Interior construction method using plate-shaped building materials, and interior material unit

Abstract

To provide an interior construction method using a plate-like building material, which realizes ease of construction equal to or greater than that of gypsum board and enhances safety after construction by using a plate-like building material that has performance equal to or greater than that of gypsum board but is significantly lighter in weight, and an interior material unit. [Solution] The interior construction method includes the steps of preparing a plate-shaped building material having two sheet materials 20, each formed into a flat plate from recycled paper, and a core member 10 formed from recycled paper so as to have a wavy cross-section, which is sandwiched between the sheet materials 20, with each peak of the wavy cross-section of the core member 10 joined to the sheet material 20, and at least one of the two sheet materials 20 and the core member 10 being formed as a laminate with metal foil, forming the plate-shaped building material into a specified shape and dimensions, and fixing a plurality of the plate-shaped building materials to a base material for the building interior with screws.

Description

[Technical field]

[0001] The present invention relates to an interior construction method using a plate-shaped building material, and an interior construction material unit. [Background technology]

[0002] Traditionally, gypsum boards, which have moderate thermal insulation and sound insulation properties, have been used as ceiling materials. However, while they have suitable properties for use as ceiling materials, gypsum boards, which have standard dimensions of 12.5mm x 910mm x 1820mm, weigh over 10kg per sheet, and installing them on ceiling underlayment made of lightweight steel frames and other materials requires a great deal of effort. Even after installation, there have been accidents in which gypsum board ceiling materials have been damaged and fallen due to earthquakes with seismic intensity level 7. Thus, for the sake of ease of installation and safety after installation, a new ceiling material that is lightweight while maintaining the same performance as gypsum boards has been required.

[0003] In an attempt to meet such demands, for example, Patent Document 1 has been proposed. Patent Document 1 describes a ceiling material composed of a cardboard panel using inorganic fiber mixed paper as the liner bonded to both the front and back sides of a corrugated sheet, with the aim of providing a ceiling material that is lightweight and easy to manufacture. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-55436 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, although the ceiling material of Patent Document 1 seems to achieve weight reduction, there is no mention of whether the inorganic fiber mixed paper can achieve low moisture absorption, flame retardancy, or sound insulation equivalent to that of gypsum board. In addition, it is not clear whether the construction method can be carried out in the same way as gypsum board, which craftsmen are familiar with. There are similar demands for wall materials for wall construction as for the above-mentioned ceiling materials.

[0006] In order to solve the above and other problems, the present invention aims to provide an interior construction method and interior material unit using a plate-shaped building material that has the same performance as gypsum board but is significantly lighter, thereby achieving ease of construction equal to or greater than that of gypsum board and increasing safety after construction. [Means for solving the problem]

[0007] A method for constructing interior decoration using plate-shaped building materials according to one embodiment of the present invention includes a first sheet and a second sheet each formed into a flat plate shape from recycled paper, and a third sheet formed from recycled paper so as to have a wavy cross-section, sandwiched between the first sheet and the second sheet, with each peak of the wavy cross-section of the third sheet being joined to the first sheet or the second sheet, and at least one of the first sheet, the second sheet, and the third sheet being formed as a laminate with metal foil, the method comprising the steps of: preparing a plate-shaped building material; forming the plate-shaped building material into a predetermined shape and dimensions; and fixing a plurality of the plate-shaped building materials to a base material for the building interior with screws.

[0008] An interior material unit according to another aspect of the present invention comprises a first sheet and a second sheet each formed into a flat plate shape from recycled paper, and a third sheet formed from recycled paper to have a wavy cross section, sandwiched between the first sheet and the second sheet, with each peak of the wavy cross section of the third sheet being joined to the first sheet or the second sheet, and at least one of the first sheet, the second sheet, and the third sheet comprising a molded body formed by molding a plate-shaped building material formed as a laminate with metal foil into a predetermined shape, and a surface finishing layer formed on the surface of the molded body from a paste-like finishing material. Effect of the Invention

[0009] According to the present invention, there is provided an interior construction method using a plate-shaped building material, which has performance equivalent to that of gypsum board but is significantly lighter in weight, thereby achieving ease of construction equal to or greater than that of gypsum board and increasing safety after construction, and an interior material unit. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing an example of the overall configuration of a ceiling material according to one embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic cross-sectional view of the ceiling material of FIG. 1. [Diagram 3] 2 is a schematic diagram illustrating an installation state of the ceiling material of FIG. 1. [Figure 4] 1 is a cross-sectional view illustrating a state in which a ceiling material is attached to a ceiling base material. [Diagram 5] 1 is a schematic cross-sectional view illustrating a state in which a heavy object is installed on a ceiling base material. FIG. [Figure 6] 1 is a schematic plan view illustrating an installation state of a wall material according to an embodiment of the present invention; [Figure 7] 7 is a schematic diagram illustrating a state in which the surface finishing of the wall material of FIG. 6 is being performed. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described below with reference to the drawings based on the embodiments. Note that the present invention is not limited to the following embodiments. Also, each drawing referred to in the following description merely shows the shape, size, and positional relationship in a schematic manner to the extent that the contents of the present disclosure can be understood. In other words, the present invention is not limited to only the shape, size, and positional relationship exemplified in each drawing.

[0012] <Composition of plate-shaped building materials> First, a configuration example of a plate-shaped building material according to one embodiment of the present invention will be described. FIG. 1 shows a schematic diagram of an overall configuration example of a plate-shaped building material according to this embodiment. As shown in FIG. 1, the plate-shaped building material 1 typically has a rectangular planar shape, and when used as a ceiling material, for example, the dimensions of a so-called 6-six board, t=4.0 mm, L1=1820 mm, and L2=910 mm, are typically adopted. In the case of a 6-six board size, the weight is about 2.35 kg. However, the planar shape is not limited to a rectangle, and may be a polygon such as a triangle or a hexagon, or a curved figure such as a circle. The dimensions in this case can also be determined according to the design of the ceiling and wall surface.

[0013] The plate-shaped building material 1 has a core member 10 as a third sheet that is continuously bent so as to have a wavy cross section, and two sheet materials 20 as a first sheet and a second sheet that are arranged to sandwich the core member 10. Fig. 2 shows a schematic cross-sectional view of the plate-shaped building material 1 in Fig. 1 when viewed from a transverse section of the core member 10.

[0014] In this embodiment, sheet materials 20, which are made by sandwiching and bonding aluminum foil as a metal sheet 30 between recycled paper, are placed on top and bottom, and the sheet materials 20 are bent to draw a corrugated shape at a predetermined pitch to form a core member 10. The core member 10 is also formed by sandwiching and bonding aluminum foil between recycled paper, as with the sheet material 20. It is not necessary to sandwich the aluminum foil between all of the sheet materials 20 and the core member 10, and it is also possible to provide the aluminum foil on at least one of them. As described later, when the plate-shaped building material 1 is fixed to the base material by a screw such as a screw, the screw penetrates the aluminum foil, thereby developing the bonding strength between the plate-shaped building material 1 and the screw. It is also possible to use a metal foil other than aluminum.

[0015] <Example of installation as a ceiling material> 3 is a schematic diagram showing a construction situation for attaching a plate-shaped building material 1 to a light-gauge steel bar 100, which is a ceiling base material. For example, the light-gauge steel bar 100, which has an angle-shaped (approximately U-shaped) cross section, is fixed in an appropriate structure to a hanging member 150 that is extended downward from a ceiling structure (not shown).

[0016] The plate-shaped building material 1 as a ceiling material can be fixed to a ceiling base material such as a light-weight steel bar 100 in the same manner as gypsum board. The following description is based on the assumption that the light-weight steel bar is the base, but a wooden frame (wooden axis) can also be used as the base material. In FIG. 3, the plate-shaped building material 1 is fastened to the light-weight steel bar 100 at the four corners using screws 40 of appropriate length and nominal diameter. FIG. 4 shows a schematic cross-sectional view of this fastening portion. As shown in FIG. 4, in the configuration example illustrated in FIG. 3, the plate-shaped building material 1 is fastened to the angle-shaped light-weight steel bar 100 from below using screws 40. This is the same as the construction method for attaching a conventional gypsum board to a ceiling base material, and the worker does not need to learn a new construction work by adopting the plate-shaped building material 1, and is excellent in ease of construction. In addition, the weight of the plate-shaped building material 1 is suppressed to about 1 / 6 of that of a gypsum board of the same size, so the worker can perform the installation work with significantly less effort than in the case of a gypsum board. Therefore, in recent years, when it has become difficult to secure on-site workers due to the declining birthrate and aging population, this method has the advantage that even elderly and female workers who are relatively weak can carry out construction work.

[0017] Furthermore, the light weight of the plate-shaped building material 1 improves safety even if the plate-shaped building material 1 falls off the lightweight steel frame bar 100 after construction due to an earthquake or other cause. The Architectural Institute of Japan recognizes that ceiling collapses can also occur due to moisture intrusion into the ceiling material, as in the case of ceilings absorbing condensation water and falling off, in addition to earthquakes. The high moisture permeability resistance of this building material also reduces the risk of falling off.

[0018] Another feature of the plate-shaped building material 1 is its excellent workability on-site. The plate-shaped building material 1 can be easily cut with a utility knife without the need for special tools. Almost no dust is generated during the process. The plate-shaped building material 1 can be attached to a lightweight steel frame base with screws using ordinary tools. In this case, the heads of the screws are treated with ordinary putty.

[0019] The method of attaching the plate-shaped building material 1 can be selected from jointless, open-ended, PVC joiner, etc. The surface finish of the plate-shaped building material 1 can be selected from painting, wallpapering, plastering, etc. The peripheral edge of the plate-shaped building material 1 can be chamfered at the cross section by pressing along the edge with a hard spatula or the like without using special tools. If such chamfering is performed on-site and then fixed to the base material, the joints between the plate-shaped building materials 1 can be made less noticeable. It is also possible to repair small damage that occurs to the plate-shaped building material 1 with putty treatment.

[0020] Next, a configuration example when a heavy object is attached to a ceiling will be described. There are cases where a heavy object, such as a lighting fixture such as a downlight, needs to be attached to a ceiling. Such a heavy object may exceed the load capacity of the plate-shaped building material 1, so in that case, it is necessary to configure the light-weight steel frame bar 100 to directly bear the load. FIG. 5 shows a configuration example when a downlight DL is provided on a ceiling. Adjacent light-weight steel frame bars 100 are fixed from below with screws or the like to brackets 110 each having a substantially L-shaped cross section. For simplicity, the screws are omitted from the illustration and are simply shown by dashed lines. Between the opposing brackets 110, a gypsum board 200 processed to match the spacing dimension is fixed to the bracket 110 with a screw. The downlight DL is fixed to a mounting hole provided in the gypsum board 200 with an appropriate structure, so that the weight of the downlight DL is supported by the light-weight steel frame bar 100 via the gypsum board 200. When the downlight DL or the like is supported by the gypsum board 200 in this manner, the shape and dimensions of the plate-like building material 1 adjacent to the installation location of the downlight DL can be easily adjusted by cutting it with a cutter as necessary. No special tools are required for this. A supporting member having the required strength other than the gypsum board 200 can also be used.

[0021] <Example of application as a wall material> FIG. 6 shows a schematic plan view of a construction example in which the plate-shaped building material 1 is used as a wall material. FIG. 6 is a plan view of a room including a wall, in which three studs 300 made of light steel frame or the like are erected. Here too, the following description is based on the assumption that the light steel frame bar is used as the base, but a wooden framework (wooden axis) can also be used as the base material. The plate-shaped building material 1 used as a wall material has a shape that curves from the top to the bottom of the figure. One of the features of the plate-shaped building material 1 is that it can be easily deformed to create a desired curved surface, as shown in FIG. 6. Due to this feature, when used as a wall material or ceiling material, not only a monotonous flat surface but also a curved surface rich in design can be easily created.

[0022] FIG. 7 shows a schematic diagram of the surface finish of the plate-shaped building material 1 as a wall material to be built. The sheet material 20 forming the surface of the plate-shaped building material 1 is recycled cardboard base paper, which is suitable for painting (acrylic emulsion paint, etc.) and wallpapering, and is particularly compatible with the moist paste-like plaster (plaster) used in plastering work, and the surface can be beautifully finished by normal plastering work. More specifically, plastering finishes that use water in the construction process are not suitable for base materials that are weak against moisture, but the plate-shaped building material 1 can withstand normal plastering finishes due to the moisture permeability resistance effect of the aluminum foil. When applying a finishing material such as plaster to a thickness of about 2 to 3 mm, the basic rule is to apply a neutral undercoat and then apply the finish coat. When applying a thicker coat, such as a rammed earth finish, a cationic material that adjusts the base for mortar painting is applied to the bottom. This is the same method as applying a finishing material to gypsum board.

[0023] One of the features of the plate-shaped building material 1 of this embodiment is that it can be easily installed on curved ceilings and walls. A curved surface can be formed by arranging and assembling light steel frames for curved ceilings and walls, bending the plate-shaped building material 1 by hand, and screwing it along the light steel frames of the base. Existing gypsum boards for curved surface processing often need to be soaked in water before bending, but in that case, the weight of the gypsum board increases when it absorbs moisture, making it more difficult to install than flat surfaces. In this respect, the ease of installation of the plate-shaped building material 1 is very useful. By directly applying a plastering base material and a finishing material to the surface of the plate-shaped building material 1 formed into a desired curved shape, it is possible to finish a curved ceiling or wall in the shortest process.

[0024] <Interior material unit> The plate-shaped building material 1 used as the interior material can be processed as a material such as adjusting the shape and dimensions and creating a curved surface before being brought to the construction site, and then, as shown in Fig. 7, can be finished as an interior material unit 500 by painting, plastering, or other surface finishing using a trowel 400 or the like. In this case, the construction at the construction site can be completed simply by attaching the interior material unit 500 to the already installed base material such as studs 300 with adhesive, thereby improving the efficiency of on-site work. In other words, the interior material unit 500 is produced in a factory or the like until only the minimum process remains, such as the final assembly to the base material, at the construction site. For surface finishing, wallpaper application may be somewhat difficult depending on the type, but wallpaper application and painting techniques are required. In addition, in plastering and other finishes where the weight increases depending on the applied finishing material, this plate-like building material 1 is lighter than existing building materials such as gypsum boards, so that even after skilled craftsmen apply and paint the material at the factory, it is lighter than existing building materials even in the finished state, which makes it possible to reduce the load of transporting it from the factory to the construction site.

[0025] The plate-shaped building material 1 can be used as an interior material for ceilings, walls, etc., as well as for applications such as the base of a table top for furniture. By using the plate-shaped building material 1 of this embodiment, it is possible to diversify the design of furniture by performing curved surface processing with a small bending radius and surface finishing by plastering work, etc.

[0026] <Example> Here, a plate-shaped building material 1 according to one example of the above-mentioned embodiment will be described. The main specifications of the plate-shaped building material 1 according to this example are as follows. - Dimensions: Thickness 4.0mm, length 1820mm, width 910mm rectangular Structure The sheet material 20 and the core member 10 are three-layered sheets, each made by sandwiching and bonding an aluminum foil with a thickness of about 0.02 mm between two sheets of recycled cardboard. The flat sheet materials 20 on the top and bottom (outside) are about 0.5 mm thick, the corrugated core member 10 sandwiched in the middle is about 3 mm thick, and the overall thickness of this plate-like building material 1 is about 4 mm. The weight of this plate-like building material 1 is about 1 m 2 The weight was about 1.4 kg per piece. When fixing such a plate-like building material 1 to a ceiling base material made of light-gauge steel bars with screws, as a non-limiting example, a ribbed screw with a length of 20 mm and a nominal diameter of 3 mm can be used. When fixing to the studs 300 described above as wall materials with screws, screws of similar specifications can be used.

[0027] The main properties confirmed for the plate-shaped building material 1 according to this embodiment are shown below. (1) Fire resistance This plate-shaped building material 1 complies with the performance evaluation criteria of Article 1, Item 5 of the Enforcement Order of the Building Standards Act [Semi-noncombustible materials].

[0028] (2) Breathability The aluminum foil interposed in the thickness direction of the plate-shaped building material 1 provides a high moisture permeability resistance, so the plate-shaped building material 1 will not corrode and come off the screws. This prevents deterioration over time and the associated falling off. Specifically, the moisture permeability resistance Zp is ≧ 500 [ng / (m 2·s·Pa), which is approximately 1,000 times the moisture permeability of ordinary gypsum board.

[0029] (3) Sound absorption The average NRC sound absorption coefficient (reverberation room method) for frequencies between 50 and 2,000 Hz was 0.08, which is roughly the same as that of general decorative gypsum board. To improve the sound absorption coefficient, it is possible to attach a rock wool sound absorbing board to the interior side, which is the same method as for general gypsum board.

[0030] (4) Sound insulation (sound transmission loss) The frequency of human speech is generally 500 to 1000 Hz. In the case of the plate-shaped building material 1 of this embodiment, the results were 20 dB at 500 Hz, 26 dB at 1000 Hz, and 20 dB as an average value from 100 to 2500 Hz. It has been confirmed that the effect of sound insulation is improved by using a sound-proofing material (thermal insulation material) in combination.

[0031] (5) Impact resistance (a) Wall pressure test When a load of 1765N, the maximum value for the BL part certification, was applied, no cracks or breaks occurred, and only slight deflection occurred. It was confirmed that the material can be used as a wall material without any problems.

[0032] (b) Material impact test A test was conducted in which a steel ball weighing 500g was dropped from a height of 500mm onto the surface of the plate-shaped building material 1 to confirm the degree of denting upon impact. It was confirmed that the plate-shaped building material 1 did not break or shatter, and had the flexibility to absorb impact.

[0033] (c) Wall impact test When a concentrated load was applied to the wall as a partition, the residual deformation after the impact was close to zero, and it was confirmed that there is no problem in using the wall as a partition under a light-gauge steel frame.

[0034] (6) Material bending test When forming a curved surface, we conducted a test to verify the load and deflection required for bending depending on the bending direction. It was confirmed that the load required for bending is slightly larger in the step direction (paper width direction, the direction on the side where the waves are not visible when viewed from the side) than in the step orthogonal direction (roll direction, the direction on the side where the waves are visible when viewed from the side), but the deflection at the bending failure load is also larger.

[0035] (7) Thermal resistance (insulation) According to the standard measurement method of the Japanese Industrial Standards (JIS), the thermal resistance measurement value is 0.041 [m 2 This value was almost the same as that of general gypsum board (approximately 0.043 or more at a thickness of 9.5 mm, and approximately 0.057 at a thickness of 12.5 mm).

[0036] As explained above, it has been confirmed that the plate-shaped building material 1 of this embodiment is significantly lighter than a typical gypsum board having a thickness of 12.5 mm, while maintaining various equivalent performance properties.

[0037] <Environmental Impact> Regarding industrial products, reducing the burden they may place on the global environment has become an important issue.

[0038] After the plate-shaped building material of the present invention has served its initial purpose as an interior ceiling or wall material, it can be recycled rather than being landfilled. When this building material is combined with waste plastic, it can be reused as a "foaming inhibitor" (a type of additive used in metal refining in a blast furnace. When added to a blast furnace, it serves to suppress the phenomenon known as foaming). This recycling method is called chemical recycling, and can be carried out even in small quantities.

[0039] One thing to keep in mind when recycling is whether it can be recycled without much effort from the state in which it was actually used. In the above-mentioned chemical recycling, as can be seen from the fact that mixing it with waste plastics becomes the raw material for foaming inhibitors, even if wallpaper, which contains a lot of plastic, is stuck to the building material, it can be recycled as is. Also, when combining this building material with rock wool, which functions as a soundproofing material, if it is installed without using adhesives, and the two are separated and processed after use, the building material can be chemically recycled and the rock wool can be material recycled.

[0040] The advantage of recycling, in addition to reusing materials, is that it also solves the problem of a shortage of waste landfill sites.

[0041] In addition, the Japan Aluminum Association, a general incorporated association, states on its website that "Aluminum foil with a thickness of 6 to 10 μm will be mostly eroded in about 4 to 5 years, turning into alumina and returning to the soil."

[0042] The method of constructing interior decoration using plate-shaped building materials according to the embodiment of the present invention described above includes the steps of preparing a plate-shaped building material 1, which comprises two sheet materials 20 each formed into a flat plate from recycled paper, and a core member 10 formed from recycled paper so as to have a wavy cross-section, which is sandwiched between the sheet materials 20, with each peak of the wavy cross-section of the core member 10 being joined to the sheet material 20, and at least one of the two sheet materials 20 and the core member 10 being formed as a laminate with metal foil, forming the plate-shaped building material 1 into a specified shape and dimensions, and fixing a plurality of the plate-shaped building materials 1 to a base material for the building interior with screws.

[0043] This makes it much lighter than existing interior materials such as gypsum boards, simplifies installation, and improves safety after installation.

[0044] Before fixing the plate-shaped building material 1 to the base material, a step may be included in which the peripheral portion of the plate-shaped building material 1 is crushed along the peripheral portion to chamfer the peripheral portion of the plate-shaped building material 1 in the thickness direction.

[0045] In this way, the joints between the plate-like building materials 1 can be made inconspicuous by a simple process that does not require special tools or the like.

[0046] A step of forming a surface finishing layer by applying a paste-like finishing material onto one of the two sheet materials 20 constituting the indoor side surface of the plate-shaped building material 1 may be included.

[0047] In this way, the surface finish layer can be formed by plastering, similar to existing interior materials.

[0048] The plate-shaped building material 1 has a plasticity that realizes a predetermined minimum bending radius, and can be installed continuously so as to form a curved surface along the interior surface of a building.

[0049] In this way, it is possible to realize an interior design with a smooth connection between the ceiling and the walls.

[0050] The interior material unit of this embodiment comprises two sheet materials 20 each formed into a flat plate from recycled paper, and a core member 10 formed from recycled paper to have a wavy cross section, which is sandwiched between the sheet materials 20, with each peak of the wavy cross section of the core member 10 being joined to the sheet material 20. At least one of the two sheet materials 20 and the core member 10 comprises a molded body formed by molding a plate-shaped building material formed as a laminate with metal foil into a predetermined shape, and a surface finishing layer formed on the surface of the molded body from a paste-like finishing material.

[0051] In this way, the finished unit as an interior material is delivered to the construction site, so construction time can be shortened and the work efficiency of the interior finishing can be improved.

[0052] The technical scope of the present invention is not limited to the above-described embodiment, and other modified examples, application examples, etc. are also included within the scope of the claims. [Explanation of symbols]

[0053] 1. Plate-shaped building materials 10 Core member 20 Sheet material 30 Metal Sheet 40 bis 100 Lightweight steel bar 110 Bracket 200 Support member 300 studs 400 Iron 500 Interior material units

Claims

1. A first sheet and a second sheet each formed into a flat plate shape from recycled paper; a third sheet sandwiched between the first sheet and the second sheet and formed from recycled paper to have a wavy cross section, each apex of the wavy cross section of the third sheet being joined to the first sheet or the second sheet, at least one of the first sheet, the second sheet, and the third sheet being formed as a laminate with a metal foil, and the surface of at least one of the first sheet and the second sheet opposite to the third sheet being formed from the recycled paper; A step of forming the plate-shaped building material into a predetermined shape and dimensions; A step of crushing the peripheral portion of the plate-shaped building material along the peripheral portion to chamfer the peripheral portion of the plate-shaped building material in the thickness direction; A step of fixing a plurality of the plate-shaped building materials to a base material of a building interior with screws; An interior construction method that has the following features.

2. 2. The interior construction method according to claim 1, further comprising a step of forming a surface finishing layer by applying a paste-like finishing material to the surface of the first sheet or the second sheet, which is the indoor side surface of the plate-shaped building material and is made of recycled paper.

3. 2. The interior construction method according to claim 1, wherein the plate-shaped building material has a plasticity that realizes a predetermined minimum bending radius, and is continuously installed so as to form a curved surface along the interior surface of a building.

4. An interior material unit comprising: a first sheet and a second sheet each formed into a flat plate shape from recycled paper; and a third sheet formed from recycled paper so as to have a wavy cross section, sandwiched between the first sheet and the second sheet, wherein each peak of the wavy cross section of the third sheet is joined to the first sheet or the second sheet; at least one of the first sheet, the second sheet, and the third sheet is formed as a laminate with metal foil; the surface of at least one of the first sheet and the second sheet opposite the third sheet is a molded body formed by molding a plate-shaped building material formed from the recycled paper into a predetermined shape; and a surface finishing layer formed of a paste-like finishing material on the recycled paper surface of the molded body.

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