Tatami mat surface

Abstract

To provide tatami mats with excellent workability. [Solution] A backing sheet 2 is attached to the back surface of a tatami mat surface 1, which is made up of weft and warp threads made of rush or artificial rush.

Description

Technical Field

[0001] The present invention relates to a tatami mat having a lining sheet laminated on the back surface thereof.

Background Art

[0002] Conventionally, tatami mats have been widely used as floor materials for buildings. As tatami mats, generally, a rice straw tatami mat floor made from rice straw, a thick tatami mat with a thickness of about 55 mm in which a tatami mat surface is sewn onto the surface of an artificial tatami mat floor made of an insulation board and a synthetic resin foam sheet, an artificial tatami mat floor laminated with a core material such as an insulation board and a synthetic resin foam sheet, a cushion sheet, etc., and a tatami mat surface is sewn thereon, and a thin tatami mat with a thickness of about 7 to 25 mm is used.

[0003] The above tatami mat surface is woven by a pick weaving method such as plain weave, eyelet weave, or large-eye weave, using rush such as natural rush or artificial rush made of synthetic resin as the weft, and hemp yarn, manila hemp yarn, cotton yarn, etc. as the warp (see, for example, Patent Documents 1 and 2).

[0004] However, pick weaving is a method of weaving in which two wefts 20, 20 are sequentially woven so as to cross two warps 21, 21 as shown in FIG. 8. Therefore, particularly when the density of the weft 20 is low, when a load is applied in a direction perpendicular to the weft 20 (parallel to the warp), the weft 20 may shift or deform, resulting in a poor appearance. In addition, the weft 20 at the end of the tatami mat surface has a drawback that it loosens during the manufacture or use of the tatami mat.

[0005] By the way, there are three basic weaving methods called the "three basic weaves": plain weave, twill weave, and satin weave. Plain weave is the simplest of the three basic weaves, made by alternately crossing one warp thread and one weft thread. Because there are many points where the threads intersect (weave points), it is characterized by a somewhat stiff and firm texture, resulting in a highly durable weave that is resistant to friction and strong. As a variation of plain weave, there are also variations in the weave that appear as crinkles or ridges on the surface of the weave, depending on the quality of the threads used, the strength of the twist, and the thickness. For example, instead of crossing one warp and one weft thread as usual, two or more threads are bundled together (ply-ply) and woven in plain weave. When two warp and two weft threads are bundled together and woven in plain weave, it is called diagonal weave, and when there are three or more ply-ply threads, it is called basket weave. Furthermore, the weave that produces ridges is made by using two warp or weft threads and one other thread. When there is one warp thread and two weft threads, it is called a warp rib weave, and when there are two warp threads and one weft thread, it is called a weft rib weave.

[0006] Twill weave is a fabric structure created by crossing warp and weft threads, often by skipping two threads at a time. Also known as diagonal weave, it is characterized by diagonal ridges visible on the surface of the fabric. These diagonal ridges are called twill lines. Compared to plain weave, the warp threads are longer and more visible on the surface (because there are more areas where the threads are left floating), resulting in a slightly less durable but supple and lustrous fabric. In typical twill weave, the twill lines are sloping upwards to the right, and this is called right-hand twill or normal twill. When the twill lines are sloping upwards to the left, this is called left-hand twill or reverse twill.

[0007] Satin weave includes variations such as "5-ply satin" (4 warp threads above, 1 weft thread below) where four warp or weft threads skip and cross underneath, as well as "8-ply satin," "10-ply satin," "12-ply satin," and "16-ply satin." Not only does it have fewer weave points, but either the warp or weft threads do not appear on the surface, resulting in a smooth, slippery, and lustrous fabric. However, because the threads float for a long distance, it has the disadvantage of being susceptible to friction and easily snagging.

[0008] For the tatami mat surface, plain weave or twill weave are preferred among the three basic weaves mentioned above. However, in the case of tatami mat surfaces that are simply plain weave or twill weave, the weight is low and the density of the culms is low, so even if a small force is applied during transportation or handling, the tatami mat surface may bend (the weave lines may meander) or the culms may come loose, causing it to fall apart. Also, when cutting to the specified length and width during tatami manufacturing, the low weight and low density of the culms due to the weave method make it difficult to cut accurately between the culms, and some culms themselves may be cut. Therefore, after removing the defective parts and adjusting to the specified length, the cut surfaces are fused together with hot melt adhesive or ultrasonic welding to finish the edges before use, but even then, the weave lines may be significantly bent and meander. Furthermore, when cutting in the width direction (called "cutting the front edge" in tatami terminology), the low density of the culms causes the tatami mat surface to be dragged in the cutting direction, causing it to warp and the weave lines to bend. In addition, the "rang" in "tatami" refers to the stem portion of the rush grass that makes up the surface of the tatami mat, the "me-suji" refers to the lines running along the length of the tatami mat, which affect the appearance and feel of the tatami, and the "i-suji" refers to the lines running along the width of the tatami mat, which affect the strength and durability of the tatami. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 10-183957 [Patent Document 2] Japanese Patent Publication No. 2002-188276 [Overview of the project] [Problems that the invention aims to solve]

[0010] The objective of the present invention is, in view of the above-mentioned problems, to provide a tatami mat surface that is free from the drawbacks of the prior art and has excellent processability. [Means for solving the problem]

[0011] The first invention of this application, which aims to achieve the above objective, is characterized in that a backing sheet is attached to the back surface of a tatami mat surface made of weft and warp threads which are made of rush or artificial rush.

[0012] The second invention of this application is characterized in that, in the first invention of this application, it is woven by plain weave or twill weave.

[0013] The third invention of this application is characterized in that, in the first or second invention of this application, the backing sheet is a foamed resin sheet.

[0014] The fourth invention of this application is a tatami mat surface in which a backing sheet is attached to the back surface, with a thickness of 3.0 to 7.0 mm and a weight of 550 to 1200 g / m², in the first or second invention of this application. 2 It is characterized by having a tensile strength of 3.6 to 6.0 MPa and a tensile elongation of 15 to 25%. [Effects of the Invention]

[0015] According to the first to fourth inventions of this application, since the backing sheet is adhered and fixed to the back surface of the tatami mat, the movement of the rush grass is suppressed, making it difficult to move in both the direction of the weave and the direction of the rush fibers, making it easy to cut and preventing it from unraveling. Furthermore, when making tatami mats, the mat is stretched taut (strongly pulled in the direction of the frame) and the frame is sewn together, but because the backing sheet is adhered and fixed to the back surface of the tatami mat, it can be stretched strongly, is easy to weave in the width direction, and maintains its shape, making tatami mat making easier. In addition, it is easy to bend diagonally and retains its shape well (with a certain degree of shape retention), so it is easy to process into shapes other than tatami mats, such as curved shapes, and it has the advantage that it can be molded into various shapes by heat forming, so it can be processed into shapes other than squares. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a cross-sectional view showing one embodiment of the tatami mat surface of the present invention, in which a backing sheet is attached to the back surface. [Figure 2] Figure 2 is a cross-sectional view showing one embodiment of a tatami mat using the tatami surface of the present invention, in which a backing sheet is attached to the back surface. [Figure 3]Fig. 3(a) is a plan view showing an example of a lining sheet adhered to the back surface of the tatami mat of the present invention, and Fig. 3(b) is a longitudinal sectional view of Fig. 3(a). [Figure 4] Figs. 4(a), (b), and (c) are longitudinal sectional views showing other examples of the lining sheet adhered to the back surface of the tatami mat of the present invention. [Figure 5] Fig. 5 is a longitudinal sectional view showing an example of a thermoplastic resin filament. [Figure 6] Fig. 6 is a schematic view showing an embodiment of an apparatus for manufacturing a foamed resin sheet. [Figure 7] Fig. 7 is a partially enlarged view of Fig. 6. [Figure 8] Fig. 8 is a sectional view showing an example of a conventional tatami mat.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described in detail.

[0018] The tatami mat of the present invention is characterized in that a lining sheet is adhered to the back surface of the tatami mat. Fig. 1 is a sectional view showing an example of the tatami mat of the present invention. In the figure, 1 is the tatami mat, and a lining sheet 2 is adhered to its back surface.

[0019] The above tatami mat 1 is a tatami mat that has been conventionally used as a tatami mat and is woven from horizontal threads made of rush and vertical threads. Examples of the rush include natural rush, artificial rush made of synthetic resin such as polyethylene resin and polypropylene resin, and artificial rush made of paper. The diameter of the rush is preferably 0.5 to 2 mm, more preferably 0.8 to 1.5 mm.

[0020] In addition, examples of the vertical threads include natural fiber threads such as hemp thread, manila hemp thread, and cotton thread, and threads made of synthetic resin such as polyethylene thread, polypropylene thread, polyester thread, polyamide thread, and polyurethane thread. The weight of the vertical thread is preferably 500 to 10000 denier, more preferably 800 to 4000 denier.

[0021] The backing sheet 2 is a sheet that suppresses the movement of the culms, making them difficult to move in both the grain direction and the straight direction, easy to cut, and preventing them from fraying. As the backing sheet 2, synthetic resin sheets containing flat yarn reinforcement, foam sheets, and polyethylene foam resin sheets are preferred. Polyethylene foam resin sheets are preferred because they can easily recover even if they become indented under load, and in particular, foam resin sheets with a foaming ratio of 10 to 50 times, preferably 20 to 40 times, are preferred because they have excellent flexibility, cushioning, and resilience, and are impermeable to water.

[0022] The synthetic resin sheet containing the flat yarn reinforcement is a fabric 6 formed by intersecting thermoplastic resin filaments 5a and 5b vertically and horizontally, and heat-sealing the intersections of the filaments, as shown in Figure 3(a). In the present invention, the fabric 6 is a general term for a flexible sheet-like body made of thermoplastic resin filaments, and includes a woven fabric made using thermoplastic resin filaments 5a and 5b made of uniaxially stretched thermoplastic resin monofilaments, tapes, yarns, split yarns, etc., or a cross-bonded fabric (sof) formed by arranging a large number of thermoplastic resin filaments 5a and 5b perpendicularly to each other and joining their intersections to form a planar surface. Furthermore, as the fiber base material for the flat yarn reinforcement, for example, a biaxial fabric can be used. Biaxial fabrics are preferred in terms of their low anisotropy as a material and the fact that they can be manufactured on commonly used looms, however, because the warp and weft threads of a biaxial fabric intersect at a 90° angle to each other, they are prone to deformation when pulled from an oblique direction. Therefore, triaxial fabrics, in which two warp threads intersect one weft thread at a 60° angle, are preferable materials because they resist tensile forces from oblique directions, exhibit isotropy in bending and tensile behavior, and possess high shear and tear resistance. The basic structure of a triaxial fabric is one in which three threads intersecting each other at a 60° angle are constrained at the intersection so as not to move. As an application of this, biplane fabrics can be used, in which an additional thread is added to the space, or in which the angle of the warp threads to the weft threads is 45° to 90°, or in which only the weft threads intersect the warp threads without the two warp threads intersecting.

[0023] The thermoplastic resin struts 5a and 5b may be a single layer of crystalline resin, as shown in Figure 4(a), or they may be a base layer 7 with a bonding layer 8 laminated on one side, as shown in Figure 4(b). Alternatively, they may be a base layer 7 with a bonding layer 8 laminated on both sides, as shown in Figure 4(c).

[0024] As the synthetic resin constituting the single layer or the base layer 7 of the laminate in the thermoplastic resin filaments 5a and 5b, a resin with a high stretchability, generally a crystalline resin, is used. Polyolefins such as high-density polyethylene, polypropylene, and ethylene-propylene copolymer, polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyamides such as nylon 6 and nylon 66 can be used. Among these, polyolefins such as polyethylene and polypropylene are preferable due to their processability and economic efficiency. High-density polyethylene is particularly preferable, and high-density polyethylene has a density of 0.930 to 0.970 g / cm³. 3 Preferably 0.940~0.960 g / cm³ 3 The MFR is preferably 0.2 to 10.0 g / 10 min, more preferably 0.3 to 3.0 g / 10 min.

[0025] The bonding layer 8 is formed by bonding thermoplastic resin wires 5a and 5b together after they have been made into a fabric 6, or by bonding the fabric 6 to other substrates. A synthetic resin with a lower melting point and better heat-sealing properties than the synthetic resin constituting the base layer 7 is used. Specifically, polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer, polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyamides such as nylon 6 and nylon 66 can be used, and a synthetic resin with a lower melting point than the base layer 7 is selected. Among these, polyolefins such as polyethylene and polypropylene are preferred due to their processability and economic efficiency, and in particular, polyethylene polymerized using a metallocene catalyst, linear low-density polyethylene, and polypropylene are preferred due to their ease of bonding.

[0026] When laminates are used as filamentous bodies 5a and 5b, the laminated film that will become the molding material for laminated flat yarn or laminated split yarn can be formed by pre-forming a film to become the base layer 7 and a film to become the bonding layer 8 and then multi-layering them using a dry lamination method or a heat lamination method, coating the surface of the film to become the base layer 7 with a synthetic resin to become the bonding layer 8, extruding and laminating the bonding layer 8 onto a pre-formed film to become the base layer 7, or extruding the laminated film by a multilayer co-extrusion method. However, in terms of ease of molding, cost, and adhesion and light transmittance between each layer of the product, it is desirable to obtain the laminate of the base layer 7 and the bonding layer 8 in one step by a multilayer co-extrusion method. For sea core structures or side-by-side structures, co-extrusion is generally used.

[0027] The fabric 6 is formed by using uniaxially stretched thermoplastic resin filaments 5a and 5b to create a woven fabric such as a plain weave or twill weave, as shown in Figure 3, or by arranging a large number of thermoplastic resin filaments 5a in one direction and a large number of thermoplastic resin filaments 5b in a perpendicular direction on top of them to form a surface, and joining the intersections to create a cross-bonded fabric (soft), as shown in Figure 5.

[0028] Furthermore, as shown in Figure 5, a structure in which a synthetic resin film 9 is laminated on both sides of thermoplastic resin wires 5a and 5b is particularly preferred as a backing sheet. As the material used for the synthetic resin film 9, thermoplastic resins are preferred, and specifically, polyesters such as polyolefins, polyethylene terephthalate, and polybutylene terephthalate, and polyamides such as nylon 6 and nylon 66 can be used, with polyolefins being particularly preferred, and as polyolefins, homopolymers such as ethylene, propylene, butene-1, hexene-1, octen-1, and decene-1, or copolymers mainly composed of these can be used.

[0029] In particular, it is desirable to use polyolefins polymerized using a metallocene catalyst, preferably polyethylene, polypropylene, or ethylene-α-olefin copolymers. The lamination of the fabric 6 and the synthetic resin film 9 can be carried out by known means, including a method of placing the synthetic resin film 9 on top of the fabric 6 and heat-pressing it using a hot roll, a method of extruding a thermoplastic resin into a film onto the fabric 6 and laminating it, or a method of bonding the synthetic resin film 9 to the fabric 6 with an adhesive such as a hot melt agent.

[0030] The synthetic resin film 9 may be laminated over the entire surface of the fabric 6, or, depending on the purpose, it may be laminated only to a portion of the fabric. The thickness of the synthetic resin film 9 can be arbitrarily selected depending on the purpose, but generally, each layer is 30 to 700 μm, preferably 50 to 500 μm, and more preferably 60 to 300 μm.

[0031] The tatami mat surface 1 described above has a backing sheet 2 attached to its back surface, but it is preferable that the entire surface of the tatami mat surface is firmly attached, even to the edges.

[0032] Any known method can be used to bond the tatami mat surface 1 and the backing sheet 2 described above. Examples include bonding with rubber-based, acrylic-based, urethane-based, or silicone-based adhesives or bonding agents, bonding with double-sided adhesive sheets, or bonding with polyolefin-based hot-melt adhesives such as ethylene-vinyl acetate copolymer or linear low-density polyethylene resin.

[0033] The thickness of the tatami mat surface 1, to which the backing sheet 2 is attached on the back side, is preferably 3.0 to 10.0 mm, and more preferably 3.0 to 7.0 mm, because if it is too thin, it becomes hard when walking, sitting in a kneeling position, or lying down, and if it is too thick, it becomes too soft, unstable when walking, and can cause tripping.

[0034] The density (number of rushes per 10cm) of the tatami mat surface 1, to which the backing sheet 2 is attached on the back side, is preferable because if it is too low, gaps will form between the rushes, allowing dirt to get in and causing snagging when walking, and if it is too high, it will be difficult to bend during processing.

[0035] The weight of the tatami mat surface 1, to which the backing sheet 2 is attached on the back, should be such that if it is too small, it becomes difficult to lay the tatami mat during the frame-laying process during manufacturing, and the backing sheet 2 may tear. Conversely, if it is too large, it becomes bulkier, making it difficult to walk on and prone to unevenness. 2 Preferably, 550-1200 g / m² 2 This is preferable.

[0036] In a compression test of the tatami mat surface 1, to which a backing sheet 2 is attached on the back, a lower initial modulus of elasticity results in a softer feeling when walking, while a higher modulus results in a harder feeling when walking. Therefore, a value of 10-120 kPa is preferable.

[0037] The tensile strength of the tatami mat surface 1, to which the backing sheet 2 is attached, is preferably 3.6 to 6.0 MPa. If it is too low, it cannot be stretched tightly during the frame-stretching process when making the tatami mat. Conversely, if it is too high, a lot of force is required to stretch it neatly, and if the force is too high, the finished tatami mat will warp. The tensile elongation of the tatami mat surface 1, to which the backing sheet 2 is attached, is preferably 15 to 25%. If it is too low, it cannot be stretched tightly during the frame-stretching process when making the tatami mat, so a lot of force is required, which puts a load on the machine and causes it to come off the fasteners. Conversely, if it is too high, it stretches too much and cannot be stretched tightly.

[0038] The back surface of the backing sheet 2 may be laminated with a non-slip sheet made of silicone resin, acrylic resin, acrylic silicone resin, or a backing finish sheet such as a cross adhesive tape.

[0039] Since the backing sheet 2 has excellent cushioning properties, the tatami mat surface of the present invention can be suitably used as a cushioning sheet in load-bearing areas such as chests of drawers, desks, chairs, and car seats.

[0040] Furthermore, a tatami mat can be obtained by laminating the tatami base onto the backing sheet.

[0041] The above-mentioned tatami mat bases are not particularly limited and include, for example, rice straw tatami mat bases and artificial tatami mat bases with a core material. Tatami mats using rice straw tatami mat bases are thick tatami mats, while tatami mats using artificial tatami mat bases with a core material can be thin or thick.

[0042] The above-mentioned rice straw tatami base is excellent in durability, flexibility, heat insulation, heat retention, and moisture absorption and release, and is a tatami base for thick tatami mats that has been widely used for a long time, with a thickness of approximately 55 mm. For example, a tatami base made by compressing approximately 400 mm of straw, which has been stacked flat in multiple layers, to a thickness of approximately 50 mm.

[0043] Figure 2 is a cross-sectional view showing an example of a tatami mat, where 3 is a laminated tatami mat surface in which a backing sheet 2 is adhered to the back surface of the tatami mat surface 1. The laminated tatami mat surface 3 is laminated so that the backing sheet 2 is in contact with the rice straw tatami base 4, and the edges are wrapped around the back side of the edges of the rice straw tatami base 4 and sewn together to form a thick tatami mat.

[0044] The artificial tatami mat base having the above-mentioned core material is a tatami mat base for thin or thick tatami mats with a thickness of approximately 7 to 55 mm, and generally consists of a core material and a cushion sheet.

[0045] The core material described above provides mechanical strength to the tatami mat and has been conventionally used as a core material for tatami mats. Examples include wood fiberboard and closed-cell synthetic resin foam board.

[0046] The above-mentioned wood fiberboard is a building material made by pulping wood or other plant fibers, binding them with a binder resin, and then heat-pressing them into a board. Examples include particleboard, plywood, insulation fiberboard (insulation board), medium-density fiberboard (MDF), and hard fiberboard (hardboard).

[0047] Since thin tatami mats generally have a thin overall thickness of 8 to 35 mm, a wood fiberboard with high mechanical strength is preferred as the core material, more preferably medium-density fiberboard (MDF), with a thickness of 3 to 7 mm, and more preferably 3.5 to 4.5 mm.

[0048] The above-mentioned cushioning sheets are laminated onto the surface (tatami surface side) of the core material to provide cushioning and sound insulation to the thin tatami mat. Examples include nonwoven fabrics, woven fabrics, mats, and felts made from fibers such as hemp fibers, cotton fibers, polyethylene fibers, polypropylene fibers, urethane fibers, polyacrylic fibers, and polyester fibers; foamed sheets such as polystyrene foam sheets, polyethylene foam sheets, polypropylene foam sheets, urethane foam sheets, and rubber foam sheets; and kraft paper, cardboard, thick paper, and corrugated cardboard.

[0049] The basis weight of the above cushion sheet is generally 100-700 g / m². 2 The thickness is 3 to 6 mm. Furthermore, the cushion sheet may consist of multiple thin sheets laminated together. Also, the cushion sheet may be laminated on both sides of the core material.

[0050] There are two types of bubble shapes: closed-cell type, where each bubble is completely separated by a diaphragm, and open-cell type, where each bubble is connected. The shape of the bubbles is determined by the balance between the amount and pressure of gas generated in the foam during manufacturing and the viscosity, which increases as the resin reaction and solidification progresses. If the amount and pressure of gas are high, the bubbles will be open-cell type, and if the viscosity increases sufficiently quickly and the bubble walls gain strength, the bubbles will be closed-cell type. Since a decrease in the closed-cell ratio reduces mechanical strength, it is preferable for foamed resin sheets to have a high closed-cell ratio with a low open-cell ratio. The open-cell ratio and closed-cell ratio are indicators of the degree to which adjacent bubbles are continuous, i.e., whether the bubble walls are broken and connected, or whether they are independent, in the bubble structure, and can be determined according to JIS K 7138:2006. The open-cell ratio is preferably 20% or less, and more preferably 15% or less. In reality, the lower limit of the open-cell ratio is about 2%. If the open-cell ratio exceeds 20%, defects can occur such as depressions in the continuous cell areas or film rupture due to thermal expansion caused by heating during secondary processing.

[0051] While polyurethane-based and styrene-based foaming materials have been commonly used as foaming resin materials, polyolefin-based foaming materials are preferred from the viewpoint of economic efficiency and environmental suitability. Compared to polystyrene foam, polyethylene foam is preferable as the foaming resin material of the present invention because it has lower water absorption, is less prone to brittle fracture at low temperatures, is easy to process such as cutting, and has excellent compressive strength while being flexible. Polypropylene foam, which has higher heat resistance than polyethylene, can also be preferably used.

[0052] A well-known method for manufacturing polyolefin-based foamed resin sheets is the extrusion foaming method, in which polyolefin resin is melt-kneaded with a foaming agent in an extruder, and this foamed molten mixture is extruded from a die at the tip of the extruder to foam it.

[0053] In extrusion foam sheet molding, the cooling process after extrusion foaming is crucial for forming fine, independent foam cells and achieving good surface properties. While circular dies and T-dies are used to form foam sheets by extrusion foaming, special cooling equipment and methods are necessary, for example, in foam sheets produced by T-dies, to stop the growth of the generated bubbles while they are still fine, and to eliminate corrugation, a wave-like phenomenon. For example, as shown in Figure 6, a polyolefin resin containing molten foaming agent is extruded from the outlet 11 of a die 10 at the tip of an extruder (not shown) to form a sheet-like foam. This sheet-like foam is then taken up by a take-up roll 12 positioned close to the outlet 11 of the die 10, and subsequently cooled by cooling rolls 13, 14, and 15 to obtain a foamed polyolefin sheet 16. In this process, as shown in Figure 7, the distance a between the outlet 11 of the die 10 and the contact point of the sheet-like foam on the take-up roll 12, and the take-up angle θ are important. If the distance a is too short, the foaming of the molten resin will be incomplete. If the distance a is too long, neck-in and wrinkles are likely to occur in the sheet-like foam, corrugation marks will increase, and gas leakage will increase, resulting in a decrease in the foaming ratio and a deterioration of the sheet surface condition. If the take-up angle θ is too small, stable take-up of the sheet-like foam will not be possible, and the effect of reducing corrugation marks will be small. If the take-up angle θ is too large, a large amount of molten resin will accumulate at the top of the outlet 11 of the die 10, making long-term continuous operation impossible.

[0054] For example, the distance a is preferably 10 to 50 mm, and the pull-back angle θ is preferably 30 to 60°.

[0055] When the take-up roll 12 takes up the sheet-like foam, it is more preferable to cool the take-up roll 12 before taking up the foam so that the surface of the foam is cooled. Also, the take-up roll 12 is not limited to one; multiple rolls may be used.

[0056] The size of the take-up roll 12 is naturally derived from the values ​​of the distance a and the angle θ, but it is preferable to make it smaller than the size of the cooling roll.

[0057] As shown in Figure 6, the distance c between the take-up roll 12 and the cooling roll is preferably 150 mm or less, particularly 40 to 100 mm, between the contact point of the foam on the take-up roll 12 and the contact point of the foam on the cooling roll 13. If the distance c exceeds 150 mm, the effect of taking up the foam via the take-up roll is reduced, which is undesirable because it increases surface roughness of the sheet due to gas leakage and defects at both ends of the sheet (thin sheet, low foaming ratio, presence of corrugation marks).

[0058] A standard single-screw extruder can be used as the extruder. The polyolefin resin is melt-kneaded at 160-230°C in the extruder along with a foaming agent and any additional additives used as needed, and then extruded and foamed into a sheet from the die outlet at the front of the extruder. [Examples]

[0059] The following describes embodiments of the present invention, but this does not limit the present invention in any way, and various changes and modifications are possible without departing from the technical scope of the present invention.

[0060] [Examples] A tatami mat surface 1 (product name "Zen" manufactured by Sekisui Seikei Kogyo Co., Ltd.) was prepared by plain weave using polypropylene resin imitation rush as the weft and cotton yarn as the warp. An acrylic adhesive was applied to a backing sheet 2 made of foamed polyethylene resin sheet (open cell rate 12%) obtained by extrusion foam molding, and the tatami mat surface 1 was laminated on top of the adhesive and cut to a predetermined size. Then, the laminate was pressure-bonded to obtain a laminated tatami mat surface 3 with a thickness of approximately 4 mm, as shown in Figure 1. The laminated tatami mat 3 obtained in this way was cut to a width of 50 mm and a length of 300 mm, including 12 warp threads. Both ends in the longitudinal direction were fixed with hot melt resin to prevent unraveling, and a tensile test was performed with a chuck distance of 200 mm and a tensile speed of 300 mm / min to determine the tensile strength and tensile elongation. As a result, a tensile strength of 4.0 MPa and a tensile elongation of 19.8% were obtained.

[0061] Next, a tatami mat base made of rice straw, approximately 55 mm thick, was cut to the required size. While bending the tatami base, the laminated tatami surface 3 was strongly pulled in the direction of the grain. The frame side was secured with a frame sewing machine, and the tatami edge was sewn with a flat stitching machine. As shown in Figure 2, a thick tatami mat was obtained in which the edges of the laminated tatami surface 3 were wrapped around the rice straw tatami base 4. No problems occurred during the above tatami-making process.

[0062] [Comparative Example] Next, when the tatami mat surface 1 was simply cut with a cutter or scissors, the weave pattern became distorted in the direction of the blade's movement when cutting to the desired size, and the rushes became prone to falling out. Therefore, to allow for some leeway beyond the desired size, a melting zone of approximately 10 mm in width was created using a hot iron and the rushes were fused together to fix them in place before cutting to the desired size to obtain the tatami mat surface. When attempting to straighten the weave pattern by joining the obtained tatami mat surface with a rice straw tatami base of approximately 55 mm in thickness, attempting to pull the mat straightened resulted in the weave pattern remaining curved if the tensile force was weak, while pulling too hard caused the warp threads to break or fall out. Furthermore, when sewing the tatami edging with a flat stitching machine, when cutting the tatami mat surface 1 to align the width to the desired size, the high degree of freedom of the rushes caused the rushes to shift, the weave pattern to become curved, and the tatami could not be processed properly. [Explanation of Symbols]

[0063] 1 Tatami mat surface 2 Backing sheet 3 Laminated Tatami Mat Surface 4. Rice straw tatami mat 5a, 5b Thermoplastic resin striae 6 Fabric 7 Base layer 8 Bonding layer 9. Synthetic resin film 10 Dies 11 Die exit 12 Pickup Rolls 13, 14, 15 Cooling Rolls 16. Foamed polyolefin sheet

Claims

1. A tatami mat surface characterized by having a backing sheet attached to the back of the tatami mat surface, which is made up of weft and warp threads made of rush or artificial rush.

2. The tatami mat surface according to claim 1, characterized in that it is woven by plain weave or twill weave.

3. The tatami mat surface according to claim 1 or 2, characterized in that the backing sheet is a foamed resin sheet.

4. The tatami mat surface has a backing sheet attached to the reverse side, with a thickness of 3.0 to 7.0 mm and a weight of 550 to 1200 g / m². ２ The tatami mat surface according to claim 1 or 2, characterized in that it has a tensile strength of 3.6 to 6.0 MPa and a tensile elongation of 15 to 25%.

Images