JPH09302544A - Spun yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sheath-core type spun yarn having different void ratios in core and sheath parts thereof, excellent in light weightiness, heat insulating property, soft feeling, high bulkiness, flexibility and pilling resistant property, and useful for a clothing and an industrial use. SOLUTION: This spun yarn has different void ratios in the core part 2 constituted by a hollow fiber or a fiber having a modified cross-section and the sheath part 3 constituted mainly by a fiber having pilling resistant property, and the void ratio of the core 2 is higher than that of the sheath part 3. Further, the sheath-core type spun yarn is obtained by producing a spun yarn containing a polyester fiber having a pilling resistant property and a solvent-based polyvinyl alcohol fiber capable of being removed in its sheath part 3 and the solvent-based polyvinyl alcohol fiber removable by dissolving in a higher ratio than that in the sheath part 3 in its core part 2, and then removing the polyvinyl-based fiber by a dissolution.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to heat retention, flexibility,
The present invention relates to a novel spun yarn capable of providing a woven or knitted fabric having a soft feel, a light feel, and an excellent pill resistance, and a method for producing the spun yarn.

[0002]

2. Description of the Related Art Conventionally, there has been a demand for a woven or knitted fabric which is lightweight, has heat retention, has a soft feeling, and has elasticity and elasticity, and various attempts have been made. For example, methods using hollow fibers or highly shrinkable fibers have been proposed.

[0003]

However, when the hollow fiber is used, there is a problem that the hollow shape is easily broken in the process of forming the spun yarn and the performance is not sufficiently exhibited. If the hollow ratio is lowered, the hollow shape is easily retained, but in this case, performances such as lightness and heat retention become insufficient. Furthermore, it is possible to adopt a method in which the central part of the fiber is removed to make a hollow fiber after the woven or knitted product is manufactured, but the quality of the woven or knitted product, especially the performance such as light weight, heat retention, hygroscopicity, and anti-pill property is sufficient. It wasn't. Further, when the high shrink fiber is used to shrink and impart bulkiness, the fabric itself shrinks and the woven or knitted fabric becomes dense and easily hardens, and is lightweight,
It is difficult to make something with a soft feel. Furthermore, when a bulky spun yarn is used, the running resistance of the bulky spun yarn increases in the weaving / knitting process, the weft driving speed decreases, and the spun yarn can be smoothly and efficiently transferred to the knitting needle during knitting. There is a problem that is difficult to supply to. Sufficient anti-pill property is not obtained when the main fiber in the conventional method is synthetic fiber or regenerated fiber, and especially in bulky woven and knitted fabrics where pilling is likely to occur, the texture and appearance deteriorate over time. Therefore, there was a problem that the product value was significantly reduced.

It is an object of the present invention to provide a novel spun yarn capable of providing a woven or knitted article excellent in heat retention, flexibility, softness, lightness and anti-pill resistance, and an efficient production method thereof. To do.

[0005]

That is, the present invention provides a core-sheath type spun yarn characterized in that the core portion and the sheath portion have different void ratios. In particular, the core portion has a void ratio of the sheath portion. The spun yarn is higher than the rate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The spun yarn referred to in the present invention has a gap between a sheath portion and a core portion, and is specifically as shown in FIG. Porosity of the sheath is 20 to 50%, especially 30 to
40% is preferable. The porosity of the core is 40 to
80%, especially 50-60% is preferable. In addition,
The porosity referred to in the present invention is expressed by the formula (S1-S2) / S1 where S1 is the spun yarn cross-sectional area and S2 is the total single fiber cross-sectional area.
A value (%) represented by × 100. Therefore, the hollow ratio of the hollow fiber and the hollow ratio of the spun yarn are clearly distinguished. In order to manufacture a yarn with voids, it is necessary to mix it with fibers that can be completely dissolved and removed, and since it is usual to add raw cotton in a weight ratio, it is possible to estimate the porosity of the spun yarn by that ratio. it can.

By forming voids in the spun yarn, lightness,
Excellent performances such as heat retention and elasticity can be obtained. Further, by using the solvent-based PVA fiber for the core portion and the sheath portion, it can be easily dissolved and removed with water at 80 ° C. or lower.
In addition, by using the anti-pill PET fiber as the main fiber constituting the sheath portion, the surface of the woven or knitted fabric looks good and has a dry feeling, and further excellent effects of hygroscopicity and quick drying can be obtained.

In the core-sheath composite spun yarn of the present invention, as shown in FIG. 2, first, a spun yarn serving as a core component is manufactured by a usual method (primary spinning). For example, easy-dissolving fibers are mixed at a predetermined mixing ratio and the mixture is passed through a kneading cotton blending process, a carding process, a drawing process, a roving process, a spinning process, and a winding process. Then, it is obtained by producing a core-sheath composite spun yarn containing the spun yarn as a core component (secondary spinning). In addition, after the core-sheath component is separately supplied and passed through the blended cotton step and the carding step to adjust to a predetermined core-sheath ratio, the core component is placed in the center and the sheath component is placed on both sides thereof. It can be obtained by supplying and drafting, spinning the obtained sliver as it is, and spinning.
In addition, the core-sheath components are separately supplied to form roving,
It can be produced by setting the spinning amount according to the desired core / sheath ratio, arranging the core component on the center and the sheath component on both sides thereof, and then supplying and spinning.

By dissolving and removing the easily soluble fibers of the obtained core-sheath type composite yarn, spun yarns having different voids in the core and the sheath can be produced. As the easily soluble fiber, water-soluble polyvinyl alcohol fiber, easily alkali-soluble polyester fiber, or the like can be used. These can be removed by dissolution with hot water, water or alkali. The easily soluble fiber is not particularly limited as long as it can be dissolved and removed later, but it is necessary to select a suitable fiber in relation to the sheath component. In the present invention, since synthetic fibers or regenerated fibers having excellent anti-pill properties are mainly used in the sheath portion, alkali-soluble type may be used, but water-soluble polyvinyl alcohol fiber is more preferable.

As the staples of water-soluble polyvinyl alcohol (PVA), there are fibers produced by using water as a solvent (water-based fibers) and fibers produced by using an organic solvent as a solvent (solvent-based fibers). It was obtained as a result of research based on the finding that the latter can obtain a better spun yarn. because,
Water-based fiber with good water solubility (dissolved at 60 ℃)
In order to make the soybeans, a state in which a large amount of Glauber's salt adhered to the fibers was inevitable, and during spinning, spinning was significantly impaired. Therefore, at present, only types that can be dissolved in hot water at 80 to 90 ° C. have been commercialized. However, since solvent-based fibers can be manufactured without using Glauber's salt at all, it has been impossible to operate at 80 ° C.
The following fibers which can be easily dissolved in water and have good spinnability can be obtained. As a result,
The problem that it is difficult to dissolve the solution during the dissolution and it takes a long time and the problem that residual meal is generated is solved, and an excellent spun yarn suitable for the initial purpose can be obtained.

The solvent-based PVA fiber referred to in the present invention has a dissolution temperature (T ° C.) in water of 0 to 100 ° C. and a maximum shrinkage ratio in water of 2
The water-soluble PVA-based fiber has a tensile strength of 0% or less, a tensile strength of 3 g / d or more, an ash content of 1% or less, and a dimensional change rate S% at 20 ° C. and a relative humidity of 93% satisfying the following formula. When 0 ≦ T ≦ 50 S ≦ 6− (T / 10) When 50 <T ≦ 100 S ≦ 1 Further, as a method for producing such a fiber, a PVA-based polymer having a dissolution temperature in water of 100 ° C. or less is organic. The spinning dope obtained by dissolving in a solvent was wet-spun or dry-wet spun in a solidifying bath mainly composed of an organic solvent having solidifying ability with respect to the polymer (hereinafter abbreviated as solidifying solvent), and obtained by spinning. 2 in Itoshino
~ 8 times wet drawing is performed, the undiluted solvent is extracted from the fiber by the solidifying solvent, dried, and if necessary, dry heat drawn,
Next, at 3 to 4 at 80 to 250 ° C. and under multi-step temperature rising conditions.
Water-soluble PVA obtained by performing 0% dry heat shrinkage treatment
It is a system fiber.

The polymer which can be used in the present invention is a PVA type polymer which is soluble in water at 0 to 100 ° C. after being formed into fibers. Pure PVA in which the PVA-based polymer is composed of 100% vinyl alcohol units is not preferable because the crystallinity after fiberization is too high to obtain the fiber soluble in water at 0 to 100 ° C. of the present invention. In particular, when it is desired to obtain a fiber soluble in water at 0 to 60 ° C., the degree of saponification is less than 96 mol% in the case of so-called partially saponified PVA, which is composed of vinyl acetate units other than vinyl alcohol units, that is, vinyl acetate units. Is preferably 4 mol% or more. However, when the saponification degree is 0.8 mol% or less, adhesion between the obtained fibers occurs, the crystallinity of the polymer in the obtained fibers is low, and dimensional stability under high humidity cannot be obtained. When it dissolves in water, it shrinks greatly and the fiber of the present invention cannot be obtained.

When it is desired to obtain a fiber which is soluble in water at 60 to 100 ° C., a vinyl alcohol unit is added to 96
It is preferable to use a PVA-based polymer containing mol% or more. For example, when partially saponified PVA is used,
It is preferable to use a product having a saponification degree of 99.5 mol%.
When PVA having a saponification degree of 99.5 mol% or more is used,
Crystallization proceeds during dry heat stretching and heat shrinkage, and the dissolution temperature in water tends to exceed 100 ° C., which is not preferable.

So-called modified PVA containing units other than vinyl alcohol units and vinyl acetate units
When it is desired to obtain a fiber having a dissolution temperature in water of less than 60 ° C. using a base polymer, when the modifying unit is a unit having a large crystallization inhibiting effect, a modified PVA-based polymer of about 0.5 mol% is used. In some cases, it can be preferably used in the present invention, but generally 1 mol% or more, particularly 2 mol%
It is preferable to use the PVA-based polymer modified as described above.
Similarly, when it is desired to obtain a fiber having a melting temperature in water of 60 to 100 ° C. using a modified PVA-based polymer, modification is less than 2 mol%, preferably 0.1 mol% or more and 1.0
It is preferable to use one having a mol% or less.

Examples of the modifying unit include ethylene, allyl alcohol, itaconic acid, acrylic acid, maleic anhydride and ring-opened products thereof, arylsulfonic acid, vinyl esters of fatty acids having 4 or more carbon atoms such as vinyl pivalate, and vinylpyrrolidone. , And a compound in which a part or the whole amount of the ionic group is neutralized. The method of introducing the modifying unit may be a method by copolymerization or a method by post-reaction. Further, the distribution of the modifying unit in the polymer chain is not particularly limited, whether it is random, block or graft. When the modification amount exceeds 20 mol%, the crystallinity is excessively lowered, the dimensional stability under high humidity cannot be obtained, and the water-soluble fiber of the present invention cannot be obtained. The average degree of polymerization of the PVA polymer used in the present invention is 100 to 35.
00 range, especially 300-3000 range is preferred,
Particularly preferably, it is in the range of 700 to 2500.

The sheath component must be synthetic fiber or regenerated fiber having anti-pill property. The inventors of the present invention have found that when a spun yarn is trial-produced using a fiber having no conventional anti-pill property and a woven or knitted fabric is trial-produced using the same, pilling is remarkably generated, which is a serious problem. Especially in the case of textiles, the occurrence was remarkable. In order to provide a comfortable woven or knitted fabric in the present invention, it is preferable to use fibers having low hygroscopicity. Although synthetic fibers such as polyester and acrylic are suitable as such fibers,
Of these, anti-pill polyester fiber is particularly preferable.

The anti-pill polyester fiber referred to in the present invention means, for example, terephthalic acid obtained by reacting a dicarboxylic acid mainly containing terephthalic acid or its lower alkyl ester derivative with a glycol mainly containing ethylene glycol or ethylene oxide. Second step reaction to obtain a glycol ester of a main dicarboxylic acid and / or a low polymer thereof and polycondensation reaction of the product to obtain a polyester having 85% or more of repeating units of ethylene terephthalate units. In the step of reacting and melt-spinning the polyester to produce polyester fiber, in the step from the completion of the reaction of the first step to the completion of the reaction of the second step, the purity of 96% or more is represented by the formula (1). A phosphorus compound containing 0.5 to 1.5 mol% of phosphorus atoms with respect to all acid components. After being made into a stell, the polyester is melt-spun to form a phosphorus-containing polyester fiber having an intrinsic viscosity of 0.38 to 0.45 and an acid terminal group concentration of 80 μeq / g or more, and the polyester fiber is further heated to 110 ° C. or more in the presence of water. It can be obtained by heat treatment at a temperature to reduce the intrinsic viscosity to 0.36 or less.

[0018]

Embedded image

In the present invention, the dicarboxylic acid or the lower alkyl ester derivative thereof used as the raw material for the polyester is mainly terephthalic acid and its lower alkyl ester derivative, and a part thereof is isophthalic acid or 5-sodiumsulfoisophthalic acid. Adipic acid,
It may be replaced with another dicarboxylic acid such as sebacic acid or a lower alkyl ester derivative thereof. In particular, 5-sodium sulfoisophthalic acid is preferably used because it increases the anti-pill property.

The glycols are mainly ethylene glycol, but some of them are glycols such as propylene glycol, 1.4-butanediol, trimethylene glycol, 1.4 hexanediol and neopentyl glycol. May be replaced.

The alkylene oxides are mainly intended for ethylene oxide, but a part of them may be replaced with propylene oxide, butylene oxide or the like. The method most commonly used in the industry for producing a polyester from these dicarboxylic acid component and glycol component, that is, in the case of polyethylene terephthalate, is explained by esterifying terephthalic acid and ethylene glycol or by using dimethyl ester. The first-stage reaction of the ethylene glycol ester of terephthalic acid and / or its low polymer by the transesterification reaction of terephthalate and ethylene glycol and the reaction product of the first stage are heated to a high temperature under reduced pressure to produce a heavy polymer. It is produced by the second stage reaction of condensation reaction.

In the production of the polyester, an esterification catalyst, a transesterification catalyst, a polycondensation catalyst, a matting agent such as titanium dioxide and the like, which are usually used in the production of polyester, an antioxidant, a stabilizer and a fluorescent agent. Whitening agents, pigments and the like can be used as necessary.

After the use of the phosphorus compound used in the present invention, the amount of phosphorus atom in the resulting polyester is 0.5 to 1.5 mol% with respect to the total acid component. If it is less than 0.5 mol%, when heat-treated at a temperature of 110 ° C. or higher in the presence of water,
It is not preferable because the intrinsic viscosity is not sufficiently lowered and the anti-pill performance is insufficient. Also, if it exceeds 1.5 mol%, not only the effect of improving the anti-pill performance is not further increased, but also the quality of the polyester is finally impaired, which is not preferable.

The phosphorus compound may be added at any step from the completion of the reaction of the first step in the above-mentioned polyester production to the completion of the reaction of the second step, but particularly after the completion of the reaction of the first step. The step immediately before the start of the reaction of the second step, or the initial step of the reaction of the second step is preferable.

The phosphorus-containing polymer obtained as described above is melt-spun to obtain a phosphorus-containing polyester fiber, in which the intrinsic viscosity of the phosphorus-containing polyester fiber is 0.38 to 0.45,
It is necessary to set the concentration of the acidic terminal group to 80 μeq / g or more. When the intrinsic viscosity is less than 0.38, the melt viscosity becomes too low, and problems such as yarn breakage during spinning are unpreferable. On the other hand, if it exceeds 0.45, it is necessary to perform heat treatment at a very high temperature for a long time in order to reduce the intrinsic viscosity of the polyester fiber to 0.36 or less when heat-treated at a temperature of 110 ° C. or higher in the presence of water. It is not preferable because it does. Further, if the concentration of the acidic end group is less than 80 μeq / g, it will be 11 in the presence of water.
When the heat treatment is performed at a temperature of 0 ° C. or higher, the intrinsic viscosity is insufficiently reduced, and the effect of improving the pill resistance becomes insufficient, which is not preferable. Further, the acidic terminal group may be any acidic group such as a carboxyl group and an acidic hydroxyl group.

As the method of containing the acidic terminal group concentration of 80 μeq / g or more, water is added in a step after the completion of polyester polycondensation until melt spinning, or the chip drying condition is adjusted so that the chip water content is higher than usual. The method of increasing the concentration of acidic terminal groups by hydrolyzing the polyester, such as remelting with a so-called direct weight method using terephthalic acid and ethylene glycol as starting materials, suppresses the progress of the esterification reaction to a low level A method such as a method of increasing the number of carboxyl groups present therein is used.

In the present invention, since the intrinsic viscosity of the phosphorus-containing polyester fiber is lowered to 0.36 or less, it is necessary to perform heat treatment at a temperature of 110 ° C. or more in the presence of water. At this time, the presence of water is indispensable, because the intrinsic viscosity is lowered by hydrolyzing the phosphorus-containing polyester. The temperature is 110 ° C. or higher, preferably 120 ° C. or higher and 180 ° C. or lower. If the temperature is less than 110 ° C, it takes a long time to reduce the intrinsic viscosity, or the intrinsic viscosity is less than 0.1.
It is not preferable because it does not decrease to 36 or less. Further, this heat treatment immediately after melt spinning, woven fabric, knitted fabric,
Although it may be carried out at any stage up to the final product such as a sewn product, it is particularly convenient to use the high temperature hot water treatment which is received in the dyeing process.

By using such spun yarn, heat retention,
Although it is possible to manufacture a woven or knitted fabric that is excellent in flexibility and pill resistance and is lightweight and soft, the spun yarn itself may be stretched by tensile stress and the voids may disappear, so the woven or knitted fabric was manufactured. It is preferable to dissolve and remove it later. Although it is possible to form a woven or knitted fabric using only such spun yarn, it is also possible to manufacture a woven or knitted fabric using a spun yarn and a solid yarn or a long fiber in view of the shape stability of the voids. The solid yarn referred to in the present invention has a porosity of the yarn of about 20% or less, and the long fiber is a filament made of processed yarn, raw yarn, or the like.

In order to prevent the voids of the spun yarn from disappearing, it is preferable that the load applied to the woven or knitted fabric be borne only by the solid. From this point, it is preferable to increase the mixing ratio of the solid yarn. If the proportion is too high, the lightness, bulkiness, softness, pill resistance, etc. of the woven or knitted material will be impaired. Therefore, in the case of a woven fabric, the ratio of the number of shots is 100: 0 to 2
It is preferably 0:80, particularly 40:60 to 60:40. In the case of a knit, it is preferably a plain knit and has a gauge of 20 to 22, particularly 22. The driving ratio and the gauge may be set appropriately according to the purpose.

As the solid yarn, yarns of any form such as spun yarn and filaments can be used, and like the hollow spun yarn, they can be composed of hollow fibers or modified cross-section fibers. The type of fiber used is not particularly limited, and synthetic fibers such as polyester fibers and polyamide fibers, and semi-synthetic fibers such as rayon may be appropriately selected and used. Those which do not deteriorate are preferable.

From the viewpoint of morphological stability of the void portion of the spun yarn,
It is preferable that the diameter (D1) of the spun yarn and the diameter (D2) of the solid yarn are close to each other, and 0.7 ≦ D1 / D2 ≦ 1 is particularly preferable. The diameter of the thread here is the diameter of a circle having the same area as the cross-sectional area of the thread (including voids and fiber portions).

The form of the woven or knitted fabric is not particularly limited and may be appropriately selected depending on the purpose and application. However, the present invention has a particularly light weight, soft feel, bulkiness and anti-pill property, and is therefore used for outer garments. Most suitable for knitting. No such knit is known in the market. In addition, the woven fabric has high elasticity, and an excellent effect can be obtained especially for clothing. The stretchability is lowered by mixing the solid yarns, and can be adjusted by the driving ratio of the solid yarns. An excellent woven or knitted product can be obtained by dissolving and removing the woven or knitted product after hot water treatment or alkali dissolution treatment. Of course, the woven or knitted material may be manufactured after the spun yarn is dissolved and removed.

The woven or knitted fabric using the spun yarn of the present invention is excellent in lightness, heat retention, hygroscopicity, stretchability, pill resistance, and the like, and thus can be used for various purposes. For example, for clothing, there are outer garments such as jackets, coats and sweaters, inner garments such as toner, polo shirts and underwear, and gloves, hats, mufflers and the like as winter clothes. Examples of living applications include decorative curtains and table cloths, and industrial applications include tents and canvas.

[0034]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. [Porosity of spun yarn] A cross section of the spun yarn is taken on an electron micrograph, and the area (S1) of the whole spun yarn is measured, and further the total area (S2) of the single fibers is measured. S1 and S2 of the other spun yarns were measured in the same manner, and the average value of S1 and S2 was obtained as the number of measurement 10 and the porosity of the spun yarn was calculated. [Loftiness, shape stability of voids, light weight, heat retention, softness, stretchability] Performance after 10 times of wearing and washing is ◎ (very good), ○ (good), △ (somewhat bad) ), ×
It was evaluated as (bad). [Anti-pill] From the pill generation status after 5 hours of ICI method, ◎
(4th grade), ◯ (3rd grade), Δ (2nd grade) × (1st grade).

Examples 1 and 2 Water-soluble polyvinyl alcohol fiber (Kuraray Co., Ltd. solvent-based PVA water dissolution temperature 60 ° C., 1.5 denier ×
38 mm) 70% by weight and polyester fiber (Kuraray Co., Ltd., 2.0 denier × 38 mm) 30% by weight are mixed and fed to a usual spinning process to supply 0.47 g / m (200 gelene / 200 gelene / A roving having a size of 30 yards was spun and spun (primary spinning).

Blending cotton process: Hopper mixer 2.5 m / min Cylinder opener 16 times / inch (beater number of strokes) Single beater 17 times / inch (beater number of strokes) Lapping machine 11 oz / yard Carding process: Takein 400 rpm / min Cylinder 200 revolutions / min Doffer 10 revolutions / min Spinning capacity 300 gellen / 6 yards (1 gellen = 1/7000 lbs) Cylinder to top gauge 15/1000 inch Drawing process: Total draft 6 to 8 times Appropriate spinning amount Grain 300 Gelen / 6 yards Roughing process: Total draft 5 to 8 times appropriate Spinning rate 200 Gelen / 30 yards Spinning process: Total draft 20 to 30 times Set appropriately according to spinning number Spindle speed 10,000 rotations / minute Traveler MS / Hf Winding process: Winding speed 50 m / min cheese amount eyes 3.75 lbs / cheese

The spun yarn A obtained was used as a core component and a sheath component in an amount of 30% by weight of water-soluble polyvinyl alcohol fiber (solvent-based PVA manufactured by Kuraray Co., Ltd., water dissolution temperature 60 ° C., 1.5 denier × 38 mm). Pill-type polyester fiber (manufactured by Kuraray Co., Ltd., has an intrinsic viscosity of 0.36 after heat treatment)
Hereinafter, a core-sheath type composite yarn was produced using a raw cotton mixed with 70% by weight of 1.4 denier × 38 mm). (Secondary spinning) A 22-gauge plain knitted fabric was produced using the composite yarn. The obtained knitted fabric is supplied to a hot air oven with a tenter at 185 ° C., heat-set at a constant length for 1 minute, boiled with hot water at 125 ° C. for 30 minutes to dissolve the solvent-based PVA, and dyeing at the same time, and then 105 ° C. And dried to obtain a bulky knit.
The results are shown in Table 1. The lightness was equivalent to the removed part. The knitted fabric was excellent in bulkiness, elasticity and heat retention. These characteristics did not change even after repeated washing.

Examples 3 and 4 The same core-sheath component as in Example 1 was used to pass through the carding step to obtain 300 gelene / 6 yard sliver.
In the subsequent drawing step, two core component slivers were supplied to the center and two sheath component slivers were supplied to both sides, and drafted 9 times to spun a 200 gelen / 6 yard sliver.
This filament sliver was fed to the roving process to obtain 0.47 g /
m of roving was spun and spun. Using the obtained core-sheath type composite yarn, a 22-gauge plain knit fabric was manufactured in the same manner as in Example 1.
The results are shown in Table 1.

Example 5 As a core component, the polyester fiber was changed to a hollow fiber (Kuraray Co., Ltd., hollow ratio: 8%, 1.5 denier × 38 mm), a spun yarn similar to that of Example 1 was spun, and 22 A gauge knitted fabric was manufactured. The results are shown in Table 1.

Comparative Example 1 A 22-gauge plain knitted fabric was produced from a spun yarn made of cotton fiber. The performance is shown in Table 1.

Comparative Example 2 A 22-gauge plain knitted fabric was produced by using a spun yarn made of raw cotton of polyester fiber (1.5 denier × 38 mm). The performance is shown in Table 1.

Comparative Example 3 Polyester hollow fiber (1.
A 22-gauge plain knitted fabric was produced using a spun yarn made of raw cotton with a denier of 5 denier x 38 mm and a hollow ratio of 8%. The performance is shown in Table 1.

[0043]

[Table 1]

[0044]

Industrial Applicability According to the present invention, it is possible to obtain a spun yarn which is excellent in lightness, heat retention and softness, and which can provide a comfortable woven and knitted fabric having bulkiness, stretchability and anti-pill property. it can. The woven or knitted fabric obtained by using such spun yarn can be used for various applications such as clothing or industrial use, but is particularly suitable for clothing because it is lightweight and has excellent heat retention and pill resistance.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a specific example of a novel spun yarn obtained by the present invention.

FIG. 2 is a schematic view showing an example of an apparatus used for primary spinning and secondary spinning.

[Explanation of symbols]

 1: Monofilament 2: Core part 3: Sheath part 4: Rough yarn 5: Back roller 6: Front roller 7: Spindle 8: Yarn obtained by primary spinning

Claims (5)

[Claims] 1. A core-sheath spun yarn, wherein the core portion and the sheath portion have different porosities. 2. The spun yarn according to claim 1, wherein the porosity of the core portion is higher than that of the sheath portion. 3. The spun yarn according to claim 1, wherein the sheath portion is mainly composed of fibers having an anti-pill property. 4. The spun yarn according to claim 1, wherein the monofilament denier of the fiber constituting the core portion is equal to or more than the monofilament denier of the fiber constituting the sheath portion. 5. The spun yarn according to claim 1, wherein the fiber forming the core is a hollow fiber or an atypical cross-section fiber.