JP2001214337A - Sliver composed of ultrafine fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sliver risen from a spinning process, using an ultrafine fiber having <=0.7 dtex single yarn fineness as a structural fiber and moreover having approximately equivalent qualities to conventional slivers made of synthetic fibers. SOLUTION: This sliver is composed of a synthetic fiber passed through a carding process and having <=30 mm fiber length and obtained by using a fibrillated-type conjugated yarn having <=0.7 dtex single yarn fineness and >=2 segment number in the single yarn as the synthetic fiber and at least randomly splitting so that the fiber has <=10.0% U% and <=8.0 (count/g) nep count in the sliver state obtained by bunching >=5,000 dtex of the single yarn and the segment further parallels the axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliver formed from synthetic fiber staples having a fiber length of 30 mm or less via a carding process.
The present invention relates to a novel sliver structure having high productivity and spinnability substantially equivalent to a conventional sliver while using ultrafine fibers having a single yarn fineness of 0.7 dtex (hereinafter, abbreviated as dt) as constituent fibers. .

[0002]

2. Description of the Related Art Conventionally, many synthetic fibers and synthetic fibers have been produced and used together with natural fibers in various fields according to their fiber characteristics. Unique technologies have been developed and unique products based on these technologies have been put to practical use. One of them is a fine fiber technology called ultrafine fiber (usually referred to as 1.1 dt or less) or ultra-fine fiber (usually referred to as 0.33 dt or less). Among the natural fibers, the thinnest one is cotton fiber 1.3 ~
1.7 dt, but recently 0.00011 for synthetic fibers
Ultra-fine fibers with a thickness of dt have been realized.

Various techniques have already been put to practical use as a technique for producing such ultrafine fibers. The typical yarn form of the mainstream polyester fiber will be described. The sea-island type described in Japanese Patent Publication No. 44-13208 (FIG. 1) and the solid fiber described in Japanese Patent Publication No. 49-29129 are disclosed. Radiation type (FIG. 2), hollow radiation type described in JP-B-53-10169, etc. (FIG. 3), JP-B-53-22
169 and the like (FIG. 4).

[0004] The fibrous structure formed by such ultrafine fibers including ultrafine fibers is characterized by being soft, having a large surface area, having a large space for a fiber assembly, and having a high brushing property. Utilizing such functions, they are frequently used in various fields such as woven and knitted fabrics, nonwoven fabrics and synthetic leathers.

[0005]

However, such ultrafine fibers including conventionally known ultrafine fibers (hereinafter referred to simply as "fine fibers") are mostly made of continuous filaments in order to maintain stable quality. It is used in the form of a filament, is not frequently used in the form of staples for spinning, and is extremely lacking in versatility in this regard.

[0006] The reason why microfibers are not frequently used for spinning is that it is difficult to produce good quality in the carding process required for spinning of microfiber materials formed with fineness. . In other words, materials with very fine fineness, which is significantly different from existing fineness, cannot produce a fiber bundle with a high degree of uniformity by merely changing the card specifications, increasing the nep, hooks, etc., and the parallelism of the single fibers is poor. In the process after sliver formation, such as a spinning machine, yarn breakage, spots, and the like frequently occur, 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, and 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 By maintaining the quality of the aggregate of the above-mentioned aggregates at a certain value or more, a novel sliver structure composed of staples of ultrafine fibers is constituted, thereby completely eliminating the lack of versatility provided by the ultrafine fibers.

[0008]

To achieve the above object, the present invention has the following arrangement. That is, the sliver is made of ultrafine fibers, and has a fiber length of 3 through a card process.
In the sliver state, which is made of a synthetic fiber of 0 mm or less and uses a fibrillated conjugate fiber having a single-fiber fineness of 0.7 dt or less and a number of segments of 2 or more in the single yarn, and the single fiber is bundled at 5,000 dt or more, U% to 10.0
% Or less, the number of neps (ke / g) is set to 8.0 or less, and the segments are split at least randomly along the axis.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, the raw yarn form of the ultrafine fibers used in the present embodiment will be described. First, FIGS.
1 are the basic forms of ultrafine fibers including polyester fibers. As is well known, the sea-island type shown in FIG. 1 swells due to the dissolution of the sea component, and the solid emission type shown in FIG. 2 swells. Alternatively, the hollow radiation type shown in FIG. 3 is peeled off by dissolution of one component, and the blend type shown in FIG. 4 is opened by dissolution of the sea component similarly to FIG. Fine and ultra-fine.

[0010] Each of the above yarns forms a staple of synthetic fibers in an extremely fine state, and can be used as a constituent fiber of a sliver. In view of the above 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 blend type shown in FIG. In particular, a fiber obtained by fibrillating (dividing) a composite fiber composed of polyamide and polyester as a raw yarn is most preferable. The ultrafine fiber obtained from such a conjugate fiber is most suitable as a material for 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 composite fiber, polymers having no affinity for each other,
For example, polyamide and polyester are joined along the longitudinal direction by composite spinning. Specifically, in the cross section, both components A and B (any of which may be a polyamide component) are used. The formed segments are side-by-side type as shown in FIG. 5 (A), side-by-side repeating type as shown in FIGS. 5 (B) and 5 (C), and as shown in FIGS. 5 (D) to (H). A component A having a radial shape and another component B having a shape complementary to the radiating portion, and a component A having a radial shape and the radiating portion as shown in (I) and (J). A component composed of another component B to be complemented has a radial shape interrupted on the center side, and a side-by-side repeating type having a hollow portion as shown in FIG. 5 (K).

The polyamide which is one component of the composite fiber is, for example, nylon 4, nylon 6, nylon 7,
Nylon 11, Nylon 12, Nylon 66, Nylon 6.10, polymetaxylene adipamide, polyparaxylylenedecaneamide, polybiscyclohexylmethanedecaneamide, and copolyamides containing these as components.

[0013] Examples of the polymer having no affinity with the polyamide forming a composite fiber together with the polyamide include polyester, polyolefin, and polyacrylonitrile. From the viewpoint of easily performing melt composite spinning with the polyamide. Polyesters and polyolefins are preferred, with polyesters being most preferred.
That is, when a combination of a polyamide and a polyester is used, the resulting fiber has the most preferable gloss, feeling and the like. Examples of the polyester include polyethylene terephthalate, polytetramethylene terephthalate, polyethylene oxybenzoate, poly-1,4-dimethylcyclohexane terephthalate, polypivalolactone, and copolyesters containing these components, and the like. Examples thereof include polyethylene, polypropylene and copolyolefin containing these as components.

Further, as another example of the conjugate fiber, there can be cited one in which two polymers, a fiber-forming polymer and a readily soluble polymer, are laminated 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 polyethylene terephthalate is particularly preferable. The easily soluble polymer can be easily selected in consideration of the combination with the fiber-forming polymer, but is preferably one or two or more of alkali-hydrolyzable copolymerized polyesters such as polyalkylene glycol or dicarboxylic acid having a metal sulfonate group. Polyethylene terephthalate copolymerized species is useful.

The conjugate fiber of the present embodiment comprising a combination of the two components is melt-spun in a filament form of continuous filaments, then bundled, and mechanically wound to a predetermined length of 30 mm.
The following is cut and used in the form of staple fiber.

Next, the segments constituting the single yarn are spread on the ultrafine fibers of the staple fiber. 1 of the present embodiment combining the above two components
In the case of a conjugate fiber in which the polymers do not have an affinity for each other, thin fibrils are usually formed by physical impact such as mechanical bending or friction, or by a chemical method of swelling the polyamide with a chemical solution. Can be split into bundles. Examples of such a chemical solution (hereinafter referred to as a “fibrillating agent”) include benzyl alcohol, β
-Phenylethyl alcohol, phenol, m-cresol, formic acid, acetic acid and the like. These are more suitable to be used as an aqueous solution or an aqueous emulsion thereof than directly using a single product. In particular, the use of an aqueous emulsion of benzyl alcohol is preferred from the viewpoint of the fibrillation effect and the relatively easy handling. And its concentration is 1 to 50% by weight, especially 3
It is preferable to set it to 30% by weight. If it is less than 1% by weight, the effect of fibrillation is weak, and if it exceeds 50% by weight, it becomes unstable in the case of an aqueous emulsion, and it becomes extremely difficult to remove the fibrillating agent later, and also it becomes difficult to remove other than the polyamide component. 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 an easily soluble polymer, the easily soluble polymer can be dissolved and split with an aqueous alkali solution such as sodium hydroxide or potassium hydroxide.

In the above embodiment, the case where the 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.

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

Normally, staples of synthetic fibers used in the cotton spinning method include fibers having a fineness of 1.1 to 1.6 dt and a fiber length of about 38 mm. According to the general spinning requirements of the carding machine, the gauge between the cylinder 1 and the doffer 2 is set to 4-5 / 1,000 inches and the cylinder 1
The gauge between the flat 3 and the flat 3 is 10 to 12 / 1,000 inches, and the gauge between the cylinder 1 and the taker-in 4 is 7 /
1,000 inches, and cylinder 1 is 170-18
At 0 rpm, taker in 4 with 350-400 rpm
set the doffer 2 to 7 to 8 rpm,
These requirements keep good operation.

However, in the present invention, which is an object to be spun from ultrafine fibers and fibrillated fibers,
Its properties are significantly different from those of conventional staple materials, and the properties of raw cotton related to spinnability on spinning include hygroscopicity, electrical resistance, bulkiness, friction resistance, collectivity, strong elongation, and compression elasticity. Need to be carefully examined. In particular, hygroscopicity, chargeability, bulkiness, high elongation, and the suitability of an oil agent to be imparted to fibers are greatly related to the quality of operation.

As an example of a carding machine specification corresponding to the fine elongation and fineness of the ultrafine fiber, the gauge between the cylinder 1 and the doffer 2 is set to 4 / 1,000 inches, and the gauge between the cylinder 1 and the flat 3 is set. Gauge to 12 / 1,000 inches, gauge between cylinder 1 to taker-in 4 7 /
Cylinder 1 is 180 rpm at 1,000 inches
There is an example in which the taker-in 4 is set to 350 rpm and the doffer 2 is set to 5 rpm. In addition, the needle cloth needs to be made of Mcc, especially for synthetic fibers.

In the above series of processes, each segment of the ultrafine fiber is individually fibrillated along the axis of the fiber, and the degree of the fibrillation is greatly related to the bulkiness of the fiber. Partially fibrillated has less sagging and retains bulkiness than is formed. Further, it is rather preferable that a uniform sliver can be obtained because the generation of neps in the carding process is small. The degree is determined by visually judging the state of the enlarged cross section.

The sliver that has gone through the card process is:
Further, the sliver is supplied to the drawing machine in a single or plural combination state, and is subjected to a predetermined drafting action to finish the sliver of the present invention with a specified weight. In the present invention, the U% of the sliver immediately after the completion of the drawing step is reduced to 5.0% or less and the NEP number (ke / g) to 8.0 or less, so that the U% of the sliver immediately after the completion of the drawing step is reduced. The NEP number (ke / g) can be set to 8.0 or less at 10.0% or less. The sliver of the present invention formed in this manner has the same quality and high productivity as the sliver of the synthetic fiber which is generally used, while having the characteristics of the ultrafine fiber sufficiently. Hereinafter, the present invention will be further described with reference to examples.

[0024]

Embodiment 1 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 complementary to the radiating portion are formed. A conjugate fiber in which a segment is formed of polyester made of polyethylene terephthalate,
Melt spinning at a composite ratio of 1: 2 by the usual process and 111 dt
/ 50f drawn yarn was obtained. The drawn yarn is mechanically cut into staples having a fiber length of 20 mm, and then the staple is subjected to a fibrillation method using benzyl alcohol described in JP-B-53-35633, with a fineness of about 0.22 d.
The fibers were finely divided into t ultrafine fiber bundles, which were used as raw fibers in the carding process.

As the carding machine, a cotton flat card with a recovery feeder is used, and the cylinder is 180 rpm.
・ M, doffer 5r ・ p ・ m, gauge between top and cylinder set to 12 / 1,000 inch, 4g / m
As a card sliver. As described above, conventionally, fibers for producing spun yarn require a fiber length of about 38 mm due to a draft mechanism in each spinning process. However, in the case of the ultrafine fibers targeted by the present invention, when the carding is performed at 38 mm, the card action between the cylinder needles is too strong, so that entanglement of the fibers, that is, nep occurs frequently, the quality is reduced, and commercialization becomes difficult. In the present embodiment, by setting the fiber length to 20 mm, it is possible to avoid entanglement of the ultrafine fibers in the card, and further to prevent the occurrence of neps by reducing the speed of drafter rotation and holding down the sliver unit weight. Has gained a high-grade card sliver.

Three of the card slivers produced by the above process were simultaneously supplied to a drawing machine, and drafted 12 times at a spinning speed of 50 m / min to obtain a uniform sliver of 1 g / m with less unevenness. The sliver has a U% of 8.0% and a NEP number of 6.0 (ke / g), and is of the same quality as a commonly used synthetic fiber sliver, and is used in various fields such as clothing and artificial leather. It was very versatile. 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. Further, when the swab is manufactured with the sliver of the present invention, the wiping performance is remarkably improved as compared with the conventional cotton products, and fine parts such as IC circuit boards, optical fiber connectors, OA equipment magnetic heads such as audio and video, and the like are manufactured. Excellent for cleaning.

[0027]

Embodiment 2 In general, in a cotton swab made of natural fiber made of cotton, absorbent cotton, or the like, a water-soluble swab typified by polyvinyl alcohol is used to prevent fluffing generated during the formation of the cotton swab and falling off of surface fibers generated during use. After impregnating a cotton swab with an aqueous solution of a molecular compound as a binder, the swab is dried to harden the fiber surface.

However, in the conventional method, even if synthetic fibers made of ultrafine fibers are used to improve the wiping performance, the binder adhering to the fiber surface when the swab is used 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 may elute into the solvent, etc. As a result, a higher degree of cleanliness than the original purpose cannot be obtained, which may not be preferable for cleaning minute parts such as IC circuit boards, optical fiber connectors, OA equipment such as audio / video, and magnetic heads.

The swab shown in Example 2 suppresses the fluffing of the swab when forming the swab without using any binder to prevent the contamination of the object to be cleaned by the binder, and prevents the fibers from falling off during use. It was obtained as a result of intensive study of the method, making the best use of the thermoplastic property of the synthetic fiber constituting the cotton swab, after forming the cotton ball, at a predetermined temperature, a predetermined time, By heating and molding, it is possible to obtain an extremely clean swab with high wiping performance.

In the embodiment shown in Example 2, the synthetic fiber sliver of the present invention composed of ultrafine fibers is cut into an appropriate length by an appropriate winding device, and then wound around a shaft such as plastic, paper, or a wooden pipe. This forms a cotton ball of the desired size, and then heat-treats this cotton ball in a heat-treatable molding machine to shrink the fibers on the surface of the cotton ball, to adjust the fluff, and to generate entanglement between the fibers. It is made to be done.

In the embodiment 2 of the present invention, ultrafine fibers are used, so that 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 becomes possible. In addition, 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 when cleaning precision instruments and the like. The temperature of the heat treatment is appropriately selected depending on the material constituting the cotton ball.
The treatment is preferably performed at a temperature lower by 100C to 100C. If the treatment temperature is too high, a part of the fiber surface is fused or shrinks to the inside of the cotton ball, causing a problem that the cotton ball is excessively solidified and causes a problem such as yellowing due to thermal deterioration. On the other hand, if the treatment temperature is low, the fiber shrinks weakly and the entanglement of the fiber is not sufficient, and the fiber is loosened during cleaning, causing 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 may 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 has the shape shown in FIG. 5 (H). Eight segments having a radial shape are formed of polyamide made of nylon 6, and eight segments having a shape complementary to the radiating portion are made of polyethylene terephthalate. The composite fiber formed by the above was melt-spun at a composite ratio of 1: 2 by a usual process to obtain a drawn yarn of 110 dt / 50f. The drawn yarn is mechanically cut to obtain a fiber length of 20 m.
m staples, and treated with a liquid carding and dyeing machine at 48 ° C NaOH, 27 cc / 1 bath ratio 1:12 at 95 ° C. for 30 minutes to produce ultrafine fiber cotton with a fineness of about 0.2 dt. A sliver of 1 g / m was formed through the steps and the drawing step. The sliver was wrapped at both ends of a 1 mmφ paper shaft using a normal wrapping device to form cotton balls, and then treated for 3 seconds in a molding machine heated to 190 ° C., so that fluff was formed on the surface. In addition, a cotton swab with high wiping performance was obtained in which the fibers of the surface layer constituting the cotton ball were entangled.

[0033]

Embodiment 3 The cross section is the shape shown in FIG. 5 (H). Eight segments having a radial shape are made of alkali-soluble polyester, and eight segments having a shape complementary to the radiating portion are made of regular polyester. The composite fiber formed by the above was melt-spun at a composite ratio of 25:75 by a usual process to obtain a drawn yarn of 111 dt / 50f. After bundling the multifilaments of the composite fiber to form a fiber bundle of about 220,000 dt, a crimp of 18 pieces / inch was applied, and then cut with a circular cutter to obtain a raw cotton having a cut length of 20 mm. Fineness of cut about 2.2 dt,
48 Baume Na using a liquid dyeing machine for raw cotton with a fiber length of 20 mm
OH, 27 cc / l, treatment at a bath ratio of 1:12 at 95 ° C. for 30 minutes to form ultrafine fibers having a fineness of about 0.2 dt, which were used as raw fibers in the carding process.

Next, the raw fiber was passed through the same carding 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 (ke / g). The obtained sliver of the present invention was versatile and versatile as in Example 1.

[0035]

The sliver of the present invention has the following effects. In other words, it has all the characteristics of the fiber structure using ultrafine fibers, such as flexibility, large surface area, and high bulkiness, and possesses sliver quality that is almost the same as that of conventional short fiber spinning synthetic fiber sliver. As a result, it is possible to use the ultrafine fibers in a wide field where spun yarn is usually used, and it is possible to almost completely eliminate the lack of versatility of the ultrafine fibers described at the beginning.

[Brief description of the drawings]

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

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

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

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

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

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

[Explanation of symbols]

 1 Cylinder 2 Doffer 3 Flat 4 Taker In

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshiro Ohno 1-2-2 Umeda, Kita-ku, Osaka-shi, Osaka Kanebo Synthetic Fiber Co., Ltd. (72) Inventor Akira Ebihara 1-2-chome Umeda, Kita-ku, Osaka, Osaka No. 2 Inside Kanebo Synthetic Fiber Co., Ltd. (72) Inventor Masao Morioka 1-2-2 Umeda, Kita-ku, Osaka City, Osaka Prefecture Inside Kanebo Synthetic Fiber Co., Ltd. (72) Inventor Masanobu Kaneko 250 Niimachi Niimachi, Hamana-gun, Shizuoka Prefecture Address Kanebo Textile Co., Ltd. (72) Katsuhiro Iwakoshi 250, Araicho, Arai-cho, Hamana-gun, Shizuoka Prefecture F-term (reference) 4L036 MA15 MA35 UA21 4L041 BA02 BA03 BA04 BA05 BA09 BA11 BA42 BA48 BA49 CA06 CA21 DD01 EE06

Claims (1)

[Claims] 1. A fibrillated composite fiber having a fiber length of 30 mm or less through a carding process and having a single fiber fineness of 0.7 dtex or less and a number of segments of 2 or more in a single yarn. In a sliver state in which the fibers are bundled at 5,000 dtex or more, the U% is set to 10.0% or less, the NEP number (ke / g) is set to 8.0 or less, and the segments are arranged at least randomly along the axis. A sliver made of ultra-fine fibers, characterized by splitting into fibers.