WO2001038619A1

WO2001038619A1 - Sliver comprising extra fine fibers

Info

Publication number: WO2001038619A1
Application number: PCT/JP2000/007861
Authority: WO
Inventors: Toshiro Ono; Akira Ebihara; Masao Morioka; Masanobu Kaneko; Katsuhiro Iwakoshi
Original assignee: Kanebo, Limited; Kanebo Gohsen Limited; Kanebo Spinning Corporation
Priority date: 1999-11-25
Filing date: 2000-11-08
Publication date: 2001-05-31
Also published as: JP3704576B2; JP2001214337A

Abstract

A sliver comprising extra fine fibers, characterized in that it comprises carded synthetic fibers having a fiber length of 30 mm or less, wherein the fiber is a fibrillated composite fiber having a single yarn fineness of 0.7 dt or less and a number of segments in the single yarn of 2 or more, wherein in a sliver state in which single fibers are collected in an amount of 5,000 dt or more, U % is 10.0 % or less and the number of neps (pieces/g) is 8.0 or less, and wherein the segment is slitted along its axis line at least randomly. The above sliver provides a spun sliver which uses extra fine fibers having a single yarn fineness of 0.7 dt or less as constituent fibers and at the same time has almost same sliver properties as those of a conventional sliver made of a synthetic fiber.

Description

Description Sliver made of microfibers Technical field

The present invention relates to a sliver formed from a synthetic fiber staple having a fiber length of 30 mm or less via a carding process. More specifically, the present invention relates to a single-fiber fineness of 0.7 dtex as a constituent fiber. The present invention relates to a novel sliver structure having the same high productivity and spinnability as a conventional sliver using the following ultrafine fibers. Background art

Conventionally, many chemical fibers and synthetic fibers have been produced and used in various fields along with natural fibers in accordance with their respective fiber characteristics. However, due to advances in production technology, technologies unique to synthetic fibers that surpass natural fibers have been developed. A unique product based on this has been developed and put into practical use. One of them is a fine fiber technology called ultra-fine fiber (usually less than 1.1 dt) or ultra-fine fiber (usually less than 33 dt). Among the natural fibers, the finest is 1.3 to 1.7 dt of cotton fiber, but recently, ultrafine fibers of 0.0001 Idt have been realized with synthetic fibers.

Various techniques have already been put to practical use as a technique for producing such ultrafine fibers. The typical yarn form of polyester fiber, which is the mainstream polyester fiber, is described as follows: Sea-island type (Fig. 1) described in Japanese Patent Publication No. 431-208, etc. Solid radiation type described in Japanese Patent Publication No. 12-29 (Fig. 2), hollow radiation type described in Japanese Patent Publication No. 53-169 (Fig. 3), Japanese Patent Publication No. 53-103 Blend type (Fig. 4) described in Japanese Patent Publication No. 216969 and the like can be mentioned.

The fibrous structures formed by such ultrafine fibers, including ultrafine fibers, are characterized by (1) softness, (2) large surface area, (3) large space for fiber aggregates, and (4) high brushing properties. Yes, these functions are used extensively in various fields such as woven and knitted fabrics, nonwoven fabrics and synthetic leather. However, in order to maintain stable quality, most of such ultrafine fibers including conventionally known ultrafine fibers (hereinafter referred to simply as “fine fibers”) are used in the form of filaments of continuous filaments. However, it was not heavily used in the form of a staple for spinning, and in this respect it was extremely lacking in versatility.

The reason why microfibers are not frequently used for spinning is that it is difficult to produce good quality as much as the card fibers required for spinning of microfiber materials formed with fineness.

In other words, for materials with ultrafine denier greatly different from existing denier, it is not possible to produce a fiber bundle with high uniformity simply by changing the card specifications, and the nep, hooks, etc. increase and the parallelism of single fibers is poor. In the process after sliver formation, such as in a spinning machine, yarn breakage, yarn spots, etc. occur frequently, and a high quality final product cannot be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to specify the single yarn structure of ultrafine fibers, the shape of the segments incorporated in the single yarns, the opened state of these segments, and the like, and to collect such fibers. By maintaining the quality of the slivers above a certain level, a new sliver structure consisting of staples of microfibers is constructed, thereby completely eliminating the lack of versatility of microfibers. Disclosure of the invention

To achieve the above object, the present invention has the following configuration. That is, it is a sliver made of ultrafine fibers, which is made of synthetic fibers having a fiber length of 30 mm or less that has passed through a cardboard process, and has a single-fiber fineness of 0.7 dt or less, and has a number of segments of 2 or more in a single yarn. In a sliver state in which single fibers are bundled for 5,000 dt or more using a brillated conjugate fiber, U% is not more than 10.0%, and the number of neps (ke Zg) is not more than 8.0. Further, the segment is characterized in that the segments are split at least randomly along the axis. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view of a single yarn of sea-island type ultrafine fiber.

FIG. 2 is a single yarn transverse cross-sectional view of a solid radiation type ultrafine fiber. FIG. 3 is a single cross-sectional view of a hollow radiation type ultrafine fiber.

FIG. 4 is a cross-sectional view of a single yarn of the blend type ultrafine fiber.

FIG. 5 is a cross-sectional view of a single yarn of the ultrafine fiber used in the example of the present invention.

FIG. 6 is an explanatory diagram of a carding machine used in an embodiment of the present invention.

Hereinafter, reference numerals in the drawings will be described. 1 is a cylinder. 2 is the buffer. 3 is flat. 4 is take-in. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the raw yarn form of the ultrafine fibers used in the present embodiment will be described. Each yarn form described above with reference to FIGS. 1 to 4 is a basic form of ultrafine fiber including polyester fiber.As is well known, the sea-island type shown in FIG. The solid radiation type shown in Fig. 2 is due to swelling or dissolution of one component, the hollow radiation type shown in Fig. 3 is due to exfoliation, and the blend type shown in Fig. 4 is due to dissolution of sea components as in Fig. 1. Then, the fibers are opened for each segment forming a single yarn of the ultrafine fiber, and ultrafineness is performed.

Each of the above yarns forms a stable synthetic fiber in an ultra-fine state, and can be used as a constituent fiber of sliver.However, in terms of ease of production, parallelism of the obtained fiber and spinning, From the viewpoint of spinnability, the solid radiation type shown in FIG. 2 and the hollow radiation type shown in FIG. 3 are more preferable than the sea-island type shown in FIG. 1 and the plain type shown in FIG. In particular, a fiber obtained by fibrillating (dividing) a composite fiber made of polyamide and polyester as a raw yarn is most preferable. The ultrafine fiber obtained from such a conjugate fiber is most suitable as the material of the sliver of the present invention because it maintains the dimensional stability of polyester and the hydrophilicity of polyamide at the same time.

The structure of such a conjugate fiber will be further described. As an example of the conjugate fiber, a polymer having no affinity to each other, for example, a polyamide and a polyester is joined along a longitudinal direction by conjugate spinning. Specifically, in the cross section, a segment formed from both components A and B (whichever is a polyamide component) is shown in FIG.

(A) Side-by-side type as shown in (B) (B) (C) Side-by-side repetition type as shown in (C) Radial as shown in (D) to (H) This component is composed of a component A having the shape of (1) and another component (B) having a shape that complements the radiating portion, but complements the radiating portion with the component (A) having a radiating shape as shown in (I) and (J). One of them is composed of the other component B, and one of the radial shapes is interrupted at the center, and the other is a side-by-side repeating type with a hollow part as shown in Fig. 5 (K).

Examples of the polyamide which is a component of the composite fiber include nylon 4, nylon 6, nylon 7, nylon 11, nylon 12, nylon 66, nylon 6,10, polymetaxylene adipamide, and polyparaxylyl. Rendecanamide, polybiscyclohexylmethanedecaneamide, and copolyamides containing these as components are exemplified.

Examples of the polymer which has no affinity for the polyamide which forms a composite fiber together with the above polyamide include polyester, polyolefin, polyacrylonitrile, etc., and from the viewpoint of facilitating melt composite spinning with the above polyamide, polyester is preferred. And polyolefins are preferred, with polyesters being most preferred. In other words, when a combination of polyamide and polyester is used, the resulting fiber has the most preferable gloss and texture. Examples of the polyester include polyethylene ate, poly 1,4-dimethylcyclohexane terephthalate, polypivalolactone, and copolyesters containing these components. Examples of the polyolefin include polyethylene, polypropylene and these components. Copolyolefin and the like.

Further, another example of the conjugate fiber is obtained by laminating two polymers of a fiber-forming polymer and a readily soluble polymer 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 twist fixing and feeling, and particularly, polyethylene terephthalate is most preferable.

The easily soluble polymer can be easily selected in consideration of the combination with the fiber-forming polymer.However, a copolymerized polyester having a large alkali-hydrolyzing property, such as one of polyalkylene dalicol or a dicarboxylic acid having a metal sulfonate group, or Copolymerize the two Polyethylene terephthalate is useful.

The conjugate fiber of the present embodiment composed of a combination of the above two components is melt-spun in a filament shape of a continuous filament, then bundled and mechanically cut into a predetermined length of 30 mm or less. Use a pull-shaped fiber.

Next, the segments constituting the single yarn are spread on the ultrafine fibers of the stable fibers. In the case of a conjugate fiber in which the polymers have no affinity for each other, which is one of the embodiments in which the above two components are combined, usually, the polyamide is made by physical impact such as mechanical bending or friction, or by the above polyamide. Can be split into thin bundles of fibrils by a chemical method of swelling with a chemical solution. Examples of such a chemical solution (hereinafter referred to as a “fibrillating agent”) include benzyl alcohol, 3-phenylethyl alcohol, phenol, m-cresol, formic acid, and acetic acid. These are more suitable to be used as the aqueous solution or the aqueous emulsion than using the single product directly. In particular, the use of an aqueous emulsion of benzyl alcohol is preferred in terms of the fibrillation effect and the relatively easy handling. The concentration is preferably set to 1 to 50% by weight, especially 3 to 30% by weight. If the amount is less than 1% by weight, the effect of fibrillation is weak. On the other hand, if the amount exceeds 50% by weight, the aqueous emulsion becomes unstable. This is because there is a tendency to adversely affect other fiber components.

In the case of a composite fiber comprising a fiber-forming polymer and an easily soluble polymer, the easily soluble polymer can be dissolved and split with an aqueous solution of sodium hydroxide, potassium hydroxide or the like.

In the above embodiment, the case where the raw fiber 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.

Then, in the present invention, the above-mentioned conjugate fiber is shortened, and after performing opening and thinning for each segment, it is supplied to a carding process.

Generally, the stableness of the synthetic fiber used in the cotton spinning method is 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 a carding machine, the gauge between cylinder 1 and doffer 2 should be adjusted to 4-5Z 1,000 mm in Fig. 6. The gauge between cylinder 1 and flat 3 is 10 to 12Z 1,000 inches, the gauge between cylinder 1 and Tekain 4 is 7Z 1 000 inches, and cylinder 1 is 170 to 180 mm. · Ρ · カーカーテカーカーテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテテ 4

However, in the present invention, which is an object of spinning ultrafine fibers and fibrillated fibers, the properties thereof are greatly different from those of the conventional staple material, which is related to spinnability in spinning. It is necessary to carefully examine the properties of raw cotton such as hygroscopicity, electrical resistance, bulkiness, friction resistance, collective doubt, high elongation and compression elasticity. In particular, hygroscopicity, chargeability, bulkiness, high elongation, and the suitability of the oil agent to be given to the fiber are greatly related to the quality of operation.

As an example of a carding machine specification corresponding to the fine elongation and fineness of microfiber, the gauge between cylinder 1-1 and doffer 1-2 is set to 4Z1 000 inches, and the gauge between cylinder 1 and flat 3 is The gauge is 12Z 1,000 inches, the gauge between cylinder 1 and car 4 is 71,000 inches, cylinder 1 is 180 rpm, and car 4 is 350 rpm. An example is shown where m is set to doffer 2 and 5 r · p · m. In addition, the needle cloth must be made by Mcc especially for synthetic fiber.

In the above series of processes, each segment of the microfiber is individually fibrillated along the axis of the fiber, and the degree of fibrillation is greatly related to the bulkiness of the fiber, and the entire filament is fibrillated. Partially fibrillated has less sag and maintains bulkiness. Further, it is more preferable that a uniform sliver can be obtained because the occurrence of neps in a force dwell can be reduced. The degree is determined by visually judging the state of the enlarged cross section.

The sliver that has passed through the carding process is further supplied to a drawing machine in a single or a plurality of slivers, 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 the completion of the drawing process is reduced to 5.0% or less, and the number of neps (Zg) is reduced to 8.0 or less, whereby the U% of the sliver after the completion of the drawing process is reduced to 10%. The NEP number (q / g) can be reduced to 8.0 or less.

The sliver of the present invention formed for this purpose only has the features of microfibers. Has the same quality and high productivity as the sliver of the synthetic fiber which is usually used. Hereinafter, the present invention will be further described with reference to examples. Example

Example 1

The cross section is the shape shown in Fig. 5 (H), and eight radial segments are formed of polyamide made of nylon 6, while eight segments having a shape complementary to the radiating portion are made of polyethylene terephne. The composite fiber formed from the polyester consisting of the latex was melt-spun at a composite ratio of 1: 2 by a normal process to obtain a drawn yarn of 11 1 dt / 50 f.

The drawn yarn is mechanically cut into a stable with a fiber length of 20 mm, which is then formed into a fibrillation method using benzyl alcohol described in Japanese Patent Publication No. 53-36563. The fiber was finely divided into ultrafine fiber bundles having a fineness of about 0.22 dt, and this was used as a raw fiber in the carding process.

As a carding machine, a flat card for cotton with a recovery feeder is used.The cylinder is 180 r · p · m, the doffer is 5 r · p · m, and the gauge between the top and the cylinder is 1 2 1, It was set at 0.000 inch and spun as a 4 g / m force sliver. As described above, conventionally, fibers for spun yarn production require a fiber length of about 38 mm due to the draft mechanism in each spinning process. However, in the case of the ultra-fine fibers targeted by the present invention, when the force is dengued, if the length is 38 mm, the card action between the needles of the cylinder is too strong, and the entanglement of the fibers, that is, NEP, occurs frequently, and the quality deteriorates. Becomes difficult.

In the present embodiment, by setting the fiber length to 20 mm, it is possible to avoid the entanglement of the ultrafine fibers in the card, and further to prevent the occurrence of neps by reducing the speed of the drafter rotation and holding down the sliver unit weight. We have obtained the expected high quality power sliver.

Three of the card slivers produced in the above process were simultaneously supplied to a drawing machine, and the draft was increased by a factor of 12 at a spinning speed of 5 OmZ to obtain a uniform sliver of 1 g Zm with few spots. The sliver has a U% of 8.0% and a NEP of 6.0 (g Zg), and is of the same quality as a commonly used synthetic fiber sliver, and is used in many fields such as clothing and artificial leather. It was very versatile to use. In particular, it is 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 remarkably improved as compared with the conventional cotton products, and the IC circuit board ゃ connectors for optical fiber, audio and video, etc. Excellent for cleaning parts.

Example 2

In general, natural cotton swabs made of cotton, absorbent cotton, etc. are made of water-soluble polymers such as polyvinyl alcohol in order to prevent fluff that occurs during the formation of the swabs and drop off of surface fibers that occur during use. A cotton swab is impregnated with an aqueous solution of a compound as a binder and then dried to solidify the fiber surface.

However, in the conventional method, even if synthetic fibers made of ultrafine fibers are used to improve wiping performance, the binder adhering to the fiber surface when using a cotton swab is scraped off by friction with the object to be cleaned. If a solvent such as water, alcohol, acetone or hexane is impregnated with the solvent, the binder will elute into the solvent, etc. However, it is not possible to obtain a higher degree of cleanliness than the original purpose, which is not desirable for cleaning fine parts such as IC circuit boards, connectors for optical fibers, OA equipment such as audio / video, and magnetic heads. Was.

In order to avoid such contamination of the object to be cleaned by the binder, the swab shown in Example 2 suppresses the fluffing of the swab when forming the cotton ball without using any binder, and a method for preventing the fibers from falling off during use. It was obtained as a result of intensive studies, making the best use of the thermoplastic properties of the synthetic fibers that make up the cotton swabs, and then forming them at a specified temperature, for a specified time, and then heat-molded. By doing so, an extremely clean swab with high wiving performance can be obtained.

In the embodiment shown in Example 2, the synthetic fiber sliver of the present invention composed of ultrafine fibers is cut into appropriate lengths by an appropriate winding device, and then wound around a shaft such as plastic, paper, or a wooden tube. A cotton ball of the desired size is formed, and the cotton ball is heat-treated in a heat-treatable molding machine to shrink the fibers on the surface of the cotton ball, to improve the fluffiness and to entangle the fibers. It is made to be done. In the embodiment 2 of the present invention, since ultrafine fibers are used, the 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 In cleaning, etc., it is possible to substantially eliminate the problem that the fibers are frayed from the surface of the cotton ball and become difficult to use.

The temperature of the heat treatment is appropriately selected depending on the material constituting the cotton ball, but it is preferable to perform the treatment at a temperature lower by 20 ° C. to 100 ° C. based on the melting point of the material. If the treatment temperature is too high, a part of the fiber surface will be fused or the inside of the cotton ball will shrink, causing the problem of excessive solidification of the cotton ball and yellowing due to thermal deterioration. On the other hand, if the processing temperature is low, the fiber shrinks weakly and the fiber is not sufficiently entangled, and the fiber is loosened during cleaning, which causes the fiber to fall off. It is sufficient that the heat treatment time is usually within 10 seconds. In any case, such a heat treatment should be appropriately adjusted according to the purpose and use of the swab.

Hereinafter, a specific embodiment of the second embodiment will be described. The cross section is the shape shown in Fig. 5 (H), and eight radial segments are formed from polyamide made of nylon 6, and eight segments having a shape complementary to the radiating part are polyethylene terephthalate. The composite fiber formed from the polyester having a latex was melt-spun at a composite ratio of 1: 2 by a usual process to obtain a drawn yarn of 110 dt Z50f.

The drawn yarn was mechanically cut into a stable having a fiber length of 20 mm, and this was drawn with a liquid card dyeing machine at a ratio of 48 Baume Na〇H, 27 cc / 1 bath ratio of 1: 1 to 955. The mixture was treated at 30 ° C for 30 minutes to produce ultrafine fiber cotton having a fineness of about 0.2 dt, which was passed through a carding step and a drawing step to form a sliver of 1 g / m.

The sliver was wound on both ends of a lmmφ paper shaft using a conventional winding device to form cotton balls, and then treated for 3 seconds in a molding machine heated to 190 ° C. A cotton swab with high wiping performance was obtained, having no fluff on the surface and intertwining the fibers of the surface layer constituting the cotton ball.

Example 3

The cross section has the shape shown in Fig. 5 (H). Eight segments having a radial shape are formed of alkali-soluble polyester, and eight segments having a shape complementary to the radiating portion are formed of regular polyester. Composite fiber is processed by the normal process. It was melt spun at a combined ratio of 25:75 to obtain a drawn yarn of 11 1 dt / 50 f.

After bundling the multifilaments of the composite fiber to form a fiber bundle of about 220,000 dt, a crimp of 18 pieces / inch is given, and then cut with a circular cutter to obtain a raw cotton having a cut length of 20 mm. Was. Raw cotton with a cut fineness of about 2.2 dt and a fiber length of 20 mm was treated with a liquid dyeing machine at 48 ° C NaOH, 27 cc Z and a bath ratio of 1:12 at 95 ° C for 30 minutes. Ultrafine fibers with a fineness of about 0.2 dt were formed and used as raw fibers in the carding process.

Next, the raw fiber was subjected to the same pressing process and drawing process as in Example 1 to form a sliver having a U% of 8.0% and a nep number of 6.0 (Zg). The obtained sliver of the present invention was versatile and versatile as in the case of Example 1. Industrial applicability

The sliver of the present invention has the following effects. In other words, it has all the features of the fiber structure using ultra-fine fibers, such as flexibility, a large surface area, and high bulkiness, and has a sliver quality almost equivalent to that of the conventional short fiber spinning synthetic fiber sliver. The possession makes it possible to use microfibers in a wide field where spun yarn is usually used, and has the effect of almost completely eliminating the lack of versatility of microfibers described at the beginning.

Claims

The scope of the claims

1. Made of synthetic fiber with a fiber length of 30 mm or less via the carding process. Use a fibrillated conjugate fiber with a single-fiber fineness of 0.7 dtex or less and two or more segments in the single-fiber as the fiber. In a sliver state with 2,000 000 dtex or more, the U% is set to 10.0% or less, the number of neps (ke / g) is set to 8.0 or less, and the segments are arranged at least randomly along the axis. A sliver made of extra-fine fibers that is specially split.