Three-dimensional mesh-like structure

Abstract

A three-dimensional mesh-like structure (1) is formed by entangling and partially thermally fusing a plurality of linear molten resins. The three-dimensional mesh-like structure (1) comprises, in a portion of the thickness thereof, a hard region (10) having a bulk density greater than that of the surrounding regions. The position of the hard region (10) in the thickness direction varies along the region. Thus, a predetermined hardness can be imparted to an arbitrary part of the three-dimensional mesh-like structure (1) without substantially increasing the weight. Further, the comfort of the three-dimensional mesh-like structure (1) can be improved.

Description

Three-dimensional mesh structure

[0001] The present invention relates to a three-dimensional network structure formed by intertwining a plurality of linear molten resins and partially heat-welding them.

[0002] Mattresses, pillows, and the like that use a three-dimensional network structure formed of woven resin are known. Here, Patent Document 1 discloses a mattress made of a woven resin network structure, in which the waist and buttock region has a waist and buttock first layer and a waist and buttock second layer, the back region has a back first layer and a back second layer, and the leg region has a leg first layer and a leg second layer, the bulk density of the back first layer is smaller than that of the waist and buttock first layer, the bulk density of the leg first layer is smaller than that of the waist and buttock first layer, the bulk density of the waist and buttock second layer is larger than that of the waist and buttock first layer, the bulk density of the back second layer is larger than that of the back first layer, and the bulk density of the leg second layer is larger than that of the leg first layer.

[0003] JP 2017-86321 A

[0004] The invention described in Patent Document 1 provides bedding that achieves optimal resilience and texture in the lower back, buttocks, back, and leg areas, and easily balances body pressure distribution and sleeping posture maintenance. However, because the bulk density varies from layer to layer, the number of areas with high bulk density increases, resulting in increased weight. Therefore, the object of the present invention is to provide a three-dimensional netted structure that can provide a predetermined hardness in any area without significantly increasing weight, and that also improves comfort.

[0005] The three-dimensional mesh structure 1 of the present invention is a structure formed by intertwining and partially heat-welding a plurality of linear molten resins, and is characterized in that hard regions 10, 20, and 30 having a higher bulk density than the surrounding areas are provided in a portion of the thickness, and the positions of the hard regions 10, 20, and 30 change along the thickness direction. The three-dimensional mesh structure 1 of the present invention is characterized in that the hard regions 10 and 30 are corrugated. The three-dimensional mesh structure 1 of the present invention is characterized in that the portions connecting the hard regions 10, 20, and 30 at one position in the thickness direction to the other position are inclined. The three-dimensional mesh structure 1 of the present invention is characterized in that the three-dimensional mesh structure 1 of the present invention is a mattress or futon, and the thickness direction position of the hard region 30 at the upper surface 1A where the shoulders 2B of the user 2 rest is closer to the lower surface 1B than the thickness direction position of the hard region 30 at the upper surface 1A where the head 2A of the user 2 rests. The present invention according to claim 5 is characterized in that, in the three-dimensional mesh structure 1 according to claim 4, the thickness direction position of the hard region 30 at the portion on the upper surface 1A where the ankle 2F of the user 2 rests is closer to the lower surface 1B than the thickness direction position of the hard region 30 at the portion on the upper surface 1A where the lower leg 2E of the user 2 rests. The present invention according to claim 6 is characterized in that, in the three-dimensional mesh structure 1 according to claim 5, the hard region 30 at the portion on the upper surface 1A where the buttocks 2D of the user 2 rests is wavy.

[0006] According to the present invention, a three-dimensional mesh structure can be given a predetermined hardness at any desired location without significantly increasing its weight compared to a structure in which no hard region is provided, and comfort can also be improved.

[0007] FIG. 1 shows a three-dimensional network structure according to a first embodiment of the present invention. FIG. 2 shows a three-dimensional network structure according to a second embodiment of the present invention. FIG. 3 shows a three-dimensional network structure according to a third embodiment of the present invention. FIG. 4 shows an example of a manufacturing device for a three-dimensional network structure. FIG. 5 shows an example of holes in the bottom surface of a resin pool.

[0008] The three-dimensional network structure according to the first embodiment of the present invention is a structure formed by intertwining and partially heat-welding a plurality of linear molten resins, and includes a hard region having a higher bulk density than the surrounding area, the position of which varies along the thickness. According to this embodiment, by providing the hard region along the thickness, a predetermined hardness can be imparted to any portion of the three-dimensional network structure without significantly increasing its weight. Furthermore, by varying the position of the hard region along the thickness, the degree of sinking and feel of the three-dimensional network structure can be more appropriately adjusted, thereby improving comfort.

[0009] In the second embodiment of the present invention, the hard regions are corrugated in the three-dimensional network structure according to the first embodiment. This embodiment makes it possible to form alternating portions with different textures along the length of the three-dimensional network structure, and to further increase the strength of the three-dimensional network structure.

[0010] In the third embodiment of the present invention, in the three-dimensional mesh structure according to the first embodiment, the portion of the hard region connecting the portion at one position in the thickness direction to the portion at the other position is inclined. According to this embodiment, it is possible to make the degree of sinking and the change in the feel of the three-dimensional mesh structure more gradual.

[0011] In a fourth embodiment of the present invention, the three-dimensional mesh structure according to the first embodiment is a mattress or a futon, and the thickness direction position of the hard region on the upper surface where the user's shoulders rest is lower than the thickness direction position of the hard region on the upper surface where the user's head rests. This embodiment prevents excessive sinking of the portion of the three-dimensional mesh structure corresponding to the head, while providing the feeling of entering the three-dimensional mesh structure at the portion corresponding to the shoulders.

[0012] In a fifth embodiment of the present invention, in the three-dimensional mesh structure according to the fourth embodiment, the position in the thickness direction of the hard region at the portion on the upper surface where the user's ankle rests is located lower than the position in the thickness direction of the hard region at the portion on the upper surface where the user's lower leg rests. This embodiment prevents excessive sinking of the portion of the three-dimensional mesh structure corresponding to the lower leg, while providing the portion corresponding to the ankle with the feeling of being inserted into the three-dimensional mesh structure.

[0013] In a sixth embodiment of the present invention, the three-dimensional mesh structure according to the fifth embodiment has a corrugated hard region on the upper surface where the user's buttocks rest, thereby increasing the strength of the region corresponding to the buttocks and improving the durability of the three-dimensional mesh structure.

[0014] Three-dimensional network structures according to embodiments of the present invention will now be described. FIG. 1 shows a three-dimensional network structure according to a first embodiment, with FIG. 1(a) being a side (cross-section) photograph, FIG. 1(b) being an image of a hard region on the side, and FIG. 1(c) being a top view. FIG. 2 shows a three-dimensional network structure according to a second embodiment, with FIG. 2(a) being a side (cross-section) photograph, FIG. 2(b) being an image of a hard region on the side, and FIG. 2(c) being a top view. A three-dimensional network structure 1 made of knitted resin is formed three-dimensionally by intertwining multiple filamentous molten resins and partially heat-welding them. The three-dimensional network structure 1 is used, for example, as a mattress, a futon, a pillow, etc., and is often rectangular in top view. The three-dimensional network structure 1 is formed by melt-kneading a thermoplastic resin at a predetermined temperature, allowing the molten resin to flow down in the form of filaments, and then cooling them. Examples of thermoplastic resins include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polytetrafluoroethylene, and acrylonitrile butadiene styrene resins, and these can be used alone or in combination. The three-dimensional network structure 1 manufactured using a thermoplastic resin as a raw material can be recycled after use and reused as a raw material for the three-dimensional network structure 1. Furthermore, the three-dimensional network structure 1 can be washed with water or the like, making it easy to keep clean.

[0015] The three-dimensional network structure 1 of this embodiment is a rectangular parallelepiped with a single-layer structure in which the bulk density is approximately constant between the upper surface 1A and the lower surface 1B, and has a predetermined length L, width W, and thickness (height) H. Between the upper surface 1A and the lower surface 1B, a part of the space has a bulk density [g / cm 3 ] higher than the surrounding area. ３ The hard regions 10, 20, each having a large thickness, are formed in a thin plate shape, and the knitted resin of the hard regions 10, 20 is intertwined with the surrounding knitted resin. The hard regions 10, 20 have longitudinal and lateral dimensions (length and width) substantially equal to the longitudinal and lateral dimensions L×W of the three-dimensional network structure 1, and are formed from the front surface 1C to the rear surface 1D and from the left side surface 1E to the right side surface 1F. In a cross section parallel to the thickness direction, the hard regions 10, 20 appear as continuous lines (bands) as shown in Figure 1(b) or Figure 2(b). By providing the hard regions 10, 20 in a portion of the thickness, a desired hardness can be imparted to any desired location of the three-dimensional network structure 1 without significantly increasing its weight.

[0016] Although the three-dimensional network structure 1 has a single layer structure in this embodiment, it may also have a multi-layer structure in which multiple layers with different bulk densities are formed between the upper surface 1A and the lower surface 1B. Furthermore, as in the third embodiment described below, the three-dimensional network structure 1 may also be a divided type. Furthermore, the length and width of the hard regions 10 and 20 may be different from the length and width L×W of the three-dimensional network structure 1, for example, by making the length shorter than the length L of the three-dimensional network structure 1, and the hard regions may also be formed discontinuously in the longitudinal direction.

[0017] The hard regions 10, 20 can be freely positioned at any location within the thickness of the three-dimensional network structure 1, and various degrees of sinking and tactile sensations can be expressed by varying the formation pattern of the hard regions 10, 20. The hard regions 10, 20 can be formed in a straight line so that their positions in the thickness direction are constant from the front surface 1C to the rear surface 1D. However, in this embodiment, the hard regions 10, 20 are formed so that their positions in the thickness direction change along the way. For example, the hard region 10 in FIG. 1 is formed as a wave shape with alternating peaks and valleys, and its position in the thickness direction changes periodically. The peaks of the peaks of the wave shapes are located above the center of the thickness direction of the three-dimensional network structure 1, and the bottoms of the valleys are located below the center of the thickness direction. On the other hand, the hard region 20 in FIG. 2 is formed so that its height is constant below the center of the thickness direction from the front surface 1C to the longitudinal center, and so that its height is constant above the center of the thickness direction from the rear surface 1D to the center, thereby varying its position in the thickness direction between the front and rear. The degree of sinking and feel when the user's head or body rests on the three-dimensional mesh structure 1 differs between the upper and lower locations of the hard regions 10, 20. Therefore, by changing the thicknesswise positions of the hard regions 10, 20 in accordance with the body parts, the degree of sinking and feel at each location of the three-dimensional mesh structure 1 can be made more appropriate, leading to improved comfort.

[0018] Furthermore, the hard regions 10, 20 have an inclined portion connecting a portion at one position (lower side) with a portion at the other position (upper side). By forming the boundary portions of the hard regions 10, 20 at an angle where the thickness direction positions change in the hard regions 10, 20 in this manner, the degree of sinking and the change in feel at each location of the three-dimensional network structure 1 can be made gentler. Furthermore, the corrugated hard region 10 shown in FIG. 1 has an inclination angle of more than 0 degrees and less than 50 degrees at the portion connecting the peak and the valley. By forming the hard region 10 in this gently inclined corrugated form, it is possible to provide portions of the three-dimensional network structure 1 with different feel, etc., alternately in the length direction.

[0019] Next, a three-dimensional mesh structure according to a third embodiment of the present invention will be described. Note that the same parts as those in the above-described embodiments are designated by the same reference numerals, and their description will be omitted. Figure 3 shows a three-dimensional mesh structure according to the third embodiment, with Figure 3(a) being a side view of the structure in use, and Figure 3(b) being an image of the hard region on the side. The three-dimensional mesh structure 1 of this embodiment is used as a mattress or a futon. Note that the mattress or futon of this embodiment is a split type in which three three-dimensional mesh structures 1 are arranged longitudinally inside a cover, but it can also be an integrally molded type, as in the first and second embodiments.

[0020] Similar to the first and second embodiments, the three-dimensional mesh structure 1 of this embodiment includes a thin, plate-like hard region 30 between the upper surface 1A and the lower surface 1B, which has a higher bulk density than the surrounding area. The length and width dimensions (length and width) of the hard region 30 are approximately equal to the length and width dimensions L x W of the three-dimensional mesh structure 1. The portion of the hard region 30 corresponding to the head 2A of a lying user 2 is at a constant height above the center of the thickness, while the portion corresponding to the shoulders 2B is at a constant height below the center of the thickness, with the portion between the two being inclined. In this way, by forming the portion of the hard region 30 on the upper surface 1A corresponding to the location where the shoulders 2B of the user 2 rest, closer to the lower surface 1B than the portion corresponding to the location where the head 2A rests, excessive sinking of the portion of the three-dimensional mesh structure 1 corresponding to the head 2A can be prevented, while the portion corresponding to the shoulders 2B can be made to feel as if they are embedded in the three-dimensional mesh structure 1.

[0021] Furthermore, the portion of the hard region 30 that corresponds to the lower leg 2E of the user 2 lying down is located above the center in the thickness direction and is constant in the thickness direction, while the portion that corresponds to the ankle 2F is located below the center in the thickness direction and is constant in the thickness direction, with the portion between the two being inclined. In this way, by forming the portion of the hard region 30 that corresponds to the location on the upper surface 1A where the ankle 2F of the user 2 rests closer to the lower surface 1B than the portion that corresponds to the location on the lower leg 2E, it is possible to prevent excessive sinking of the portion of the three-dimensional network structure 1 that corresponds to the lower leg 2E, while providing the feeling of entering the three-dimensional network structure 1 at the portion that corresponds to the ankle 2F.

[0022] Furthermore, the portions of the hard regions 30 corresponding to the lumbar region 2C and buttocks 2D of the user 2 lying down are formed in a wave shape. The peaks of the wave shapes are located above the center in the thickness direction, and the bottoms of the valleys are located below the center in the thickness direction. The wavelength of this wave shape is shorter than that of the wave shape of the first embodiment, and the slope angle of the portion connecting the peak and valley is 50 degrees or more and less than 90 degrees. Because the portions where the hard regions 30 are formed with steeply inclined wave shapes are stronger than the portions where the hard regions 30 are formed linearly, providing the hard regions 30 with steeply inclined wave shapes in the portions corresponding to the lumbar region 2C and buttocks 2D, which tend to sink, can improve the durability of the three-dimensional mesh structure 1.

[0023] FIG. 4 shows an example of a manufacturing apparatus for a three-dimensional network structure according to the present invention, and FIG. 5 shows an example of holes in the bottom surface of a resin pool. The manufacturing apparatus according to this embodiment includes an extruder 110 that melts and kneads a thermoplastic resin at a predetermined temperature to form a molten resin and extrudes the molten resin at a predetermined extrusion speed; a resin pool 130 that receives the molten resin extruded from the extruder 110 and allows the molten resin to flow down in threads from multiple holes (nozzles) in the bottom surface 131; a cooling water tank 140 that stores cooling water; and a take-up machine 150 that takes up the knitted resin 121 formed by the molten resin threads 120 flowing down from the resin pool 130 and being cooled by the cooling water. The take-up machine 150 has multiple take-up rollers 151 facing each other and is disposed within the cooling water tank 140. A guider 170 is also provided between the resin pool 130 and the take-up machine 150. The molten resin threads 120 are formed by flowing down through the holes in the bottom surface 131 of the resin pool 130. The knitted resin 121, obtained by cooling the filamentous molten resin 120 with cooling water, is drawn by a drawer 150 to the bottom plate side of the cooling water tank 140. After passing through the drawer 150, the knitted resin 121 is drawn diagonally upward while being cooled in the cooling water by a plurality of conveying rollers 160, which are drawing-up members arranged in the cooling water tank 140, and conveyed out of the cooling water tank 140. The knitted resin 121 is then cooled and cut to a predetermined size to form a three-dimensional network structure 1. The direction perpendicular to the extrusion direction is the length direction of the three-dimensional network structure 1, and the direction parallel to the extrusion direction is the width direction of the three-dimensional network structure 1. The thickness of the three-dimensional network structure 1 is approximately equal to the spacing between the draw rollers 151. Furthermore, the width of the bundle of filamentous molten resin 120 is narrowed as it passes through the guider 170, thereby smoothly forming the upper surface 1A and the lower surface 1B of the three-dimensional network structure 1.

[0024] The hard regions 10, 20, and 30 in the three-dimensional network structure 1 can be freely formed at any desired location by, for example, locally increasing the number of holes along a predetermined line on the bottom surface 131 of the resin pool 130 as shown in Fig. 5. In Fig. 5, the holes increased to form the hard regions are shown in black. The holes increased to form the hard regions can be the same size as the original holes (white holes in the figure) or can be a different size.

[0025] 1. Three-dimensional network structure 1A. Top 1B. Bottom 1C. Front 1D. Back 1E. Left side 1F. Right side 2. User 2A. Head 2B. Shoulders 2C. Waist 2D. Hips 2E. Lower legs 2F. Toe 10, 20, 30. Hard area

Claims

1. A three-dimensional mesh structure comprising a structure formed by intertwining a plurality of linear molten resins and partially heat-welding them, characterized in that a hard region having a higher bulk density than the surrounding area is provided in part of the thickness, and the position of the hard region in the thickness direction changes midway.

2. The three-dimensional mesh structure according to claim 1, wherein the hard region is corrugated.

3. The three-dimensional mesh structure according to claim 1, wherein the portion of the hard region that connects a portion at one position in the thickness direction to a portion at the other position is inclined.

4. The three-dimensional mesh structure described in claim 1, characterized in that it is a mattress or futon, and the thickness direction position of the hard region at the upper surface where the user's shoulders rest is lower than the thickness direction position of the hard region at the upper surface where the user's head rests.

5. The three-dimensional mesh structure according to claim 4, characterized in that the thickness direction position of the hard region at the point where the user's ankle rests on the upper surface is lower than the thickness direction position of the hard region at the point where the user's lower leg rests on the upper surface.

6. The three-dimensional mesh structure according to claim 5, wherein the hard region on the upper surface where the user's buttocks rest is wavy.

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