JP2002191477A - Mattress - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mattress which does not buckle and has durability after it is used for a long time and has comfortable feeling to sleep and good folding properties and storing properties. SOLUTION: This mattress 30 is a thick and plane-shaped mattress, freely foldable, and is provided with an inner bag body 42 having a plurality of mutually independently storing bags 40 extending long along the width direction of the mattress so as to be adjacent to each other in parallel in the longitudinal direction, a bedding side fabric 44 storing the inner bag body, an inner core material 36, and a fiber layer 38 surrounding the outer periphery of the inner core material. The inner core material has a pipe 32 made of a synthetic resin foam and a corrugated pipe 34 consisting of a synthetic resin foam consisting of a material with a higher hardness than that of the synthetic resin foam forming the pipe and a lower hardness than that of wood as a filler for filling at least a part of the hollow part of the pipe in the longitudinal direction of the pipe and they are inserted one by one in each storing bag of the inner bag body, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bedding to be laid under a mattress or a bedding to be used as a bed material of a bed. The present invention relates to a bedding having a comfortable sleeping comfort, and good folding and storing properties.

[0002]

2. Description of the Related Art With the spread of Western-style bedding, the style of Japanese-style bedding has changed, and more and more people have laid a bedding such as a so-called mattress on a tatami or floor and laid a conventional mattress on it. In addition, many people go to bed with the bedding instead of the mattress and directly lay the mattress on the bedding. Furthermore, the bedclothes can be used as a bed material of a bed which is a Western-style bedding. The bedclothes are required not to give a person lying on the floor a feeling of bottoming, to have appropriate air permeability, and to provide comfortable sleeping comfort. In addition, it is required that it be easy to fold and have good storage properties in a storage place such as push-in.

Here, the structure of the conventional bedding will be described with reference to FIGS. FIG. 4 is a cross-sectional view of the first example of the conventional bedding, FIG. 5 is a cross-sectional view of the second example of the conventional bedding,
6 is a cross-sectional view of a modification of the second example of the conventional bedding. As shown in FIG. 4, the bedding 10 of the first example of the related art has a quilt 14 wound around a core 12 made of a fiber such as solid cotton, and the quilt 14 is further wound. The core material 12 is inserted into a cloth bag, that is, an inner bag 16, and the inner bag 16 is wrapped with a bag-like futon-side cloth 18 made of outer cloth.

Further, as shown in FIG. 5, the bedding 20 of the second example is formed by stacking different types of plastic foam sheets 22A to 22C so as to withstand compression and to have elasticity. It is a bedding having a structure of a core material 24. Second
As a modified example of the bedding of the example, a bedding using a laminated body of a plastic foam layer in which irregularities are appropriately formed on the uppermost surface as a core material has also been proposed. Furthermore, as the bedding of the third example, although not shown, a plastic foam is processed into a pipe shape or a rod shape, and a material arranged in parallel in the width direction is used as a core material,
A bedding having a configuration in which a core material is surrounded by futon cotton has also been proposed.

[0005]

However, the conventional bedding has various problems as described below. First, in the bedclothes of the first example of the related art, although there is little problem with respect to air permeability, as the user uses, the solid cotton constituting the core 12 is compressed by the weight of the user and becomes thinner. The elasticity is reduced, that is, the core 12 is severed and the sleeping comfort is poor. Further, although the bedclothes of the first example can be stored in a roll shape, if stored in that state for a long time, there is also a problem that the core material is a fire. Also, when folded and stored, the core material was broken at the fold. That is, it is difficult to restore the bedclothes to the original form in the case of storing for a long time by roll-shaped winding or folding. In other words, there is a problem that the durability is poor and the storability is poor. Conversely, bed bedding made of compressed futon cotton and made of a plate-shaped core material is difficult to set, but has poor foldability, and has a problem that it is difficult to store because it is difficult to fold.

In the bedclothes of the second example and its modified example, the plastic core sheet 24 composed of closed cells is superposed to form the core material 24, so that it is hard to set and the elasticity and durability are compared. Although it is easy to secure the target, there is a problem that air permeability is poor. In addition, although it differs depending on the material of the foam sheet, in general, the foldability is not good,
In addition, there is a problem that the both end portions (both end portions in the width direction) after the folding are hard to bend, so that the storage property is poor.

In view of this, as shown in FIG. 6, there is a type in which a ventilation hole, for example, an elliptical hole 26 for ventilation is penetrated in the thickness direction of the core material 25 to ensure air permeability. As shown in FIG. 7, a measure is taken to improve the foldability by forming a long hole 28 extending in the width direction of the core material 27 so as to penetrate the core material 27 and folding the long hole 28 as a starting point. There are also things. However, even if these measures are taken, the notch 28
It is inconvenient to store because it is difficult to fold the fold, for example, to fold other than the three folds, that is, it is difficult to fold many or roll.

In the bedclothes of the third example using a pipe-shaped core material as the core material, the pipe of the core material is flattened while being folded and stored, and the entire hollow portion is in close contact with the permanent bend. Becomes It has been difficult to correct the permanent deformation of the core material once generated and to restore the thickness of the bedding to the original thickness. In the case of the bedclothes of the third example using the rod-shaped core material as the core material, the body load acts on the rod-shaped core material of the bedclothes during use, in addition to the storage, and the rod-shaped core material is used. Is crushed and becomes permanent distortion. Fixing the permanent distortion of the core material and restoring the thickness of the bedding,
It was difficult. For this reason, the bedclothes of the third example have a problem that durability and storage properties are inferior.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bedding which is durable, durable, comfortable to sleep, and has good folding and storing properties even when used for a long time. .

[0010]

In order to improve the air permeability of the bedclothes, the inventor of the present invention has arranged pipes formed of a synthetic resin foam as a core material in parallel, and has set the pipes so as to be hard to set. It was conceived that a filler made of a synthetic resin corrugated pipe or the like was inserted into the hollow part of the above, and that the load acting on the pipe and the deformation of the pipe were received by the filler existing in the hollow part of the pipe. Then, the experiment was repeated to arrive at the present invention.

[0011] In order to achieve the above object, a bedclothe according to the present invention is a flat, foldable bedclothe having a thickness, and is a bag-shaped mutual bedding extending long in one direction of the bedclothe. An inner bag body having a plurality of independent storage bags adjacent to each other in a direction orthogonal to one direction and in parallel, a futon-side cloth for housing the inner bag body, a synthetic resin foam pipe, and a pipe. A core made of a material having a hardness higher than that of the synthetic resin foam to be formed and having a hardness lower than that of a metal piece, and having at least a part of a hollow portion of the pipe filled in a longitudinal direction of the pipe; And a fiber layer surrounding the outer periphery of the inner bag body, wherein the core material is inserted one by one into each storage bag of the inner bag body.

In the present invention, since the filler fills at least a part of the hollow portion of the pipe in the longitudinal direction of the pipe constituting the core material, the load due to the weight of the user during use or the load during storage is reduced. Even if the load due to the deformation of the pipe acts on the pipe, the filler receives the load or a part of the load, so that the pipe does not collapse and permanent deformation does not occur.

Further, since the pipes are placed in a storage bag and arranged in parallel, a slight gap is formed between the pipes, so that the pipes are rolled along a line perpendicular to the pipes or viewed from the side. S-shaped winding or "" around a line parallel to the pipe
It is easy to wind it into a U-shaped winding or the like. In addition, the folded or wound form can be stably maintained, so that it is suitable for storage. When the pipes are accommodated, the dimensions are set so that there is a gap in consideration of the foldability described above between adjacent pipes.

According to the present invention, since the pipes are arranged in parallel with a gap, air permeability is good. Furthermore, since the pipe made of synthetic resin foam is used, it is lightweight and easy to handle, and the sleeping comfort is good due to the cushioning property of the foam and the acupressure effect due to the unevenness of the pipe row.

In the bedding of the present invention, the pipe of the core material is
It may be extended in a direction along the body of the sleeping person or in a direction perpendicular to the body. That is,
If the shape of the bedding is rectangular, when a person lays down in the longitudinal direction of the bedding, the pipes may be arranged in parallel along the longitudinal direction of the bedding, and may be orthogonal to the longitudinal direction of the bedding. May be arranged in parallel in the direction in which the bedding is placed, that is, in the width direction of the bedding.

In a preferred embodiment of the present invention, the filling is a corrugated synthetic resin tube. Thereby, it is possible to maintain a cushioning property between the pipe and the filling body, and to prevent settling. The material of the pipe is not limited as long as it is a synthetic resin foam pipe, but a cross-linked polyethylene foam, a non-cross-linked polyethylene foam, a cross-linked polypropylene foam, a non-cross-linked polypropylene foam, a cross-linked vinyl acetate foam , A non-crosslinked vinyl acetate foam, a urethane foam, or a composite structure thereof can be preferably used. These materials are also suitable for the packing.

In a preferred embodiment of the present invention, based on experimental results, the pipe constituting the core material has an outer diameter of 20 mm.
Not less than 100 mm, thickness is not less than 4 mm and not more than 25 mm,
It is formed of a synthetic resin foam having an inner diameter of 12 mm or more and 62 mm or less and an expansion ratio of 5 times or more and 55 times or less. In the present invention, the expansion ratio of the foam is set to 5 times or more and 55 times or less because a foam having an expansion ratio of less than 5 times is harder in foam itself, deteriorates sleeping comfort and deteriorates pipe moldability, Conversely, a foam having a foaming ratio of more than 55 times is too soft to be comfortable on the contrary, and permanent deformation remains due to the settling, resulting in poor durability, and a feeling of bottoming out of the filler is generated on the foam. This is because the sleeping comfort is deteriorated.
A more preferable expansion ratio is 20 times or more and 40 times or less.

[0018]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment Example This embodiment example is an example of an embodiment of the bedding according to the present invention. FIG. 1 is a perspective view showing an example of the bedding of this embodiment, and FIG. 3 is a cross-sectional view showing a part of the cross section of the bedding at X, and FIG. 3 is a cross-sectional view showing a part of the cross section of the bedding at line YY in FIG. Bedding 30 of the present embodiment example
Is a flat bedding having a thickness T, a width W, and a length L, as shown in FIG. 1, which is foldable along a line XX and wound in a roll shape. It is free and a person is usually able to lie down in a direction parallel to the line XX.

As shown in FIGS. 2 and 3, the bedding 30 includes a plurality of independent pipes 32 each having a length W or slightly shorter than W, and a hollow portion 32 extending in the longitudinal direction of each pipe 32.
a core material 36 composed of a filling body 34 filled in at least a portion of a, a fiber layer 38 surrounding the outer periphery of the core material 36, and a bedding with the core material 36 surrounded by the fiber layer 38 An inner bag body 42 having a plurality of storage bags 40 housed in parallel along the width W direction of 30 and a futon-side cloth 44 housing the inner bag body 42 are provided. In FIG. 2, the core material 36 and the fiber layer 38 including the pipe 32 and the filler 34 are shown only in one storage bag 40.
The core material 36 surrounded by the fiber layer 38 is accommodated in the center material.

As the pipe 32, a synthetic resin foam pipe is used in order to improve the elasticity of the core material 36. There is no limitation on the method of forming the pipe 32. The molded article may be a molded article obtained by molding a synthetic resin foam sheet into a pipe, or a pipe-shaped molded article of a synthetic resin foam obtained by extrusion molding.
A pipe-shaped molded article of a synthetic resin foam obtained by molding may be used. From the viewpoint of cost, a molded article obtained by molding the foam sheet into a pipe is preferable. In the bedclothes 30 of the present embodiment, the pipe 32 is a molded article obtained by molding a polyolefin foam sheet such as a polyethylene foam sheet having closed cells into a pipe shape.

The filling body 34 is formed of a material having the same or higher hardness as the synthetic resin foam forming the pipe 32 and having a lower hardness than the metal piece. It is formed of a synthetic resin foam to improve the properties. The filling body 34 is formed of, for example, a corrugated synthetic resin tube. In the present embodiment, as the filling body 34,
As shown in FIG. 3, a corrugated tube made of synthetic resin is used.

The fiber layer 38 surrounding the outer periphery of the core material 36 may be made of natural fiber as long as it has moisture absorption and air permeability.
Synthetic fibers may be used. In this embodiment, a fiber layer made of futon cotton is used. The storage bag 4 adjacent to the inner bag body 42
0s are connected to each other. The inner bag body 42 may be made of a natural fiber or a synthetic fiber as long as it has hygroscopicity and air permeability. Also, the futon side cloth 44 may be a natural fiber or a synthetic fiber as long as it has hygroscopicity and air permeability. As the futon-side cloth 44, a patterned cloth is usually used in consideration of the appearance. In this embodiment, the inner bag body 42 is formed of two pieces of cotton cloth, and the futon side cloth 42 is formed of another two pieces of cotton cloth. By suturing four cotton cloths at seam lines 46 at predetermined intervals shown by broken lines in FIG. 1, the two cotton cloths of the inner bag body 42 between the seam lines function as the storage bag 40. The distance between the seams 46 is such a distance that the core members 36 are arranged with a predetermined gap therebetween in consideration of the foldability and storability of the bedding 30.

Next, with reference to FIG. 1 to FIG.
0 will be described. As shown in FIGS. 2 and 3,
A required number of core materials 36 in which the pipes 32 are filled with the fillers 34 are prepared. On the other hand, one of the two cotton cloths constituting the futon side cloth 44 is laid on the lowermost layer, and one of the two cotton cloths constituting the inner bag body 42 is placed thereon. Further, two fiber layers 38 composed of a futon cotton layer are placed on the cotton cloth of the inner bag body 42. Subsequently, the other cotton cloth of the inner bag body 42 and the other cotton cloth of the futon-side cloth 44 are placed on the fiber layer 38.

Next, from the other cotton cloth of the futon-side cloth 44, the fibrous layer 38 is stitched at predetermined intervals shown by broken lines in FIG.
The inner bag body 42 and the futon-side cloth 44 are stitched. Thereby, the storage bag 40 having the fiber layer 38 on the inner periphery, which is formed of two pieces of cotton cloth, of the inner bag body 42 between the seam lines.
Can be formed. Next, the core material 36 is inserted between the two fiber layers 38 to complete the bedding 30.
In the present embodiment, since the fiber layer 38, the inner bag body 42, and the futon-side cloth 44 are simultaneously sewn, the sewing process can be streamlined.

Embodiment 1 The bedding of this embodiment has a length L of 2050 mm and a width W of 9
50 mm, 16 storage bags 40, each storage bag 40
The medium core material 36 is accommodated therein. The core material 36 was obtained by molding a crosslinked foamed polyethylene foam having a foaming ratio of 40 times, a length of 930 mm, an inner diameter of 30 mm, and a wall thickness of 12 mm.
And a filling body 34 made of a cross-linked polyethylene corrugated pipe having a length of 920 mm, an inner diameter of 25 mm, and a wall thickness of 2 mm. Polyester duvet 1k
g was used as the fiber layer 38, and the futon-side cloth 44 made of cotton cloth, the inner bag body 42 made of cotton cloth, and the fiber layer 38 were stitched in accordance with the above-described method to form 16 accommodation portions 40. Next, the core material 36 is inserted into each storage bag 40, and the bedding 3 of the present embodiment is inserted.
0 was finished.

Under the following conditions, the bedding 12 of Example 1 was evaluated for its foldability, storability, and sleeping comfort. (1) Foldability a) Evaluation of “excellent”: Regarding the bedding which can be easily folded in two or three at any position in the longitudinal direction regardless of the front and back of the bedding 12, the evaluation of the foldability is evaluated as “excellent”. ”In Table 1 with a double circle. b) "Good" evaluation: Regarding the bedding that can be folded twice and three times from the position where the folding habit was once applied in the longitudinal direction regardless of the front and back of the bedding 12, the evaluation of the foldability is ""Good" is indicated by a circle in Table 1. c) "Slightly inferior" evaluation: irrespective of the front and back of the bedclothes 12, only from the position where several folds are made in the longitudinal direction,
The bedding that can be folded in two or three was evaluated as "slightly inferior" in terms of the foldability, and Table 1 shows a triangle. d) Evaluation of “Inferior”: Regarding the bedding that rebounds when folded at any position in the longitudinal direction regardless of the front and back of the bedding 12, the evaluation of the foldability is set to “Inferior”, and a cross mark in Table 1 is given. Indicated.

(2) Storability a) Evaluation of “Excellent”: Regardless of the front and back of the bedclothes 12, when folded in a three-fold state, when both hands are spread and the hands are turned in the width direction and lifted, The bedding that is curved at a plurality of positions in the width direction was evaluated as “excellent” in terms of the storability, and is indicated by a double circle in Table 1. b) Evaluation of “Good”: Regardless of the front and back of the bedding 12, when both hands are extended and the hands are turned in the width direction while being folded in three, only both ends in the width direction are curved. For the bedding, the evaluation of the storability was “good”, and Table 1 shows a circle. c) "Slightly inferior" evaluation: Regardless of the front and back of the bedclothes 12, when folded in a three-fold state and spread both hands to rotate in the width direction, only the center in the width direction is lifted. In the case of the curved bedding, the evaluation of the storability was "slightly inferior". d) Evaluation of “Inferior”: Regardless of the front and back of the bedding 12, when the three-fold folded state, the hands are spread, and the hands are turned in the width direction and lifted, the bedding is not bent in the width direction. Indicates that the evaluation of the storability is “poor”, and is indicated by an X mark in Table 1.

(3) Sleeping comfort Sleeping directly on the bedding 12 to evaluate the sleeping comfort,
Good, slightly poor, and poor evaluations were made. "Yu",
The evaluations of "good", "slightly inferior", and "poor" are shown in Table 1 by ◎, △, Δ, and ×.

[Table 1]

Embodiment 2 The bedding of this embodiment has a pipe 32 obtained by molding a cross-linked foamed polyethylene foam having an expansion ratio of 30 times, and a length 92 mm.
A core material 36 comprising a filler 34 made of a cross-linked polyethylene corrugated pipe having a diameter of 0 mm, an outer diameter of 34 mm, and a thickness of 4 mm.
The same configuration as that of the bedclothes of Example 1 is provided except that the bedding is formed. Example 1 of the bedding 30 of Example 2
In the same manner as in the above, the foldability, the storability, and the sleeping comfort were examined, and the results are shown in Table 1.

Example 3 The bedding of this example is a pipe 32 having a length of 930 mm, an inner diameter of 35 mm, a thickness of 10 mm, and a length of 920 m.
m, an outer diameter of 30 mm, and a filler 34 made of a cross-linked polyethylene corrugated pipe having a thickness of 1.5 mm, and the same structure as that of the bedding of Example 1 except that the core material 36 was formed. . With respect to the bedding 30 of Example 3, the foldability, the storability, and the sleeping comfort were examined in the same manner as in Example 1, and the results are shown in Table 1.

Embodiment 4 The bedding of this embodiment is a pipe 32 having a length of 930 mm, an inner diameter of 25 mm, a thickness of 16 mm, and a length of 920 m.
m, an outer diameter of 24 mm, and a wall thickness of 2 mm, and the same structure as that of the bedclothes of Example 1 except that a core material 36 is formed from a filler 34 formed of a crosslinked polyethylene corrugated pipe. With respect to the bedding 30 of the fourth embodiment, the foldability, the storability, and the sleeping comfort were examined in the same manner as in the first embodiment.
The results are shown in Table 1.

Embodiment 5 The bedding of this embodiment is a pipe 32 having a length of 930 mm, an inner diameter of 25 mm, a thickness of 16 mm, and a length of 870 m.
m, an outer diameter of 24 mm, and a wall thickness of 2 mm, and the same structure as that of the bedclothes of Example 1 except that a core material 36 is formed from a filler 34 formed of a crosslinked polyethylene corrugated pipe. With respect to the bedding 30 of the fifth embodiment, the foldability, the storability, and the sleeping comfort were examined in the same manner as in the first embodiment.
The results are shown in Table 1.

Example 6 The bedding of this example is a pipe 32 having a length of 930 mm, an inner diameter of 25 mm, a thickness of 16 mm, and a length of 870 m, which is obtained by molding a cross-linked expanded polyethylene foam having an expansion ratio of 20 times.
m, an outer diameter of 24 mm, and a wall thickness of 2 mm, and the same structure as that of the bedclothes of Example 1 except that a core material 36 is formed from a filler 34 formed of a crosslinked polyethylene corrugated pipe. With respect to the bedding 30 of the sixth embodiment, the foldability, the storability, and the sleeping comfort were examined in the same manner as in the first embodiment.
The results are shown in Table 1.

COMPARATIVE EXAMPLE 1 The bedding of this comparative example has a core material 36 obtained by molding a crosslinked foamed polyethylene foam having a foaming ratio of 30 times, and has a length of 93.
It is formed of only a pipe having a diameter of 0 mm, an inner diameter of 30 mm, and a thickness of 12 mm, that is, formed of only the same pipe as the pipe 32 of the core material 36 in Examples 2 and 3, except that it does not have the filler 34. It has the same configuration as the bedding of Example 1. The bedding of Comparative Example 1 was examined for foldability, storability, and comfort in the same manner as in Example 1, and the results are shown in Table 1.

COMPARATIVE EXAMPLE 2 The bedding of this comparative example was obtained by molding a core material 36 into a cross-linked foamed polyethylene foam having a foaming ratio of 40, and a length of 93.
It is formed only of a pipe having a diameter of 0 mm, an inner diameter of 32 mm, and a thickness of 10 mm, that is, formed of only a pipe having substantially the same specifications as the pipe 32 of the core material 36 in Examples 1 and 4.
4, except that it has the same configuration as the bedding of the first embodiment. The bedding of Comparative Example 2 was examined for foldability, storability, and sleeping comfort in the same manner as in Example 1, and the results are shown in Table 1.

From the comparison between Examples 1 to 6 and Comparative Examples 1 and 2, the bedding of Comparative Examples 1 and 2 using the core material 36 having no filling material 34 has the foldability and the storability. 1
Although the evaluation is the same as that of the bedclothes 30 to 7, the evaluation of the sleeping comfort is extremely low because the pipe is crushed by the body load. That is, the bedding 30 according to the first to seventh embodiments having the core material composed of the pipe and the filler specified in the present invention.
Can be evaluated as being excellent in all of the foldability, storability and sleeping comfort.

[0037]

As is apparent from the above description, according to the present invention, the hollow core of a pipe formed of a synthetic resin foam is filled with a filler to constitute a core material. The bedding can be folded at the desired position of the bedding by folding the bedding with the line along the pipe without causing the core material to lose its elasticity due to squatting. Also, a moderate acupressure effect due to the unevenness of the pipe row is helped, and a bed with good sleeping comfort is realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a bedding according to an embodiment.

FIG. 2 is a sectional view showing a part of a section of the bedding taken along line XX in FIG. 1;

FIG. 3 is a cross-sectional view showing a part of the cross section of the bedding taken along line YY in FIG. 1;

FIG. 4 is a cross-sectional view of a first example of conventional bedding.

FIG. 5 is a cross-sectional view of a second example of conventional bedding.

FIG. 6 is a cross-sectional view of a modification of the bedding of the second example of the related art.

FIG. 7 is a cross-sectional view of another modification of the conventional bedding of the second example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Bedding of the 1st example of the prior art 12 Core material 14 Futon cotton 16 Inner bag 18 Futon side cloth 20 Bedding of the 2nd example 22 Plastic foam sheet 24 Core material 25 Core material 26 Elliptical hole for ventilation 27 core material 28 cut portion 30 bedding of the embodiment 32 pipe 32a pipe hollow portion 34 filling material 36 core material 38 fiber layer 40 containing bag 42 inner bag body 44 futon side cloth 46 seam

Claims (3)

[Claims] 1. A flat, foldable bedding having a thickness, wherein a plurality of mutually independent bag-like storage bags extending long in one direction of the bedding are orthogonal to one direction. Inner bag body that is adjacent to and parallel to the direction in which the inner bag body is placed, a futon-side cloth that houses the inner bag body, a synthetic resin foam pipe, and a hardness higher than the synthetic resin foam that forms the pipe, and a metal piece. A core material made of a material having a low hardness and having a filler filled at least a part of the hollow portion of the pipe in the longitudinal direction of the pipe, and a fiber layer surrounding the outer periphery of the core material, wherein the core material is A bedding which is inserted one by one into each storage bag of the inner bag body. 2. The bedding according to claim 1, wherein the filler is a corrugated synthetic resin tube. 3. The pipe constituting the core material has an outer diameter of 20 mm.
2. A synthetic resin foam having a thickness of 4 mm to 100 mm, a thickness of 4 mm to 25 mm, an inner diameter of 12 mm to 62 mm, and an expansion ratio of 5 to 55 times. Or the bedding according to 2.