JPH10259657A - Cushion material for tatami mat and tatami mat using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the shape holding property and cushioning property by setting the density of a cushion material for a tatami mat and the density difference between a nonwoven fabric having the maximum fiber density and a nonwoven fabric having the minimum fiber density to specific ranges. SOLUTION: Two kinds of nonwoven fabrics 16A, 16B having different densities are laminated, and the nonwoven fabric having the maximum fiber density is provided on the outermost layer to form a cushion material 16. The fiber density of the whole cushion material is 0.06-0.20 g/cm<3> , and the fiber density difference between the nonwoven fabric having the minimum fiber density and the nonwoven fabric having the maximum fiber density is 0.04-0.10 g/cm<3> . A surface of the nonwoven fabric 16B side having a small fiber density of the cushion material 16 is covered with a tatami facing 17 woven with rush. A verge fabric 18 is stuck or sewn to form an edge section. Since the cushion material 16 is formed with a laminated body of the nonwoven fabrics different in fiber density, the hardnesses on both sides differ, and contrary characteristics such as the cushioning property and shape holding property can be satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nonwoven tatami cushion material which is lightweight and has excellent cushioning properties and shape retention properties, and a portable tatami mat using the same.

[0002]

2. Description of the Related Art Tatami, a flooring material traditionally used in Japanese houses, is sewn on a tatami floor with straw sewn with hemp, and sewn on a tatami mat with cotton thread and sewn with hemp. Is covered with a cloth edge.

However, tatami flooring using natural straw has come to be disliked because tatami mats are hardly used due to recent changes in lifestyles, and mite and mold are likely to occur. In recent years, there is a simple tatami that can be folded and made portable so that it can be used at a desired place as needed. However, in the case of a simple tatami, there is a demand that the tatami be further lightweight.

In order to meet such demands, synthetic resin cushion materials have been used instead of natural straw tatami floors. For example, Japanese Utility Model Publication No. 62-154
No. 127 discloses a folding fold using a synthetic resin foamed floor, and Japanese Utility Model Registration No. 3019112.
Japanese Patent Application Publication No. JP-A-2003-115125 discloses a structure in which a plurality of parallel ribs connecting two liner plates are integrally extruded to form a pair of synthetic resin hollow plates, and a foamed plastic sheet is laminated on the upper surface.

[0005]

Since tatami mats are used as flooring materials, a certain degree of hardness is required to maintain the shape. When constructing a tatami floor with a synthetic resin foam, the foam is a porous body having a large number of pores throughout, so that in order to satisfy the required strength and shape retention, the porosity was suppressed. However, a hard foam must be used. Hard foam cushioning materials tend to have insufficient cushioning properties, and tend to be less comfortable and softer than the original tatami mats.

A tatami floor using a synthetic resin hollow plate is:
The shape retention is excellent, and the cushioning property is to be ensured by foamed plastic. However, in order to secure the strength in the vertical direction with respect to the tatami mat surface, a certain thickness is required for each synthetic resin plate. However, there is a problem that the weight of the tatami floor increases. The heavy weight of the tatami floor is unsuitable, for example, for a tatami floor of a simple tatami mat that is folded and carried.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a tatami mat that is excellent in shape retention and cushioning properties, and is lightweight and convenient to be folded and carried. It is to provide a cushion material and a tatami mat using the cushion material.

[0008]

That is, the cushion material for tatami of the present invention is a tatami cushion material obtained by laminating two or more nonwoven fabrics having different fiber densities such that the nonwoven fabric having the maximum fiber density is the outermost layer. a cushion material, a density of 0.06g / cm ³ ~0.20g / cm ³ of該畳cushioning material, and the density difference between the non-woven fabric having a minimum fiber density and a nonwoven fabric having a maximum fiber density 0 .04g / cm ³ ~0.1
0 g / cm ³ . The spring-type hardness of the surface of the nonwoven fabric having the maximum fiber density is 51 to 65.
The spring hardness of the other side is preferably 40 to 50. In addition, in at least one kind of nonwoven fabric constituting the cushion material for tatami, it is preferable that 50 to 85% of the constituent fibers of the nonwoven fabric are hollow fibers. Further, at least one kind of nonwoven fabric constituting the cushion material for tatami mats has a low melting point fiber having a melting point of 110 to 190 ° C.
It is preferable that the low melting point fiber is fused with the adjacent nonwoven fabric by melting the low melting point fiber.

The tatami mat according to the present invention is characterized in that the surface of the nonwoven fabric having the maximum fiber density, which is not the nonwoven fabric, of the cushion material of the present invention is covered with a tatami mat surface, and the edge of the cushion material is covered with a border cloth. I do.

[0010]

Embodiments of the present invention will be described below.

The tatami cushion material of the present invention is obtained by laminating two or more types of nonwoven fabrics having different fiber densities.
As shown in FIG. 1A, a two-layer body in which two types of nonwoven fabrics A and B are laminated, and as shown in FIG. 1B, three types of nonwoven fabrics A, B and C are sequentially laminated. And the like three-layered body.

In laminating nonwoven fabrics having different fiber densities,
The nonwoven having the highest fiber density is provided on the outermost layer. This is because the nonwoven fabric layer having the maximum fiber density becomes the lowermost surface and comes into contact with the floor surface, thereby exhibiting the shape retention of the cushioning material. Therefore, in the case of a two-layer body (FIG. 1A),
The fiber density of the nonwoven fabric A on the lower side (floor side) is large,
In the case of the layered body (FIG. 1 (b)), the fiber density of the nonwoven fabric A as the lowermost layer is the highest. The fiber density of the entire cushioning material is 0.06~0.20g / cm ^3, preferably a upper limit of 0.15 g / cm ³ having a lower limit of 0.09. 0.20
If the amount exceeds g / cm ³ , the cushioning material is too hard and too heavy to be used for a portable tatami floor. On the other hand, if it is less than 0.06 g / cm ³ , the floor material lacks shape retention.

Further, among the nonwoven fabrics constituting the cushioning material, the difference in fiber density between the nonwoven fabric having the minimum fiber density and the nonwoven fabric having the maximum fiber density is 0.04 to 0.10 g / cm ³ . If the density difference is less than 0.04 g / cm ³ , the cushioning property is lacking.

Therefore, when the cushion material is a two-layer body shown in FIG. 1A, the fiber density (d1) of the nonwoven fabric A and the nonwoven fabric B
Difference from the fiber density (d2) of 0.04 to 0.10 g / cm
It becomes ³ . On the other hand, in the case of a laminate of three or more layers, the nonwoven fabric having the minimum fiber density, which is a layer exhibiting cushioning properties, may be provided on the outermost layer and become the uppermost surface, that is, the tatami surface when used, or a part of the inner layer. May be laminated so as to form
Therefore, in the case of the three-layer body shown in FIG. 1B, when the fiber density (d2) of the nonwoven fabric B is the minimum, the fiber density difference (d1−d2) between the nonwoven fabric A and the nonwoven fabric B becomes the fiber density (d1) of the nonwoven fabric C.
When 3) is minimum fiber density difference of the nonwoven fabric A and the nonwoven fabric C is (d1-d3), the 0.04~0.10g / cm ^3.

In the case of a two-layered body, a three-layered body, or a multilayered body having more layers, the fiber density of each nonwoven fabric is adjusted so that the difference between the minimum fiber density and the maximum fiber density is within the above range. May be appropriately selected, but generally, the minimum fiber density is 0.06 to 0.105 g / cm ³ and the maximum fiber density is 0.1.
It is preferable to select the amount to be 0.6 to 0.20 g / cm ³ .

The thickness of each nonwoven fabric (T1 in FIG. 1)
To T5) is appropriately selected depending on the thickness of the whole cushion material for tatami, and is not particularly limited. Generally, since the thickness of the whole cushion material is 1.0 to 3.5 cm, a two-layer body is used. In this case, the thickness of the nonwoven fabric having the higher fiber density (the thickness T1 of the nonwoven fabric A in FIG. 1A) is 3 to 15 m.
m, the thickness of the nonwoven fabric having the smaller fiber density (the thickness T2 of the nonwoven fabric B in FIG. 1A) is preferably selected in the range of 7 to 20 mm.

Further, it is preferable that one side of the cushion material has a spring hardness of 51 to 65, and the other side has a spring hardness of 40 to 50. Here, the spring-type hardness is a hardness determined from a depression by pushing a needle with a spring, and is a test method SRIS-1 of the Japan Rubber Association.
It is a value measured according to 010. One side is the side of the nonwoven fabric having the maximum fiber density, and if it is less than 51, the shape retention is poor. The other side is the side opposite one side,
If it exceeds 50, the cushioning property and comfort are inferior, and if it is less than 40, it is too soft and inferior in shape retention.

The fibers constituting each nonwoven fabric are synthetic fibers such as polyester, nylon, acrylic and polypropylene; recycled fibers such as rayon, polynosic and cupra;
Semi-synthetic fibers such as acetate; natural fibers such as cotton and wool can be used. Of these, polyester fibers are excellent in terms of recycling such as waste collection, and are safe and inexpensive. It is preferably used because it is affordable.

The form of each fiber is not only circular cross section,
Fibers with irregular cross-sections such as triangular, Y-shaped, and star-shaped may be used. Depending on the shape of the spinneret used for melt spinning, fibers with various cross-sectional shapes can be obtained. Further, not only solid fibers but also hollow fibers may be used.

Since the hollow fiber contains air in the fiber, it is light and has high heat retention, so that the weight of the cushion material as a whole can be reduced, which is preferable. As shown in FIG. 2, as hollow fibers, in addition to the cylindrical shape (FIG. 2 (a)),
Various types of hollow fibers, such as a modified hollow type (FIG. 2B) and a type having a plurality of hollow portions (FIG. 2C), can be used. The hollow ratio in the fiber cross section is preferably 10 to 50%, and particularly preferably 30 to 50% in order to contribute to weight reduction. If the hollow ratio exceeds 50%, the elasticity cannot be recovered even if the fibers are crushed or broken.

Further, a composite fiber obtained by compounding two or more kinds of polymers may be used. The conjugate fiber may be of a core-sheath type in addition to a laminated structure of two layers. In the core-sheath type, the core portion may be a hollow fiber. The conjugate fiber may be a combination of different polymers such as polyethylene and polyester, polyolefin and polyester, polyethylene and polypropylene, or a combination of fibers represented by the same repeating unit but having different melting points. In the case of a bonded structure of different kinds of fibers, a coil-like crimp is developed by heat treatment due to a difference in coefficient of thermal expansion, so that it is preferable in that bulkiness can be obtained. In the case of the core-sheath type structure, as described later, it is preferable to use a polymer having a lower melting point in the sheath portion than in the core portion, particularly from the viewpoint of convenience in the production of the nonwoven fabric. It is preferable that the sheath is composed of a low melting point polymer. For example, a material in which the core is composed of a polyester homopolymer (melting point: 250 to 300 ° C.) and the sheath is composed of a polyester copolymer having a melting point of about 110 to 190 ° C. is preferably used. Examples of low-melting-point polyester copolymers include those in which the use of terephthalic acid and isophthalic acid in combination as dicarboxylic acid components causes the degree of crystallinity to decrease in accordance with the content of isophthalic acid, and the melting point to decrease.

The fibers may be long fibers or short fibers. It is appropriately selected according to the method for producing the nonwoven fabric. The fineness of each fiber is appropriately selected in the range of 5 to 30 deniers.
Since the nonwoven fabric with the minimum fiber density needs to satisfy the cushioning property, it is preferable to configure the nonwoven fabric with 10 to 30 denier fibers. From the viewpoint of shape retention, the nonwoven fabric with the maximum fiber density is preferably 5 to 15 denier fibers. It is preferable to configure. Generally, the fiber density of the nonwoven fabric tends to decrease as the fiber is made of thicker fiber, because the elastic recovery of the fiber in the nonwoven fabric manufacturing process increases.

These fibers may be subjected to special processing such as insect repellent, mite repellent, mold repellent and water repellency.

The fibers constituting each non-woven fabric are appropriately selected from the above-mentioned fibers, and the non-woven fabric may be manufactured using only one type of the above-mentioned fibers, or two or more types of fibers having different chemical compositions or fineness having the same chemical composition. However, two or more kinds of fibers different from each other may be mixed to produce a nonwoven fabric.

In particular, when a nonwoven fabric manufacturing method as described later is used, it is preferable to mix low melting point fibers. Here, the low melting point fiber is used in the production of nonwoven fabric,
A fiber having a low melting point that can serve as an adhesive, specifically a fiber having a melting point of 110 to 190 ° C. Among the low melting point fibers having such a melting point, the melting point is 160 ° C to 190 ° C.
The fibers are particularly preferable because the nonwoven fabric produced is excellent in bulkiness and also excellent in bonding the web.
As the low melting point fiber, for example, the melting point is 110 to 190 ° C.
Fiber comprising a homopolymer, a fiber comprising a copolymer of a polyester having a low melting point such as polyethylene and a polyester, and a composite fiber having a core-sheath structure in which a sheath portion is composed of a polymer having a low melting point (110 to 190 ° C.). Can be Examples of the fiber composed of the low melting point polymer alone include a polyester copolymer fiber in which the melting point of the polyester is lowered by using isophthalic acid in combination with terephthalic acid as a dicarboxylic acid component. As the composite fiber having a core-sheath structure, the core portion is formed of a normal polyester (melting point: 250 to 300).
Polyester copolymer or polyethylene having a melting point of 110 to 190 ° C and a melting point of 110 to 140 ° C.
℃), the core is polypropylene (melting point 160-180 ℃)
And a fiber whose sheath portion is made of polyethylene (melting point: 110 to 140 ° C.).

Among these low-melting fibers, it is preferable to use low-melting fibers composed of core-sheath composite fibers.
When low-melting fiber composed of low-melting polymer alone is used, all of the low-melting fiber is melted in the nonwoven fabric manufacturing process, but when low-melting fiber composed of a core-sheath composite fiber is used. In the nonwoven fabric manufacturing process, only the sheath melts and the core remains. Therefore, it is possible to contribute to the adhesion of the web without impairing the bulkiness of the nonwoven fabric. The core is made of polypropylene (melting point 160
-180 ° C) and the sheath is polyethylene (melting point 110-14)
0 ° C), when the core also belongs to the low melting point polymer, the melting point is higher than the melting point of the sheath,
By selecting a temperature lower than the melting point of the core, only the polymer of the sheath can contribute to the adhesion.

When mixing the above low melting point fibers, the mixing ratio is 15% of the total constituent fibers in one nonwoven fabric.
Preferably, the lower limit is 20% by weight and the upper limit is 35% by weight. Mixing ratio of low melting fiber is 15
If the amount is less than the percentage by weight, the adhesion between the fibers is reduced, and fuzzing occurs, so that a desired hardness cannot be obtained. On the other hand, 50% by weight
When it exceeds, the hardening action of the low melting point fiber, the hardness of the whole nonwoven fabric to be manufactured becomes high and the cushioning property is impaired, and in addition, the sewing machine needle is broken in the production of tatami, the sewing speed is reduced, This is because sewing workability is inferior.

The fiber density of the nonwoven fabric can be adjusted as appropriate depending on the type of fiber constituting the nonwoven fabric, the fineness, the mixing ratio of the fibers, the hollowness of the hollow fibers and the like. Therefore, the types of constituent fibers of the nonwoven fabrics having different fiber densities may be the same or different. However, in order to obtain a predetermined density difference, and from the viewpoint of the ease of lamination of the nonwoven fabric, the chemical composition is the same,
Preferably, only the fineness differs.

As a method for producing each nonwoven fabric, various conventionally known methods can be used. Specifically, an adhesive method in which a sheet-like web is mixed with an adhesive or a low-melting fiber and heat-treated to fix each web in a state of being overlapped; by piercing the web with a needle (needle punch method), By high-speed jet water flow (span lace method),
Stitch bonding (stitch bond method), mechanical bonding method to integrate fibers; spun bond method to form web directly from a large number of filaments, blow-off of polymer melt by high-speed high-temperature air flow, cooling and A direct method such as a melt blown method in which a web is collected on a belt to form a web; a papermaking method in which short fibers are dispersed in water to form a sheet with a paper machine, and the like. Of these methods, the mechanical bonding method, particularly the needle punching method, generally has a high fiber density and is inferior in bulkiness, and therefore is not preferable for producing a nonwoven fabric having a minimum fiber density which requires cushioning properties.

The nonwoven fabric of the present invention is obtained by laminating two or more types of nonwoven fabrics having a density difference produced by such a method. As a lamination method, separately manufactured nonwoven fabrics may be bonded using an appropriate adhesive, or may be fused by utilizing the melting of low melting point fibers contained in each nonwoven fabric. In addition, a plurality of nonwoven fabrics having different fiber densities can be simultaneously prepared and laminated. For example, the low-melting fibers are mixed in advance, and the low-melting fibers are melted by heat treatment, whereby the webs are fixed to each other to form the respective nonwoven fabrics, and the nonwoven fabrics can be laminated and integrated. According to such a method, the bonding step becomes unnecessary,
It is convenient.

The method for manufacturing and laminating the nonwoven fabric will be described in more detail with reference to FIG. FIG.
(A) is a view of the nonwoven fabric device as viewed from above, and FIG.
FIG. 2 is an aa cross-sectional view of the nonwoven fabric manufacturing apparatus.

First, raw cotton of fibers constituting a nonwoven fabric, for example, raw cotton of polyester and low melting point fiber are weighed and supplied to the cotton feeding lattice 1. The supplied raw cotton is opened by the cotton opener 2 and the raw materials are uniformly mixed.
The air is transferred to the stock chambers 4A and 4B through the air transfer pipes 3A and 3B, respectively. In addition, the air conveyance pipe 3A
Alternatively, 3B is switchable, and is stocked in the stock chamber 4A when conveyed through the air conveying pipe 3A, and stocked in the stock chamber 4B when conveyed through the air conveying pipe 3B. In stock rooms 4A and 4B,
For fusing the web, low melting point fibers are uniformly mixed at a predetermined ratio. The fibers in the stock rooms 4A and 4B are
The cards are conveyed to the cards 5A, 5B connected to the respective stock chambers, where they are entangled to form webs 6A, 6B.
And sent to the web conveyor 7. In the web conveyor 7, the sequentially sent webs are laminated to form laminated webs 13A and 13B, respectively. Here, the laminated web 1 laminated on the upstream side in the running direction of the web conveyor 7
3A is the lower side, and the laminated web 1 laminated on the downstream side
3B is laminated on the laminated web 13A,
Conveyed. In a state where the laminated web 13B is further laminated on the laminated web 13A, the laminated web 13B is pressed by a press roller 8, and further conveyed to a heat treatment chamber 10 while being pressed by a pair of upper and lower press conveyors 9,9. It is set to a predetermined thickness by the press conveyors 9 and 9. Further, in the heat treatment chamber 10, the low melting point fibers contained in the laminated webs 13A and 13B are melted by being heated to the melting point of the low melting point fibers or higher.
And the laminated web 13A and the laminated web 13B are also pressure-bonded and integrated. Next, it is conveyed to the cooling chamber 11 into which the cool air is blown, where it is cooled. The laminated nonwoven fabric 15 in which two types of nonwoven fabrics are integrated by pressure bonding is sent out by the feed rollers 12 and 12.

In the apparatus shown in FIG.
For A and 5B, any of a roller card that performs a carding operation by a cylinder and a group of rollers, and a flat card that performs a carding operation by a cylinder and a flat on the cylinder can be used. Although the apparatus shown in FIG. 3 is an apparatus for manufacturing a two-layer body, a three-layer body and a four-layer body can be manufactured in a similar manner by arranging three or four stock chambers and cards, respectively. can do.

In such a manufacturing method, the fiber density of each nonwoven fabric is adjusted by the thickness and the fiber amount of the nonwoven fabric, and the fiber density of the entire laminate is adjusted by the thickness of the entire laminate. The thickness of the nonwoven fabric can be adjusted by the pressing force of the press roller 8 and the press conveyors 9, 9. Therefore, there is an advantage that the fiber density can be easily adjusted.
In addition, a bulky nonwoven fabric can be obtained because mechanical bonding is not used in the manufacturing process of the nonwoven fabric. Therefore, by finishing one of the nonwoven fabrics constituting the cushion material into a bulky shape, it is possible to satisfy cushioning properties that cannot be obtained with a foam or a single nonwoven fabric, without impairing the shape retention.

As described above, the cushioning material formed by laminating two or more types of non-woven fabrics having different fiber densities ensures that the non-woven fabric having the high fiber density secures the hardness required for maintaining the shape, and the non-woven fabric having the low fiber density has the floor. Since the cushioning property that feels comfortable as a material is ensured, it is possible to satisfy the conflicting properties of cushioning property and form retention. Moreover, the cushioning material of the present invention has a very low fiber density of 0.06 to 0.2 g / cm ^3, and is therefore very lightweight. Therefore, it is also suitable for a tatami floor for a simple tatami type that can be folded and carried. Furthermore, when hollow fibers are used as the fibers constituting the nonwoven fabric, the fibers also have heat retention.

The tatami mat according to the present invention, as shown in FIG.
The surface of the cushion material 16 having the above structure on the side of the nonwoven fabric 16B having a low fiber density is covered with a tatami mat 17 formed by weaving rush, and an edge portion is pasted with a marginal cloth 18 made of synthetic fiber such as polyester. Alternatively, it is created by sewing to cover the edge. Such a tatami 19
Is that the nonwoven fabric 16A having the maximum fiber density is on the lower side to maintain the form as the flooring material, and the soft nonwoven fabric 16B having the smaller fiber density is the upper surface (use surface), so that the cushioning property is satisfied. it can.

It is to be noted that both sides of the cushion material 16 may be covered with a tatami mat made by weaving a rush. In this case, it is clarified that the side with the lower fiber density is the upper surface (used surface). It is enough. Further, although the cushion material 16 used for the tatami mat shown in FIG. 4 is a two-layered body, any cushion material of the present invention may be used, and a multilayered cushion material having three or more layers may be used.

Further, two or three tatami mats 19 of the same shape and configured as described above are juxtaposed, connected to an adjacent tatami mat by sharing one side of the tatami mat, and bent at the joint. You may do so. The tatami mat of the present invention is convenient as a simple tatami that can be folded and carried because the tatami floor is lightweight. FIG. 5 shows an example of a folding simple tatami mat formed by connecting three tatami mats 19.
5A shows a state in which the foldable tatami is opened, FIG. 5B shows a state in which the foldable tatami is folded at the connecting portion 20, and FIG. 5C shows a state in which the foldable tatami is folded.

The connecting portion 20 may be formed by simply stitching the edge cloth of the connecting portion of the two tatami mats, or may be constituted by a connecting tool such as a hinge.

[0040]

Next, the present invention will be described with reference to specific examples.

Production Examples 1 to 9: In each of the stock chambers 4A and 4B of the apparatus shown in FIG. 3, a hollow polyester fiber having a fineness shown in Table 1, a melting point of 110 ° C., a fineness of 4 denier, and a fiber length of 51 mm were used. Melting point fiber (4 × 51-EE7 (trade name) manufactured by Toyobo Co., Ltd.) was supplied. The low melting point fibers are mixed at a ratio of 30% by weight of the total amount of the fibers. Using such fibers, a cushion material having an overall fiber density of 0.107 g / cm ³ , an overall thickness of 14 mm, and a total basis weight of 1500 g / m ² was prepared. In the apparatus, when fibers having different densities are supplied to the card 5A and the card 5B, the laminated web 1 made of the card 5A is used.
A cushion material in which two types of nonwoven fabrics, that is, a nonwoven fabric A made of 3A and a nonwoven fabric B made of a laminated web 13B made of the card 5B are laminated is produced. On the other hand, in Production Examples 1, 4, and 6, the fibers supplied to the cards 5A and 5B are the same, and in Production Examples 7 to 9, a mixture of two types of fibers having different finenesses is applied to each of the cards 5A and 5B. Because of the use, the laminated web 13A made of the card 5A and the laminated web 13B made of the card 5B have the same fiber density, and as a result, a single-layer cushion material is created.

In the above production examples, the fiber density difference was 0.04.
Production Example 5 corresponding to a laminate having a thickness of up to 0.1 g / cm ³ corresponds to an example of the present invention.

Production Example 10 A nonwoven fabric having a thickness of 15 mm was produced by a needle punch method using the fibers shown in Table 1 (a mixture of two types of fibers having different finenesses). Therefore, the cushioning material is a single-layered nonwoven fabric having the fiber density shown in Table 1.

Reference Example 1 Expanded Polystyrene (Expansion Ratio 1)
(8 to 20 times).

[Evaluation] Production Example 1 prepared as described above
The cushioning properties, walking properties, form retention properties, and sewing workability of the cushioning materials of Comparative Examples Nos. 1 to 10 and Reference Example 1 were evaluated by the following methods. Table 1 shows the evaluation results.

Cushioning property The cushioning property when the manufactured cushioning material was pressed by hand in the vertical direction was evaluated based on the sensory evaluation of nine monitors, from 1 (hard and no cushioning property) to 5 (soft and excellent cushioning property). Yes) in five stages. In addition, about the laminated body, the cushion property was evaluated about the surface of the nonwoven fabric B side with the smaller fiber density.

Gaitability The ease of walking when walking on the upper surface of the manufactured cushioning material is determined based on the sensory evaluation of nine monitors, from 1 (difficult to walk) to 5 (easy walking). It was evaluated on a scale.

Morphological Retention The warp of the cushioning material when left on the floor with the nonwoven fabric A having the higher fiber density on the lower side is reduced by 1 (2.5 mm from the floor) based on the degree of floating from the floor. (Floating above) ~
The evaluation was made on a scale of 5 (with almost no lifting) and in steps of 0.5 mm.

Sewing workability The edge of the manufactured cushion material was covered with a polyester edge cloth, and the edge was sewn. At this time, the ease of sewing when the sewing was performed at a constant speed was evaluated on a scale of 1 (impossible) to 5 (good). In addition, sewing workability is not possible when the sewing machine needle is broken because it is hard, the thread is cut, or the edge part is too soft and the edge part is too dented, so the edge and center part on the surface of the finished tatami Means a case where a notice is occurring.

Comprehensive evaluation Based on the evaluation results evaluated by the above method, the comprehensive evaluation as a cushion material for tatami was performed in the order of superiority.
△, △, × were evaluated on a three-point scale.

[0051]

[Table 1]

In Table 1, the unit of density is g / cm ³
It is.

According to Production Examples 1, 4, and 6, even if the overall fiber density is generally the same, the cushioning property and walking property tend to be improved as the nonwoven fabric is composed of thick fibers. Also,
It can be seen that the shape retention is better as thick fibers are used, even at the same fiber density.

On the other hand, the laminates obtained by laminating non-woven fabrics composed of fibers having a thickness of 6 denier or 15 denier all have excellent cushioning properties (Production Examples 2, 3).
5). This tendency can be attributed to a single-layered body composed of 6-denier and 15-denier mixed fibers (Production Example 9), a single-layered body composed only of 6-denier fibers (Production Example 4), and a monolayer composed only of 15-denier fibers. It is clear from the comparison with the layer body (Production Example 6). On the other hand, the walking property requires an appropriate cushioning property and various factors such as a density difference and a thickness of the soft nonwoven fabric B are involved. As for the shape retention, it is understood that the nonwoven fabric is composed of a 15-denier thick fiber and the density difference must be in the range of 0.04 to 0.1 g / cm ³ (see Production Examples 3 and 5). Comparison).
In addition, the shape retention of the single-layer body using the mixed fiber was an intermediate evaluation result of the single-layer body of the nonwoven fabric constituted by each fiber to be mixed alone (Production Examples 7 to 9). Regarding the sewing workability, it is understood that the larger the fineness of the constituent fibers, that is, the more the nonwoven fabric composed of thick fibers is superior, regardless of the single layer body or the laminated body (see Production Examples 1 to 9).

It should be noted that, from Production Example 10, the nonwoven fabric produced by the needle punching method has a better cushioning property than a single-layer nonwoven fabric produced using fibers having the same fineness (Production Example 9).
Both walking property and shape retention were inferior. Also, from Reference Example 1, the foam was excellent in shape retention, but was inferior in cushioning property, walking property and sewing workability as compared with the nonwoven fabric.

<Relationship with Mixing Ratio of Low Melting Fiber> Production Examples 11 to 16;
A composite fiber type low-melting-point fiber (hereinafter, referred to as a polyester) having a sheath portion made of a normal polyester at 0 ° C.
Abbreviated as “HMF”), manufactured by Toyobo Co., Ltd.
× 51-EE7 (trade name) was used. It has a fineness of 4 denier and a fiber length of 51 mm. In nonwoven fabric B, 1
5 denier polyester fiber having a fiber length of 64 mm is used. In the nonwoven fabric A, 6 denier polyester fiber having a fiber length of 64 mm (6 × 64-7 manufactured by Toyobo Co., Ltd.)
85 (trade name)). All are hollow fibers.
Table 2 shows the HMF for the polyester fibers constituting each nonwoven fabric.
Then, a cushion material composed of a laminate in which nonwoven fabrics were laminated by the apparatus shown in FIG. 3 was prepared. The total weight of the cushioning material was 15
00 g / m ² , the thickness of each nonwoven fabric is 7 mm,
The total thickness is 14 mm.

In the cushion material manufactured, the non-woven fabric B is on the upper side.
(Use surface), and the nonwoven fabric A is on the lower side (floor side). Table 2 also shows the results of the evaluation of the cushioning property, form retention and sewing workability based on the above evaluation method.

[0058]

[Table 2]

As can be seen from Table 2, if the mixing ratio of the low melting point fiber is less than 50% by weight, the cushioning property is excellent, but the content ratio is required to be 15% by weight or more for form retention. In addition, it can be seen that 20 to 35% by weight of the sewing workability is excellent. Therefore, if the mixing ratio of the low-melting fiber is 20 to 35% by weight, all of the cushioning property, form retention and sewing workability can be satisfied.

<Relationship with Hardness> Production Examples 17 to 22; fineness of nonwoven fabric constituent fibers, low melting point fiber (4 × manufactured by Toyobo Co., Ltd. used in Production Examples 11 to 16)
Table 3 shows the mixing ratio and fiber density of 51-EE7 (trade name).
The cushion material was manufactured using the apparatus shown in FIG. Production Examples 18 to 20 are two-layer laminates of two types of nonwoven fabrics having different finenesses. Production Example 1
7, 21, and 22 are single-layer bodies. Production Example 1 having a two-layer structure and a fiber density difference in the range of 0.04 to 0.1 g / cm ³
8, 20 correspond to an Example.

The cushion material produced (Production Examples 17 to 2)
About 2), the surface hardness was measured according to the test method SRIS-1010 of the Japan Rubber Association using a hard tester which is a spring-type hardness tester manufactured by Shimadzu Corporation. Table 3 also shows the measurement results.

Further, with respect to Production Examples 17 to 22, cushioning properties, form retention properties, and walking properties were evaluated based on the above evaluation methods. The evaluation was performed in three stages of ○ (corresponding to evaluations 4 and 5), Δ (corresponding to evaluation 3), and × (corresponding to evaluations 1 and 2). Table 3 also shows the evaluation results. In addition, about the laminated body, cushioning property and walkability evaluated nonwoven fabric B (upper side), and shape retention property evaluated nonwoven fabric A (lower side).

[0063]

[Table 3]

Reference Examples 2 to 6; Reference Examples 2 and 3 are boards in which cardboard is laminated. Comparative Example 4 is expanded polystyrene (expansion ratio: 18 to 20 times). Reference Example 5 is a commercially available tatami mat. Reference Example 6 is a single-layer nonwoven fabric made by the needle punch method. In each case, the thickness and the basis weight are as shown in Table 4. About these reference examples, hardness, cushioning property, shape retention property, and walking property were similarly evaluated, and the results are shown in Table 4.

[0065]

[Table 4]

As can be seen from Tables 3 and 4, all of the cardboard laminated board, foam and tatami are inferior in softness to the nonwoven fabric, and it is better to produce the same single-layer nonwoven fabric by the needle punch method. It can be seen that the cushioning property is inferior to the fusion method using the low melting point fiber. Furthermore, even if it is a laminate of nonwoven fabrics, if the hardness of the upper nonwoven fabric B exceeds 50, cushioning properties and walking properties are insufficient, and if the hardness of the lower nonwoven fabric A is less than 51, shape retention is poor. .

[0067]

The cushion material for a tatami mat according to the present invention is composed of a laminate of non-woven fabrics having different fiber densities, so that both sides of the cushion material have different hardnesses, and satisfy the conflicting properties of cushioning property and shape retention. be able to. In addition, the cushion material in which hollow fibers are mixed as the constituent fibers of the nonwoven fabric is further lightweight and excellent in heat retention. further,
By making some of the constituent fibers of the nonwoven fabric low-melting fibers, the production and lamination and integration of each nonwoven fabric can be performed simultaneously, and the productivity is also excellent.

The tatami mat of the present invention is excellent in cushioning property and shape retention property due to the effect of the cushion material used as the tatami mat floor. Moreover, since it is lightweight, it can be used as a simple tatami that can be folded and carried.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a tatami cushion material according to the present invention.

FIG. 2 is a diagram showing a cross-sectional shape of a hollow fiber.

FIG. 3 is a schematic view showing a configuration of an embodiment of a nonwoven fabric manufacturing apparatus.

FIG. 4 is a diagram showing a configuration of an embodiment of a tatami mat according to the present invention.

FIG. 5 is an embodiment of a folding simple tatami mat.

[Explanation of symbols]

 4A, 4B Stock room 6A, 6B Web 13A, 13B Laminated web 15 Cushion material 16 Cushion material 19 Tatami mat

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisao Nishinaka 2-8-2 Dojimahama, Kita-ku, Osaka-Toyobo Co., Ltd. (72) Inventor Saburo Goto 1-5-17 Dojima, Kita-ku, Osaka-shi Koizumi Seiza Co., Ltd. Osaka Office (72) Inventor Hajime Suzuki 1-5-17 Dojima, Kita-ku, Osaka City Koizumi Seiza Co., Ltd. Osaka Office

Claims (5)

[Claims] 1. A method for producing two or more nonwoven fabrics having different fiber densities,
What is claimed is: 1. A tatami cushion material comprising a nonwoven fabric having the maximum fiber density laminated so as to be an outermost layer, wherein the tatami cushion material has a density of 0.06 g / cm ^{3 to} 0.2.
0 g / cm ³ , and the difference in density between the nonwoven fabric having the maximum fiber density and the nonwoven fabric having the minimum fiber density is 0.04 g.
/ Cm ^{3 to} 0.10 g / cm ³ , a cushion material for tatami mats. 2. The tatami cushion material according to claim 1, wherein the nonwoven fabric side surface having the maximum fiber density has a spring-type hardness of 51 to 65, and the other side has a spring-type hardness of 40 to 50. 3. The at least one non-woven fabric constituting the tatami cushion material, wherein 50 to 8 of the constituent fibers of the non-woven fabric are used.
The cushion material for tatami according to claim 1 or 2, wherein 5% is a hollow fiber. 4. At least one kind of nonwoven fabric constituting the cushion material for tatami is composed of a fiber obtained by mixing 15 to 50% by weight of a low melting point fiber having a melting point of 110 to 190 ° C. The tatami cushion material according to any one of claims 1 to 3, wherein the cushion material is fused to an adjacent nonwoven fabric by melting. 5. The cushion material according to claim 1, wherein the surface of the non-woven fabric on the side other than the non-woven fabric having the maximum fiber density is covered with a tatami mat, and the edge of the cushion material is covered with a border cloth. Tatami and.