JP7629073B2 - Cushion member and manufacturing method thereof - Google Patents

Description

The present invention relates to a cushioning material that can be used in mattresses, pillows, chairs, etc. and is useful for preventing bedsores, and a method for manufacturing the same.

Bed sores, commonly known as bed sores, develop when the skin's capillaries are compressed by body weight for a long period of time, cutting off blood flow in the capillaries and preventing sufficient oxygen and nutrients from reaching the skin cells. Healthy people can turn over in their sleep, so even if the skin's capillaries are temporarily compressed and blood flow is cut off, the pressure is relieved by turning over, so the risk of developing bed sores is low.

However, if you are unable to turn over freely while sleeping due to weakened muscles, pressure on the skin continues for long periods of time, making you more susceptible to developing bedsores. Similarly, if you remain seated in a chair for long periods of time, you are more likely to develop bedsores.

Figure 19 shows a user lying on his back using a conventional mattress cushion member 101 and a pillow cushion member 102. Figure 20 shows a user sitting on a chair using a conventional chair cushion member 103. Figure 21 shows parts of the human body where bedsores are likely to develop.

When lying on one's back, the cushioning material creates a large amount of localized pressure due to the rebound force of the user's weight on bony prominences (bony protuberances) such as the shoulder blades, sacrum, heels, or back of the head, making bedsores more likely to develop. When sitting, bedsores are more likely to develop on bony prominences such as the tailbone.

As a method for preventing bedsores, for example, Patent Document 1 discloses a urethane mattress in which three-dimensional data of the human body is acquired and depressions are provided that fit the shape of the body. While this provides excellent body pressure dispersion, the urethane foam used as the material for the mattress has drawbacks, such as low breathability, which makes it prone to becoming stuffy, and the fact that it cannot be washed with water, which makes it prone to becoming unsanitary.

Patent Document 2 also discloses an air mat made up of multiple air cells with adjustable internal pressure. Although this provides excellent body pressure dispersion, it requires a complex device to control the pressure of each air cell, which increases costs, and has not yet become widespread.

On the other hand, Patent Document 3 and Patent Document 4 disclose mattresses using three-dimensional filament bonds (three-dimensional mesh structures) that are well ventilated and have excellent body pressure dispersion and breathability. Mattresses using three-dimensional filament bonds can easily adjust their resilience to suit the body shape of each individual user, and because they have excellent breathability and body pressure dispersion, they are effective in reducing pressure (local pressure) and stuffiness (humidity), which are major enemies of bedsores.

JP 2017-074333 A WO2011/096114 publication JP 2010-154965 A WO2017/122370 publication

However, even if a cushion member using a three-dimensional filament bond with excellent body pressure dispersion is used, the cushion member has the characteristics of an elastic body in which the repulsive force increases according to the amount of sinking. Therefore, there is an issue that the repulsive force of the mattress is high near bone protrusions (downward convex parts) where the amount of sinking is locally maximum, and blood flow in the capillaries in such areas is obstructed, making bedsores more likely to occur.

In view of the above problems, the present invention aims to provide a cushion member that is less likely to become stuffy, does not require complicated equipment, and can prevent the occurrence of bedsores in specific areas such as bone prominences, as well as a manufacturing method that can easily manufacture such a cushion member.

The manufacturing method according to the present invention is a method for manufacturing a cushion member that supports a user in the thickness direction by using a roughly plate-shaped three-dimensional filament assembly in which multiple filaments made of thermoplastic resin or thermoplastic elastomer are partially fused together, and includes a pressure treatment in which the upper surface of the three-dimensional filament assembly is pressed with a pressure member to cause plastic deformation and provide smooth depressions at positions corresponding to one or more specific parts of the user, and a heat treatment in which the three-dimensional filament assembly is heated so that the plastic deformation is easily generated.

This manufacturing method makes it possible to easily manufacture a cushioning member that is less likely to become stuffy, does not require complicated equipment, and can suppress the occurrence of bedsores in specific areas such as bone prominences. Note that the "smooth depression" in this application refers to a depression whose surface is formed in a roughly curved shape, and which is formed so that there are essentially no sharp edges such as steps.

More specifically, the manufacturing method may be such that the heat treatment is a process of heating the three-dimensional filament bond to a predetermined temperature, and the predetermined temperature is within a range from a temperature 30°C lower than the melting point of the raw material to a temperature 5°C lower than the melting point. More specifically, the manufacturing method may be such that the heat treatment is a process of bringing hot water at the predetermined temperature into contact with the three-dimensional filament bond.

More specifically, the manufacturing method may be such that the heat treatment is a process of immersing a portion of the three-dimensional filament bond from the underside to a predetermined height in the hot water, the predetermined height being 20% to 60% of the thickness of the three-dimensional filament bond. More specifically, the manufacturing method may be such that the heat treatment is a process of applying hot air at the predetermined temperature to the three-dimensional filament bond.

More specifically, the manufacturing method may be such that the heating process is performed in parallel with the pressurizing process, and hot air is applied to the upper surface of the three-dimensional filament bond while cold air is applied to the lower surface of the three-dimensional filament bond. Note that "cold air" in this application refers to air that is at least cooler than hot air, and is preferably air at room temperature (e.g., 25°C) or lower.

More specifically, the above manufacturing method may include a conditioning process carried out after the heating process and the pressurizing process, and the conditioning process may be a process of applying hot air to the lower surface of the three-dimensional filament bond while applying cold air to the upper surface of the three-dimensional filament bond.

The cushion member according to the present invention is a cushion member that supports a user in the thickness direction, and is composed of a roughly plate-shaped three-dimensional filament assembly in which multiple filaments made of thermoplastic resin or thermoplastic elastomer are partially fused together, and has smooth depressions formed on the upper surface at positions corresponding to one or more specific parts of the user.

The cushion member according to the present invention may also be a cushion member having the above-mentioned cushion member and a cushion body arranged to cover the upper side of the cushion member, the cushion member being composed of a substantially plate-shaped three-dimensional filament bond formed by partially fusing a plurality of filaments made of a thermoplastic resin or a thermoplastic elastomer.

The cushion member according to the present invention is less likely to become stuffy, does not require complicated equipment, and can prevent the occurrence of bedsores in specific areas such as bony prominences. Furthermore, the cushion member according to the present invention can be easily manufactured.

FIG. 2 is a plan view of the cushion member 1 according to the embodiment. 2 is a cross-sectional view of the cushion member 1 as viewed from the right side. FIG. 4 is a flowchart of a method for manufacturing the cushion member according to the first embodiment. 6A to 6C are explanatory views relating to a recess forming step in the first embodiment. FIG. 2 is a front view of a first pressure member 11a. 11 is a diagram showing the configuration of a vertical protrusion 15 which is a component of a first pressure member 11a. FIG. 4 is a diagram showing the configuration of a horizontal plate 16 which is one component of the first pressure member 11a. FIG. 1 is a cross-sectional view of a cushion member 1W having a two-layer structure. 1 is a cross-sectional view of a cushion member 1X for a pillow according to the present embodiment. FIG. 2 is a plan view of the cushion member 1X. 1 is a cross-sectional view of a cushion member 1Y for a chair according to the present embodiment. FIG. 2 is a plan view of the cushion member 1Y. 13A to 13C are explanatory views relating to a recess forming step in the second embodiment. 10A to 10C are explanatory diagrams relating to a change in density during the recess forming step. 13A to 13C are explanatory views relating to a recess forming step in the third embodiment. 11 is an explanatory diagram regarding hot air supply in the recess forming step. FIG. FIG. 11 is a front view of a first pressure member 11a according to a third embodiment. FIG. 2 is a perspective view of the pressure member 11a as viewed obliquely from above. FIG. 2 is a perspective view of the pressing member 11a as seen obliquely from below. 13A to 13C are explanatory views relating to a recess forming step in the fourth embodiment. 13 is a flowchart of a method for manufacturing a cushion member according to a fifth embodiment. FIG. 13 is an explanatory diagram relating to a pressure treatment according to a fifth embodiment. FIG. 13 is an explanatory diagram relating to a reversal process according to the fifth embodiment. FIG. 13 is an explanatory diagram relating to a state adjustment process according to the fifth embodiment. 11A to 11C are explanatory diagrams relating to the formation of a low-density region by the condition adjustment process. FIG. 1 is an explanatory diagram showing a state in which a user is sleeping in a supine position. FIG. 1 is an explanatory diagram showing a state in which a user is sitting on a chair. FIG. 1 is an explanatory diagram showing parts of the human body where bedsores are likely to occur.

Each embodiment of the present invention will be described below with reference to the drawings. Note that the up-down, left-right, and front-back directions (directions perpendicular to each other) in the following description are as shown in each drawing. These directions are merely defined for the convenience of the description.

1. First embodiment First, a first embodiment of the present invention will be described. Fig. 1A is a plan view (appearance view as seen from above) of a cushion member 1 according to this embodiment. Fig. 1B is a cross-sectional view of the cushion member 1 as seen from the right (cross-sectional view taken along the plane indicated by the dashed line X in Fig. 1A).

The cushion member 1 can be used as bedding, and it is assumed that a user lies on the upper side of the cushion member 1 as shown by the dashed lines in Figures 1A and 1B. On the upper surface of the cushion member 1, there are formed smooth depressions, namely, scapular depressions 1a at two locations corresponding to the left and right scapular regions of the user, a sacral depression 1b at one location corresponding to the sacrum region of the user, and heel depressions 1c at two locations corresponding to the heels of both feet of the user.

Figure 2 is a flowchart of the manufacturing method for the cushion member 1 (steps S1 to S3). Below, an overview of these steps is explained.

The process of step S1 is a process (preparation process) of preparing a plate-like body 1p to be used in forming the cushion member 1. The plate-like body 1p corresponds to the cushion member 1 before processing. The plate-like body 1p is a plate-like three-dimensional filament bonded body in which multiple filaments made of thermoplastic resin or thermoplastic elastomer are partially fused together.

As the plate-like body 1p, for example, a plate-like three-dimensional filament assembly obtained by partially fusing multiple filaments made of polyethylene resin and having a diameter of 1 mm can be used. A specific example of the plate-like body 1p is a plate-like three-dimensional filament assembly having a porosity of 95%, a length (front-rear dimension) of 2 m, a width (left-right dimension) of 0.6 m or 1 m, and a thickness (up-down dimension) of 5 cm. Note that the shape of the plate-like body 1p in this embodiment is rectangular when viewed from above and formed into a plate of uniform thickness, but various approximately plate-like shapes can be adopted within the scope of the present invention.

The raw material for the plate-like body 1p (filament three-dimensional bond) is not particularly limited, but for example, polyethylene-based elastomers, polypropylene-based elastomers, polyester polyether-based elastomers, or polystyrene-based elastomers can be used. As a method for manufacturing the filament three-dimensional bond (three-dimensional network structure), various known methods can be applied, and for example, the methods disclosed in Patent Document 3 (JP Patent Publication 2010-154965 A) or Patent Document 4 (WO2017/122370 A) can be used.

By manufacturing using the methods disclosed in these publications, a smooth, high-density surface layer is formed on the surface of the obtained plate-like body 1p. However, the surface of the plate-like body 1p only needs to be smooth enough that the protrusions caused by the filaments are not felt (the filaments do not tingle when they touch the body), and the surface layer does not necessarily need to be high density.

Step S2 is a process (depression forming process) for forming the aforementioned depressions 1a to 1c in the plate-like body 1p prepared in step S1. In the depression forming process, a heat treatment S2a and a pressure treatment S2b are performed. In this embodiment, the heat treatment S2a is a process for adjusting the temperature of the plate-like body 1p by supplying hot water (heating means) adjusted to a predetermined temperature to the plate-like body 1p.

On the other hand, the pressure treatment S2b is a process in which pressure is applied to predetermined positions on the upper surface of the plate-like body 1p using protruding pressure members while heating the plate-like body 1p using the above-mentioned warm water. The positions to be pressurized are set to correspond to one or more specific parts of the user (bony protrusions where bedsores are likely to occur). As an example of this in the present embodiment, the positions are set to the positions of a total of five depressions (1a to 1c) shown in Figure 1A.

By applying pressure to the plate-like body 1p with a pressure member while maintaining the plate-like body 1p at a predetermined temperature below the melting point of its raw material (thermoplastic resin or thermoplastic elastomer), the pressurized portion of the plate-like body 1p undergoes plastic deformation and forms a depression. As a method of applying pressure, for example, a method of applying pressure continuously for a predetermined time, or a method of applying pressure intermittently while measuring the depth of the depression formed by plastic deformation may be used, but other methods may also be used.

Step S3 is a step (cooling step) of cooling the plate-like body 1p that was heated in the depression forming step (step S2). In this cooling step, the supply of hot water to the plate-like body 1p is stopped and the hot water is removed, and then an air blower (not shown) is used to blow air toward the plate-like body 1p, thereby cooling the plate-like body 1p to a temperature at which plastic deformation does not occur (e.g., 25°C). Through the above steps, a cushion member 1 is formed with smooth depressions 1a-1c on its upper surface.

Figure 3A shows the state of the recess formation process (step S2) for the plate-like body 1p housed in the water tank 10. Note that Figure 3A (as well as Figures 6, 9, 10 to 12, 16, and 18A to 18D described below) is shown as a cross-sectional view from the same perspective as Figure 1B. Also, Figure 3B is a front view of the first pressure member 11a (a schematic diagram from the right perspective).

As shown in FIG. 3A, the plate-shaped body 1p is pressurized by the pressurizing members 11a to 11c while being heated in the hot water HW stored in the water tank 10. Note that in this embodiment, the water level of the hot water HW is set high enough so that the entire plate-shaped body 1p is immersed in the hot water HW, and the entire plate-shaped body 1p is heated.

Two first pressure members 11a are provided to correspond to the two scapular recesses 1a, one second pressure member 11b is provided to correspond to the sacral recess 1b, and two third pressure members 11c are provided to correspond to the two heel recesses 1c. By applying pressure using these pressure members 11a-11c, it is possible to form the cushion member 1 having the recesses 1a-1c described above. Furthermore, as in this embodiment, a method is adopted in which the plate-shaped body 1p is plastically deformed by applying pressure using pressure members to form the recesses 1a-1c, rather than by cutting or the like, so that it is easy to make these recesses smooth.

In this embodiment, the specific areas where bedsores are to be prevented are the scapula, sacrum, and heels, and the cushion member 1 for the mattress has smooth depressions at positions corresponding to each of these areas. However, the cushion member according to the present invention is not limited to this example, and it is possible to designate only some of the scapula, sacrum, and heels as specific areas, or to add other areas as specific areas.

Next, the configuration of the first pressure member 11a will be described in more detail. The configurations of the second pressure member 11b and the third pressure member 11c are basically the same as that of the first pressure member 11a, so detailed description will be omitted here. Figure 4 is a diagram of the vertical protrusion 15, which is one component of the first pressure member 11a, and Figure 5 is a diagram of the horizontal plate 16, which is one component of the first pressure member 11a. In Figures 4 and 5, the upper part shows a diagram of the configuration from an upward perspective, and the lower part shows a diagram of the configuration from a side perspective.

The first pressure member 11a is composed of a vertical protrusion 15 and a horizontal plate 16. The vertical protrusion 15 is a metal member (e.g., a stainless steel member) having a hemispherical tip 15a and a cylindrical body 15b. The horizontal plate 16 is a square plate-shaped metal member (e.g., a stainless steel member) having a circular through hole 16a in the center. By inserting the vertical protrusion 15 into the through hole 16a and fixing it to the horizontal plate 16, it is possible to obtain the first pressure member 11a in which the hemispherical tip 15a protrudes a predetermined amount from the underside of the horizontal plate 16.

Means for fixing the vertical protrusion 15 to the horizontal plate 16 include, for example, welding or bonding with an adhesive. In addition, other means may be used, such as a screw-type fixing means by providing a spiral groove in each of the cylindrical body 15b and the through hole 16a (means in which the vertical protrusion 15 is a male thread and the horizontal plate 16 is a female thread, and these are screwed together to fix them), etc.

The amount of protrusion of the hemispherical tip 15a from the horizontal plate 16, as well as the size and curvature of the curved surface of the hemispherical tip 15a, can be set according to the shape of the specific part of the user where bedsores are to be prevented (the bony protrusion where bedsores are to be prevented), and may be set differently for all or part of each of the pressure members 11a-11c. Additionally, the vertical protrusion 15 may be shaped to effectively prevent bedsores based on the shape of the user's bones, etc.

The top of the vertical protrusion 15 of the first pressure member 11a is connected to a drive device (not shown) and is moved vertically to appropriately pressurize the plate-like body 1p. When the horizontal plate 16 is moved until the bottom surface of the horizontal plate 16 approaches or contacts the top surface of the plate-like body 1p, the plate-like body 1p is pressurized by the amount of the hemispherical tip 15a protruding from the horizontal plate 16. Furthermore, the smoothly curved hemispherical tip 15a presses against the plate-like body 1p, easily forming a smooth depression.

The temperature of the hot water HW stored in the water tank 10 is adjusted to a predetermined temperature using, for example, a heating device, a circulation device, and a temperature sensor (not shown). If the temperature of the hot water HW is too low, plastic deformation is unlikely to occur and depressions are not properly formed. Conversely, if the temperature of the hot water HW is too high, unwanted plastic deformation is likely to occur in unpressurized areas.

Therefore, it is preferable that the temperature of the hot water HW is adjusted to a predetermined temperature within the range from 30°C lower than the melting point of the raw material (thermoplastic resin or thermoplastic elastomer) of the plate-like body 1p to 5°C lower than the melting point (hereinafter, for convenience, may be referred to as the "appropriate temperature range"). This makes it possible to heat the plate-like body 1p (filament three-dimensional bond) so that it approaches the predetermined temperature within the appropriate temperature range.

The cushion member 1 manufactured by the above-mentioned manufacturing method is formed of a filament three-dimensional bond that can reduce pressure and stuffiness, and has smooth depressions 1a to 1c formed on the upper surface at positions corresponding to bone prominences such as the scapula, sacrum, and heel. This makes it possible to locally reduce the repulsive force from the cushion member 1 that the user's bone prominences receive. Therefore, the cushion member 1 has a simple structure, but can suppress excessive pressure on the skin near the bone prominences and prevent bedsores. Since the depressions 1a to 1c are smooth, the skin near the bone prominences is prevented from hitting the angular parts inside the depressions, and the user can obtain a smooth fit without feeling any unevenness. The cushion member 1 can be used as a mattress as it is, but it may also be used covered with a separately prepared mattress cover.

The cushion member 1 can also be used in combination with another cushion body. Figure 6 is a cross-sectional view of a two-layer cushion member 1W obtained by laminating a cushion body CS on top of the cushion member 1. The cushion body CS is a roughly plate-shaped three-dimensional filament bond in which multiple filaments made of thermoplastic resin or thermoplastic elastomer are partially fused together. The cushion body CS may be the same as the plate-shaped body 1p, but made even thinner.

As shown in FIG. 6, the cushion member 1W has a cushion body CS arranged to cover the upper surface of the cushion member 1 in which the depressions 1a-1c are formed, and the user lies on the cushion body CS. This allows the cushion body CS to be interposed between the area (specific area) where the user wishes to prevent bedsores and each of the depressions 1a-1c, making it possible to further increase the dispersion of pressure (pressure received from the cushion member 1W) that is locally maximized at the bony prominence of the specific area. The thickness of the cushion body CS can be adjusted as appropriate according to the user's body type, etc. Furthermore, with the cushion member 1W, even if the difference between the shape of the specific area of the user and the shape of the depressions is relatively large, the cushion body CS can be deformed to reduce the difference in pressure applied near the specific area of the user.

The above describes the cushion member according to this embodiment as being for a mattress, but the cushion member and the manufacturing method thereof are not limited to this and can be applied to cushion members and their manufacturing methods for various uses, such as cushion members for pillows and cushion members for chairs.

Figure 7A is a cross-sectional view of a cushion member 1X for a pillow according to this embodiment (cross-sectional view when the cushion member 1X is cut in a plane that divides the cushion member 1X into two equal halves, left and right). Also, Figure 7B is a plan view of the cushion member 1X (exterior view seen from above). A smooth occipital depression 1Xa is formed on the top surface of the cushion member 1X at a position that comes into contact with the occipital region of the user's head. This makes it possible to prevent bedsores at the bony prominences of the occipital region as much as possible. In this embodiment, the occipital region corresponds to the area (specific area) of the user where bedsores should be prevented.

Figure 8A is a cross-sectional view of cushion member 1Y for a chair according to this embodiment (cross-sectional view when cutting cushion member 1Y at a plane that divides it into left and right halves). Also, Figure 8B is a plan view of cushion member 1Y (exterior view from above). A smooth coccyx depression 1Ya is formed on the top surface of cushion member 1Y at the position where it comes into contact with the coccyx of the user. This makes it possible to prevent bedsores at the bony prominence of the coccyx as much as possible. Note that in this embodiment, the coccyx corresponds to the part of the user's body where it is desired to prevent bedsores (specific part).

2. Second embodiment Next, a second embodiment of the present invention will be described. The second embodiment is basically the same as the first embodiment, except that the water level of the hot water HW is lowered in the manufacturing method of the cushion member 1. In the following description, the emphasis will be placed on the matters that are different from the first embodiment, and the description of the matters that are common to the first embodiment may be omitted.

Figure 9 shows the state of the recess formation process (step S2) in the manufacturing method of the cushion member according to the second embodiment. Also, Figure 10 shows the state of density change (plastic deformation) that occurs in the plate-like body 1p near the first pressure member 11a in the recess formation process. Note that the state near the other pressure members 11b and 11c is basically the same as in the case of the first pressure member 11a.

In this embodiment, as shown in FIG. 10, the water level of the hot water HW is set to about half the thickness of the plate-like body 1p, and only the lower half of the plate-like body 1p is directly heated. This allows plastic deformation of the plate-like body 1p due to stress caused by pressure applied by the first pressure member 11a to occur preferentially in the lower half of the plate-like body 1p, forming a high-density region HD in the lower half of the plate-like body 1p and preventing the density of the plate-like body 1p near the upper surface from increasing (i.e., becoming hard).

As a result, the repulsive force of the upper surface of the cushion member 1 that comes into contact with the area of the user where bedsores need to be prevented can be prevented from increasing excessively. In order to fully obtain this effect, it is preferable to set the water level of the hot water HW to 20% or more and 60% or less of the thickness of the plate-shaped body 1p.

3. Third embodiment Next, a third embodiment of the present invention will be described. The third embodiment is basically the same as the first embodiment, except for the form of the heating means and the pressure member for the plate-like body 1p and points related thereto. In the following description, the emphasis will be placed on the matters different from the first embodiment, and the description of the matters common to the first embodiment may be omitted.

Figure 11 shows the state of the recess formation process (step S2) in the manufacturing method of the cushion member according to the third embodiment. Also, Figure 12 shows the state of hot air HA being supplied to the plate-like body 1p near the first pressure member 22a in the recess formation process according to this embodiment. Note that the state near the other pressure members 11b and 11c, and the configuration of the other pressure members 11b and 11c, are basically the same as in the case of the first pressure member 11a.

The manufacturing method of the cushion member according to the third embodiment is generally similar to that of the first embodiment in terms of the overall flow, but differs from that of the first embodiment in that hot air HA is used as a heating means (a means for performing a heat treatment) for the plate-like body 1p. In the recess forming process according to the third embodiment, the plate-like body 1p is placed on a ventilated support base 20, and then heated by hot air HA supplied from hot air supply members 21a to 21c arranged on the lower side of the ventilated support base 20. The ventilated support base 20 is provided with a number of ventilation holes 20a (holes that penetrate vertically) to allow the hot air HA discharged from the hot air supply members 21a to 21c to pass upward.

The first hot air supply member 21a is disposed at a position facing the first pressure member 12a vertically (two positions corresponding to the left and right shoulder blades of the user), and supplies hot air HA upward to heat the portion of the plate-like body 1p located almost directly above the first hot air supply member 21a. The second hot air supply member 21b is disposed at a position facing the second pressure member 12b vertically (one position corresponding to the sacrum of the user), and supplies hot air HA upward to heat the portion of the plate-like body 1p located almost directly above the second hot air supply member 21b. The third hot air supply member 21c is disposed at a position facing the third pressure member 12c vertically (two positions corresponding to the heels of both feet of the user), and supplies hot air HA upward to heat the portion of the plate-like body 1p located almost directly above the third hot air supply member 21c.

In the depression forming process, the plate-like body 1p is heated with hot air HA as described above, while the upper surface of the plate-like body 1p is pressurized using the pressure members 11a to 11c. This causes the plate-like body 1p to plastically deform at that position, forming a depression. As described above, the heating process S2a in this embodiment is a process of adjusting the temperature of the plate-like body 1p by supplying hot air HA to the plate-like body 1p. On the other hand, the pressure process S2b is a process of pressurizing a predetermined position on the upper surface of the plate-like body 1p using a protruding pressure member while heating it with the hot air HA. The heating process S2a may be performed not only in parallel with the pressure process S2b, but also before the pressure process S2b is started, so that the temperature of the plate-like body 1p can be adjusted in advance.

Figure 13 is a front view of the first pressure member 11a according to this embodiment. Also, Figure 14 is a perspective view of the pressure member 11a from an obliquely upward perspective, and Figure 15 is a perspective view of the pressure member 11a from an obliquely downward perspective. As shown in these figures, the first pressure member 11a is configured using a vertical protrusion 25 and a horizontal plate 26.

The vertical protrusion 25 is a metal member (e.g., a stainless steel member) having a hemispherical tip 25a and a cylindrical body 25b, and multiple ventilation holes 25h are formed in the hemispherical tip 25a. Each ventilation hole 25h is connected to the internal space 25c of the cylindrical body 25b, and the upper side of the internal space 25c is open. As a result, the hot air HA supplied from the hot air supply members 21a to 21c passes through the plate body 1p, and is then discharged above the cylindrical body 25b through each ventilation hole 25h and the internal space 25c.

The horizontal plate 26 is a square plate-shaped metal member (stainless steel) with a circular through hole 26a in the center, and by inserting the vertical protrusion 25 into the through hole 26a and fixing it to the horizontal plate 26, a first pressure member 11a can be obtained in which the hemispherical tip 25a protrudes a predetermined amount from the underside of the horizontal plate 26.

Means for fixing the vertical protrusion 25 to the horizontal plate 26 include, for example, welding or bonding with an adhesive. In addition, other means may be used, such as a screw-type fixing means by providing a spiral groove in each of the cylindrical body 25b and the through hole 26a (means for fixing by screwing the vertical protrusion 25 as a male thread and the horizontal plate 26 as a female thread)

The amount of protrusion of the hemispherical tip 25a from the horizontal plate 26, as well as the size and curvature of the curved surface of the hemispherical tip 25a, can be set according to the shape of the specific part of the user where bedsores are to be prevented (the bony protrusion where bedsores are to be prevented), and may be set differently for all or part of each of the pressure members 11a to 11c. Additionally, the vertical protrusion 25 may be shaped to effectively prevent bedsores based on the shape of the user's bones, etc.

The temperature of the hot air HA is adjusted to a predetermined temperature using, for example, a heating device, a circulation device, and a temperature sensor (not shown). If the temperature of the hot air HA is too low, plastic deformation is difficult to occur and the depressions are not properly formed. Conversely, if the temperature of the hot air HA is too high, deformation due to plastic deformation is likely to occur.

Therefore, it is preferable that the temperature of the hot air HA is adjusted to a predetermined temperature within the range (appropriate temperature range) from 30°C lower than the melting point of the raw material (thermoplastic resin or thermoplastic elastomer) of the plate-shaped body 1p to 5°C lower than the melting point. This makes it possible to heat the plate-shaped body 1p (filament three-dimensional bond) so that it approaches the predetermined temperature within the appropriate temperature range.

In this embodiment, since hot water is not used as a heating means, after the recess formation process (step S2) is completed and the supply of hot air HA is stopped, it is possible to proceed to the cooling process (step S3) without removing the hot water. In the cooling process of this embodiment, cold air may be supplied from both or one of the pressure members 11a-11c and the hot air supply members 21a-21c toward the plate-like body 1p, and the plate-like body 1p may be cooled by the cold air. The cooling process cools the plate-like body 1p to a temperature at which plastic deformation does not occur (e.g., 25°C), and the cushion member 1 can be obtained.

4. Fourth embodiment Next, a fourth embodiment of the present invention will be described. The fourth embodiment is basically the same as the third embodiment, except that cold air is supplied from the pressure member to the plate-like body 1p. In the following description, the emphasis will be placed on the differences from the third embodiment, and the description of the commonalities with the third embodiment may be omitted.

Figure 16 shows how hot air HA and cold air CA are supplied to the plate-like body 1p near the first pressure member 11a in the recess formation process (step S2) according to this embodiment. Note that the state near the other pressure members 11b and 11c is basically the same as in the case of the first pressure member 11a.

In this embodiment, as shown in FIG. 16, cold air CA is sent from the outside into the first pressure member 11a in parallel with the supply of hot air HA to the plate-like body 1p, and this cold air CA is discharged downward through each ventilation hole 25h. This makes it possible to heat the lower half of the plate-like body 1p in a focused manner. That is, in the vicinity of the first pressure member 22a, the lower portion of the plate-like body 1p is strongly influenced by the hot air HA supplied from the first hot air supply member 21a and is heated moderately, while the upper portion of the plate-like body 1p is less heated by the supply of cold air CA from the first pressure member 22a.

This allows the plastic deformation of the plate-like body 1p due to the stress generated by the pressure applied by the first pressure member 11a to occur preferentially in the lower half of the plate-like body 1p, forming a high-density region HD in the lower half of the plate-like body 1p and preventing the density of the plate-like body 1p near the upper surface from increasing (i.e., becoming hard). As a result, it is possible to prevent the repulsive force of the upper surface of the cushion member 1 that comes into contact with the area of the user where it is desired to prevent bedsores from increasing excessively.

5. Fifth embodiment Next, a fifth embodiment of the present invention will be described. The fifth embodiment is basically the same as the fourth embodiment except for the recess forming step. In the following description, the emphasis will be placed on the differences from the fourth embodiment, and the description of the commonalities with the fourth embodiment may be omitted.

Figure 17 is a flowchart of the manufacturing method of the cushion member according to the fifth embodiment (steps S1 to S3). Step S1 is a step (preparation step) of preparing a plate-like body 1p to be used in forming the cushion member 1. This preparation step is similar to the preparation steps in the other embodiments, so a detailed description of it will be omitted here.

The process of step S2 is a process (depression forming process) of forming depressions 1a to 1c in the plate-like body 1p prepared in the process of step S1. In the depression forming process (step S2) in this embodiment, a temperature adjustment process S2c, a pressure process S2d, an inversion process S2e, and a condition adjustment process S2f are performed.

The temperature adjustment process S2c is a process in which hot air HA is supplied from each hot air supply member 21a-21c toward the plate-like body 1p at positions corresponding to each pressure member 11a-11c, and cold air CA is supplied from each pressure member 11a-11c toward the plate-like body 1p. With this temperature adjustment process, the temperature of the lower portion of the plate-like body 1p is adjusted by the hot air HA, and the temperature of the upper portion of the plate-like body 1p is adjusted by the cold air CA, at positions corresponding to each pressure member 11a-11c.

As shown in FIG. 18A, the pressure treatment S2d is a process in which pressure is applied to a predetermined position on the upper surface of the plate-like body 1p using the pressure members 11a to 11c while continuing to adjust the temperature of the plate-like body 1p using hot air HA and cold air CA. This pressure treatment process plastically deforms the plate-like body 1p to form a depression. Note that the pressure application position and pressure application method are similar to those in the pressure treatment S2b of the fourth embodiment, and therefore will not be described here. The process of applying (supplying) hot air HA to the plate-like body 1p in the temperature adjustment process S2c and pressure treatment S2d corresponds to the heating process according to the present invention.

The inversion process S2e is a process for inverting the plate-like body 1p upside down on the ventilated support base 20. Figure 18B shows the state in which the plate-like body 1p is inverted upside down on the ventilated support base 20 as a result of this inversion process.

The condition adjustment process S2f is a process in which hot air HA supplied from hot air supply members 21a-21c is applied to the area (upper surface of plate 1p) where a depression has occurred due to plastic deformation in upside-down plate 1p, and in parallel with this, cold air CA supplied from each pressure member 11a-11c is applied to the lower surface of plate 1p. Figure 18C shows the state in which condition adjustment process S2f is being performed. By performing condition adjustment process S2f, only the vicinity of the depression is plastically deformed, and a low-density region LD (soft layer) can be formed as shown in Figure 18D, making it possible to obtain a cushion member 1 with reduced repulsive force on the upper surface that comes into contact with specific parts of the user.

In other words, just before the condition adjustment process S2f is performed, it is highly likely that the area near the depression in the plate-like body 1p has a relatively high density due to the pressure treatment S2d, and residual stress may have been generated. Therefore, by performing the condition adjustment process S2f, it is possible to plastically deform the area near the depression on the upper surface of the plate-like body 1p to reduce its density and release the residual stress, while minimizing deformation of the lower surface side of the plate-like body 1p. In this way, the condition of the plate-like body 1p is adjusted, and a cushion member 1 can be obtained in which the repulsive force near the depression on the upper surface is further reduced.

In this embodiment, the position on the plate-shaped body 1p that is hit by the hot air and the cold air are reversed by performing the inversion process S2e to change the orientation of the plate-shaped body 1p. However, instead of doing this, when performing the condition adjustment process S2f, cold air may be supplied from the hot air supply members 21a to 21c, and hot air may be supplied from each of the pressure members 11a to 11c. In addition, the temperature of the above-mentioned hot air HA is preferably within a range from the melting point of the raw material of the plate-shaped body 1p to a temperature 20°C higher than the melting point, and hot air may be supplied intermittently to prevent heat from building up.

The process of step S3 is a process (cooling process) for cooling the plate-shaped body 1p that was heated in the recess formation process (step S2). This cooling process is similar to the cooling process of the fourth embodiment, so a detailed description thereof will be omitted here.

6. Others As described above, the manufacturing method of the cushion member according to each embodiment includes a pressure treatment in which the upper surface of the plate-like body 1p (filament three-dimensional combined body) is pressed with a pressure member to plastically deform the plate-like body 1p and provide smooth depressions at positions corresponding to one or more specific parts of the user, and a heat treatment in which the plate-like body 1p is heated so as to facilitate the plastic deformation.

As a result, the surface of the plate-like body 1p can be plastically deformed by the pressure member while being heated, and smooth depressions can be formed at positions corresponding to specific areas such as bone protrusions without the need to use complex dies, etc. As a result, it is possible to easily manufacture a cushioning member that is less likely to become stuffy and can reduce large localized pressure in bone protrusions, etc.

The above-mentioned heat treatment is a process for heating the plate-like body 1p to a predetermined temperature, and the predetermined temperature is within a range from a temperature 30°C lower than the melting point of the raw material of the plate-like body 1p to a temperature 5°C lower than the melting point. This makes it possible to control the temperature of the plate-like body 1p to a temperature at which efficient plastic deformation can be achieved, and to efficiently form smooth depressions.

In the first and second embodiments, the heat treatment is a process in which hot water HW at the predetermined temperature is brought into contact with the plate-like body 1p. This makes it possible to appropriately control the temperature of the plate-like body 1p while minimizing deformation. In particular, the heat treatment in the second embodiment is a process in which the portion of the plate-like body 1p from its underside to a predetermined height is immersed in hot water HW, and the predetermined height is set to 20% to 60% of the thickness of the plate-like body 1p.

As a result, plastic deformation of the plate-like body 1p caused by compression with the pressure member is less likely to occur near the top surface where the filaments do not come into contact with the hot water HW, and is more likely to occur near the bottom where the filaments come into contact with the hot water HW. This makes it possible to prevent the filament density on the top surface of the cushion member from increasing, and to prevent as much as possible the top surface of the cushion member that comes into contact with bone protrusions, etc. from becoming hard (increasing the repulsive force).

On the other hand, in the third to fifth embodiments, the heating process is a process in which hot air HA at the specified temperature is applied to the plate-like body 1p. This allows the surface of the plate-like body 1p to be heated and plastically deformed simply by using a hot air supply device and a pressure member, making it possible to form smooth depressions without using large equipment such as a water tank.

In particular, the heating process in the fourth embodiment is a process carried out in parallel with the pressure process, in which hot air HA is applied to the upper surface of the plate-like body 1p while cold air CA is applied to the lower surface of the plate-like body 1p. This makes it difficult for plastic deformation of the plate-like body 1p caused by compression with the pressure member to occur near the upper surface where the filaments are easily affected by the cold air CA, and more likely to occur near the bottom where the filaments are easily affected by the hot air HA. This makes it possible to suppress an increase in the filament density on the upper surface of the cushion member, and to prevent as much as possible the upper surface of the cushion member that comes into contact with bone protrusions, etc. from becoming hard (increasing the repulsive force).

The manufacturing method of the cushion member in the fifth embodiment includes a condition adjustment process that is carried out after the heating and pressurizing processes are performed. This condition adjustment process involves applying cold air to the upper surface of the plate-like body 1p while applying hot air to the lower surface of the plate-like body 1p. This adjusts the condition of the plate-like body 1p, and makes it possible to obtain a cushion member with reduced repulsive force near the depression on the upper surface.

Although the embodiment of the present invention has been described above, the configuration of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. In other words, the above embodiment should be considered to be illustrative in all respects and not restrictive. The technical scope of the present invention is indicated by the claims, not the description of the above embodiment, and should be understood to include all modifications that are equivalent in meaning and scope to the claims.

The present invention can be used for cushion members and their manufacturing methods.

1, 1W, 1X, 1Y Cushion member 1a Scapular recess 1b Sacrum recess 1c Heel recess 1Xa Occipital recess 1Ya Coccyx recess 1p Plate-like body 10 Water tub 11a First pressure member 11b Second pressure member 11c Third pressure member 15 Vertical protrusion 15a Hemispherical tip 15b Cylindrical body 16 Horizontal plate 16a Through hole 20 Ventilated support base 20a Air vent 21a First hot air supply member 21b Second hot air supply member 21c Third hot air supply member 25 Vertical protrusion 25a Hemispherical tip 25b Cylindrical body 25c Internal space 25h Air vent 26 Horizontal plate 26a Through hole

Claims (3)

A method for manufacturing a cushion member that supports a user on an upper surface in a thickness direction by using a substantially plate-like three-dimensional filament assembly in which a plurality of filaments made of a thermoplastic resin or a thermoplastic elastomer are partially fused, the method comprising the steps of:
a pressure treatment for pressing the upper surface of the filament three-dimensional assembly with a molding pressure member to plastically deform the upper surface, and providing smooth bone protrusion depressions corresponding to the shape of one or more bone protrusions of the user at positions corresponding to the bone protrusions;
A manufacturing method characterized by including a heat treatment in which the lower surface side of the portion of the approximately plate-shaped filament three-dimensional bonded body where the bone protrusion depression is to be provided is heated to a higher temperature than the upper surface side so as to make the plastic deformation more likely to occur. The manufacturing method according to claim 1, characterized in that after the heat treatment and the pressure treatment, a conditioning process is performed to reduce the density of the vicinity of the bone protrusion depression on the upper surface side of the approximately plate-shaped filament three-dimensional combination body. The manufacturing method according to claim 2, characterized in that the conditioning treatment is a treatment in which only the vicinity of the bone protrusion depression on the upper surface side of the approximately plate-shaped filament three-dimensional combination body is heated to reduce the density of only that vicinity.