JP2005232672A - Sliver comprising ultrafine fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliver finished in a spinning process, using as a constituent fiber an ultrafine fiber having ≤0.7 dtex single fiber fineness and having approximately the same qualities as those of conventional slivers made of a synthetic fiber. <P>SOLUTION: The sliver comprises a synthetic fiber carded in a carding process, having ≤30 mm fiber length and obtained by using a fibrillated-type composite yarn having ≤0.7 dtex single fiber fineness and ≥2 segment number in the single yarn, wherein, in a sliver state in which single fibers are collected in an amount of ≥5,000 dtex, U % is ≤10.0% and the number of neps (count/g) is ≤8.0, and wherein the segment is slit along its axis at least randomly. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a sliver formed from a synthetic fiber staple having a fiber length of 30 mm or less via a card process, and more specifically, a single yarn fineness of 0.7 dtex (hereinafter, dtex is abbreviated as dt) as a constituent fiber. The present invention relates to a novel sliver structure having the same high productivity and spinnability as a conventional sliver while using the following ultrafine fibers.

Conventionally, many chemical fibers and synthetic fibers have been produced and used together with natural fibers in various fields according to their respective fiber characteristics, but with the development of production technology, a technology specific to synthetic fibers that exceeds natural fibers has been developed. A unique product based on this has been put into practical use. One of them is a finening technique called ultrafine fibers (usually 1.1 dt or less) or ultrafine fibers (usually 0.33 dt or less). Among the natural fibers, the thinnest one is 1.3 to 1.7 dt of cotton fibers, but synthetic fibers have recently realized ultrafine fibers with a thickness of 0.00011 dt.

Various techniques have already been put to practical use as techniques for producing such ultrafine fibers. When the typical yarn form is explained for the mainstream polyester fiber, the sea-island type described in Patent Document 1 (FIG. 1), the solid radiation type described in Patent Document 2 (FIG. 2), the patent Examples thereof include a hollow radiation type (FIG. 3) described in Document 3 and the like, and a blend type (FIG. 4) described in Patent Document 4 and the like.
Japanese Examined Patent Publication No. 44-13208 Japanese Patent Publication No.49-29129 Japanese Patent Publication No.53-10169 Japanese Patent Publication No.53-22169

The fiber structure formed by such ultrafine fibers including ultrafine fibers is (1) soft, (2) has a large surface area, (3) has a large space for the fiber assembly, and (4) has a raised property. It has a feature such as being high, and it is frequently used in various fields such as woven and knitted fabrics, nonwoven fabrics, and synthetic leathers using such functions.

However, such ultrafine fibers including conventionally known ultrafine fibers (hereinafter simply referred to as ultrafine fibers) are mostly used in the form of filaments of continuous long fibers in order to maintain stable quality. It was not frequently used in the form of staples for spinning, and was not very versatile in this respect.

The reason why the ultrafine fibers are not frequently used for spinning is based on the fact that it is difficult to produce good quality in the card process required for spinning by the ultrafine fiber material formed with fineness. In other words, a material with an extremely fine fineness that is significantly different from the existing fineness cannot produce a fiber bundle with a high degree of homogeneity by simply changing the card specifications. In the spinning machine and the like, yarn breakage, yarn unevenness, etc. occur frequently in the process after sliver formation, and there is a problem that a final product with good quality cannot be obtained.

The present invention aims to solve the above-mentioned problems, and specifies the single yarn structure of ultrafine fibers, the shape of the segments contained in the single yarn, the state of opening of these segments, and the like, and an assembly of such fibers. Is maintained at a certain value or more, thereby forming a novel sliver structure composed of staples of ultrafine fibers, thereby completely eliminating the lack of versatility of the ultrafine fibers.

In order to achieve the above object, the present invention has the following configuration. That is, a sliver composed of ultrafine fibers, comprising a synthetic fiber having a fiber length of 30 mm or less that has passed through a card process, and the fiber is a fibrillated composite fiber having a single yarn fineness of 0.7 dt or less and having two or more segments in the single yarn. In a sliver state in which single fibers are focused for 5,000 dt or more, U% is set to 10.0% or less, Nep number (ke / g) is set to 8.0 or less, and the segments are aligned along the axis. The structure is characterized in that it is split at least at random.

The sliver of the present invention has the following effects. In other words, it has all the features such as flexibility, wide surface area, high bulkiness, etc. of the fiber structure using ultrafine fibers, and possesses sliver quality that is almost equivalent to conventional short fiber spinning synthetic cotton sliver. Therefore, it becomes possible to use ultrafine fibers in a wide field in which spun yarn is usually used, and there is an effect of almost completely eliminating the lack of versatility of the ultrafine fibers described at the beginning.

Embodiments of the present invention will be described below with reference to the drawings. First, the raw yarn form of the ultrafine fiber used in the present embodiment will be described. 1 to 4 are basic forms of ultrafine fibers including polyester fibers, and as is well known, the sea-island type shown in FIG. 1 is shown in FIG. Solid radiation type is formed by swelling or dissolution of one component, hollow radiation type shown in FIG. 3 is peeled off, and blend type shown in FIG. 4 is formed by dissolving sea components as in FIG. Each segment is opened and ultra-fine.

Each of the above-mentioned raw yarns forms a staple of synthetic fiber in an extremely thinned state and can be used as a constituent fiber of a sliver, but it is easy to manufacture, the degree of parallelism of the resulting fiber and the possibility of spinning. From the viewpoint of spinnability, the solid radiation type shown in FIG. 2 and the hollow radiation type shown in FIG. 3 are preferable to the sea-island type shown in FIG. 1 and the blend type shown in FIG. In particular, it is most preferable to use a composite fiber made of polyamide and polyester as a raw yarn and fibrillate (divide) it. The ultrafine fiber obtained from such a composite fiber retains the dimensional stability of the polyester and the hydrophilicity of the polyamide at the same time, and is therefore optimal as a material for the sliver of the present invention.

The structure of such a composite fiber will be further described. As an example of the composite fiber, polymers having no affinity for each other, for example, polyamide and polyester are joined along the longitudinal direction by composite spinning. In the cross section, a segment formed from both components A and B (which may be any polyamide component) is a side-by-side type as shown in FIG. C) a side-by-side repeat type, as shown in (D) to (H), and a component A having a radial shape and another component B having a shape that complements this radiating part As shown in (I) and (J), it is composed of a component A having a radial shape and another component B that complements this radiating portion-the radial shape of one is interrupted on the center side, FIG. ) In a side-by-side repetitive as it is shown such that there is a hollow portion and the like are.

Examples of the polyamide as one component of the composite fiber include nylon 4, nylon 6, nylon 7, nylon 11, nylon 12, nylon 66, nylon 6.10, polymetaxylene adipamide, polyparaxylylene decanamide, Examples thereof include polybiscyclohexylmethanedecanamide and copolyamides containing these components.

In addition, examples of the polymer having no affinity with the polyamide that forms the composite fiber together with the polyamide include polyester, polyolefin, polyacrylonitrile, and the like. From the viewpoint of easily performing melt composite spinning with the polyamide, the polyester and the polyolefin are used. Of these, polyester is most preferable. That is, when a combination of polyamide and polyester is used, the gloss, texture and the like of the obtained fiber are most preferable. Examples of the polyester include polyethylene terephthalate, polytetramethylene terephthalate, polyethylene oxybenzoate, poly 1,4-dimethylcyclohexane terephthalate, polypivalolactone, and copolyesters containing these as components. Examples thereof include polyethylene, polypropylene, and copolyolefins containing these as components.

Furthermore, as another example of the composite fiber, there may be mentioned one in which two polymers of a fiber-forming polymer and a readily soluble polymer are bonded in a radial or parallel manner.
As the fiber-forming polymer, polyamide, polyester, polyolefin and the like are used, and polyester is preferable in terms of ease of fixing the twist and feel, and polyethylene terephthalate is most preferable.
The easily soluble polymer can be easily selected in consideration of the combination with the fiber-forming polymer. However, the copolymer polyester having a high alkali hydrolyzability, for example, polyalkylene glycol or one or two dicarboxylic acids having a metal sulfonate group is used. Polyethylene terephthalate copolymerized with seeds is useful.

The composite fiber of this embodiment comprising the combination of the above two components is melt-spun in the form of a continuous long fiber filament, then bundled, mechanically cut to a predetermined length of 30 mm or less, and formed into a staple fiber shape. Use what you did.

Next, opening of the segments constituting the single yarn is performed on the ultrafine fibers of the staple fiber. In the case of a composite fiber in which the polymers of each of the present embodiments formed by combining the above two components have no affinity for each other, usually by physical impact such as mechanical bending or friction, or the polyamide It can be split into a bundle of thin fibrils by a chemical method of swelling the membrane with a chemical solution. Examples of such a chemical solution (hereinafter referred to as “fibrillating agent”) include benzyl alcohol, β-phenylethyl alcohol, phenol, m-cresol, formic acid, acetic acid and the like. These are suitable for use as an aqueous solution or an aqueous emulsion thereof rather than directly using a single product. In particular, use of an aqueous emulsion of benzyl alcohol is preferable in terms of the fibrillation effect and relatively easy handling. The concentration is preferably set to 1 to 50% by weight, especially 3 to 30% by weight. If it is less than 1% by weight, the effect of fibrillation is weak. Conversely, if it exceeds 50% by weight, it becomes unstable in the case of an aqueous emulsion, and it becomes very difficult to remove the fibrillating agent later. This is because there is a tendency to adversely affect the fiber component.
In the case of a composite fiber composed of a fiber-forming polymer and a readily soluble polymer, the easily soluble polymer can be dissolved and split using an aqueous alkali solution such as sodium hydroxide or potassium hydroxide.

In the above embodiment, the case where the raw yarn form of the ultrafine fiber is a solid radiation type or a hollow radiation type has been described, but the present invention can also be used for a sea-island type.

And in this invention, after shortening the said composite fiber and carrying out the opening and finening for every segment, it supplies to a card | curd process.

In general, the staples of synthetic fibers used in the cotton spinning system have a variety of fibers having a fineness of 1.1 to 1.6 dt and a fiber length of about 38 mm. In accordance with the general spinning requirements of the carding machine, the gauge between the cylinder 1 and the doffer 2 is 4 to 5 / 1,000 inch and the gauge between the cylinder 1 and the flat 3 is 10 to 10 in accordance with this. 12 / 1,000 inch, the gauge between cylinder 1 and taker in 4 is 7 / 1,000 inch, cylinder 1 is 170 to 180 r · p · m, taker in 4 is 350 to 400 r · p · m, The doffer 2 is set to 7 to 8 r · p · m, and good operation is maintained by such requirements.

However, in the present invention, which is an ultrafine fiber and a fibrillated fiber, the properties of the raw cotton are greatly different from those of conventional staple materials and related to the spinnability in spinning. It is necessary to thoroughly examine the hygroscopicity, electrical resistance, bulkiness, frictional resistance, collective suspicion, strong elongation, and compression elasticity. In particular, hygroscopicity, chargeability, bulkiness, high elongation, and the suitability of the oil applied to the fiber are greatly related to the quality of the operation.

As an example of the cotton machine specification corresponding to the fine elongation and fineness of ultrafine fiber, the gauge between cylinder 1 and doffer 2 is 4 / 1,000 inch, and the gauge between cylinder 1 and flat 3 is 12 / 1,000 inch, gauge between cylinder 1 and taker in 4 to 7 / 1,000 inch, cylinder 1 to 180 r · p · m, taker in 4 to 350 r · p · m, doffer 2 to 5 r · An example of setting p · m is given. Note that the needle cloth must be made of Mcc, especially for synthetic fibers.

In the above series of processes, each segment of the microfiber is individually fibrillated along the fiber axis, and the degree of fibrillation is greatly related to the bulkiness of the fiber, and the entire filament is fibrillated. The fibrillation partly has less sag and retains bulkiness than the fibrillation. In addition, the generation of neps in the card process is small, and a uniform sliver can be obtained. The degree is determined by visually judging the state of the enlarged cross section.

The sliver that has passed through the card process is further supplied to the drawing machine in a combined state of one or more, and is subjected to a predetermined draft action to be finished into a sliver of the present invention having a specified weight.
In the present invention, the U% of the sliver immediately after completion of the carding process is set to 5.0% or less, and the Nep number (ke / g) is set to 8.0 or less, thereby reducing the U% of the sliver after completion of the drawing process. The Nep number (ke / g) can be made 8.0 or less at 10.0% or less.
The sliver of the present invention formed for this purpose has the same quality and high productivity as a synthetic fiber sliver that is usually used while having the features of ultrafine fibers. Hereinafter, the present invention will be further described with reference to examples.

The cross section is the shape shown in FIG. 5 (H), and eight segments having a radial shape are formed of polyamide made of nylon 6, while eight segments having a shape that complements the radiating portion are made of polyethylene terephthalate. The composite fiber formed from the polyester obtained was melt-spun at a composite ratio of 1: 2 by a normal process to obtain a drawn yarn of 111 dt / 50f.
The drawn yarn is mechanically cut to form a staple having a fiber length of 20 mm, and this is then made into an ultrafine fiber bundle having a fineness of about 0.22 dt by a fibrillation method using benzyl alcohol described in Japanese Patent Publication No. 53-35633. It was refined and used as the raw fiber for the card process.

A cotton flat card with a recovery feeder is used as the carding machine, the cylinder 180r · p · m, the doffer 5r · p · m, the gauge between the top and the cylinder is set to 12 / 1,000 inch, 4g / It was spun as a card sliver of m. As described above, conventionally, a fiber for producing spun yarn is required to have a fiber length of about 38 mm in terms of a draft mechanism in each spinning process. However, in the case of the ultrafine fiber targeted by the present invention, when the carding is performed at 38 mm, the carding action between the cylinder needles is too strong, and the fiber is entangled, that is, the nep occurs frequently, the quality is lowered, and it is difficult to produce the product.
In this embodiment, the fiber length is set to 20 mm to avoid entanglement of ultrafine fibers in the card, and further, the generation of neps is prevented by reducing the rotation speed of the drafter and suppressing the sliver unit weight. Has gained a high-quality card sliver.

Three card slivers produced by the above process were simultaneously supplied to the drawing machine and subjected to a draft of 12 times at a spinning speed of 50 m / min to obtain an even sliver with few spots of 1 g / m. The sliver has a U% of 8.0% and a Nep number of 6.0 (ke / g), which is of the same quality as a commonly used synthetic fiber sliver and is used in many areas such as clothing and artificial leather. It was versatile.
It is particularly suitable for wiping applications utilizing the fineness of fibers, and is effective for wiping glasses, industrial wiping cloths, and the like. Furthermore, when a cotton swab is manufactured with the sliver of the present invention, the wiping performance is significantly improved compared to conventional cotton products, and the fine parts of OA equipment magnetic heads such as IC circuit boards, optical fiber connectors, audio, video, etc. Excellent for cleaning.

Generally, in a cotton swab made of natural fibers made of cotton, absorbent cotton, etc., an aqueous solution of a water-soluble polymer compound typified by polyvinyl alcohol is used in order to prevent fluffing that occurs during the formation of the cotton swab and surface fibers falling off during use. After impregnating a cotton swab as a binder, it is dried to harden the fiber surface.

However, in this conventional method, even if a synthetic fiber made of ultrafine fibers is used to improve the wiping performance, the binder attached to the fiber surface during use of the swab is scraped off by friction with the object to be cleaned, In addition, when impregnated with a solvent such as water, alcohol, acetone or hexane as a solvent, troubles such as elution of the binder into the solvent occur, and on the contrary, the object to be cleaned is contaminated. Higher cleanliness than the intended purpose could not be obtained, and it was not preferable for cleaning fine parts such as IC circuit boards, optical fiber connectors, OA equipment such as audio video, and magnetic heads.

The cotton swab shown in Example 2 is a method for preventing the fibers from falling off during use without using any binders and suppressing fluffing during the formation of the cotton balls without using any binders in order to avoid contamination of the object to be cleaned by the binder. It was obtained as a result of examination, and the thermoplasticity that is the characteristic of the synthetic fiber constituting the cotton swab was utilized to the maximum, and after the formation of the cotton ball, it was heat-formed at a predetermined temperature for a predetermined time. In this way, a cotton swab having an extremely clean and high wiping performance can be obtained.

In the form shown in Example 2, the synthetic fiber sliver of the present invention made of ultrafine fibers is appropriately cut by an appropriate squeezing device and then squeezed onto a shaft body such as plastic, paper, wood tube, etc. The size of the cotton ball is formed, and the cotton ball is heat-treated in a molding machine that can be heat-treated to shrink the fibers on the surface of the cotton ball so as to adjust the fluff and generate entanglement between the fibers. It is a thing.

In the form of Example 2, since ultrafine fibers are used, heat transfer between the fibers is good, the efficiency of the heat treatment is increased, and the fiber density is high, so that strong fiber entanglement is possible and precision equipment It can be substantially eliminated that fibers are frayed from the surface of the cotton ball and become difficult to use during cleaning.
Although the temperature of the said heat processing is suitably selected by the raw material which comprises a cotton ball, it is preferable to process at the temperature 20-20 degreeC low on the basis of melting | fusing point of a raw material. If the treatment temperature is too high, a part of the fiber surface is fused or contracted to the inside of the cotton ball, causing the problem of excessive solidification of the cotton ball and causing problems such as yellowing due to thermal deterioration. On the other hand, when the treatment temperature is low, the fiber contraction is weak and the fiber is not sufficiently entangled, and the fiber loosens during cleaning, causing the fiber to fall off. The heat treatment time is usually sufficient if it is within 10 seconds. In any case, such heat treatment is suitably adjusted according to the purpose and application of the cotton swab.

Hereinafter, a specific embodiment of Example 2 will be described. The cross section is the shape shown in FIG. 5 (H), 8 segments having a radial shape are formed of polyamide made of nylon 6, and 8 segments of a shape that complements the radiating portion are made of polyester made of polyethylene terephthalate. The composite fiber formed by the above process was melt-spun at a composite ratio of 1: 2 by a normal process to obtain a stretched yarn of 110 dt / 50f. The drawn yarn is mechanically cut into a staple having a fiber length of 20 mm, and this is processed with a liquid dyeing machine with 48 Baume NaOH, 27 cc / 1 bath ratio 1:12 at 95 ° C. for 30 minutes and a fineness of about 0.00. A 2 dt ultrafine fiber cotton was produced and passed through a card process and a drawing process to form a 1 g / m sliver.
The sliver is rubbed on both ends of a 1 mmφ paper shaft using a normal scouring device to form cotton balls, and then treated for 3 seconds in a molding machine heated to 190 ° C., so that fluff is formed on the surface. In addition, a cotton swab having high wiping performance in which the fibers of the surface layer constituting the cotton ball were intertwined was obtained.

A composite in which the cross section is the shape shown in FIG. 5 (H), 8 segments having a radial shape are made of alkali-soluble polyester, and 8 segments having a shape to complement the radiating portion are made of regular polyester. The fiber was melt-spun at a composite ratio of 25:75 by a normal process to obtain a 111 dt / 50 f drawn yarn.
After the multifilaments of the composite fibers were converged to form a fiber bundle of about 220,000 dt, 18 pieces / inch of crimp were applied, and then cut with a circular cutter to obtain a raw cotton having a cut length of 20 mm. Ultrafine fiber with a fineness of about 0.2 dt is treated with raw cotton having a fineness of about 2.2 dt and a fiber length of 20 mm in a liquid dyeing machine at 48 Baume NaOH, 27 cc / l, bath ratio 1:12 at 95 ° C. for 30 minutes. This was used as the raw fiber for the card process.

Next, the raw fiber was passed through the same curd process and drawing process as in Example 1 to form a sliver with U% 8.0% and Nep number 6.0 (ke / g). The obtained sliver of the present invention was rich in versatility that could be used in many ways, as in Example 1.

It is a single yarn cross-sectional view of a sea-island type ultrafine fiber. It is a single yarn cross-sectional view of a solid radiation type ultrafine fiber. It is a single yarn cross-sectional view of a hollow radiation type ultrafine fiber. It is a single yarn cross-sectional view of a blend type ultrafine fiber. It is a single yarn cross-sectional view of the ultrafine fiber used for the Example of this invention. It is explanatory drawing of the carding machine used for the Example of this invention.

Explanation of symbols

1 cylinder 2 doffer 3 flat 4 taker in

Claims (1)

It consists of a synthetic fiber having a fiber length of 30 mm or less that has passed through the carding process, and a fibrillated composite fiber having a single yarn fineness of 0.7 decitex or less and two or more segments in the single yarn is used. In a sliver state focused at a decitex or higher, U% was set to 10.0% or less, Nep number (ke / g) was set to 8.0 or less, and the segments were split at least randomly along the axis. A sliver made of ultrafine fibers.

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