CN111328354A - Fiber structure and method for producing same - Google Patents

Abstract

The present invention relates to a fiber structure comprising a coiled crimped fiber (a) and a non-coiled crimped fiber (B), wherein the fiber structure has a wound part (A) comprising the coiled crimped fiber (a) and a wound part (B) comprising the non-coiled crimped fiber (B), and the distance between at least one wound part (B) in the direction of circulation of the fiber structure is less than the apparent average fiber length of the coiled crimped fiber (a).

Description

Fiber structure and method for producing same

Technical Field

The present invention relates to a fiber structure suitable for use as a bandage or the like, and a method for producing the same.

Background

Conventionally, in the fields of medical treatment, sports, and the like, various kinds of bands such as bandages and protective bands have been used for the purpose of appropriately compressing, fixing, and protecting applied parts such as limbs, affected parts, and the like. These tapes are required to have stretchability, conformability, sweat absorption, air permeability, and the like, as well as fixability by self-adhesion or adhesion.

Generally, a soft component such as rubber or acrylic latex is applied to the surface of a bandage for the purpose of satisfying stretchability and fixability (patent documents 1 to 5). However, these soft components may cause irritation to the skin, stuffiness due to lack of air permeability, or even allergy, and are not preferable from the viewpoint of safety.

In order to reduce irritation to the skin, a medical material using a low-protein natural rubber latex as an adhesive (patent document 6) and a self-adhesive bandage using a specific acrylic polymer as an adhesive (patent document 7) have been proposed. However, these medical materials and self-adhesive bandages still use adhesives, and the problems are not fundamentally solved.

As nonwoven fabrics that can realize self-adhesion without adding an adhesive, there have been proposed composite fibers having latent heat crimpability, nonwoven fabrics that have elasticity and can be easily torn by hand (patent document 8), and high-stress elastic nonwoven fabrics that can be reused (patent document 9).

Documents of the prior art

Patent document

Patent document 1: japanese examined patent publication No. 48-000309

Patent document 2: japanese patent application laid-open No. 63-068163

Patent document 3: japanese patent application laid-open No. 63-260553

Patent document 4: japanese unexamined patent publication Hei 01-19035

Patent document 5: japanese unexamined patent publication No. 11-089874

Patent document 6: japanese Kokai publication No. 2003-514105

Patent document 7: japanese unexamined patent application publication No. 2005-095381

Patent document 8: international publication No. 2008/015972

Patent document 9: international publication No. 2016/031818

Disclosure of Invention

Technical problem to be solved by the invention

However, the nonwoven fabric described in patent document 8 is easily broken when strongly entangled. The nonwoven fabric described in patent document 9 has a characteristic of being hard to break when strongly entangled because of high stress, but tends to have high stress when stretched at low elongation, and there is still room for improvement in initial conformability.

Accordingly, an object of the present invention is to provide a fiber structure that has extremely low stress at low elongation and good initial conformability, has extremely high stress at high elongation and can be strongly entangled, is easily elongated, and is difficult to break.

Technical solution for solving technical problem

The inventors of the present invention have found that the nonwoven fabric described in patent document 8 has low strength and is easily elongated, but may be broken, because the developed curled portions are entangled with each other. Further, the nonwoven fabric obtained by treating with high-speed steam is bonded by entangling with the sheet itself by the spunlace method and the needle punching method described in patent document 9, and the developed curl is not generated, and it is difficult to obtain the shrinkage.

The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that the above object can be achieved if a fiber structure has a wound part (a) composed of coiled crimped fibers (a) and two or more wound parts (B) composed of non-coiled crimped fibers (B), and the distance between at least one wound part (B) in the flow direction of the fiber structure is shorter than the apparent average fiber length of the coiled crimped fibers (a).

That is, the present invention includes the following components.

[1] A fiber structure comprising a coiled crimped fiber (a) and a non-coiled crimped fiber (B), wherein the fiber structure has a wound part (A) comprising the coiled crimped fiber (a) and two or more wound parts (B) comprising the non-coiled crimped fiber (B), and the distance between at least one wound part (B) in the direction of circulation of the fiber structure is less than the apparent average fiber length of the coiled crimped fiber (a).

[2] The fiber structure according to [1], wherein the ratio of the area of the wound part (A) to the surface area of the fiber structure is 20 to 85%.

[3]Such as [1]]Or [2]]The fiber structure, the thickness (T) of the wound part (A)_A) With the thickness (T) of the winding part (B)_B) Has a ratio of T_A/T_B＝1.1～10。

[4] The fiber structure according to any one of [1] to [3], wherein the stress at 50% elongation in the flow direction of the fiber structure is 15N/5cm or less, and the stress at 80% elongation is 20N/5cm or more.

[5] The fiber structure according to any one of [1] to [4], wherein the ratio of the stress at 50% elongation to the stress at 80% elongation in the flow direction of the fiber structure, i.e., the stress at 80% elongation/the stress at 50% elongation is 2.7 or more.

[6] The fiber structure according to any one of [1] to [5], wherein the coiled crimped fiber (a) is composed of a conjugate fiber having a phase structure formed by a plurality of resins having different thermal shrinkage rates or thermal expansion rates.

[7]Such as [1]]～[6]The fiber structure of any one of the above, having a mass per unit area of 50 to 200g/m²。

[8] A bandage comprising the fiber structure according to any one of [1] to [7 ].

[9] A method for producing a fiber structure according to any one of [1] to [8], comprising:

1) a step of forming a web of the fibers;

2) a step of forming a entangled portion (B) by entangling a part of the web by spraying or jetting water;

3) and a step of forming a wound part (A) by heating the web with high-temperature steam.

ADVANTAGEOUS EFFECTS OF INVENTION

The fiber structure of the present invention has excellent initial conformability and can be strongly wound, and therefore, is suitably used for a bandage or the like.

Drawings

Fig. 1 is a schematic view showing an arrangement pattern of a winding part (B) in a flow direction of a fiber structure obtained in example 1.

FIG. 2 is a schematic diagram showing a method of preparing a sample for measuring a sliding stress of a curved surface.

FIG. 3 is a schematic sectional view showing a sample for measuring a sliding stress on a curved surface.

Fig. 4 is a schematic diagram showing a method for measuring the curved surface sliding stress.

Detailed Description

[ fiber Structure ]

The fiber structure of the present invention (hereinafter simply referred to as "fiber structure") has a wound portion (a) composed of coiled crimped fibers (a) and a wound portion (B) composed of non-coiled crimped fibers (B). The fiber structure of the present invention has a structure in which coiled crimped fibers (a) are wound around each other at their coiled-coil portions and are bound or hooked at the wound portion (a). On the other hand, in the wound portion (B), the wound portion is formed not by the curling of the non-coil-like curled fibers (B) but by compressing the fibers. The coiled crimped fiber (a) and the non-coiled crimped fiber (b) are preferably oriented in the direction of flow of the fiber structure, and the coiled crimped fiber (a) is preferably coiled along the orientation axis.

The flow direction of the fiber structure means a flow direction (MD direction) of the fiber structure in the production process, and when the fiber structure has a longitudinal direction and a width direction, for example, like a bandage, the longitudinal direction is preferable. In this case, the fibrous structure serving as a bandage can be elongated in the longitudinal direction thereof and wound around an application site. When the fiber structure has a longitudinal direction and a width direction, it is preferable that the CD direction, which is a direction orthogonal to the MD direction, is the width direction.

The fiber structure of the present invention has extremely low stress at low elongation and excellent initial conformability because the fibers are weakly entangled with each other in the entangled portion (a). Since the fibers are strongly entangled with each other in the entangled portion (B), the fibers can be entangled with extremely high stress at the time of high elongation.

The distance between at least one wound portion (B) in the fiber structure flowing direction of the fiber structure of the present invention (hereinafter simply referred to as "the distance between the wound portions (B)) is smaller than the apparent average fiber length of the coiled crimped fiber (a). The distance between the winding parts (B) in the direction of flow of the fiber structure is the shortest distance in the direction of flow between an arbitrary winding part (B) of the fiber structure and another winding part (B) closest to the winding part (B) in the direction of flow. When the distance between the wound portions (B) is equal to or longer than the apparent average fiber length of the coiled crimped fiber (a), the wound portions (B) are entangled with each other only by the coiled spiral portion of the coiled crimped fiber (a), and the entangled spiral portion is stretched and spread at high elongation, and therefore, the wound portions tend to be easily cut at the wound portions. On the other hand, if the distance between the wound portions (B) is shorter than the apparent average fiber length of the coiled crimped fiber (a), at least one end of the coiled crimped fiber (a) is entangled in the wound portions (B), and therefore the coiled crimped fiber (a) does not unravel even at high elongation and tends to easily exert high stress at high elongation. From the above viewpoint, it is preferable that both ends of at least a part of the coiled crimped fiber (a) are entangled in the wound part (B).

It is preferable that the two winding portions (B) constituting the distance between the winding portions (B) are arranged such that at least a part of them is entangled with the coiled crimped fiber (a) oriented in the circulating direction. When the wound portion (B) is entangled with the coiled crimped fiber (a), high stress tends to be easily obtained at high elongation. The larger the number of the coiled crimped fibers (a) entangled with the wound portion (B), the more likely the wound portion (B) and the coiled crimped fibers (a) are strongly entangled with each other. The wound portions (B) may be formed regularly in the plane of the sheet when the fiber structure is in the form of a sheet, and are preferably arranged in a boundary pattern in which the wound portions (a) and the wound portions (B) are alternately arranged with respect to the flow direction, or in a planar lattice pattern in which the wound portions (B) having a specific shape are regularly arranged, such as a square lattice pattern, a rhombic lattice pattern, a rectangular lattice pattern, or the like. Fig. 1 shows a distance 4 between a wound part (B)2, a wound part (a)3, and a wound part (B) of a fiber structure 1 having a diamond lattice pattern, which can be obtained in example 1 described later.

When the winding part (B) is arranged in a boundary-like pattern, the width (length in the circulating direction) of the winding part (B) may be, for example, 0.5 to 30mm, preferably 1 to 20mm, more preferably 2 to 10mm, and further preferably 3 to 8 mm.

When the winding parts (B) are arranged in a planar lattice pattern, the interval in the direction perpendicular to the flow direction (the interval in the direction perpendicular to the "distance between the winding parts (B)) may be, for example, 0.5 to 30mm, preferably 1 to 20mm, more preferably 2 to 10mm, and still more preferably 3 to 8 mm.

When the winding portions (B) are arranged in a planar lattice pattern, the shape of the winding portions (B) is not particularly limited, but may be, for example, an oblong shape, an oval shape, a circular shape, a square shape, a rectangular shape, or the like, and is preferably an oblong shape. In the case of the oblong shape, the length in the major axis direction may be, for example, 1 to 80mm, preferably 5 to 60mm, and more preferably 10 to 40mm, and the length in the minor axis direction may be, for example, 1 to 80mm, preferably 3 to 50mm, and more preferably 5 to 30 mm.

In the fiber structure, the higher the proportion of the wound portions (B) to each other below the apparent average fiber length of the coiled crimped fiber (a), the more easily the high stress at high elongation tends to be exerted. Therefore, in the fiber structure, for example, the distance between 10% or more of the wound portions (B) in the circulating direction of the fiber structure is lower than the apparent average fiber length of the coiled crimped fiber (a), preferably 30% or more, more preferably 60% or more, further preferably 90% or more, particularly preferably 95% or more of the distance between the wound portions (B) existing in the circulating direction of the fiber structure, and the distance between them is lower than the apparent average fiber length of the coiled fiber (a).

The apparent average fiber length of the coiled crimped fiber (a) (hereinafter simply referred to as "apparent average fiber length") is not a fiber length (actual fiber length) obtained by linearly elongating a fiber crimped in a coiled shape, but is an average value of fiber lengths (apparent fiber lengths) in a state in which the fiber is crimped in a coiled shape. Thus, the apparent average fiber length is measured to be shorter than the actual fiber length. The apparent average fiber length was measured by an electron microscope on the surface of the fiber structure, and 100 apparent fiber lengths selected arbitrarily from the coiled crimped fibers (a) present per 1cm2 on the surface of the arbitrary wound portion (a) of the fiber structure were measured to determine the average value.

The apparent average fiber length may be, for example, 10mm or more, preferably more than 10mm, more preferably 11mm or more, further preferably 12mm or more, and particularly preferably 13mm or more. On the other hand, the apparent average fiber length may be, for example, 70mm or less, preferably 55mm or less, more preferably 40mm or less, further preferably 30mm or less, and particularly preferably 21mm or less.

The distance between the wound portions (B) may be, for example, 2.5mm or more, preferably 3mm or more, and more preferably 3.5mm or more. At least one of the distances between the winding portions (B) may be, for example, 20mm or less, preferably less than 20mm, more preferably 15mm or less, and still more preferably 10mm or less. When at least one of the distances between the wound portions (B) is between the upper limit value and the lower limit value, the wound portions (B) are entangled with each other by the coiled crimped fiber (a), and tend to be highly stressed at the time of high elongation and less likely to be torn even when strongly wound.

In the present invention, the wound portion (B) may contain a small amount of, for example, at most 3 mass% of the coiled crimped fiber (a) relative to the total mass of the wound portion (B), and the wound portion (a) may contain a small amount of, for example, at most 3 mass% of the non-coiled crimped fiber (B) relative to the total mass of the wound portion (a). Also, one fiber may have a coiled coil portion and a non-coiled coil portion.

In the fiber structure, the ratio of the area of the wound part (a) to the surface area of the fiber structure may be, for example, 20 to 85%, preferably 30 to 83%, and more preferably 40 to 81%. The area of the wound portion (a) is a value determined by a measurement method described in examples to be described later. When the ratio of the area of the wound portion (a) is in the above range, the stress at low elongation is low, and excellent conformability tends to be obtained.

In the fiber structure, the ratio TA/TB of the Thickness (TA) of the wound part (A) to the Thickness (TB) of the wound part (B) may be, for example, 1.1 to 10, preferably 2 to 7, and more preferably 3 to 5. In the case where the ratio TA/TB of the Thickness (TA) of the winding portion (a) to the Thickness (TB) of the winding portion (B) is in the above range, it is advantageous in that the balance of flexibility and strength is good.

The Thickness (TA) of the winding part (A) may be, for example, 1 to 10mm, preferably 1.5 to 7mm, and more preferably 2 to 5 mm.

Thickness (T) of the wound part (B)_B) For example, it may be 0.2 to 1mm, preferably 0.3 to 0.9mm, and more preferably 0.4 to 0.8 mm.

Thickness (T) of the wound part (A)_A) And the thickness (T) of the wound part (B)_B) The thickness was measured according to JISL1913, general short fiber nonwoven test method.

The fiber structure preferably has a mass per unit area of 50 to 200g/m²More preferably 70 to 180g/m²。

When the mass per unit area and the thickness are in the above ranges, the stretchability, flexibility, texture, and cushioning properties of the fiber structure are balanced. The density (bulk density) of the wound portions (a) and (B) of the fiber structure can be a value corresponding to the mass per unit area and the thickness. The density (bulk density) of the wound part (A) of the fiber structure may be, for example, 0.03 to 0.15g/cm³Preferably 0.04 to 0.1g/cm³. The density (bulk density) of the wound part (B) of the fiber structure can be equal to the above-mentioned unitThe area mass and thickness are 0.15-1.5 g/cm³Preferably 0.2 to 1g/cm³。

The stress at which the fiber structure is elongated by 50% in the flow direction of the fiber structure is, for example, 15N/5cm or less, preferably 13N/5cm or less, and more preferably 12N/5cm or less. When the stress at 50% elongation in the flow direction of the fiber structure is not more than the above upper limit, the stress at low elongation tends to be low, and the initial conformability tends to be excellent. The lower limit of the stress at 50% elongation in the flow direction of the fiber structure is not particularly limited, but may be, for example, 1N/5cm or more.

In the fiber structure, the stress at 80% elongation in the flow direction of the fiber structure may be, for example, 20N/5cm or more, preferably 25N/5cm or more, and more preferably 30N/5cm or more. When the stress at 80% elongation in the flow direction of the fiber structure is not less than the above value, the fiber structure becomes highly stressed at high elongation and tends to be less likely to be broken even when strongly wound. The upper limit of the stress at 80% elongation in the flow direction of the fiber structure is not particularly limited, but is usually, for example, 50N/5cm or less.

In the fiber structure, the ratio of the stress at 50% elongation to the stress at 80% elongation, i.e., the stress at 80% elongation/the stress at 50% elongation in the flow direction of the fiber structure may be, for example, 2.7 or more, preferably 3.0 or more, and more preferably 3.2 or more. When the ratio of the stress at 50% elongation to the stress at 80% elongation of the fiber structure in the flow direction is not less than the lower limit, the fiber structure exhibits low stress at low elongation and excellent initial conformability, and exhibits high stress at high elongation and tends to be less likely to be broken even when strongly wound. The ratio of the stress at 50% elongation to the stress at 80% elongation, i.e., the stress at 80% elongation/the stress at 50% elongation in the flow direction of the fiber structure is not particularly limited, and may be, for example, 10 or less, preferably 8 or less, and more preferably 5 or less.

The stress at 50% elongation and the stress at 80% elongation of the fiber structure in the flow direction represent the stress at elongation after elongation at 50% and 80% elongation in the flow direction of the fiber structure, and can be measured by a tensile test according to JISL1913 "general nonwoven fabric test method". The stress at 50% elongation and the stress at 80% elongation of the fiber structure of the present invention in the flow direction were values that can be obtained using AG-IS manufactured by shimadzu corporation as a constant-speed elongation tensile tester.

In the fiber structure, the recovery after 50% elongation in at least one direction (hereinafter also referred to as the recovery after 50% elongation) may be, for example, 70% or more, preferably 80% or more, and more preferably 90% or more. The upper limit of the recovery after 50% elongation is not particularly limited, but is usually 100% or less. When the 50% elongation recovery rate is within the above range, the following property with respect to elongation is improved, and for example, when the fiber structure is used as a bandage, the fiber structure can sufficiently follow the shape of a site to be used, and improvement of self-adhesiveness by friction between the stacked fiber structures is advantageous. When the elongation recovery rate is too small, the used portion has a complicated shape, and when the fiber structure is moved during use, the fiber structure cannot follow the movement, and the portion deformed by the movement of the body cannot be restored, so that the fixation of the wound fiber structure becomes weak.

The at least one direction is preferably a flow direction of the fiber structure. In the case where the fiber sheet has a longitudinal direction and a width direction, such as in a bandage, the longitudinal direction of the fiber sheet is preferable.

In a tensile test according to JISL1913 "general nonwoven fabric test method", when a residual strain (%) after the test when a load is removed immediately after the elongation reaches 50% is X, the recovery after the elongation of 50% is defined by the following formula:

the recovery (%) after 50% elongation was 100-X.

The recovery rate after 50% elongation in the width direction in a direction other than the at least one direction of the fiber structure, for example, the CD direction, or a case where the fiber structure has the longitudinal direction and the width direction like a bandage, may be 70% or more (100% or less), and preferably 80% or more.

Preferably, the fiber structure exhibits self-adhesiveness. In the present specification, "self-adhesiveness" refers to a property capable of hooking or fixing by engaging or closely fitting fibers on the surface of a fiber structure with each other by overlapping (contacting) the fibers. Having self-adhesiveness is advantageous in the case where the fiber structure is a bandage or the like. For example, in the case where the fiber structure is a bandage, after the bandage is wound around the application site, the wound fiber sheets are pressed while being stretched by an operation of overlapping the end portions of the bandage with the surface of the bandage placed therebelow, and the fiber structures are joined and fixed to each other, thereby exhibiting self-adhesiveness.

The fiber structure has self-adhesiveness, and a layer made of a self-adhesive agent such as a high elastic body or an adhesive is formed on the surface of the fiber structure, so that it is not necessary to separately prepare a jig for fixing the wound tip end portion. The fiber structure is preferably made of only a non-highly elastic material, more specifically, is preferably made of only fibers. For example, Japanese patent application laid-open No. 2005-095381 (patent document 7, claim 1, paragraphs 0004 to 0006) describes a self-adhesive agent comprising an acrylic polymer or latex adhered to at least one surface of a base material of a bandage. However, when a layer made of such a highly elastic material is formed on the surface of the fibrous sheet and wound around an application site for a long time, blood circulation is inhibited or pain is caused. Further, the layer made of a highly elastic material may cause skin irritation and allergy when wound around an application site.

The self-adhesiveness of the fiber structure can be evaluated by a curved surface sliding stress. The curved surface sliding stress of the fiber structure may be, for example, 1N/50mm or more, preferably 3N/50mm or more, and is preferably larger than the breaking strength. Further, since it is desirable that the wound fiber structure can be easily made into three openings when necessary, the curved surface sliding stress is preferably 30N/50mm or less, more preferably 25N/50mm or less. The curved surface sliding stress can be measured using a tensile tester according to the method described in the first example (fig. 2 to 4).

The fiber structure preferably has hand tearability. In the present specification, "hand tearability" refers to a property that can be broken (torn) by stretching with a hand. The hand-tearability of the fiber structure can be evaluated by the breaking strength. When the fiber structure is in the form of a sheet, the breaking strength in at least one direction in the plane is preferably 5 to 100N/50mm, more preferably 8 to 60N/50mm, and still more preferably 10 to 40N/50mm, from the viewpoint of hand-tearability. By setting the breaking strength within the above range, good hand tearability can be obtained in which the breaking (tearing) is relatively easy by hand. If the breaking strength is too high, the hand-tearability is deteriorated, and for example, it tends to be difficult to tear the fiber structure with one hand. If the breaking strength is too low, the fiber structure tends to have insufficient strength and to be easily broken, resulting in poor durability and workability. The breaking strength can be measured by a tensile test according to JISL1913 "general nonwoven fabric test method".

At least one direction in the sheet surface is a drawing direction when the fiber structure is torn by hand, and is preferably a flow direction of the fiber structure. In the case where the fiber structure has a longitudinal direction and a width direction, such as in a bandage, the longitudinal direction of the fiber structure is preferable. That is, when the fiber structure is used as a bandage, the bandage is generally stretched in the longitudinal direction thereof, wound around an application site, and then broken in the longitudinal direction, and therefore the direction of circulation is preferably the stretching direction, that is, the longitudinal direction.

The breaking strength in the width direction of the fiber sheet in a direction other than at least one direction in the sheet surface, for example, in the CD direction, such as in the case of a bandage, having a longitudinal direction and a width direction, may be, for example, 0.1 to 300N/50mm, preferably 0.5 to 100N/50mm, and more preferably 1 to 20N/50 mm.

From the viewpoint of hand-tearability, the fiber structure is preferably made of only the non-elastomeric material, more specifically, only the fiber. If a layer made of an elastomer is formed on the surface of the fiber structure, the hand-tearability is lowered.

The elongation at break in at least one direction in the plane of the fiber structure may be 50% or more, preferably 60% or more, and more preferably 80% or more, for example. The elongation at break in the above range is advantageous in improving the stretchability of the fiber structure. Further, when the fiber structure is used as a bandage, the followability when the fiber structure is applied to a site having a large range of motion, such as a joint, can be improved. The elongation at break in at least one direction in the sheet plane is usually 300% or less, preferably 250% or less. The elongation at break can also be measured by a tensile test according to JISL1913, general nonwoven test methods.

Preferably, at least one direction in the plane of the sheet is the first direction. When the first direction is the MD direction, in the case where the fiber structure has a longitudinal direction and a width direction, such as a bandage, the longitudinal direction of the fiber structure is preferable.

The sheet may have a breaking elongation in a direction other than at least one direction in the plane, for example, a CD direction, or a width direction in the case where a fiber structure has a longitudinal direction and a width direction like a bandage, for example, 10 to 500%, preferably 100 to 350%.

The coiled crimped fiber (a) can be formed of a conjugate fiber having latent heat crimpability (hereinafter, simply referred to as "conjugate fiber").

The conjugate fiber is a conjugate fiber having a phase structure formed by a plurality of resins having different thermal shrinkage rates or thermal expansion rates, and has an asymmetric or layered (so-called bimetallic) structure in which a curl is generated when heating due to the difference in thermal shrinkage rates or thermal expansion rates. The softening point or melting point of the plurality of resins is generally different. The plurality of resins may be selected from, for example, the following thermoplastic resins: polyolefin resin (e.g., low, medium or high density polyethylene, polypropylene, etc. poly C_2-4Olefin-based resins, etc.), acrylic resins (e.g., acrylonitrile-based resins having an acrylonitrile monomer such as an acrylonitrile-vinyl chloride copolymer, etc.), polyvinyl acetal-based resins (e.g., polyvinyl acetal resin, etc.), polyvinyl chloride-based resins (e.g., polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-acrylonitrile copolymer, etc.), polyvinylidene chloride-based resins (e.g., vinylidene fluoride-vinyl chloride copolymer, etc.)Vinylidene fluoride-vinyl acetate copolymer, etc.), styrene resin (e.g., heat-resistant polystyrene, etc.), polyester fiber resin (e.g., poly (C) such as polyethylene terephthalate resin, polypropylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, etc_2-4Arylate ester resins, etc.), polyamide resins (for example, aliphatic polyamide resins such as polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 612, etc., semi-aromatic polyamide resins, aromatic polyamide resins such as polyphenylene isophthalamide, polyhexamethylene terephthalamide, poly-p-phenylene terephthalamide, etc.), polycarbonate resins (for example, bisphenol a type polycarbonate, etc.), poly-p-phenylene benzobisoxazole resins, polyphenylene sulfide resins, polyurethane resins, cellulose resins (for example, cellulose esters, etc.). In addition, these respective plastic resins may contain other monomers that can be copolymerized.

Among them, from the viewpoint that the fibers are not fused even when melted or softened by heat treatment with high-temperature water vapor, non-moist heat-adhesive resins (or heat-resistant hydrophobic resins, non-aqueous resins) having a softening point or melting point of 100 ℃ or higher are preferable, and for example, polypropylene-based resins, polyester fiber-based resins, polyamide-based resins, and the like are preferable, and particularly, from the viewpoint of balance between heat resistance and fiber moldability, aromatic polyester-based resins and polyamide-based resins are more preferable. In the present invention, the resin exposed on the surface of the conjugate fiber is preferably a non-wet heat-bondable fiber so that the fibers constituting the fiber structure are not fused by the high-temperature steam treatment.

The heat shrinkage rates of the plurality of resins constituting the conjugate fiber may be different from each other, and may be a combination of the same resin or a combination of different resins.

In the present invention, it is preferable to combine the resins of the same system from the viewpoint of adhesion. In the case of a combination of resins of the same system, a combination of the component (a) forming a homopolymer and the component (B) forming a modified polymer (copolymer) is generally used. That is, for example, the crystallinity is further reduced than that of the homopolymer by modifying the homopolymer by copolymerizing a copolymerizable monomer for reducing the crystallinity, the melting point, the softening point, or the like, or the melting point, the softening point, or the like may be reduced than that of the homopolymer by forming an amorphous state. By changing the crystallinity, melting point, or softening point in this manner, a difference can be provided with respect to the thermal shrinkage rate. The difference between the melting point and the softening point may be, for example, 5 to 150 ℃, preferably 50 to 130 ℃, and more preferably about 70 to 120 ℃. The copolymerizable monomers used for modification may be, for example, about 1 to 50 mol%, preferably about 2 to 40 mol%, and more preferably about 3 to 30 mol% (particularly about 5 to 20 mol%) based on the total amount of the monomers. The compounding ratio (mass ratio) of the homopolymer-forming component and the modified polymer-forming component can be selected depending on the structure of the fiber, but the homopolymer component (a)/modified polymer component (B) may be, for example, about 90/10 to 10/90, preferably about 70/30 to 30/70, and more preferably about 60/40 to 40/60.

From the viewpoint of easy production of a composite fiber having latent crimping properties, the composite fiber may be a combination of aromatic polyester resins, particularly a combination of the polyarylate resin (a) and the modified polyarylate resin (b). The polyarylate resin (a) may be an aromatic dicarboxylic acid (e.g., a symmetric aromatic dicarboxylic acid such as terephthalic acid or naphthalene-2, 6-dicarboxylic acid) and an alkanediol component (e.g., C such as ethylene glycol or butanediol)_2-6Alkanediols, etc.). Specifically, a poly C such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) is used_2-4As the polyalkylene terephthalate resin, PET used for general PET fibers having an inherent viscosity of about 0.6 to 0.7 is generally used.

On the other hand, in the modified polyarylate resin (b), a copolymer component which lowers the melting point, softening point or crystallinity of the polyarylate resin (a), for example, a dicarboxylic acid component such as an asymmetric aromatic dicarboxylic acid, alicyclic dicarboxylic acid or aliphatic dicarboxylic acid, an alkanediol component having a chain length longer than that of the alkanediol of the polyarylate resin (a) and/or a diol component containing an ether bond can be used.

These copolymerizable components can be used alone or in combination of two or more. This is achieved byOf these, as the dicarboxylic acid component, an asymmetric aromatic dicarboxylic acid (isophthalic acid, phthalic acid, sodium 5-sulfoisophthalate, etc.) and an aliphatic dicarboxylic acid (C such as adipic acid, etc.) can be used_6-12Aliphatic dicarboxylic acid), etc., as the diol component, alkanediols (1, 3-propanediol, 1, 4-butanediol, 1, 6-hexanediol, neopentyl glycol, etc. C can be used_3-6Alkanediol, etc.), polyoxyalkylene glycol (polyoxy C such as diethylene glycol, triethylene glycol, polyethylene glycol, polytetramethylene glycol, etc_2-4Alkylene glycols, etc.). Among them, preferred are asymmetric aromatic dicarboxylic acids such as isophthalic acid and polyoxyC such as diethylene glycol_2-4Alkylene glycols, and the like. The modified polyarylate resin (b) may be C_2-4High elastomers having arylates (e.g., ethylene terephthalate and butylene terephthalate) as hard segments and (poly) alkylene glycols as soft segments.

In the modified polyarylate resin (b), the proportion of the dicarboxylic acid component (for example, isophthalic acid or the like) for lowering the melting point or softening point as the dicarboxylic acid component may be, for example, about 1 to 50 mol%, preferably about 5 to 50 mol%, and more preferably about 15 to 40 mol% with respect to the total amount of the dicarboxylic acid components. The proportion of the diol component (e.g., diethylene glycol) for lowering the melting point or softening point of the diol component may be, for example, 30 mol% or less, and preferably 10 mol% or less (e.g., about 0.1 to 10 mol%) relative to the total amount of the diol component. If the proportion of the copolymerizable component is too low, sufficient coiled crimp cannot be developed, and the morphological stability and stretchability of the fiber structure after crimping are deteriorated. On the other hand, if the proportion of the copolymerizable component is too high, the development of coiled curl becomes high, but it is difficult to stably spin the yarn.

The modified polyarylate resin (b) may contain, as monomer components, a polyvalent carboxylic acid component such as trimellitic acid or pyromellitic acid, or a polyvalent alcohol component such as glycerin, trimethylolpropane, trimethylolethane or pentaerythritol.

The cross-sectional shape (cross-sectional shape perpendicular to the longitudinal direction of the fiber) of the composite fiber is not limited to a circular cross-section and a non-circular cross-section [ e.g., flat, oval, polygonal, 3 to 14-lobed, T-shaped, H-shaped, V-shaped, dog-bone (I-shaped) ], which are common solid cross-sectional shapes, but may be a hollow cross-sectional shape, or the like.

The cross-sectional structure of the composite fiber includes phase structures formed on a plurality of resins, and examples thereof include core-sheath type, sea-island type, blend type, side-by-side type (side-by-side type or multilayer type), radiation type (radial type), hollow radiation type, bulk type, and random composite type. Of these cross-sectional structures, a structure in which phase portions are adjacent (so-called bimetal structure) is preferable from the viewpoint that the curl is likely to spontaneously develop by heating, and a structure in which the phase structures are asymmetric, for example, an eccentric core-sheath type or a side-by-side type structure is preferable.

In the case where the conjugate fiber has a core-sheath structure such as a core-sheath-offset structure, the core portion may be composed of a moist heat adhesive resin (e.g., a vinyl alcohol polymer such as an ethylene-vinyl alcohol copolymer or polyvinyl alcohol) or a thermoplastic resin having a low melting point or softening point (e.g., polystyrene or low density polyethylene), and the core portion may be composed of a moist heat adhesive resin having a poor thermal shrinkage property and being capable of being crimped with the non-moist heat adhesive resin of the sheath portion located on the surface.

The average fineness of the conjugate fiber may be, for example, 1 to 5dtex, preferably 1.3 to 4dtex, and more preferably 1.5 to 3 dtex. If the fineness is too small, the production of the fiber itself becomes difficult, and it becomes difficult to secure the fiber strength. In addition, in the step of developing the curl, it is difficult to develop a coil-like curl having good appearance. On the other hand, if the fiber is too thick, the fiber becomes hard and it becomes difficult to develop sufficient crimp.

The average fiber length (actual fiber length) of the composite fiber may be, for example, 20 to 70mm, preferably 25 to 65mm, and more preferably 40 to 60 mm. If the fiber length is too short, it is difficult to form a web, and in the step of developing crimp, entanglement of fibers is insufficient, and it is difficult to secure strength and stretchability. Further, if the fiber length is too long, it is difficult to form a fiber web having uniform mass per unit area, and a large amount of fibers are entangled with each other when forming the web. In the present invention, if the fiber length is in the above range, a part of the fibers crimped on the surface of the fiber structure is appropriately exposed on the surface of the fiber structure, and thus the self-adhesiveness of the fiber structure can be improved.

The conjugate fiber is thermally treated to develop a curl (develop a curl) and is a fiber having a substantially coil-like (coil-like or coil-spring-like) three-dimensional curl.

The number of crimps (number of mechanical crimps) before heating may be, for example, 0 to 30 crimps/25 mm, preferably 1 to 25 crimps/25 mm, and more preferably 5 to 20 crimps/25 mm. The number of crimps after heating is, for example, 20 to 120 crimps/25 mm, preferably 25 to 120 crimps/25 mm.

As described above, the coiled crimped fiber (a) has a substantially coiled crimp. The average radius of curvature of a circle formed by the winding of the crimped fiber can be selected from a range of, for example, about 10 to 250 μm, and is, for example, about 20 to 200 μm (e.g., about 50 to 200 μm), preferably about 50 to 160 μm (e.g., about 60 to 150 μm), and more preferably about 70 to 130 μm. Here, the average radius of curvature is an index representing the average size of a circle formed by crimping a coil of a fiber, and in the case where the value is large, the formed coil has a loose shape, in other words, a shape with a small number of crimps. Further, if the number of crimps is small, entanglement of fibers is also small, and it tends to be unfavorable to exhibit sufficient stretch performance. On the other hand, when a coil-like curl having an excessively small average radius of curvature is present, it is difficult to sufficiently entangle fibers with each other, and it is likely to be difficult to produce a latent curled fiber exhibiting such a curl as well as to secure web strength.

In the coiled crimped fiber (a), the average pitch of the coil is preferably 0.03 to 0.5mm, more preferably 0.03 to 0.3mm, and still more preferably 0.05 to 0.2 mm.

The non-coiled crimped fiber (b) may be composed of the conjugate fiber used for the coiled crimped fiber (a) or may be composed of a fiber (non-conjugate fiber) other than the conjugate fiber. When the same conjugate fiber is used for the coiled crimped fiber (a) and the non-coiled crimped fiber (b), the production process tends to be easy. In the fiber structure, regardless of the type of the fibers constituting the coiled crimped fiber (a) and the non-coiled crimped fiber (B), the wound portion (a) and/or the wound portion (B) may contain other fibers (non-composite fibers) in an amount within the range that can achieve the object of the present invention.

Examples of the non-conjugate fibers include, in addition to fibers composed of the non-thermal adhesive resin or the thermal adhesive resin, cellulose fibers, such as regenerated fibers of natural fibers (e.g., cotton, wool, silk, hemp, etc.), semisynthetic fibers (e.g., acetate fibers such as triacetyl fiber), rayon, high-wet-modulus viscose fiber, cuprammonium rayon, lyocell (e.g., trade name: TENCEL, etc.), and the like. The average fineness and average fiber length of the non-composite fibers are the same as those of the composite fibers. These non-composite fibers can be used alone or in combination of two or more. Among these non-composite fibers, regenerated fibers such as rayon, semisynthetic fibers such as acetate fibers, polyolefin fibers such as polypropylene fibers and polyethylene fibers, polyester fibers, polyamide fibers, and the like are preferable. In particular, from the viewpoint of blending property and the like, the fibers may be the same as the conjugate fibers, and for example, in the case where the conjugate fibers are polyester fibers, the non-conjugate fibers may be polyester fibers.

When the fiber structure includes the conjugate fibers and the non-conjugate fibers in the wound part (a) and/or the wound part (B), the ratio (mass ratio) of the conjugate fibers to the non-conjugate fibers may be, for example, 80/20 to 100/0 (e.g., 80/20 to 99/1), preferably 90/10 to 100/0, and more preferably about 95/5 to 100/0. By mixing the non-conjugate fibers, the strength of the fiber structure can be adjusted. However, if the proportion of the conjugate fibers (latent crimped fibers) is too small, the non-conjugate fibers hinder shrinkage when the crimped fibers stretch after crimping, particularly when the fibers shrink after elongation, and therefore, it tends to be difficult to ensure recovery stress.

The fiber structure (web) further contains usual additives, for example, stabilizers (heat stabilizers such as copper compounds, ultraviolet absorbers, light stabilizers, antioxidants, etc.), antibacterial agents, deodorizing agents, perfumes, colorants (dyes and pigments, etc.), fillers, antistatic agents, flame retardants, plasticizers, lubricants, crystallization rate retarders, etc. These additives can be used alone or in combination of two or more. These additives may be carried on the surface of the fiber or may be contained in the fiber.

[ method for producing fiber Structure ]

The method for producing a fiber structure of the present invention includes: 1) a step of forming a web of fibers (hereinafter also referred to as a web forming step); 2) a step of forming a entangled portion (B) by entangling a part of the web by spraying or jetting water (hereinafter also referred to as entangled step 1); 3) and a step (hereinafter, also referred to as a winding step 2) of heating the web with high-temperature steam to form a wound portion (a).

In the web forming step, as a method for forming the web, a commonly used method, for example, a direct method such as a spunbond method or a meltblown method, a carding method using meltblown fibers or staple fibers, or a dry method such as an air-laid method can be used. Among these methods, a carding method using meltblown fibers or staple fibers, particularly a carding method using staple fibers, is generally selected. Examples of the web obtained by using the staple fibers include a random web, a semi-random web, a parallel web, and a cross-entangled web.

Next, in the entangling step 1, the obtained fiber web is partially entangled by spraying or jetting water to form an entangled portion (B). The sprayed or jetted water may be blown from one side of the web or may be blown from both sides, but from the viewpoint of efficiently performing strong entanglement, it is preferably blown from both sides. The portion where water is blown becomes the winding portion (B), and the portion where water is not blown becomes the winding portion (a) through the subsequent winding process 2.

Examples of the method of forming the entangled portion (B) include a method of jetting water through a nozzle or the like via a plate-like object (a perforated plate, a slit plate, or the like) or a cartridge (a perforated cartridge, a slit cartridge, or the like) having a regular spray region or a spray pattern formed of a plurality of holes, a method of forming the entangled portion (B) by switching the jetting of water from the nozzle to open and close, and a method of combining these methods. These methods can be performed by appropriately selecting a method of continuously or periodically moving the nozzle, a method of continuously or periodically transferring the web by a belt conveyor such as an endless conveyor, and a combination thereof, according to the shape or size of the web, the shape of the formed entangled portion (B), the arrangement pattern, and the like. For example, the winding part (B) can be continuously formed by providing a nozzle in the cylinder and transferring the web while rotating the cylinder while spraying water. The material constituting the plate-like object and the tube may be, for example, metal, plastic, wood, or the like.

In the case of forming a boundary-like pattern in which the winding portions (a) and the winding portions (B) are alternately arranged with respect to the circulating direction, the winding portions (B) can be formed by, for example, spraying water onto the web through a plate-like object or a cylinder having a slit with a certain width in a direction perpendicular to the circulating direction by a nozzle. The slit width may be, for example, 0.5 to 30mm, preferably 1 to 20mm, more preferably 2 to 10mm, and still more preferably 3 to 8 mm. The pitch of the pioneers is, for example, 2.5mm or more, preferably 3mm or more, and more preferably 3.5mm or more. On the other hand, the pitch of the slits may be, for example, 20mm or less, preferably less than 20mm, more preferably 15mm or less, and further preferably 10mm or less.

In the case of forming the boundary pattern, the entangled portion (B) can be formed by, for example, switching the water jet from nozzles arranged linearly with respect to the flow direction on and off while continuously moving the web.

When the winding part (B) having a specific shape is formed in a regularly arranged planar lattice pattern, the winding part (B) can be formed by spraying water onto the web from a plate or a drum formed regularly with a plurality of holes therebetween, for example.

The shape of the hole is not particularly limited, and may be, for example, an oblong, an oval, a circle, a square, a rectangle, or the like, and is preferably an oblong. In the case of the oblong shape, the length in the major axis direction is, for example, 1 to 80mm, preferably 5 to 60mm, and more preferably 10 to 40mm, and the length in the minor axis direction is, for example, 1 to 80mm, preferably 3 to 50mm, and more preferably 5 to 30 mm. The plurality of holes may be arranged in a planar lattice pattern, for example, a square lattice pattern, a diamond lattice pattern, a rectangular lattice pattern, or the like. The pitch of the holes may be, for example, 2.5mm or more, preferably 3mm or more, and more preferably 3.5mm or more. On the other hand, the pitch of the holes may be, for example, 20mm or less, preferably less than 20mm, more preferably 15mm or less, and still more preferably 10mm or less.

The discharge pressure of water may be, for example, 4MPa or more, preferably 8MPa, more preferably 10MPa or more, further preferably 15MPa or more, and particularly preferably more than 15 MPa. When the water discharge pressure is not less than the lower limit, the fibers are in a stacked state, and even if the steam injection is performed in the subsequent winding step 2, the fibers are not fixed and the coiled curl is hard to develop, so that the wound portion (B) tends to be easily formed. On the other hand, the upper limit of the water discharge pressure may be, for example, 20MPa or less.

The temperature of the water is preferably 5 to 50 ℃, more preferably 10 to 40 ℃, and further preferably 15 to 35 ℃ (normal temperature).

As a method of spraying or jetting water, a method of jetting water using a nozzle or the like having a regular spray area or spray pattern is preferable from the viewpoint of simplicity and the like. Specifically, water can be sprayed onto a web conveyed by a belt conveyor such as an endless conveyor while the web is placed on a conveyor belt. The conveyor belt may be water permeable and water may be sprayed onto the web from the backside of the web through the water permeable conveyor belt. When water is sprayed from the back side of the web, it is preferable to spray water to the web through a plate-like object or a cylinder having a spray area or a spray pattern on the back side of the web. In order to suppress scattering of fibers by water jetting, the web may be wetted with a small amount of water in advance. When the sheet is conveyed by a conveyor, the conveying speed may be, for example, 5 to 40 m/min, preferably 10 to 20 m/min.

The nozzle for spraying or jetting water may be configured such that the micropores are arranged in the width direction of the supplied web using a plate or a die in which predetermined micropores are continuously arranged in the width direction in accordance with the pattern of the formed entangled portion (B). The rows of the micropores may be one or more, or may be arranged in parallel. Further, a plurality of nozzle dies having a row of micro-holes may be arranged in parallel. The nozzle pitch may be, for example, 1.0 to 2.5 mm. The nozzle diameter may be, for example, 0.2 to 0.5 mm.

In the winding step 2, the fiber web is heated by high-temperature steam, and the composite fibers in the portion where water is not blown in the winding step are curled in a coil shape to form a wound portion (a). In the process of treatment by high temperature steam, the web is exposed to a high temperature or superheated steam (high pressure steam) stream, thereby producing coil-like crimp on the composite fibers (latent crimped fibers). Since the fiber web has air permeability, even if the treatment is performed from one direction, high-temperature steam can penetrate into the fiber web, and the fiber web shows a substantially uniform curl in the thickness direction, and the fibers are uniformly entangled with each other. The temperature of the high-temperature steam may be, for example, 50 to 150 ℃, preferably 40 to 130 ℃, and more preferably 60 to 120 ℃.

The composite fiber in the portion where water is not blown in the web winding process 1 is shrunk simultaneously with the high-temperature steam treatment. Therefore, it is preferable that the supplied fiber web is excessively supplied before being exposed to high-temperature steam in accordance with the required area shrinkage of the fiber structure. The ratio of the overfeeding is preferably 110 to 250% of the required length of the fiber structure.

For supplying the water vapor to the fiber web, a common water vapor spraying device can be used. Preferably, the water vapor injection means is a means capable of blowing water vapor substantially uniformly across the entire width of the web at a desired pressure and amount. The steam jet device may be provided only on one surface side of the fiber web, and may be further provided on the other surface side in order to perform steam treatment on the front and back surfaces of the fiber web at a time.

Since the high-temperature steam ejected from the steam ejection device is an air stream, the fibers in the fiber web are introduced into the fiber web without being moved greatly, unlike the water-jet entangling process and the needling process. By the entry of the steam into the web, the steam flow efficiently covers the surface of each fiber present in the web, enabling uniform thermal curling to be achieved. In addition, since heat can be sufficiently conducted to the inside of the web as compared with the dry heat treatment, the degree of curling in the plane direction and the thickness direction is substantially the same.

The nozzle for jetting the high-temperature steam may be a plate or a die having predetermined micropores arranged continuously in the width direction, as in the case of the water-jet-entangled nozzle, and may be arranged such that the micropores are arranged in the width direction of the supplied web. The rows of the micropores may be one or more, or may be arranged in parallel. Further, a plurality of nozzle dies having a row of micro-holes may be arranged in parallel.

The pressure of the high-temperature steam to be used can be selected from the range of 0.1 to 2MPa (e.g., 0.2 to 1.5 MPa). When the pressure of the steam is too high, the fibers forming the web may move more than necessary, and the texture may vary, or the fibers may be entangled more than necessary. In the case where the pressure is too weak, the heat required to develop the crimp of the fibers cannot be applied to the web, water vapor cannot penetrate the web, and the crimp of the fibers in the thickness direction tends to be unevenly developed. The temperature of the high-temperature steam can be selected from a range of 70 to 180 ℃ (e.g., 80 to 150 ℃), depending on the material of the fiber. The treatment rate of the high-temperature steam can be selected from a range of 200 m/min or less (e.g., 0.1 to 100 m/min).

After the composite fibers in the web are crimped in this manner, moisture may remain in the fiber structure, and therefore, a drying step of drying the fiber structure as needed may be provided. Examples of the drying method include a method using a drying device such as a drum dryer or a tenter, a non-contact method such as far infrared ray irradiation, microwave irradiation, or electron beam irradiation, and a method in which hot air is blown and passed through the hot air.

The fiber structure of the present invention has excellent initial conformability, can be strongly wound, and has self-adhesiveness without containing an adhesive, and therefore, is suitably used for applications in contact with a human body, for example, tapes such as bandages and protective tapes used in the medical and sports fields. Another gist of the present invention resides in a bandage comprising the fiber structure.

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.

Examples

The physical property values of the fiber structures obtained in examples and comparative examples were measured by the following methods.

(1) Apparent average fiber length

The surface of the fiber structure was measured by an electron microscope, and the surface of the optional wound portion (A) of the fiber structure was measured every 1cm²The apparent fiber lengths of 100 randomly selected ones of the existing coiled crimped fibers (a) were averaged.

(2) Number of crimps

The evaluation was carried out in accordance with JISL1015 "test method for staple fibers" (8.12.1).

(3) Mass per unit area

The measurement was carried out in accordance with JISL1913, general short fiber nonwoven fabric test method.

(4) Thickness (T) of the wound part (A)_A) (height of convex part)

The thickness was measured according to JISL1913, general short fiber nonwoven test method.

(5) Thickness (T) of the wound part (B)_B) (height of base)

The thickness was measured according to JISL1913, general short fiber nonwoven test method.

(6) Density of the wound part (A)

The density was calculated from the mass per unit area measured in (3) and the thickness measured in (4) above.

(7) Density of the wound part (B)

The density was calculated from the mass per unit area measured in (3) and the thickness measured in (5) above.

(8) Area ratio of the wound part (A)

Each 0.5cm of the fiber structure was determined as follows²The area ratio of the winding part (a) present in (a). At 0.5cm²The surface of the fiber structure was observed at 300 times using an electron microscope. The sum of the results of the observation in one field of view by an electron microscope was defined as 1 when only crimped fibers were seen, 0.5 when crimped fibers were mixed with other fibers, and 0 when crimped fibers were not present, and the ratio of the sum to the number of fields of view observed was defined as the area ratio of the wound portion (a).

(9) As a method of measuring the distance between the wound portions (B), the distance between two points of the portion farthest from the center of the wound portion is measured using a gauge.

(10) 50% recovery from elongation

The measurement was carried out according to JISL1096 general Fabric test method. In the evaluation of the present invention, the recovery rate of 50% elongation was uniformly selected, and the next operation was performed after returning to the original position after 50% elongation without waiting time. The measurement is performed in the direction of flow (MD) of the fiber structure. As the constant-speed elongation type tensile testing machine, AG-IS manufactured by Shimadzu corporation was used.

(11) Stress at elongation

Measured according to JISL1096, general methods for testing fabrics. The respective elongation stresses at 50% and 80% elongation were measured. As the constant-speed elongation type tensile testing machine, AG-IS manufactured by Shimadzu corporation was used.

(12) Self-adhesive property

The curved surface sliding stress (N/50mm) was measured by the following method. If the ratio is more than 1N/50mm, the adhesive is regarded as self-adhesive.

First, a fiber sheet was cut into a size of 50mm wide by × 600mm long with the MD direction as the longitudinal direction to obtain a sample 5, and then, as shown in fig. 2(a), one end of the sample 5 was fixed to a core 7 (a polypropylene resin tube roll having an outer diameter of 30mm × mm and a length of 150 mm) by a single-sided tape 6, and then, a 150g weight 9 was attached to the other end of the sample 5 so as to apply a load uniformly to the entire width of the sample 5 by using a spring clip 8 (having a clip width of 50mm and a rubber sheet having a thickness of 0.5mm fixed to the inside of the mouth by a double-sided tape in use) at the other end of the sample 5.

Next, in a state where the winding core 7 to which the sample 5 is fixed is lifted up and the sample 5 and the weight 9 are suspended, the winding core 7 is rotated for 5 revolutions so as not to largely shake the weight 9, and the sample 5 is rolled up and the weight 9 is lifted up (see fig. 2 (b)). In this state, the spring clamp 8 and the weight 9 are slowly removed so as not to shift the base point 10, with the base point 10 being the contact point between the cylindrical portion of the outermost peripheral portion of the sample 5 wound around the core 7 and the planar portion of the sample 5 not wound around the core 7 (the boundary line between the portion of the sample 5 wound around the core 7 and the portion of the sample 5 that is vertical by the weight of the weight 9). Next, at a position 11 along a half circumference (180 °) of the sample 5 wound around the core 7 from the base point 10, the outermost circumferential portion of the sample 5 is cut by a blade so as not to damage the sample of the inner layer, and a cut 12 is provided (see fig. 3).

The curved surface sliding stress between the outermost layer portion and the inner layer portion wound around the core 7 therebelow (inner layer) in this sample 5 was measured. The measurement was carried out using a tensile tester ("Autograph" manufactured by Shimadzu corporation). The core 7 was fixed to a jig 13 (see fig. 4) provided on a fixed-side chuck base of a tensile testing machine, and a chuck 14 on a load cell side was used to clamp an end portion of the sample 5 (an end portion to which the spring clip 8 was attached) and to perform stretching at a stretching speed of 200 mm/min, and a measured value (tensile strength) of the sample 5 when the cut 12 was removed (separated) was defined as a curved surface sliding stress.

< example 1 >

As the potentially crimping fibers, side-by-side type composite staple fibers (Sofit PN780 ", 1.7dtex × 51mm long, mechanical crimping number) composed of polyethylene terephthalate resin having an inherent viscosity of 0.65 [ component (A) ] and modified polyethylene terephthalate resin obtained by copolymerizing 20 mol% of isophthalic acid and 5 mol% of diethylene glycol [ component (B) ] were prepared29 pieces/25 mm, and the number of crimps after × 1 minutes treatment at 130 ℃ was 29 pieces/25 mm) Using 100 mass% of the side-by-side type composite staple fiber, the mass per unit area was 30g/m by carding²A card web of (1).

(winding step 1)

The card web was moved on a transport web so as to pass between perforated cylinders having a major axis dimension of 50mm, a minor axis dimension of 5mm and openings in a diamond-shaped lattice shape (oblong shape) at 15mm intervals, and a water stream was sprayed in a mist form at 10MPa to the transport web through the perforated cylinders, thereby performing a fiber winding process.

Next, the card web was fed to the winding step 2 with an excess of about 200% while being supplied so as not to interfere with the shrinkage in the next winding step 2 by steam.

(winding step 2)

Next, the card web was introduced into a steam jet device provided in the belt conveyor, and steam was jetted perpendicularly to the card web at a temperature of about 160 ℃ under 0.5MPa from the steam jet device to perform steam treatment, thereby causing the latent crimped fibers to assume a coil-like crimp and entangling the fibers. The steam jet device is provided with a nozzle in one conveyor so as to blow steam to the card web through a conveyor belt. In addition, a device in which water vapor injection nozzles having an aperture of 0.3mm were arranged in a row at a pitch of 2mm in the width direction of the conveyor was used. The processing speed was 8.5 m/min, and the distance between the nozzle and the conveyor belt on the suction side was 7.5 mm. Finally, the resultant was dried with hot air at 120 ℃ for 1 minute to obtain a stretchable sheet-like fiber structure 1.

Various measurements were performed on the obtained fiber structure 1. The results are shown in Table 1. Fig. 1 is a schematic view of the alignment pattern of the winding part (B)2 in the flow direction of the obtained fiber structure 1.

< example 2 >

In the winding step 1, a fiber structure was produced in the same manner as in example 1, except that a water jet was injected at a water pressure of 20 MPa. The evaluation results are shown in table 1.

< example 3 >

In the winding step 1, a fiber structure was produced in the same manner as in example 1, except that the fiber structure passed through porous cylinders having a major axis dimension of 50mm and a minor axis dimension of 10mm and having openings in a rhombic lattice shape (oblong shape) at a pitch of 10 mm. The evaluation results are shown in table 1.

< example 4 >

In the winding step 1, a fiber structure was produced in the same manner as in example 1, except that the fiber structure passed through porous tubes having a major axis dimension of 400mm, a minor axis dimension of 5mm, and openings formed in a boundary shape at a pitch of 15 mm. The evaluation results are shown in table 1.

< comparative example 1 >

A fiber structure was produced in the same manner as in example 1, except that the winding step 1 was not performed. The evaluation results are shown in table 1.

< comparative example 2 >

A fiber structure was produced in the same manner as in example 1 except that the web was moved on a conveyor so as to pass through between perforated cylinders having a diameter of 2mm phi and having openings in an oblique square lattice shape (circular shape) at a pitch of 2mm, a water stream was sprayed from the inside of the perforated cylinders toward the web and the conveyor at 0.8MPa to periodically form a low density region and a high density region of the fibers, and then the web was transferred to a belt conveyor equipped with a 76-mesh 500 mm-wide resin endless belt, and water was sprayed at a water pressure of 4MPa using nozzles having 0.1 mm-diameter micropores arranged in a row at 0.6mm intervals in the web width direction. The evaluation results are shown in table 1.

[ Table 1]

The fiber structures of examples 1 to 3 had a smaller stress at 50% elongation, excellent initial conformability, and an excellent 50% elongation recovery as compared with comparative example 2. Further, the fiber structures of examples 1 to 3 were highly stressed at 80% elongation compared to comparative example 1, and could be strongly wound. That is, the fiber structures of examples 1 to 3 have performances required for low elongation and high elongation in a well-balanced manner as compared with comparative examples 1 and 2.

Description of the reference numerals

1 fiber structure, 2 wound portions (B), 3 wound portions (a), 4 wound portions (B) with a distance therebetween, 5 samples, 6 single-sided tape, 7 cores, 8 spring clips, 9 weights, 10 base points, 11 positions half-circumference from the base points, 12 cuts, 13 clips, 14 chucks.

Claims (9)

1. A fiber structure comprising coiled crimped fibers (a) and non-coiled crimped fibers (b),

the fiber structure has a wound part (A) composed of coiled crimped fibers (a) and two or more wound parts (B) composed of non-coiled crimped fibers (B), and the distance between at least one wound part (B) in the direction of circulation of the fiber structure is less than the apparent average fiber length of the coiled crimped fibers (a).

2. The fiber construct of claim 1,

the ratio of the area of the wound part (A) to the surface area of the fiber structure is 20-85%.

3. The fiber construct according to claim 1 or 2,

the thickness (T) of the winding part (A)_A) With the thickness (T) of the winding part (B)_B) Has a ratio of T_A/T_B＝1.1～10。

4. The fiber structure according to any one of claims 1 to 3,

the stress at 50% elongation in the flow direction of the fiber structure is 15N/5cm or less, and the stress at 80% elongation is 20N/5cm or more.

5. The fiber structure according to any one of claims 1 to 4,

the ratio of the stress at 50% elongation to the stress at 80% elongation in the flow direction of the fiber structure is 2.7 or more of the stress at 80% elongation/the stress at 50% elongation.

6. The fiber structure according to any one of claims 1 to 5,

the coiled crimped fiber (a) is composed of a composite fiber having a phase structure formed by a plurality of resins having different thermal shrinkage rates or thermal expansion rates.

7. The fiber structure according to any one of claims 1 to 6,

the mass per unit area is 50 to 200g/m²。

8. A bandage comprising the fiber structure according to any one of claims 1 to 7.

9. A method for producing the fiber structure according to any one of claims 1 to 8, comprising:

1) a step of forming a web of the fibers;

2) a step of forming a entangled portion (B) by entangling a part of the web by spraying or jetting water;

3) and a step of forming a wound part (A) by heating the web with high-temperature steam.

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