Cushion material and method for manufacturing cushion material

Abstract

To provide a cushion material that can provide uniform repulsive force (compression recovery property) within a cushion surface, requires only a small force for folding, and suppresses uncomfortable noise and squeaking noise during compression.SOLUTION: In the cushion material according to the present invention, one or more layers of a three-dimensional knitted fabric and / or one or more layers of a three-dimensional knitted fabric and another material are laminated, an outer periphery is covered with an edge cover material and sewn, and a thickness of a sewn portion covered with the edge cover material is 20% or more and 70% or less of a thickness of a central portion.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cushioning material formed by laminating mesh-like three-dimensional knitted fabrics, and a method for manufacturing the cushioning material. [Background technology]

[0002] Cushioning materials made by laminating three-dimensional knitted fabrics can provide better body pressure distribution than single layers, and are therefore widely used in a variety of applications, including bedsore prevention mats for hospitals, facilities, and home care, wheelchairs, pillows, and position-changing cushions, as well as bedding such as mattresses and bed pads for the general healthy population, and cushioning materials for seats, etc. As such a laminated cushioning material, a cushioning material has been proposed in which multiple layers of three-dimensional knitted fabrics with honeycomb-shaped knitted fabrics on both sides are laminated, and which has excellent durability at the sewn parts even after repeated washing (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4001890 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the cushioning material described in Patent Document 1 has a problem in that there is a difference in resilience between the peripheral portion covered with the edge covering material and the central portion. Furthermore, there are problems such as the need for force and unpleasant noise when bending or folding the cushioning material due to the thickness of the peripheral portion. Furthermore, the thickness of the peripheral portion reduces the durability of the fabric and seams, making them more susceptible to tearing.

[0005] The present invention has been proposed in light of the above-described conventional situation, and an object of the present invention is to provide a cushioning material that provides a uniform resilience (compression recovery) within the cushion surface, requires little force for folding, and suppresses unpleasant noises and squeals when compressed, as well as a method for manufacturing such a cushioning material. [Means for solving the problem]

[0006] As a result of extensive research into achieving the above object, the inventors of the present invention have found the optimum conditions for the degree of compression of the sewn portions, and have completed the present invention. That is, the present invention is as follows. [1] A cushion material in which one or more three-dimensional knitted fabrics and / or one or more three-dimensional knitted fabrics and other materials are laminated, and the outer periphery is covered with an edge covering material and sewn together, A cushioning material characterized in that the thickness of the sewn portion covered with the edge covering material is 20% to 70% of the thickness of the central portion. [2] The method includes a step of laminating one or more three-dimensional knitted fabrics and / or one or more three-dimensional knitted fabrics and other materials, covering the outer periphery with an edge covering material, and sewing the resulting material together. This method for manufacturing a cushioning material is characterized in that, during the sewing, the position of the presser foot of the sewing machine is set to any position between "lowered to the needle plate, which is the standard position" and "raised 12 mm from the standard position," and sewing is performed with the upper thread tension set to a range of 80% to 115% of the lower thread tension. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a cushioning material that has a uniform resilience (compression recovery) within the cushion surface, requires little force for folding, and suppresses unpleasant noises and squeals when compressed, as well as a method for manufacturing such a cushioning material. [Brief explanation of the drawings]

[0008] [Figure 1] Schematic diagram showing the locations where each physical property was measured in the examples. [Figure 2] An enlarged cross-sectional photograph of the cushioning material of the present invention, where the outer periphery is covered with an edge cover material and sewn. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an exemplary embodiment of the present invention (hereinafter abbreviated as "the present embodiment") will be described in detail. The present invention is not limited to the present embodiment, and various modifications can be made within the scope of the gist of the present invention. In the present specification, the upper and lower limits of each numerical range can be combined arbitrarily.

[0010] The cushioning material of the present invention is constructed by laminating one or more layers of three-dimensional knitted fabric and / or one or more layers of three-dimensional knitted fabric and other material, and covering the outer periphery with an edge covering material and sewing them together. The cushioning material of the present invention is characterized in that the thickness of the sewn part covered with the edge covering material is 20% to 70% of the thickness of the central part.

[0011] As a result, the cushioning material of the present invention provides uniform resilience (compression recovery) across the cushion surface and suppresses unpleasant noises and squeals when compressed. Furthermore, by optimizing the thickness of the stitched portions, the force required to fold the cushion is small, while at the same time maintaining the durability of the fabric and thread.

[0012] In this invention, the term "three-dimensional knitted fabric" refers to a three-dimensional knitted fabric formed of at least three layers: a front layer, a connecting layer, and a back layer, with two layers of knitted fabric connected by a connecting yarn, and refers to a knitted fabric formed on a knitting machine with two rows of needles, such as a double Russell knitting machine or a double circular knitting machine. In this specification, the thickness of the cushioning material at the stitched portions and at the center portion is a value measured using a vernier caliper and a thread and needle.

[0013] At the hem, where the edge of a three-dimensional knitted fabric (FUSION) is covered with a covering material and sewn, the sewn portion is sewn in a somewhat compressed state, so the thickness is smaller than other places (for example, the center portion). The inventors have found that there is an appropriate range for the degree of compression. If the thickness of the sewn portion is within this range, the compression recovery is uniform across the cushion surface, and uniform resilience can be obtained everywhere. This is thought to be because the hem prevents the compression force from escaping in the same way as it does in the center.

[0014] In this specification, "uniform resilience (compression recovery)" refers to a variation of 10% or less within the cushion surface.

[0015] On the other hand, if the thickness of the sewn portion is less than 20% of the thickness of the center portion, excessive tension is applied to the thread and fabric, resulting in a high shrinkage rate, which can lead to fabric tearing, thread breakage, and fraying, reducing the durability of the fabric and thread. Furthermore, if the thickness of the sewn portion exceeds 70% of the thickness of the center portion, the hem and the three-dimensional knitted fabric cannot be firmly fixed together, requiring more force when folding, making the garment less easy to fold and bend. Furthermore, the hem and the three-dimensional knitted fabric cannot be firmly fixed together, resulting in unpleasant noises and squeals when compressed.

[0016] As described above, the thickness of the sewn portion of the cushioning material of the present invention covered with the edge cover material may be 20% to 70% of the thickness of the central portion, and preferably 30% to 50%. This makes it possible to improve the uniformity of the resilience (compression recovery) within the cushion surface, suppress unpleasant noises and squeals when compressed, make it easier to fold, and improve the durability of the fabric and threads.

[0017] In the present invention, the sewn portion covered with the edge covering material is thinner than the central portion, but the thickness outside the sewn portion (on the edge side) can be adjusted. It is preferable to have a portion outside the sewn portion covered with the edge covering material that is thicker than the sewn portion. By adopting such a shape, the sewn portion is less likely to come into physical contact with other substances when the cushion is used or washed, resulting in a cushion material with excellent durability at the sewn portion.

[0018] Figure 2 shows the "sewn part covered by the edge covering material" and "thickest part outside the sewn part covered by the edge covering material" in the present invention. T1 in the figure is the "sewn part covered by the edge covering material," and T2 indicates the position of the "thickest part outside the sewn part covered by the edge covering material."

[0019] The ratio (T2 / T1) of the maximum thickness T2 outside the sewn area covered by the edge covering material to the thickness T1 of the sewn area is preferably 120-250%, more preferably 140-200%. A ratio of 120% or more reduces the possibility of other substances coming into contact with the sewn area, improving durability. A ratio of 250% or less prevents the bulge at the edge from touching the body during use, causing discomfort.

[0020] The present invention will be described in detail below. The cushioning material of the present invention is constructed by laminating one or more layers of three-dimensional knitted fabric and / or one or more layers of three-dimensional knitted fabric and other material. In order to further improve body pressure distribution, it is preferable that the three-dimensional knitted fabric is laminated with three-dimensional knitted fabric or other material, and it is more preferable that the cushioning material is constructed entirely of three-dimensional knitted fabric, as this greatly improves the ability to prevent stuffiness.

[0021] The three-dimensional knitted fabric used in the present invention has at least one of the front and back knitted fabrics made of a mesh knitted fabric. The mesh knitted fabric here refers to a knitted fabric having openings, such as a honeycomb pattern, diamond pattern, lattice pattern, or circular pattern. By having at least one side of the three-dimensional knitted fabric made of a mesh knitted fabric, high breathability is maintained and stuffiness prevention performance is improved. When the outer periphery of the cushioning material is covered with an edge covering material and sewn, it is preferable that the distance from the end of the three-dimensional knitted fabric to the sewn part is 5 to 20 mm. If it is less than 5 mm, the sewn part is very prone to fraying, and if it exceeds 20 mm, more than necessary loss will occur on the outer periphery, which is not preferable.

[0022] In the mesh knitted fabric, the knitted fabric width B in the course direction between the meshes constituting the meshes is 0.8 to 5 mm. If it is less than 0.8 mm, the three-dimensional knitted fabric is easily crushed and the sweat-preventing properties are poor, and if it exceeds 4 mm, the breathability becomes insufficient and the sweat-preventing properties are poor. A more preferable range for the knitted fabric width B is 1 to 4 mm.

[0023] The stitch length C of the stitched portion around the periphery of the cushioning material is 1.5 to 10.0 mm per stitch. The stitch length C here refers to the length of one stitch, and refers to the distance from the center of the needle hole formed when forming one stitch to the center of the next needle hole. If the stitch length C is less than 1.5 mm, it becomes difficult to sew a thick, three-dimensional knitted fabric whose middle layer is made of highly rigid monofilament. If it exceeds 10.0 mm, the stitched portion becomes prone to fraying.

[0024] Furthermore, even if fraying occurs at the end of the three-dimensional knitted fabric, the ratio of knitted stitches and frayed yarns (C / B) needs to be 0.5 to 5.0 so that the stitches and frayed yarns can be fixed at the seams to prevent the fraying from spreading. If C / B is less than 0.5, fraying can be prevented but it becomes difficult to sew thick cushioning materials. If C / B exceeds 5.0, it becomes difficult for the sewing thread to penetrate through the knitted fabric width B, making it difficult to fix fraying at the end of the three-dimensional knitted fabric (especially in the knitting end direction) at the seams, and the seams become prone to fraying. A more preferable range for C / B is 0.7 to 4.

[0025] The periphery of the cushioning material is covered with an edge covering material and sewn to it. The edge covering material here refers to a narrow woven fabric, knitted fabric, nonwoven fabric, synthetic leather, etc. The fiber material used for the edge covering material is not particularly limited, and may be synthetic fiber, regenerated cellulose fiber, natural fiber, or a composite of these fibers. The fineness of the fiber, the density of the woven or knitted fabric, etc., are also not limited. The narrow slit may be straight cut or bias cut. The thickness of the cover material used in the present invention is preferably in the range of 0.3 mm to 1.5 mm from the viewpoints of ease of sewing and durability of the sewn parts.

[0026] To prevent the fragments of monofilament from the end of the three-dimensional knit fabric from penetrating through the edge covering material, the edge covering material preferably has a puncture strength in the range of 2 to 20 N. The puncture strength of the edge covering material is measured by attaching a sewing needle (TVx7#19 manufactured by Organ Co., Ltd.) to a Tensilon chuck, fixing the edge covering material to a circular pin frame with a diameter of 30 mm, and piercing the edge covering material with the sewing needle at a speed of 50 mm / min to determine the maximum stress at the time of penetration.

[0027] In this case, the puncture strength of the edge covering material can be adjusted to the range of 2 to 20 N by increasing the cover factor of the edge covering material, performing a calendering process to close the pores, or coating or dipping one or both sides with a synthetic resin such as polyurethane or polyacrylonitrile. The sewing method for the outer peripheral seam may be any of the commonly used methods such as single chain stitch, lock stitch, double chain stitch, flat stitch, or hand stitch, and may also be any of the straight, curved, or zigzag methods.

[0028] The fibers used in the three-dimensional knitted fabric of the present invention may be any synthetic fiber, such as polytrimethylene terephthalate fiber, polyethylene terephthalate fiber, polybutylene terephthalate fiber, polyamide fiber, polypropylene fiber, polyvinyl chloride fiber, or polyester-based elastomer fiber, for the connecting yarn. To achieve the target compression displacement and provide good cushioning properties, the connecting yarn is preferably a monofilament. In particular, a polytrimethylene terephthalate monofilament connecting yarn is preferred, as it provides good dimensional stability in the thickness, length, and width directions of the three-dimensional knitted fabric, makes the three-dimensional knitted fabric less prone to wrinkling, and has good durability against repeated compression.

[0029] The fibers used for the front and back knitted fabrics may be any fibers, including synthetic fibers such as polyester fibers, polyamide fibers, polyacrylic fibers, and polypropylene fibers; natural fibers such as cotton, hemp, and wool; and regenerated fibers such as cupra rayon, viscose rayon, and lyocell. Other materials that can be laminated one or more times with the three-dimensional knitted fabric include the cotton-like material of the fiber used in the front and back knitted fabrics, padding, nonwoven fabric, woven or knitted fabric, or urethane foam.

[0030] To improve the feel of the surface of the three-dimensional knitted fabric, it is preferable to use bulky yarns as the fibers constituting the surface knitted fabric, and for example, bulky yarns such as false twisted yarns, jet stuffered yarns, push-textured yarns, spun yarns, and fluid jet textured yarns with loop-like fluff are preferred. Furthermore, the use of highly hygroscopic fibers such as cotton and rayon is preferable for improving stuffiness prevention. Cupra rayon, which has particularly high moisture absorption and release properties, provides even better stuffiness prevention.

[0031] Furthermore, the surface knit fabric of the three-dimensional knitted surface layer needs to have a total cover factor (TCF) of 750 to 1250 to minimize skin irritation and achieve a soft texture. If the total cover factor is less than 750, the surface tends to be rough and too irritating to the skin. On the other hand, if the total cover factor exceeds 1250, breathability is impaired, the sweat-preventing performance decreases, and the texture becomes hard and unsatisfactory to the touch. The total cover factor is more preferably in the range of 800 to 1150, and even more preferably 850 to 1100.

[0032] Here, the total cover factor (TCF) is calculated using the following formula: Total Cover Factor (TCF) = Course Cover Factor (CCF) + Wale Cover Factor (WCF) However, the course cover factor (CCF) = (number of courses; courses / 2.54 cm) x (thickness of the yarn that constitutes the surface knitted fabric; dtex) 1 / 2 Wale Cover Factor (WCF) = (number of wales; pieces / 2.54 cm) x (thickness of yarns constituting the surface knitted fabric; dtex) 1 / 2

[0033] The thickness of the yarn that makes up the surface knitting is 2.54 cm square (6.45 cm 2 For example, when two face yarns are supplied to the same needle from two reeds to form one stitch, the thickness refers to the sum of the thicknesses of the two face yarns, excluding the connecting yarn that connects the front and back surfaces.

[0034] If the thickness of the yarns that make up the stitches is different, first divide the surface knitting area 2.54 cm square (6.45 cm 2 The total number of stitches (n) present in the area of ​​the stitch (D1, D2, D3, ..., Dn; dtex) and the thickness of the yarns that make up each stitch (D1, D2, D3, ..., Dn; dtex) are measured. Then, the sum of the thicknesses of the yarns that make up each stitch (D1 + D2 + D3 + ... Dn; dtex) is divided by the total number of stitches (n).

[0035] In the present invention, the course cover factor (CCF) is preferably 400 to 800, particularly preferably 450 to 750, and further preferably 500 to 700, and the wale cover factor (WCF) is preferably 250 to 550, particularly preferably 300 to 500, and further preferably 350 to 450. Furthermore, the ratio of course cover factor (CCF) to wale cover factor (WCF), (CCF / WCF), is preferably 1.0 to 2.5, and particularly preferably 1.3 to 2.0.

[0036] To achieve an appropriate cover factor, the three-dimensional knit surface layer must be produced by taking into full consideration the gauge of the knitting machine used, the fineness of the fibers constituting the surface knit, the knitting structure, the width adjustment during finishing, and the overfeed rate. It is preferable to use an 18-24 gauge knitting machine, use a fiber fineness of 100-280 decitex for the knit fabric on the surface side of the three-dimensional knit, and have 25-40 courses / 2.54 cm and 16-25 wales / 2.54 cm for the three-dimensional knit after finishing.

[0037] In order to obtain good body pressure dispersion in the cushioning material of the present invention, the three-dimensional knitted fabric is preferably made of connecting threads made of monofilaments of 180 to 1000 decitex and has a thickness of 3 to 15 mm. If the thickness is less than 3 mm, the body pressure distribution will be insufficient, and if it exceeds 15 mm, it will be difficult to process the edges of the three-dimensional knitted fabric, and the durability will decrease when used for long periods of time, making it prone to sagging.

[0038] Furthermore, if the connecting yarn is less than 180 decitex, the three-dimensional knitted fabric will be crushed without being able to fully support the body weight, and good body pressure distribution will not be achieved, and an air layer will not be secured, resulting in a significant decrease in sweat-preventing properties. If the connecting yarn is more than 1000 decitex, the three-dimensional knitted fabric will be too stiff and good body pressure distribution will not be achieved. The connecting yarn of the three-dimensional knitted fabric is preferably 150 to 900 decitex, and more preferably 150 to 700 decitex.

[0039] The thickness of the cushioning material of the present invention is preferably 3 to 30 mm. If the thickness is less than 3 mm, the body pressure distribution will be poor, and if it exceeds 30 mm, the stability of the outer peripheral seams will be insufficient and they will easily fray after repeated washing. In the cushioning material of the present invention, when three-dimensional knitted fabrics are laminated, it is preferable that the central portions of the three-dimensional knitted fabrics are partially joined to the upper and lower layers by quilting or the like, since this prevents the upper and lower layers from shifting or losing their shape.

[0040] Next, a method for manufacturing such a cushioning material will be described. The method for manufacturing a cushioning material of the present invention includes the steps of stacking one or more layers of three-dimensional knitted fabric and / or one or more layers of three-dimensional knitted fabric and another material, covering the outer periphery with an edge covering material, and sewing them together. During the sewing, the position of the presser foot of the sewing machine is set to any position between "lowered to the needle plate, which is the reference position" and "raised 12 mm from the reference position," and sewing is performed with the upper thread tension set to a range of 80% to 115% of the bobbin thread tension.

[0041] This method makes it possible to suitably manufacture cushioning material in which the thickness of the sewn portion covered with the edge covering material is 20% to 70% of the thickness of the central portion, and the ratio of the maximum thickness outside the sewn portion covered with the edge covering material to the thickness of the sewn portion is 120 to 250%. When sewing cushioning material, the degree of tightness during sewing can be adjusted by adjusting the height and pressure of the sewing machine's presser foot and setting the tension of the upper and lower threads during sewing, and the thickness of the sewn part can be adjusted to the appropriate range as described above.

[0042] The three-dimensional knit fabric used in the present invention can be finished by subjecting the grey fabric to processes such as scouring, dyeing, and heat setting, or it can be finished by omitting the scouring and dyeing processes and only heat setting the grey fabric. Furthermore, in the course of finishing and setting, finishing processes such as resin finishing, water absorption finishing, antistatic finishing, antibacterial finishing, water repellent finishing, and flame retardant finishing, which are generally used in textile processing, can be applied as long as they do not impair the object of the present invention. As the heat treatment machine used in the finishing set, a pin tenter, clip tenter, short loop dryer, shrink surfer dryer, drum dryer, continuous or batch type tumbler, etc. can be used.

[0043] Although the embodiment of the present invention has been described above, the present invention is not limited to this and can be modified as appropriate within the scope of the invention. [Example]

[0044] Next, the present embodiment will be described in more detail with reference to examples and comparative examples. However, the present embodiment is not limited to the following examples as long as they do not deviate from the gist of the present invention. FIG. 1 is a schematic diagram showing the locations where the physical properties were measured in the examples, and FIG. 2 is an enlarged cross-sectional photograph of the portion of the cushioning material of the present invention where the outer periphery is covered with an edge covering material and sewn.

[0045] <Cushioning material production> (Examples 1 to 3, Comparative Examples 1 to 3) The three-dimensional knit fabric was prepared with a thickness of 7.5 mm, with the connecting yarn being 156 decitex monofilament yarn made of 100% polyester and the surface being 96 multifilament yarn made of 167 decitex 100% polyester. Two sheets of the three-dimensional knitted fabric were layered, and the outer periphery was covered with an edge covering material and sewn together to create a cushioning material sample measuring 30 cm x 30 cm. The edge covering material was made of polyurethane-coated 100% polyester woven fabric, 14 mm wide and 0.7 mm thick.

[0046] The cushioning materials were sewn using a JUKI Corporation lockstitch integrated feed sewing machine (LU-1520NCS-7) with a No. 23 needle and AceClan Tetron thread No. 8, with a stitch length of 7 mm. In both cases, the distance from the edge of the three-dimensional knitted fabric to the sewn part was 14 mm.

[0047] When sewing the hem, the position of the presser foot of the sewing machine was set between "lowered to the needle plate, which is the standard position" and "raised 12 mm from the standard position," and the upper thread tension was set in the range of 80% to 115% of the lower thread tension to produce cushioning material samples of Examples 1 to 3 with different sewn thicknesses. Furthermore, cushioning material samples of Comparative Examples 1 to 3 were produced by setting the upper thread tension to less than 80% or more than 115% of the lower thread tension.

[0048] The cushioning materials obtained in each of the examples and comparative examples were subjected to performance evaluation as follows. The results are shown in Table 1. For each measurement, the average value was calculated for the central portion near number 3 in Figure 1, and for the sewn portion near numbers 1, 2, 4, and 5 in Figure 1.

[0049] <Thickness measurement> The thickness of the cushioning material at the stitching, center, and maximum thickness outside the stitching were measured using vernier calipers and a needle and thread. The thickness of the stitching was measured at the most compressed point (T1) in Figure 2 by passing a needle and thread through this point and marking the top and bottom. The maximum thickness outside the stitching was measured at the thickest point (T2) outside the stitching (T1) in Figure 2 using the same method as for the thickness of the stitching. The thickness (%) of the sewn area covered by the edge covering material was calculated when the central area was taken as 100%. Similarly, the maximum thickness (%) outside the sewn area was calculated when the thickness of the sewn area was taken as 100%.

[0050] <Compression recovery (RC) measurement> Measurements were performed using a Kato Tech KES-FB3-A. First, one or more layers of cushioning material were placed on the test table, and then a 5cm2 area was measured. 2 A copper pressure probe with a circular flat surface was applied from above the sample at a speed of 0.5 cm / sec and a maximum compressive stress of 4.90 N / cm. 2 The specimen was compressed under the conditions and the data was measured. From the obtained data, RC was calculated by numerical processing. The larger the RC, the better the recovery.

[0051] <Evaluation of uniformity of compression recovery> Measurements were taken at five points in total, at the four corners (1, 2, 4, and 5 in Figure 1) and the center (3 in Figure 1) that are the edges of the cushioning material sample. The four edge points were measured within 5 mm of the area where the edge cover material was sewn. The compression recovery (RC) measured at one point in the center was compared to the average of the four edge points, and uniformity was evaluated using the following formula. The RC measured at the four edge points showed the effect of sewing. RC ratio of edge to center [%] = (average of RC at four edge points ÷ RC at center) × 100

[0052] <Evaluation of cushion foldability> Evaluation was performed using an autograph and a three-point bending jig. In accordance with JIS standards (JIS K7171), the cushioning material samples were bent at one point from the center and two points from below, and the force (N) required to displace the samples to the specified positions was evaluated. These three-point bending evaluations were used to indicate ease of folding.

[0053] <Evaluation of noise> A 30cm square cushioning material sample was placed in an artificial climate chamber at a temperature of 20°C ± 2°C and a relative humidity of (65 ± 4)%, and the noise generated when the edge was compressed was evaluated using the following scores. The average score of seven adults was calculated. 3 points: Noise is heard 2 points: Some noise is felt 1 point: No noise is felt

[0054] <Durability evaluation> A 30cm square cushioning material sample was prepared, the outer periphery of which was covered with an edge covering material and sewn together. In accordance with JIS-L-0217, Method 103, the degree of fraying at the stitching after 100 washes was evaluated according to the following criteria. ○: No fraying is observed △: Fraying of less than 1cm is observed ×: Fraying of 1cm or more is observed

[0055] [Table 1]

[0056] As is clear from Table 1, in Examples 1 to 3, in which the thickness of the sewn portion covered with the edge covering material was 20% to 70% of the thickness of the central portion, a uniform resilience (within a difference of 10%) was obtained within the cushion surface. Furthermore, the force required for folding was low, and noise during compression was suppressed. Furthermore, fraying was suppressed, and durability was good. In contrast, in Comparative Examples 1 and 2, where the thickness of the sewn portion was more than 70% of the thickness of the central portion, a large force was required for folding, and noise was generated when compressed. Furthermore, in Comparative Example 3, where the thickness of the sewn portion was less than 20% of the thickness of the central portion, durability deteriorated. [Industrial Applicability]

[0057] By using the cushioning material of the present invention, a uniform resilience (compression recovery) can be obtained within the cushion surface, the force required for folding is small, and unpleasant noises and squeals during compression are suppressed. The cushioning material can be widely used as bedding such as bed pads and mattresses, as well as chair cushions, etc.

Claims

1. A cushion material in which one or more three-dimensional knitted fabrics and / or one or more three-dimensional knitted fabrics and other materials are laminated, and the outer periphery is covered with an edge covering material and sewn together, The cushioning material is characterized in that the thickness of the sewn portion covered with the edge covering material is 20% to 70% of the thickness of the central portion.

2. The method includes a step of laminating one or more three-dimensional knitted fabrics and / or one or more three-dimensional knitted fabrics and other materials, covering the outer periphery with an edge covering material, and sewing the resulting material together. This method for manufacturing a cushioning material is characterized in that, during the sewing, the position of the presser foot of the sewing machine is set to any position between "lowered to the needle plate, which is the reference position" and "raised 12 mm from the reference position," and sewing is performed with the upper thread tension set to a range of 80% to 115% of the lower thread tension.

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