermore, when a cloth was woven using the composite spun yarn produced in Example 1, there was no unevenness in the exposed core fibers on the surface, and an extremely excellent strong woven cloth was obtained. (Effects of the Invention) As described above, the composite spun yarn with a core-sheath structure obtained by the production method of the present invention uses an aromatic polyamide fiber in the core, and the fiber has high strength, high cutting strength, heat resistance, etc. It is an extremely excellent composite yarn that takes advantage of the characteristics of the yarn and eliminates drawbacks such as discoloration and fading by completely and strongly covering it with sheath fibers. Moreover, the completeness and strength of the coating are remarkable, and it can be dyed evenly with a one-bath dyeing method, and the core fibers will not be exposed due to wear due to friction during weaving. There is no. However, it is used not only for industrial purposes but also for general items that require strength and aesthetic beauty, and its effects are further demonstrated.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a composite spun yarn with a core-sheath structure obtained by the method of the present invention, FIG. 2 is an explanatory diagram of an example of a manufacturing apparatus for carrying out the method of the present invention, and FIG.
Figures 4 and 4 are enlarged views showing the main parts of the device, and Figure 5.
6 and 6 are explanatory diagrams showing the state of the yarn just before passing through the front roller, and FIG. 7 is an explanatory diagram of the test method. DESCRIPTION OF SYMBOLS 1...Core fiber, 2...Sheath fiber, 3...Stretching mechanism, 4...Sheath fiber guide, 4a...Yam path, 5...
...Front roller, 6... Merging guide, 7...
...Core fiber supply path, 8...Core fiber guide, 8a...
... Thread path, 9 ... Suction drum, 10 ... Thread pull-out roll, 11 ... Machine stand, 12 ... Bolt, 13 ...
...Natsuto, C...Kens.

Claims (1)

[Claims] 1. When producing a composite spun yarn with a core-sheath structure in which a core made of aromatic polyamide fiber filaments or spun yarns is covered with staples of natural fibers and/or synthetic fibers, a stretching mechanism for covering the sheath fibers is used. For sheath fibers, the position of at least one of the core fibers from the core fiber supply path can be adjusted in a direction perpendicular to the yarn running direction, and the overlapping state of both fibers can be adjusted by adjusting their mutual positions. After passing through the guide and core fiber guide respectively,
The yarn is supplied to a merging guide disposed just before the front roller of the stretching mechanism, and is then passed between two parallel suction drums that rotate in the same direction in close contact with each other, as well as a yarn drawing roll consisting of a plurality of rolls. A method for producing a composite spun yarn having a core-sheath structure, characterized in that the composite yarn is passed through sequentially to produce a composite yarn having an abrasion strength of 110 or more according to the JIS L 1095 7.10.2B method.