CN107208321B

CN107208321B - Polyester hollow fiber spheroids

Info

Publication number: CN107208321B
Application number: CN201680007252.4A
Authority: CN
Inventors: 吉田哲弘; 宫内俊马; 安达皓太
Original assignee: Toray Industries Inc
Current assignee: Toray Industries Inc
Priority date: 2015-01-26
Filing date: 2016-01-22
Publication date: 2020-02-28
Anticipated expiration: 2036-01-22
Also published as: WO2016121643A1; KR20170104442A; JPWO2016121643A1; JP6645421B2; CN107208321A; KR102416737B1

Abstract

The invention provides a polyester hollow fiber spheroid which is light in weight, has excellent fluffiness, is soft and rich in texture similar to feathers, and is suitable for being used as a filling material of cushions, down coats and the like. The polyester hollow fiber spheroid of the invention is a fiber spheroid obtained by using polyester hollow fibers with single fiber fineness of 2.0 to 6.6dtex, a hollow rate of 15 to 35 percent, a crimp number of 2 to 8/25 mm, a crimp rate of 6 to 14 percent and a fiber length of 20 to 50mm, and has a bulk of more than 8,200 and 11,500cm³The volume is less than 50 g.

Description

Polyester hollow fiber spheroids

Technical Field

The present invention relates to polyester hollow fiber spheroids. More specifically, the present invention relates to a fibrous spheroid obtained using a polyester hollow fiber, which is not only lightweight and has excellent bulkiness, but also is soft and rich in texture similar to feathers, has excellent heat retaining properties, and is suitable as a filler material for mats, down jackets, and the like.

Background

Feathers and polyester staple fibers have been widely used as a filler material and a cushion material for down jackets and sleeping bags.

Feathers are generally feathers of waterfowls, and are known to have a bulky texture, light weight, excellent heat retaining properties, easy attachment to the body, excellent filling power, and a high recovery rate. However, when natural feathers are to be obtained, there are problems in that the supply amount is limited and the supply amount fluctuates due to the influence of natural conditions and epidemic diseases.

Further, from the viewpoint of natural conservation, there is a limit in catching wild birds, and when waterfowl is desired to be raised to obtain feathers, it is necessary to raise a large number of waterfowls, and as a result, not only a large amount of feed is required, but also water pollution due to the excrement of waterfowl, and the occurrence and spread of infectious diseases are problematic.

Further, in order to use the feathers as lining cotton, it is necessary to go through a plurality of steps such as feather collection, selection, sterilization, degreasing, covering and filling, and the like, and the work becomes complicated in terms of scattering of the feathers, and as a result, the product manufacturing tool obtained by using the feathers tends to be expensive.

Further, meat remains at the end of feathers during hair collection, which causes putrefactive odor, and in europe and the like, there is a movement to abolish feathers from the viewpoint of animal protection.

On the other hand, polyester staple fibers are inexpensive and have excellent bulkiness, and are excellent in spinning properties when produced into fibers and processability when processed into products such as nonwoven fabrics. Thus, it is well known that: a method in which polyester staple fibers are opened by a carding machine or the like, and fiber webs are laminated to obtain a sheet, and the obtained sheet is covered with a covering. However, this method has a problem in that much effort is required to cover the layered fiber web laminate with the sheath.

In order to solve such problems, fillers made of highly elastic fibrous spheroids (fibrous balls) having a soft texture, excellent elasticity, and excellent compression durability and having morphological stability have been proposed (see patent documents 1 and 2).

Further, as a main material of the spherical cotton, polyester fiber, polyamide fiber, polyolefin fiber, and acrylic fiber have been proposed (see patent documents 3 and 4).

However, the proposals of patent documents 1, 2, 3 and 4 have a problem that the fiber material used is, for example, a fibrous sphere composed of a polyester fiber and a binder fiber, and the binder fiber is thermally fused by hot air or the like when the fibrous sphere is formed, and therefore, the fiber shrinks during thermoforming to form a fibrous sphere having a high density, and the flexibility of the fibrous sphere is poor, or the flexibility of the spherical sphere is poor due to the presence of a thermally bonded portion.

Further, a cushion material has been proposed in which a surface of spherical cotton is sprayed with an adhesive liquid and the spherical cotton is subjected to mold molding to bond the surface of spherical cotton and the surface of another spherical cotton (see patent document 5). However, this proposal has a problem that since the binder liquid is sprayed to the spherical cotton and the mold is formed, the spherical bodies are bonded to each other, and thus the processability, that is, the blowability of the final product is poor, the flowability of the spherical bodies is poor, or the bulkiness is reduced.

Furthermore, a fiber spheroid is proposed, which is obtained by: the tow is stretched and then heat-treated to thermally cure the silicone smoothing agent applied to the surface, and after cutting, the tow is heat-treated again to obtain a fiber, and the obtained fiber is molded to obtain a fiber sphere (see patent document 6). However, since the tow is thermally cured before cutting by stretching and then heat-treating the tow to cure the silicone smoothing agent and then heat-treating the tow again after cutting, the tow has a problem in that the crimped form is a three-dimensional spiral form and forms a random form in the S direction and the Z direction, and the obtained fibrous spheroids are excessively entangled, have a hard texture, and have poor bulkiness.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2002-212868

Patent document 2: japanese patent laid-open publication No. 2007-169846

Patent document 3: japanese laid-open patent publication No. H10-259559

Patent document 4: japanese patent laid-open publication No. S61-125377

Patent document 5: japanese patent laid-open publication No. 2003-1699978

Patent document 6: japanese patent laid-open publication No. 62-033856.

Disclosure of Invention

Problems to be solved by the invention

Accordingly, an object of the present invention is to solve the above problems of the prior art and to provide a polyester hollow fiber sphere which is light in weight, has excellent bulkiness, is soft and has a texture similar to that of a feather, and is suitable as a filler material for a mat, a down jacket, or the like.

Means for solving the problems

The inventors believe that: in order to obtain a fibrous sphere having both light weight and bulkiness, a polyester hollow fiber is suitably used. Further, attention has been paid to the relationship between the crimp form of the polyester hollow fiber and the bulkiness of the obtained fiber spherical body, and studies have been repeated in order to obtain an appropriate crimp form. Further, the single fiber fineness and the hollow ratio of the polyester hollow fiber were also repeatedly studied, and the present invention was conceived.

That is, the present invention has been made to achieve the above object, and the polyester hollow fiber spherical body of the present invention is a fiber spherical body having a single fiber fineness of 2.0 to 6.6dtex, a hollow ratio of 15 to 35%, a crimp number of 2 to 8/25 mm, a crimp rate of 6 to 14%, and a fiber length of 20 to 50mm, and is characterized by having a bulk density of 8,200 to 11,500cm inclusive³The volume is less than 50 g.

According to a preferred embodiment of the polyester hollow fiber spheroid of the present invention, the intrinsic viscosity of the polyester hollow fiber is 0.60 to 0.75.

According to a preferred embodiment of the polyester hollow fiber spheroid of the present invention, an oil agent containing polysiloxane is attached to the polyester hollow fiber in a proportion of 0.3 to 1.0 mass% with respect to the mass of the polyester hollow fiber.

According to a preferred embodiment of the polyester hollow fiber spheroid of the present invention, the fiber friction coefficient μ s of the polyester hollow fiber is 0.06 to 0.14.

According to a preferred embodiment of the polyester hollow fiber spheroid of the present invention, the polyester hollow fiber has a crimp ratio represented by the following formula (1) of 1.5 to 3.0,

seeds and seeds (1) with the seed and seed curvature ratio = curvature/curl ratio.

The method for producing a polyester hollow fiber spheroid of the present invention is characterized in that polyester is spun from a spinning die for hollow fibers, asymmetrically cooled by blowing cooling air from one side of the spun fibers, then drawn and hot-drawn, then an oil solution containing polysiloxane is applied without passing through a crimp-imparting step, cut to a predetermined fiber length, then a crimp is expressed in a spiral shape by heating steam treatment, and then heat-set to obtain a polyester hollow fiber, and the obtained polyester hollow fiber is opened to be processed into a fiber spheroid.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a fibrous spheroid obtained using polyester hollow fibers, which is light in weight, has excellent bulkiness, is soft, has a texture similar to that of feathers, has excellent heat retaining properties, and is suitable as a filler material for mats, down jackets, and the like, can be obtained.

Drawings

Fig. 1 is a drawing substitute photograph illustrating a polyester hollow fiber spheroid of the present invention.

Detailed Description

Next, embodiments of the polyester hollow fiber spherical body and the method for producing the same of the present invention will be specifically described.

The polyester hollow fiber spheroid is a fiber spheroid obtained by using polyester hollow fiber, the polyester hollow fiber is formed by polyester with the intrinsic viscosity of 0.60-0.75, the single fiber fineness of the polyester hollow fiber is 2.0-6.6 dtex, the hollow rate is 15-35%, the number of curls is 2-8/25 mm, the percentage of curliness is 6-14%, the fiber length is 20-50 mm, an oil agent containing polysiloxane is attached in a proportion of 0.3-1.0% relative to the mass of the polyester fiber, and the fiber friction coefficient mu s is 0.06-0.14; and the polyester hollow fiber spheroid has a filling power of more than 8,200 to 11,500cm³Less than 50g of spheroids formed by polyester hollow fibers.

Examples of the polyester constituting the polyester hollow fiber used in the present invention include polyethylene terephthalate, polybutylene terephthalate, poly-1, 3-propylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, and among them, polyethylene terephthalate is preferably used.

The intrinsic viscosity of the polyester used in the present invention is preferably 0.60 to 0.75. The intrinsic viscosity is more preferably 0.62 to 0.72. When the intrinsic viscosity is less than 0.6, the expression of the crimp decreases, the degree of crimp decreases, and the fibers are less likely to be formed into a spherical shape when processed into a fibrous spheroid, and the fibrous spheroid is less likely to be formed. Further, the rigidity of the fiber is also low, and thus a fiber spheroid having a sufficient bulkiness may not be obtained. On the other hand, if the intrinsic viscosity exceeds 0.75, the melt viscosity may become high, making it difficult to produce fibers.

It is important that the single fiber fineness of the polyester hollow fiber used in the present invention is 2.0 to 6.6 dtex. The single fiber fineness is preferably 2.2 to 4.4 dtex. If the common single fiber fineness is less than 2.0dtex, the common single fiber fineness becomes small, and hence the expression of crimp is reduced, and the degree of crimp is lowered, so that the fibers are difficult to be agglomerated into a spherical shape when processed into a fibrous spheroid, and the fibrous spheroid is difficult to be formed. Further, the rigidity of the fiber is low, and thus a fiber spheroid lacking in bulkiness is formed. On the other hand, if the single fiber fineness exceeds 6.6dtex, the rigidity when the fiber is produced becomes high, and a soft fibrous spheroid similar to a feather cannot be obtained.

It is important that the hollow ratio of the polyester hollow fiber used in the present invention is 15 to 35%. The hollow rate is more preferably 20 to 30%. If the hollow ratio is less than 15%, asymmetric cooling becomes insufficient, the expression of curling decreases, the degree of curling decreases, and the fibers are less likely to be formed into a spherical shape when processed into a fibrous sphere, and the fibrous sphere is less likely to be formed. On the other hand, if the hollow rate exceeds 35%, there are cases where the number of broken ends in yarn production is large and it is difficult to stably produce fibers.

The hollow ratio of the polyester hollow fiber can be calculated by enlarging a cross section of the fiber, and the ratio of the area of the hollow portion to the total area of the cross section of the fiber including the hollow portion can be expressed by%.

In the present invention, the hollow means: in the cross section of the fiber, a hollow part is provided inside the outer shape of the fiber. The hollow portion is preferably located at the center of the fiber, but may be located eccentrically from the center of the fiber, and is preferably located at the center of the fiber.

The hollow rate depends on the tube head design, the intrinsic viscosity of the polyester and the cooling conditions, and can be controlled by a person skilled in the art through various specific settings.

It is important that the number of crimps of the polyester hollow fiber used in the present invention is 2 to 8/25 mm. The number of crimps is preferably 3 to 7/25 mm. If the number of crimps is less than 2/25 mm, the fibers are less likely to be formed into a spherical shape when processed into a fibrous sphere, and the fibrous sphere is less likely to be formed. On the other hand, if the number of crimps exceeds 8/25 mm, the diameter of the obtained fiber spherical body becomes small and the density thereof becomes high, thereby forming a fiber spherical body lacking in bulkiness.

The crimp ratio of the polyester hollow fiber used in the present invention is preferably 6 to 14%. The curling rate is more preferably 8 to 12%. If the percentage of crimp is less than 6%, the fibers are less likely to form balls when processed into fibrous spheroids, and the fibrous spheroids are less likely to be formed. On the other hand, if the crimping rate exceeds 14%, the diameter of the obtained fiber spherical body becomes small and the density becomes high, and a fiber spherical body lacking bulkiness is formed.

It is important that the length of the polyester hollow fiber used in the present invention is 20 to 50 mm. The fiber length is preferably 25 to 40 mm. If the fiber length is less than 20mm, the entanglement of the fibers becomes weak when processed into a fibrous spheroid, and the entanglement of the fibers is released, making it difficult to maintain the shape of the spheroid. On the other hand, if the fiber length exceeds 50mm, the fibers are less likely to be agglomerated into a spherical shape when processed into a fibrous sphere, and the fibrous sphere is less likely to be formed, and further the fibrous spheres are more likely to be entangled with each other, so that the fluidity is insufficient and the product quality is poor.

It is preferable that the oil agent containing polysiloxane is applied and adhered in a range (ratio) of 0.3 to 1.0 mass% with respect to the mass of the polyester hollow fiber used in the present invention. The amount of oil agent deposited is more preferably 0.4 to 0.8 mass%. If the amount of the oil agent containing polysiloxane is less than 0.3% by mass, the smoothness of the fiber is lowered, and the fiber spheroids are likely to be entangled with each other, so that the flowability of the fiber spheroids may be poor, and the product quality may be poor. On the other hand, even if the amount of oil agent deposited exceeds 1.0 mass%, further improvement in fiber smoothness is not observed, and there is a problem that unit consumption is deteriorated.

As the polysiloxane used in the present invention, for example, amino-modified silicone or the like can be used. The silicone is applied to the polyester hollow fibers and the polyester hollow fibers are adhered to the polyester hollow fibers by applying an oil agent containing silicone. The oil agent preferably contains a phosphoric acid-based compound, an aliphatic compound, and a halogen-based compound in addition to the polysiloxane, and more preferably contains an antioxidant, a flame retardant, and an antistatic agent.

The oil agent containing polysiloxane is preferably applied immediately before the tow is cut in the step of producing the short fibers of the polyester hollow fibers used in the present invention. When the oil is applied, it is preferable to apply an oil aqueous solution having a polysiloxane concentration of preferably 3 to 10% by mass, more preferably 4 to 8% by mass to the polyester hollow fiber, and then dry the polyester hollow fiber at an arbitrary temperature.

The fiber friction coefficient μ s of the polyester hollow fiber used in the present invention is preferably 0.06 to 0.14. The fiber friction coefficient μ s is more preferably 0.07 to 0.12. When the fiber friction coefficient μ s is less than 0.07, the smoothness of the fiber is lowered, and the fiber spheroids are likely to be entangled with each other, which may cause the fiber spheroids to lack fluidity and deteriorate the product grade. On the other hand, even if the fiber friction coefficient μ s exceeds 0.12, no further improvement in fiber smoothness is observed.

Importantly, the bulkiness of the polyester hollow fiber spheroid is more than 8,200 and less than 11,500cm³The volume is less than 50 g. The preferred bulk density is more than 9,000-10,700 cm³The volume is less than 50 g. If the bulk is less than 8,200cm³50g, bulkiness was not obtained, and fibrous spheroids with poor light weight and filling were formed. On the other hand, it is difficult to obtain a bulkiness of more than 11,500cm³Production conditions of 50g of fibrous spheroids.

The ratio of the crimp ratio of the polyester hollow fiber used in the present invention is preferably 1.5 to 3.0. The percentage crimp ratio is more preferably 8 to 12%. If the crimp ratio is less than 1.5, the fibers are less likely to be formed into a spherical shape when processed into a fibrous spheroid, and the formation of a fibrous spheroid is less likely to occur. On the other hand, if the crimp ratio exceeds 3.0, it is difficult to stably produce fibers for obtaining high crimp expression.

The ratio of the curling rate is represented by the following formula (1).

Curvature ratio = curvature/curl number, seed (1).

Next, a description will be given by specifically exemplifying one embodiment of a polyester hollow fiber used in the present invention and a method for producing a polyester hollow fiber spheroid.

First, polyester is melted, and melt-spun at a spinning temperature of about 15 to 30 ℃ higher than the melting point through a spinneret preferably having 90 to 400 hollow fiber ejection holes to form a hollow portion, and immediately after spinning, air having a temperature of preferably 10 to 25 ℃ is asymmetrically cooled at an air volume of preferably 80 to 130 m/min, further air having a temperature of preferably 10 to 25 ℃ is cooled at an air volume of preferably 140 to 170 m/min, and a spinning finish is applied, and the resultant is temporarily stored in a kettle at a drawing speed of preferably 1000 to 1700 m/min, thereby obtaining an undrawn yarn bundle.

Next, the obtained undrawn yarn bundle is subjected to a stage 1 drawing preferably at a draw ratio of 2.3 to 3.0 times, preferably using a liquid bath at a temperature of 75 to 100 ℃, an oil solution containing an oil agent containing polysiloxane preferably at a concentration of 3 to 10 mass% is applied by spraying so as to preferably reach a range of 0.3 to 1.0 mass% with respect to the mass of the fiber without passing through a crimp application step, the fiber is cut into a predetermined fiber length, a crimp is expressed in a spiral shape by a heating steam treatment at a temperature of preferably 100 to 250 ℃, and heat setting is performed at a temperature of preferably 145 to 165 ℃ for preferably 5 to 20 minutes, whereby a polyester hollow fiber can be produced.

The spiral crimp refers to a coil-like crimp exhibited by the fiber.

In the method for forming a polyester hollow fiber spheroid of the present invention, the polyester hollow fiber obtained in the above-described manner is sufficiently opened using a carding machine or the like provided with a plurality of rollers having saw-toothed strips on the surface thereof, a rotating body which rotates with a plurality of blades is provided in a cylindrical space in which air turbulence is easily caused in a room, and the fiber sufficiently opened is spheroidized by a device or the like which blows the fiber and turbulently stirs the fiber for a predetermined time and then takes out the fiber, or the fiber sufficiently opened is spheroidized by causing air turbulence in a room having a large degree of size to be accumulated, and the fiber is subjected to a mechanical force from a rigid body (blade) or air, whereby the curl of a loop is further increased, and a fiber spheroid can be formed.

The size of the polyester hollow fiber spheroids is preferably 3 to 8mm, more preferably 4 to 6mm, in average diameter. The fibrous spherical bodies having an average diameter of less than 3mm are difficult to process, and if the average diameter exceeds 8mm, the fibrous spherical bodies are not easy to process such as blowing.

Fig. 1 is a drawing substitute photograph illustrating a polyester hollow fiber spheroid of the present invention. The polyester hollow fiber spheroids of fig. 1 had small dimensional variations, good bulkiness, and substantially no unformed fibers.

The polyester hollow fiber spheroids of the present invention are light in weight, have excellent bulkiness, are soft and rich in texture similar to feathers, and are suitable as filler materials for mats, down jackets, and the like.

Examples

Next, the polyester hollow fiber spherical body and the method for producing the same according to the present invention will be described in detail with reference to examples. The measurement methods of physical properties and the like are as follows.

(intrinsic viscosity)

The sample was dissolved in o-chlorophenol, the natural falling time was measured using an Ubbelohde viscometer, and the intrinsic viscosity was determined as a relative value to the standard sample using an average value of N = 3.

(Single fiber fineness, number of crimps, crimp ratio, fiber length and fiber friction coefficient. mu.s)

Measured according to JIS L1015 (2010).

(ratio of crimping rate)

The number of crimps and the degree of crimp were measured in accordance with JIS L1015 (2010), and the ratio of the degree of crimp was calculated by the method shown in formula 1.

(formula 1) crimp ratio = crimp/number of crimps.

(amount of oil agent containing polysiloxane adhered to the fiber mass.)

The sample was decomposed with fuming sulfuric acid and fuming nitric acid, carbonized in an electric furnace, and then dissolved with alkali. Thereafter, the mixture was developed with ammonium molybdate, the absorbance was measured with a spectrophotometer, the inorganic silicone (Si) amount was calculated from the calibration curve, and the average value of N =3 was converted into the oil amount.

(hollow ratio)

The cross section of the resulting polyester hollow fiber was photographed at 400 times using a microscope, and the photograph of the cross section was further magnified and copied. The copy paper was cut to obtain a fiber section, and the mass of N =20 was measured by an electronic balance. Next, the hollow portion was cut out, and the mass of N =20 was measured with an electronic balance, and the mass ratio was calculated as shown in the following formula (2).

Void fraction (%) = (hollow portion mass/fiber portion cross-sectional mass) × 100, seeds, and seeds (2).

(filling power of fiber spheroid)

A sample of fibrous spheroids (50 g. + -. 0.1 g) was weighed out, and put into a measuring cylinder having an inner diameter of 28.8cm and a height of 50cm, and a load of 94.3g was applied thereto to measure the bulk after 5 minutes. The measurement results were averaged 5 times and calculated by the following formula (3).

Bulk = V = π d²H/4 (unit: cm)³/50g)・・・(3)

(wherein d is the inner diameter d =28.8cm of a measuring cylinder described below; H is the bulk (average value) of the sample in cm).

(diameter of fiber spheroid)

The diameter of an arbitrarily selected fiber spheroid was measured by a vernier caliper, and the average value of N =100 was obtained.

(texture/softness of fiber spheroids)

The 10 experts rated the feel (texture; softness/softness) when touched with a hand, and rated good to bad as 5 to 0 points, and if the average point exceeded 4 points, it was rated as good (○) and below 4 points, it was rated as bad (x).

[ example 1]

The polyester hollow fiber was produced by the following method. Polyethylene terephthalate (melting point 260 ℃) having an intrinsic viscosity of 0.650 was melted, melt-spun at a spinning temperature of 280 ℃ through a hollow die having 300 discharge holes, immediately after spinning from the die, air having a temperature of 20 ℃ was asymmetrically cooled at an air flow rate of 100 m/min, and then an undrawn yarn was obtained at a drawing speed of 1500 m/min.

Next, the obtained undrawn yarn was subjected to 1-stage drawing at a draw ratio of 2.6 times using a liquid bath at a temperature of 80 ℃, an oil agent containing polysiloxane was applied by spraying without passing through the crimp-imparting step, the yarn was cut into a predetermined fiber length shown in table 1, the yarn was wound into a spiral shape by a heating steam treatment at a temperature of 200 ℃, and heat-set at a temperature of 165 ℃ for 10 minutes, thereby producing polyester hollow fibers having each characteristic shown in table 1.

Then, the obtained polyester hollow fiber was sufficiently opened by a carding machine provided with a plurality of rolls each having a saw-toothed strip on the surface thereof, a rotating body which rotates with a plurality of blades was provided in a cylindrical space in a room where air turbulence is likely to occur, and a device which blows in the fiber, turbulently agitates the fiber for a predetermined period of time, and then takes out the fiber in the room, thereby obtaining a polyester hollow fiber spherical body. It was confirmed that the obtained fiber structure had excellent bulkiness and was a soft polyester hollow fiber spheroid. The results are shown in Table 1.

Comparative example 1

Polyester hollow fibers were produced under the same conditions as in example 1 except that polyester hollow fibers having a fiber length of 64mm were produced, and polyester hollow fiber spheroids were obtained. Since the polyester hollow fibers constituting the obtained polyester hollow fiber spheroids have a long fiber length, the fibers are less likely to be agglomerated into a spherical shape when processed into a fiber spheroid, and defective portions of the shape of the fiber spheroids and portions where the fiber spheroids are entangled with each other are observed. The results are shown in Table 1.

Comparative example 2

A polyester hollow fiber was produced under the same conditions as in example 1 except that a polyester hollow fiber having a single fiber fineness of 1.7dtex was produced, to obtain a fiber spheroid. Since the single fiber fineness and the crimp rate are low, the fibers are less likely to be agglomerated into a spherical shape when processed into a fiber sphere, and the polyester hollow fiber sphere cannot be formed. The results are shown in Table 1.

Comparative example 3

Polyester hollow fibers were produced under the same conditions as in example 1 except that polyester hollow fibers having a single fiber fineness of 7.5dtex were produced, and fiber spheroids were obtained. Since the single fiber fineness was large and the fiber rigidity was high, a fibrous spheroid lacking in softness was obtained. The results are shown in Table 1.

Comparative example 4

In example 1, the same procedure was followed as in the step of applying the oil agent containing polysiloxane by spraying, and thereafter, heat-setting was performed at 160 ℃ for 10 minutes, and then, the fiber was cut into a predetermined fiber length, and heat-setting was performed at 160 ℃ for 10 minutes, thereby producing polyester hollow fibers having the characteristics shown in table 1, and obtaining fibrous spheroids. Since the curled form is a three-dimensional spiral and is random in the S direction and the Z direction, the obtained fibrous spheroids are excessively entangled, and are hard, and further, the fibrous spheroids having poor bulkiness are formed. The results are shown in Table 1.

[ Table 1]

。

Claims

1. A polyester hollow fiber spheroid, which is a fiber spheroid obtained by using a polyester hollow fiber with a single fiber fineness of 2.0 to 6.6dtex, a hollow rate of 15 to 35 percent, a crimp number of 2 to 8/25 mm, a crimp rate of 6 to 14 percent and a fiber length of 20 to 50mm, and is characterized in that the power of the spheroid is more than 8,200 and 11,500cm³The volume is less than 50 g.

2. The polyester hollow fiber spheroid of claim 1, wherein the intrinsic viscosity of the polyester hollow fiber is 0.60 to 0.75.

3. The polyester hollow fiber spheroid according to claim 2, wherein an oil agent containing polysiloxane is attached to the polyester hollow fiber in a proportion of 0.3 to 1.0 mass% with respect to the mass of the polyester fiber.

4. The polyester hollow fiber spheroid of claim 3, wherein the fiber friction coefficient μ s of the polyester hollow fiber is 0.06 to 0.14.

5. The polyester hollow fiber spheroid of claim 1, wherein the polyester hollow fiber represented by the following formula (1) has a crimp ratio of 1.5 to 3.0,

crimp ratio = crimp/crimp number · (1).

6. A down jacket comprising the hollow fiber spheroids of claim 1 as a filler.

7. A process for producing a polyester hollow fiber spheroid according to claim 1, characterized in that a polyester is spun from a spinning die for a hollow fiber, asymmetrically cooled by blowing a cooling air from one side of the spun fiber, drawn, hot-drawn, then a finish comprising a polysiloxane is applied without passing through a crimp-imparting step, cut to a predetermined fiber length, a crimp is expressed in a spiral shape by heating steam treatment, and then heat-set to obtain a polyester hollow fiber, and the obtained polyester hollow fiber is opened to be processed into a fiber spheroid.