JP3176472U - Mattress fiber structure and mattress - Google Patents

Abstract

Disclosed is a fiber structure for a mattress that has excellent cushioning properties, reduces stuffiness caused by a large amount of perspiration, and further has excellent body pressure dispersibility, and a mattress using the fiber structure.
An inelastic crimped short fiber, and a heat-adhesive composite short fiber in which a polymer having a melting point lower by 25 ° C. or more than a polymer constituting the inelastic crimped short fiber is disposed on a surface thereof as a heat fusion component; Is obtained by laminating webs blended so that the weight ratio is 90/10 to 10/90, and is a heat-bonded fixing point in a state where the heat-adhesive composite short fibers intersect with each other and / or At least one surface of the mattress fiber structure in which the heat-bonding composite short fibers and the non-elastic crimped short fibers cross and the heat-adhered fixing points are scattered, the major axis is 500 mm or more and the minor axis is A recess having a depth of 500 mm or more and a depth of 15 to 100 mm is formed.
[Selection] Figure 1

Description

  The present invention relates to a mattress fiber structure that has excellent cushioning properties, reduces stuffiness due to a large amount of perspiration, and has excellent body pressure dispersibility, and a mattress using the fiber structure.

  2. Description of the Related Art Conventionally, a bed for raising both sides (having a side-up function) has been used as a medical / nursing bed so as to wrap up the body for fall prevention in conjunction with a back-up function. Urethane mattresses are known as mattresses that can be used for beds that rise on both sides. However, urethane mattresses have problems such as stuffiness due to poor breathability and inability to wash with water. was there.

Also, as a mattress that can reduce stuffiness and can be washed in water, a fiber cushion material is used in which short fibers containing heat-bondable short fibers are made into a web and then fixed points are formed by heat-bonding the heat-bondable short fibers. Is known. (For example, refer to Patent Document 1 and Patent Document 2).
However, a mattress using such a fiber cushion material has a problem that the body pressure dispersibility is not sufficient.

JP-A-8-318066 JP 2007-308831 A

  The present invention has been made in view of the above background, and uses a fiber structure for a mattress that has excellent cushioning properties, reduces stuffiness due to a large amount of sweat, and further has excellent body pressure dispersibility, and the fiber structure. It is to provide a mattress.

  As a result of diligent investigations to achieve the above object, the present inventor has obtained a fiber structure for a mattress using a web in which inelastic crimped short fibers and heat-adhesive composite short fibers are mixed. At least on one side, the inventors have found that body pressure dispersibility can be improved by forming a concave portion having a predetermined size, and have further intensively studied to arrive at the present invention.

  Thus, according to the present invention, “a thermal adhesive property in which a non-elastic crimped short fiber and a polymer having a melting point lower by 25 ° C. or more than the polymer constituting the non-elastic crimped short fiber are arranged on the surface as a thermal fusion component. Adhesive bonding obtained by laminating a web blended so that the weight ratio of the composite short fibers is 90/10 to 10/90, and being heat-sealed in a state where the heat-adhesive composite short fibers intersect with each other A mattress fiber structure in which dots and / or the heat-bonded composite short fibers and the non-elastic crimped short fibers intersect with each other and the fixing points thermally fused are scattered, and at least one of the fiber structures There is provided a fiber structure for mattress characterized in that a concave portion having a major axis of 500 mm or more, a minor axis of 500 mm or more and a depth of 15 to 100 mm is formed on the surface.

  In that case, it is preferable that the said web is laminated | stacked by folding a web in the shape of an accordion. Moreover, it is preferable that a plurality of grooves are formed in the width direction on the upper surface or the lower surface of the mattress fiber structure. In that case, in the said groove | channel, it is preferable that the depth is in the range of 20-30 mm, and the space | interval of the mutually adjacent groove | channel is in the range of 50-100 mm. The inelastic crimped short fibers are preferably made of polyester fibers. Moreover, it is preferable that the said heat-fusion component consists of a polyester-type elastomer.

In the fiber structure for mattress of the present invention, the thickness of the fiber structure is preferably in the range of 40 to 100 mm, and the density of the fiber structure is preferably in the range of 20 to 50 kg / m ³ .
Moreover, according to this invention, the mattress containing the said fiber structure for mattresses is provided. In such a mattress, it is preferable that a cushion material having a compression ratio of 60 to 80% by a load of 980N (a disk-shaped load having a diameter of 200 mm) is fitted in the concave portion. The mattress is preferably used for medical purposes or for nursing care.

  ADVANTAGE OF THE INVENTION According to this invention, the mattress formed using the fiber structure for mattresses which was excellent in cushioning properties, reduced the dampness by a large amount of perspiration, and was further excellent in body pressure dispersibility, and this fiber structure.

It is an example of the fiber structure for mattresses of the present invention. In this invention, it is a figure which shows a groove | channel typically. It is a schematic diagram for demonstrating the measuring method of T / W.

  Hereinafter, embodiments of the fiber structure for mattresses of the present invention (hereinafter sometimes simply referred to as “fiber structure”) will be described in detail.

The inelastic crimped short fibers in the present invention include natural fibers such as cotton and wool, inorganic fibers such as carbon fibers, cellulosic fibers, aramid, polyolefin and polyester synthetic fibers, as well as cotton and wool. Recycled fiber called so-called can also be used. Among these, synthetic fibers are preferable from the viewpoints of handleability and recyclability. In particular, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polytetramethylene terephthalate, poly-1,4-dimethylcyclohexane terephthalate, polyethylene naphthalate, polypivalolactone, polylactic acid (PLA), stereo Examples thereof include polyesters such as complex polylactic acid, short fibers made of these copolymers, mixed cotton of these short fibers, or composite short fibers made of two or more of the above polymer components. In addition, polyester that has been material-recycled or chemically recycled, polyethylene terephthalate that uses a monomer component obtained from biomass, that is, a biologically-derived substance, described in JP2009-01694, The short fiber which consists of polyester etc. which were obtained using the catalyst containing a specific phosphorus compound and a titanium compound as described in Unexamined-Japanese-Patent No. 2004-270097 and 2004-21268 may be sufficient. Among these short fibers, short fibers made of polyethylene terephthalate or polybutylene terephthalate are particularly preferable from the viewpoint of fiber forming property and the like.
In the above-mentioned inelastic crimped short fiber, the cross-sectional shape of the single fiber may be any of ordinary round, flat, constricted flat such as four-sided flat, triangle or square polygon, hollow such as round hollow or triangular hollow, etc. .

  In the above-mentioned inelastic crimped short fibers, the single yarn fineness is preferably 2 to 700 dtex (more preferably 4 to 200 dtex, particularly preferably 5 to 10 dtex). If the single yarn fineness is smaller than 2 dtex, the bulkiness may be insufficient, and the cushioning property and the resilience may be poor. On the contrary, if the single yarn fineness is larger than 700 dtex, it is difficult to form a web, and if the basis weight is the same, there is a possibility that sufficient cushioning properties cannot be obtained because the number of fibers constituting the fiber structure is reduced. The fiber length of the inelastic crimped short fiber is preferably cut to 3 to 100 mm.

  In the inelastic crimped short fibers, the number of crimps is preferably 4 to 25 pieces / 2.54 cm (preferably 7 to 15 pieces / 2.54 cm), and the crimp rate is 20 to 35%. It is preferable. If the number of crimps and the crimp rate are smaller than these ranges, the web is difficult to be bulked, and there is a possibility that it will be difficult to form a web. At the same time, there is a possibility that only a fiber structure with poor durability and a low durability can be obtained. On the other hand, if the number of crimps and the crimp ratio are larger than these ranges, the bulkiness of the web is low, and only a high-density fiber structure can be obtained, or the entanglement of fibers becomes strong during web formation. There is a risk that unevenness of the shape tends to occur.

  As a crimping method, a spiral crimp is applied using a composite fiber in which polymers having different heat shrinkage rates are bonded to a side-by-side type, a spiral crimp is applied by anisotropic cooling, and a normal indentation crimper method is used. Various methods such as imparting mechanical crimp may be used, but it is optimal to impart mechanical crimp from the viewpoints of bulkiness and manufacturing cost.

  On the other hand, the low-melting polymer having a melting point of 25 ° C. or more (more preferably 25 to 150 ° C.) lower than the melting point of the polymer constituting the inelastic crimped short fiber is at least as a heat-bonding component. Short fibers placed on the surface. The heat-fusion component is melted by heating, and the intersection between the heat-adhesive short fibers and the intersection between the heat-adhesive short fibers and the inelastic crimped short fibers are fused. At that time, when the difference in melting point is less than 25 ° C., the processing temperature is close to the melting point temperature of the inelastic crimped short fiber, so that the physical properties and crimp characteristics of the inelastic crimped short fiber or the cushioning property of the fiber structure are deteriorated. In addition, there is a fear that the shrinkage rate at the time of molding may increase, which is not preferable.

  The fibers constituting the heat-adhesive short fibers include copolymer polyester fibers, thermoplastic elastomer fibers, polyolefin fibers, polyvinyl alcohol fibers, and composites having a composite form formed of a heat fusion component and a core component. Examples thereof include fibers. In particular, a composite fiber having a heat fusion component is preferable because of its excellent shape retention stability and moldability. In cushion applications where the amount of compression, that is, the amount of deformation is large due to repeated compression deformation, deformation is easy when deformation stress is applied to the fixing point (fusion point), and restoration is performed without leaving distortion when the deformation stress is removed. It is preferable to do. When a large deformation amount is applied to the fiber structure, a force such as a larger angle change, extension, or twist is applied to the fixing point included in the fiber structure. For this reason, it is preferable that the low melting-point polymer which forms a heat-fusion component is a thermoplastic elastomer.

  As such a thermoplastic elastomer, a polyester elastomer having heat resistance and capable of high temperature thermoforming is particularly preferable. Polyester ester copolymer is a polyetherester copolymer obtained by copolymerizing thermoplastic polyester as a hard segment and poly (alkylene oxide) glycol as a soft segment, more specifically terephthalic acid, isophthalic acid, phthalic acid, naphthalene. -2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, alicyclic dicarboxylic acid such as 1,4-cyclohexanedicarboxylic acid, succinic acid, oxalic acid, adipic acid , At least one dicarboxylic acid selected from aliphatic dicarboxylic acids such as sebacic acid, dodecanedioic acid and dimer acid, or ester-forming derivatives thereof, 1,4-butanediol, ethylene glycol trimethylene glycol, tetramethylene Glycol, penta Aliphatic diols such as tylene glycol, hexamethylene glycol neopentyl glycol, decamethylene glycol, or alicyclic diols such as 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecane methanol, or esters thereof Polyethylene glycol, poly (1,2- and 1,3-polypropylene oxide) glycol, poly (tetramethylene oxide) having at least one diol component selected from formable derivatives and the like, and an average molecular weight of about 400 to 5000 A ternary copolymer composed of at least one of poly (alkylene oxide) glycols such as glycols, copolymers of ethylene oxide and propylene oxide, copolymers of ethylene oxide and tetrahydrofuran, etc. It can be mentioned coalescence.

  In particular, a block copolymer polyether ester having polybutylene terephthalate as a hard component and polyoxybutylene glycol as a soft segment is preferable from the viewpoint of adhesiveness with inelastic crimped short fibers, temperature characteristics, and strength. In this case, the polyester portion constituting the hard segment is polybutylene terephthalate in which the main acid component is terephthalic acid and the main diol component is a butylene glycol component. Of course, part of this acid component (usually 30 mol% or less) may be substituted with another dicarboxylic acid component or oxycarboxylic acid component, and part of the glycol component (usually 30 mol% or less) is also butylene. It may be substituted with a dioxy component other than the glycol component. Further, the polyether portion constituting the soft segment may be a polyether substituted with a dioxy component other than butylene glycol.

When the heat-adhesive short fibers are composite fibers, the polymer forming the core component is polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polytetramethine terephthalate, poly-1,4. -Dimethylcyclohexane terephthalate, polypivalolactone or a copolymer ester thereof can be used.
In addition, various stabilizers, ultraviolet absorbers, thickening branching agents, matting agents, coloring agents, other various improving agents, and the like may be blended in the above-described polymer as necessary.

  When the heat-adhesive short fibers are composite fibers, it is preferable that the heat-sealing component occupies at least a half of the surface area. It is appropriate that the weight ratio of the heat fusion component and the core component is in the range of 30/70 to 70/30 as a composite ratio. The composite form is not particularly limited as long as at least the heat fusion component is exposed on the surface, and examples include a side-by-side type, a core-sheath type, and an eccentric core-sheath type.

  In the heat-adhesive short fibers, the single yarn fineness is preferably 2 to 170 dtex (more preferably 1 to 15 dtex, particularly preferably 2 to 10 dtex), the fiber length is 38 to 255 mm, and the number of crimps is 4 to 70. A range of /2.54 cm is preferred. If it is out of this range, the process stability such as blended cotton and web formation may be deteriorated. Moreover, there exists a possibility that the cushion performance and compression durability of a fiber structure may fall.

  In the present invention, the fiber structure is formed by laminating a web in which the above-mentioned inelastic crimped short fibers and the heat-adhesive short fibers are laminated, and then heat-treating so that the heat-adhesive short fibers intersect with each other. The heat-bonded fixing points and / or the heat-bonded short fibers and the non-elastic crimped short fibers intersect with the heat-bonded fixing points. At that time, it is important that the weight ratio of the inelastic crimped short fibers to the heat-bonded short fibers is 90/10 to 10/90. When the ratio of the heat-adhesive short fibers is smaller than this range, the fixing points are reduced, and the compression resilience and the compression durability may be lowered. On the contrary, when the ratio of the heat-adhesive short fibers is larger than this range, it is difficult to obtain a desired molded product shape due to the shrinkage of the heat-adhesive short fibers, and quality control in production is difficult, which is preferable. Absent.

  Here, it is preferable that the heat-adhesive composite short fibers and the inelastic crimped short fibers are arranged in the thickness direction of the fiber structure because cushioning properties, elasticity, and swelling reduction effects are improved. Here, “arranged in the thickness direction” means that the total number of fibers arranged in parallel to the thickness direction of the fiber structure is (T) as shown in FIG. When the total number of fibers arranged perpendicular to the body thickness direction is (W), T / W is 1.5 or more.

  In the present invention, at least one surface of the fiber structure (preferably the upper surface in contact with the human body, more preferably only the upper surface in contact with the human body), the major axis (preferably the major axis direction and the longitudinal direction of the fiber structure (that is, the height of the human body). The length of 500 mm or more (preferably 500 to 3000 mm, more preferably 900 to 1300 mm) and the short diameter (width direction of the fiber structure) of 500 mm or more (preferably 500 to 800 mm). A recess having a depth of 15 to 100 mm is formed. By forming such recesses, body pressure dispersibility is improved.

  The major axis is the long side in the cross section of the recess, and the minor axis is the short side in the cross section. When the cross section of the recess is rectangular, the major axis is the length of the long side, and the minor axis is the length of the short side. When the cross section of the recess is elliptical, the major axis is the length in the major axis direction of the ellipse, and the minor axis is the length in the direction perpendicular to the major axis.

  Here, when the major axis of the recess is less than 500 mm or the minor axis is less than 500 mm, the range in which the user lies is limited, and sufficient body pressure dispersibility may not be obtained. Moreover, sufficient body pressure dispersibility may not be obtained even when the depth is less than 15 mm. On the contrary, when the major axis of the concave portion is larger than 3000 mm, or the minor axis is larger than 800 mm or the depth is larger than 100 mm, the waist to the hips may sink too much and it may be difficult to turn over.

  In the fiber structure, it is preferable that grooves are formed on at least one surface in the width direction of the mattress. In particular, when the plurality of grooves are formed in the width direction on the upper surface or the lower surface of the fiber structure, the surface on which the grooves are formed is opposite to the human body side (that is, the mattress back surface) The use of a mattress facilitates bending in response to the bed back up function.

  In that case, it is preferable that the depth is in the range of 20 to 30 mm in the groove. Moreover, it is preferable that the space | interval of the adjacent groove | channel is in the range of 50-100 mm in the centerline space | interval (W) of a groove | channel. The groove width is preferably in the range of 2 to 20 mm. It is preferable that the groove is within such a range that the effect on the cushioning property is small. The groove shape may be any of a V-shaped groove and a concave groove.

  The said fiber structure can be manufactured with the following manufacturing methods, for example. First, a web is prepared in which the above-described inelastic crimped short fibers and heat-bondable composite short fibers are mixed so that the weight ratio is 90/10 to 10/90.

  Next, the web is temporarily fused with a far-infrared ray or hot air heater if necessary, laminated in accordance with a predetermined density and thickness, put into a mold, and then reduced in pressure to 50 Torr or less using a steam pot. Then, a method of heat-moisture treatment for a certain time and then cooling and drying is preferable. At that time, it is important that the web lamination direction is the width direction of the mattress.

Here, in order to arrange the fibers constituting the fiber structure in the fiber thickness direction, a heat treatment machine as shown in FIG. 2 of Japanese Patent Application Laid-Open No. 2007-308831 (in the case of a commercially available, Struto equipment manufactured by Struto, etc.) The web may be heated after laminating the web by folding it into an accordion type by pushing the web into a hot air suction heat treatment machine set to a melting point of the low melting point polymer or higher by a driving roller.
Further, in order to form the concave portion as described above, the web is compressed and held between the upper and lower two plates in which the convex portion corresponding to the concave portion is formed on one of the upper and lower plates. It is good to heat.

  Further, when a plurality of grooves are formed on the upper surface or the lower surface of the mattress fiber structure, one of the two upper and lower plates of the mold is provided with a chevron or convex corresponding to the groove. A method of compressing and holding between the two upper and lower plates provided with the projections of the mold and heating is preferable. Alternatively, after overlapping the fiber structure as necessary, one of the two upper and lower plates is provided with two upper and lower plates provided with a mountain-shaped or convex projection corresponding to the groove. It may be compressed between the plates and heated.

In the fiber structure thus obtained, the density is preferably in the range of 20 to 50 kg / m ³ . If the density of the fiber structure is smaller than the above range, the resilience and compression durability may be reduced. On the other hand, if the density of the fiber structure is larger than the above range, it may become hard. Moreover, it is preferable that it is 40-100 mm as thickness of a fiber structure. If the thickness of the fiber structure is smaller than 40 mm, the cushioning property may not be sufficiently exhibited. On the other hand, when the thickness of the fiber structure is larger than 100 mm, the handleability may be impaired.

The shape of the fiber structure is not limited to a flat plate shape or a rectangular parallelepiped shape, and may be an arbitrary shape such as a disk shape. In addition, known functional processing such as normal water repellent processing, flameproof processing, flame retardant processing, and negative ion generation processing may be added.
In the fiber structure of the present invention, since the concave portion is formed on at least one surface of the fiber structure, the cushion structure is excellent, the stuffiness due to a large amount of perspiration is reduced, and the body pressure dispersibility is also excellent.

  Next, the mattress of the present invention is a mattress including the fiber structure. In that case, you may comprise a mattress by the said fiber structure individually or in piles. In addition, it is preferable that a cushioning material having a compressibility of 60 to 80% by a load of 980 N (100 kgf, disk-shaped load having a diameter of 200 mm) is fitted in the concave portion to further improve body pressure dispersibility. In that case, it is preferable that the size of the cushion material to be fitted is the same as the size of the concave portion (length in the longitudinal direction, length in the width direction, depth). Furthermore, it is preferable to laminate a fabric such as a woven fabric, a knitted fabric, or a non-woven fabric. As such a fabric, a three-dimensional knitted fabric is preferable. In particular, it is preferable that a three-dimensional knitted fabric is laminated on the surface opposite to the surface on which grooves are formed in the width direction of the mattress, because excellent air permeability, cushioning properties, and high appearance are obtained. As such a three-dimensional knitted fabric, a solid knitted fabric having a thickness of 2 to 50 mm, which is composed of a two-layer knitted fabric (preferably a mesh) and a monofilament connecting yarn connecting the two-layer knitted fabric, is preferable. Among commercially available products, for example, Fusion (registered trademark) manufactured by Asahi Kasei Corporation is preferable.

  When other fabrics are laminated on the fiber structure, the fabric may be bonded to the fiber structure with an adhesive. However, the web and the fabric may be placed in a mold at the same time and subjected to wet heat treatment, or the web. It is preferable to heat-adhere by compressing and holding between two upper and lower plates in a state where the fabric and the fabric are laminated.

  In the mattress of the present invention, accessories other than the fabric may be added. It is also preferable to coat with a covering material made of a fabric. Further, the shape of the mattress is not limited to a flat plate shape, and may be an arbitrary shape. Furthermore, known functional processing such as normal water repellent processing, flameproof processing, flame retardant processing, and negative ion generation processing may be added.

  In the mattress of the present invention, since the fiber structure is composed of the inelastic crimped short fibers and the heat-bondable composite short fibers as described above, it is excellent in elasticity and cushioning properties, and is easy to dry after water washing. Can be melted after use and recycled again into new fibers, molded plastics, etc., and has the excellent effect of generating less toxic gas when burned.

  The mattress of the present invention can be particularly suitably used as a medical mattress or a nursing mattress, but may be used for other purposes. In that case, it uses so that the said recessed part may be located in the human body side. Further, it is preferable to use the mattress so that the surface on which the grooves are formed in the width direction is the back surface of the mattress (that is, the surface opposite to the human body side), but the front and back surfaces may be reversed.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail by an Example, this invention is not limited to this. In addition, each measurement item in an Example was measured with the following method.

(1) Melting point Using a differential thermal analyzer 990 manufactured by Du Pont, measured at a temperature increase of 20 ° C./min, and obtained a melting peak. If the melting temperature is not clearly observed, the melting point is the temperature at which the polymer softens and starts to flow (softening point) using a trace melting point measuring device (manufactured by Yanagimoto Seisakusho). In addition, the average value was calculated | required by n number 5.

(2) Intrinsic viscosity Measured at 35 ° C. using orthochlorophenol as a solvent. In addition, the average value was calculated | required by n number 5.

(3) Number of crimps and crimp rate Measured by the method described in JIS L 1015. In addition, the average value was calculated | required by n number 5.

(4) Compressibility by load 980N (100 kgf, disc-shaped load having a diameter of 200 mm) The compressibility by load 980N (100 kgf, disc-shaped load having a diameter of 200 mm) was measured by the method described in JIS K 6400. In addition, the average value was calculated | required by n number 5.

(5) Body Pressure Dispersibility Ten subjects tested their maximum pressure on the buttocks using the XSENSOR (registered trademark) Pressure Mapping system XS96, lying on their back on the mattress. The average value of 10 test subjects was obtained, and the body pressure dispersibility was better as the numerical value was smaller in relative evaluation, and 100 mmHg or less was determined to be acceptable.

(6) Back-up support A mattress is placed on a side-up bed manufactured by France Bed Co., Ltd. (Part No. FBSU-720 / 32TD), and a man with a height of 175 cm and a weight of 65 kg is lying on his back with a back angle of 70 degrees. The length (L1) was measured so that the line extending from the back-up bending point of the bed floor board was perpendicular to the back surface of the mattress, and evaluation was performed according to the following criteria.
Correspondence: L1 ≦ 70mm, no compatibility: L1> 70mm

(7) Formability of concave portion A cushion material was fitted into a recess formed in the center portion of the mattress, and the gap (S) and step (G) between the cushion material and the fiber structure for mattress were evaluated according to the following evaluation criteria. .
Pass: S ≦ 2 mm and G ≦ 2 mm, Fail: S> 2 mm or G> 2 mm

(8) T / H
The fiber structure is cut in the thickness direction, and the total number of fibers (0 ° ≦ θ ≦ 45 ° in FIG. 3) arranged in parallel to the thickness direction in the cross section is defined as (T). Fibers arranged perpendicular to the thickness direction of the cushion material (45 ° <θ ≦ 90 ° in FIG. 3)
T / H was calculated with the total number of In addition, the measurement of the number was carried out by observing 30 fibers for each of 10 arbitrary positions with a transmission optical microscope, and counting the number. When T / W was 1.5 or more, it was determined that “fibers are arranged in the thickness direction”.

[Example 1]
An acid component obtained by mixing terephthalic acid and isophthalic acid at 80/20 (mol%) and butylene glycol are polymerized, and the obtained polybutylene terephthalate 38 wt% is further added with polytetramethylene glycol (molecular weight 2000) 62 wt%. A block copolymerized polyether polyester elastomer was obtained by heating reaction. The melting point of this thermoplastic elastomer was 155 ° C. This thermoplastic elastomer is spun into a sheath (sheath), polybutylene terephthalate (melting point 224 ° C.) into the core (core), and the sheath / core weight ratio is spun to be 70/70 to obtain an eccentric sheath / core type composite fiber. Obtained. The obtained composite fiber was stretched 2.0 times, dried at 80 ° C. to develop crimps, then applied with an oil agent and cut into 51 mm to obtain heat-adhesive short fibers. In the heat-bondable short fibers, the single yarn fineness was 7.3 dtex, the number of crimps was 13 / 2.54 cm, and the crimp rate was 30%.
Next, 30% by weight of the heat-adhesive short fibers and a polyethylene terephthalate short fiber obtained by a conventional method as an inelastic crimped short fiber (single yarn fineness 7.3 dtex, fiber length 64 mm, number of crimps 9/2. 54 cm, crimp rate 34%, cross-sectional shape is round hollow, melting point 256 ° C.) 70% by weight, a web is produced with a normal carding machine, and a roller surface speed of 2. Folding into an accordion type by pushing into a hot air suction heat treatment machine (heat treatment zone length 5 m, moving speed 1 m / min) with a driving roller of 5 m / min, treated at 190 ° C. for 5 minutes, thickness 30 mm, basis weight 460 g / min A fiber structure in which m ² inelastic crimped short fibers and heat-adhesive short fibers were arranged in the thickness direction of the fiber structure was obtained.
Four of these fiber structures were laminated, compressed and held between 80 mm between the two upper and lower plates, and heat molded. In addition, a jig was installed on the upper plate so that a recess having a depth of 35 mm, a length of 1100 mm, and a width of 650 mm was formed in the center portion of the mattress. In addition, the lower plate was provided with a plate having a thickness of 5 mm and a height of 30 mm at intervals of 70 mm on the surface on which the fiber structure was placed, and standing vertically to the width direction of the mattress. Thus, as shown in FIG. 1, a mattress fiber in which a concave portion (depth 35 mm, length in the longitudinal direction (long diameter) 1100 mm, width (short diameter) 650 mm) of the fiber molded body is provided on one surface of the fiber molded body. A structure was produced.
To the concave portion at the center of the mattress fiber structure obtained, Breath Air (registered trademark) product number M4535 manufactured by Toyobo Co., Ltd. having the same size as the concave portion ((length in the longitudinal direction, length in the width direction, depth)) An inset mattress was made.
The obtained mattress has excellent body pressure dispersibility. It was suitable as a medical mattress and a nursing mattress.

[Example 2]
In Example 1, the web was not folded in an accordion shape, but treated at 190 ° C. for 5 minutes, and 30 mm thick and 460 g / m ² inelastic crimped short fibers and thermally adhesive short fibers were arranged in the thickness direction of the fiber structure. A mattress was produced in the same manner as in Example 1 by stacking the four fiber structures.
The resulting fiber structure for mattress has poor moldability in the depression at the center, and there are some gaps and steps between Breath Air (registered trademark), and the mattress surface compared to that obtained in Example 1 The uniformity was slightly reduced.

[Comparative Example 1]
In Example 1, the jig of the upper plate when the fiber structure was laminated and heat-molded was removed, and the surface on which the fiber structure was abutted was made flat. As a result, a mattress was produced in the same manner as in Example 1 except that both sides of the mattress became flat.
The obtained mattress was inferior to Example 1 in body pressure dispersibility. The evaluation results are shown in Table 1.

1: Concavity formed on one surface of fiber structure 2: Groove formed on one surface of fiber structure

Claims (10)

The weight ratio of the inelastic crimped short fiber and the heat-adhesive composite short fiber disposed on the surface of the polymer having a melting point 25 ° C. lower than that of the polymer constituting the inelastic crimped short fiber as a heat-fusible component Adhering point obtained by laminating webs blended so as to be 90/10 to 10/90 and thermally bonded in a state where the heat-adhesive composite short fibers intersect with each other and / or the heat-adhesive property A fiber structure for a mattress in which composite short fibers and fixing points heat-sealed in a state where the inelastic crimped short fibers intersect with each other,
A fiber structure for a mattress, wherein a recess having a major axis of 500 mm or more, a minor axis of 500 mm or more and a depth of 15 to 100 mm is formed on at least one surface of the fiber structure.   The fiber structure for mattresses according to claim 1, wherein the web is laminated by folding the web into an accordion shape.   The fiber structure for mattress according to claim 1 or 2, wherein a plurality of grooves are formed in the width direction on the upper surface or the lower surface of the fiber structure for mattress.   The fiber structure for a mattress according to claim 3, wherein the groove has a depth in a range of 20 to 30 mm, and an interval between adjacent grooves is in a range of 50 to 100 mm.   The fiber structure for mattresses according to any one of claims 1 to 4, wherein the inelastic crimped short fibers are made of polyester fibers.   The fiber structure for a mattress according to any one of claims 1 to 5, wherein the heat fusion component is made of a polyester elastomer. The fiber structure for mattresses according to any one of claims 1 to 6, wherein the thickness of the fiber structure is in the range of 40 to 100 mm, and the density of the fiber structure is in the range of 20 to 50 kg / m ^3. body.   The mattress containing the fiber structure for mattresses in any one of Claims 1-7.   The mattress according to claim 8, wherein a cushion material having a compression rate of 60 to 80% by a load of 980 N (100 kgf, disk-shaped load having a diameter of 200 mm) is fitted in the recess.   The mattress according to claim 8 or 9, wherein the mattress is for medical use or for nursing care.

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