JPH1158570A - Fiber structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber structure having excellent improvement in degree of residual strain at the time of compressing by providing a net-like sheet layer at least at one position between laminated nonwoven fabric layers. SOLUTION: Nonwoven fabric to be applied is constituted by short fiber and contains at least matrix fiber and heat fusion bondable binder fiber. Particularly, the nonwoven fabric contains 5 to 80 wt.% of nonwoven fabric base material is preferably contained in the binder fiber. As the matrix fiber, semisynthetic fiber such as thermoplastic synthetic fiber, rayon or the like, or natural fiber such as cotton or the like is used. But the matrix fiber is not limited to these. As the binder fiber, normally copolymerized or blended polymer such as, for example, copolymerized polymer obtained by lowering its melting point by copolymerized component such as isophthalic acid or the like or heat fusion bonded polymer such as blended polyester or the like is suitably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fibrous structure excellent in improving a residual strain rate during compression, and is suitably used for cushioning.

[0002]

2. Description of the Related Art Conventionally, nonwoven fabrics made of thermoplastic synthetic fibers have been widely used as interior materials for bed mats used in homes, hospitals, and the like, and vehicles. For example, JP
JP-A-182213 describes an example of a nonwoven fabric mat containing thermoplastic synthetic fibers. However, since such a nonwoven fabric is made of thermoplastic synthetic fibers, the non-woven fabric has a problem that the residual strain rate during compression is extremely large and easily sagged in an atmosphere at or above the glass transition point of the polymer as the raw material of the fibers.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fibrous structure which is excellent in improving the residual strain during compression.

[0004]

Means for Solving the Problems The present inventors have studied the preparation of the materials constituting the nonwoven fabric and the manufacturing method, and have completed the present invention. That is, the present invention is a fibrous structure formed by laminating nonwoven fabrics, wherein the fibrous structure has a mesh sheet layer in at least one position between the nonwoven fabric layers.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The term “residual strain rate during compression” as used in the present invention refers to the degree of recovery when a load is applied to the upper surface of a sample for a certain period under certain conditions, and then the load is removed.

[0006] The nonwoven fabric applied to the present invention is composed of short fibers, and comprises at least a matrix fiber and a heat-fusible binder fiber. Preferably, it is contained at 80% by weight. In the case of a content of 5% by weight to 80% by weight, such a heat-fusible binder fiber joins a part of the intersection with the non-woven fabric base constituent fiber by heat fusion to stabilize the non-woven fabric formed into a predetermined shape. Is good.

The matrix fibers include, but are not limited to, thermoplastic synthetic fibers, semi-synthetic fibers such as rayon, and natural fibers such as cotton. When thermoplastic synthetic fibers are used, for example, polyolefins such as polypropylene and polyethylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, and copolymers thereof can be used. . Further, a mixture of two or more of these fibers may be used.

As the binder fiber, a copolymer or a blend polymer, for example, a copolymer whose melting point is lowered by a copolymer component such as isophthalic acid, or a heat fusion polymer such as a blend polyester is preferably used.

The heat treatment is carried out at a temperature lower than the softening point of the matrix fibers and at a temperature higher than the temperature at which the fusibility of the binder fibers is exhibited, but it may be carried out as a single step or in conjunction with the heat molding step. By such heat treatment, the constituent fibers intersecting with the binder fibers adhere at the intersections to impart morphological stability to the nonwoven fabric substrate, and the binder fibers cooperate with the support function of the matrix fibers to give the nonwoven fabric substrate an appropriate rigidity. Furthermore, the use of the binder fiber makes it possible to absorb the irregularities attached to the surface of the nonwoven fabric or to intentionally impart irregularities to the surface of the nonwoven fabric.

The binder fiber may be a single-component fiber made of the above-mentioned heat-fusible polymer, but a sheath-core conjugate fiber having a low-melting polymer for the sheath component and a higher-melting polymer for the core component is used. It is more preferable that the heat-sealing function can be achieved while maintaining the support function of the core component. As such binder fibers, those having a common polyethylene terephthalate polymer as a core component and a low melting point copolymerized polyethylene terephthalate polymer as a sheath component are known, but not limited thereto.

[0011] Other than that, the material of other fibers to be mixed to newly impart functionality is not particularly limited. What is necessary is just to select suitably according to a use. Common synthetic fibers, natural fibers,
Recycled fibers can be used.

The fineness of the short fibers is preferably 0.1 to 15.0 denier. When the content is within this range, the passability of the card machine when forming the nonwoven fabric is high and good.

[0013] The nonwoven fabric applied to the present invention preferably has an average thickness of 5 mm or more in a main portion excluding a special portion of an end portion and a mounting portion in use. When the average thickness is 5 mm or more, sufficient rigidity as a support can be maintained, and a feeling of fixation, a sense of stability, and cushioning properties are obtained.

Further, the average density of the nonwoven fabric is 0.01 to
It is preferably 0.50 g / cm ³ . When the content is within this range, sufficient strength as a support can be obtained, and a good tactile sensation and appropriate cushioning properties can be obtained.

The non-woven fabric comprising the above fibers can be produced by a usual method. That is, specifically, cotton as a raw material is opened and mixed, then a card is made through a card, a web is produced, and a needle punch is performed to produce a nonwoven fabric.

Further, these nonwoven fabrics are laminated so as to have a predetermined basis weight, and heated and compressed at a temperature higher than that of the polymer of the sheath component of the binder fiber to obtain a fiber structure.

At this time, it is necessary to have a mesh sheet layer in at least one place of the nonwoven fabric layer. When a load is applied from above the nonwoven fabric by laminating the mesh-like sheets, the load is dispersed throughout the nonwoven fabric, and the residual strain rate during compression is improved.

The mesh sheet preferably contains a heat-fusible polymer. In the case where the heat-fusible polymer is not contained, the nonwoven fabrics sandwiching the sheet peel off from each other, which is inappropriate.

The filament used in the mesh sheet is a single component composed of a copolymer or a blend polymer, for example, a copolymer whose melting point is lowered by a copolymer component such as isophthalic acid, or a heat-fusible polymer such as a blend polyester. However, if a sheath-core conjugate fiber with a low-melting polymer for the sheath component and a higher-melting polymer for the core component is used, the heat-sealing function can be performed while maintaining the support function of the core component. Is more preferable because As such a mesh-like sheet, Bellcouple of Kanebo Synthetic Co., Ltd., which is composed of a core-sheath type composite fiber having a normal polyethylene terephthalate polymer as a core component and a low melting point copolymerized polyethylene terephthalate polymer as a sheath component, is already commercially available. But not limited to these.

The nonwoven fabric layer and the mesh sheet need to be integrated. As a method of integration, a needle is punched between webs after passing the card, or a needle is punched, or sandwiched between a nonwoven fabric and a nonwoven fabric, and heat-treated at a temperature equal to or higher than the melting point of binder fibers in the nonwoven fabric. Is mentioned.

The mesh of the mesh sheet applied to the present invention is preferably less than 200 mesh / cm ² . When the mesh size is 200 mesh / cm ² or more, the needle area does not pass when the needle is punched between webs because the area of the hole is small, and the nonwoven fabric sandwiching the net adheres through the mesh of the net even when heat bonding is performed. The problem arises that you cannot do that.

The basis weight of the mesh sheet is 10 g / m ^2.
It is preferable that it is above. In this case, since the rigidity of the sheet is moderate, when a load is applied from the upper portion of the nonwoven fabric, the load is uniformly dispersed throughout the nonwoven fabric, which is favorable.

When a nonwoven web and a mesh sheet are laminated to obtain a fibrous structure band, the density of the laminated web does not need to be constant. For example, it is possible to improve the vibration damping performance by changing the density of the nonwoven fabric above and below the mesh sheet, and forming a high density nonwoven fabric layer on the upper layer and a low density nonwoven fabric layer on the lower layer.

[0024]

According to the present invention, there is provided a fibrous structure which is excellent in improving the residual strain rate during compression.

[0025]

【Example】

(Method for measuring residual strain rate during compression) JASOB408-
According to 89B method, sample size is 350mm × 350m
m. At this time, the thickness under no load is defined as the initial thickness. A 150 mmφ pressure plate is placed on the center of the sample, and a heat treatment at 70 ° C./22 hr is performed with a weight placed so that the entire load becomes 13.4 kgf. The weight is removed after 22 hours, the thickness is measured after 0.5 hour (thickness after compression), and the compression residual strain rate of the sample is calculated by the following formula. Residual compression ratio (%) = ((initial thickness-thickness after compression) /
Initial thickness) x 100

Example 1 Hollow conjugate polyester fiber 13 denier, 5
82% by weight of 1 mm, binder polyester fiber 3
18% by weight of Neil, 51mm mixed with normal non-woven fabric
Carding, cross lay and infrared heat treatment
Thickness 10mm, basis weight 200g / m^TwoNon-woven
And thickness 20 mm, basis weight 400 g / m ^TwoOf non-woven fabric
Was.

[0027] of these, a basis weight of 200g / m ² non-woven fabric 2
A mesh net "Bell Couple" of Kanebo Gosen Co., Ltd., 50 mesh, 26 g / m ² was sandwiched between the sheets, and the thickness was set to 10 mm with a hot press machine.

One more 400 g / m ² non-woven fabric is further laminated on the upper layer, and five 400 g / m ² non-woven fabrics are laminated on the lower layer.
A fibrous structure with a mesh net laminate of 035 g / cm ³ was obtained. It was 31.97% when the compressive residual strain rate of the fibrous structure of the mesh net laminate was measured.

Example 2 Hollow conjugate polyester fiber 13 denier, 5
82% by weight of 1 mm, binder polyester fiber 3
18% by weight of Neil, 51mm mixed with normal non-woven fabric
Carding, cross lay and infrared heat treatment
Thickness 10mm, basis weight 200g / m^TwoNon-woven
And thickness 20 mm, basis weight 400 g / m ^TwoOf non-woven fabric
Was.

[0030] was in a thickness of 10mm in this one mesh-like net "bell couple" of Kanebo Synthetic Fiber Co., Ltd. on the basis weight of 200g / m ² of non-woven fabric 50 mesh, needle punched place the 26g / m ^2.

One 400 g / m ² non-woven fabric is further laminated on the upper layer, and five 400 g / m ² non-woven fabrics are laminated on the lower layer.
A fibrous structure with a mesh net laminate of 035 g / cm ³ was obtained. It was 33.42% when the compression set of this fibrous structure of a mesh net laminated | stacked was measured.

Comparative Example 1 Hollow conjugate polyester fiber 13 denier, 5
82% by weight of 1 mm, 3 denier of binder polyester fiber, and 18% by weight of 51 mm are mixed, and the thickness is 80 mm and the density is 0.035 by carding, cross lay and infrared heat treatment and setter processing in a usual nonwoven fabric manufacturing process.
g / cm ³ of the nonwoven fabric was obtained. The measured compression residual strain of this nonwoven fabric was 41.90%.

As described above, in the example, the compression residual strain rate was improved by 10% as compared with the comparative example, and good results were obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiaki Nishida 213-1 Isae, Hofu City, Yamaguchi Prefecture (72) Inventor Satomi Sugiyama 767 Nishiura, Hofu City, Yamaguchi Prefecture

Claims (4)

[Claims] 1. A fibrous structure obtained by laminating nonwoven fabrics, wherein the fibrous structure has a mesh sheet layer at least at one position between the nonwoven fabric layers. 2. The fibrous structure according to claim 1, wherein the reticulated sheet contains a heat-fusible polymer. 3. A fibrous structure characterized by laminating a mesh sheet in at least one place when producing a laminate from a nonwoven fabric, and integrating this with a nonwoven fabric layer on both sides of the net layer by needle punching. Body making. 4. A method of manufacturing a laminate from a nonwoven fabric, comprising laminating a mesh sheet at at least one location, and heat-treating the mesh sheet to be integrated with the nonwoven fabric layers on both sides of the net layer. Manufacturing method of fiber structure.