JPH0939129A - Core material for sandwich panel and manufacture thereof, sandwich panel and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bond a core material of polyethylene or polypropylene with good water resistance and chemical resistance to the surface of another material. SOLUTION: This core material for a sandwich panel is composed of a core material main body 12 having numbers of adjacent cells 16 extending almost in the same direction and a porous nonwoven fabric 14 which has a higher melting point than polyethylene and is fusion-bonded to both ends of the cell walls 12a, 12b of the main body 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core material for sandwich panels made of polyethylene or polypropylene, a method for producing the same, a sandwich panel and a method for producing the same.

[0002]

2. Description of the Related Art Heretofore, core materials for sandwich panels have generally been made of paper such as corrugated cardboard and metal such as aluminum foil.

[0003]

However, the core materials made of paper or metal are weak against water and cannot be used outdoors for a long period of time. Further, the metal core material is vulnerable to acids and alkalis, and has various problems such as high manufacturing cost.

A water-resistant polyethylene or polypropylene resin is considered there. These resins are excellent not only in water resistance but also in chemical resistance and have an advantage that they can be recycled. However, polyethylene and polypropylene have poor adhesiveness to other substances, and are not useful for general purpose adhesives such as vinyl acetate emulsion. Also, some expensive instant adhesives using a primer have poor workability due to immediate drying, and when the bonding area is large, sufficient adhesive force cannot be obtained.

A first object of the present invention is to provide a core material for a sandwich panel, which is made of polyethylene or polypropylene to enhance water resistance and chemical resistance and which can be adhered to a face material, and a method for producing the same. Especially.

A second object of the present invention is to provide a sandwich panel using a core material made of polyethylene or polypropylene and a method for producing the same.

[0007]

In order to achieve the above object, the present invention provides a polyethylene or polypropylene core material body having a large number of cells extending substantially in the same direction and adjacent to each other, and polyethylene or polypropylene. Provided is a core material for a sandwich panel, which has a higher melting point and has a porous base material fused to at least one surface of the core material body.

Further, according to the present invention, a step of producing a core material main body having a large number of cells extending adjacent to each other in substantially the same direction, using polyethylene or polypropylene as a material, and a porous material having a melting point higher than that of polyethylene or polypropylene. A method for producing a core material for a sandwich panel, comprising the steps of: fusing the base material to at least one surface of the core material body; and, after the fusion, cooling and solidifying the core material body.

Further, according to the present invention, a core material body made of polyethylene or polypropylene having a large number of adjacent cells extending in substantially the same direction and a melting point higher than that of polyethylene or polypropylene and having at least one surface of the core material body. Provided is a sandwich panel having a fused porous base material and a face material adhered to at least one surface of a core material body via the base material.

The present invention also provides a step of producing a core material body having a large number of cells extending adjacent to each other in substantially the same direction, using polyethylene or polypropylene as a material, and a porous material having a melting point higher than that of polyethylene or polypropylene. The step of fusing the base material to at least one surface of the core material body, the step of cooling and solidifying the core material body after the fusion, and the adhesion of the surface material to the at least one surface of the core material body through the base material with an adhesive. And a method of manufacturing a sandwich panel, the method including:

[0011]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

In the embodiment shown in FIG. 1, a sandwich panel core 10 has a rectangular core body 12 and a thin porous base material 14 fused to both sides of the core body 12. . The core body 12 is made of polyethylene, and is composed of a plurality of corrugated plates 12a that are cell walls and a plurality of flat plates 12b that are fused or adhered to both sides of the corrugated plates 12a. Of course, the corrugated plate 12a and the flat plate 12b may be integrally formed from the beginning by extrusion molding. The cells 16 having a mountain-shaped cross section defined by the corrugated plate 12a and the flat plate 12b are adjacent to each other and extend in the same direction. The base material 14 is a nonwoven fabric made of polyester and has a thickness of, for example, 0.11 mm (17 g per square meter in terms of basis weight). The melting point of polyethylene, which is the material of the core body 12, is 102 to 110 degrees Celsius, and the melting point of polyester is 250 to 264 degrees Celsius, that is, higher than the melting point of the core body 12. The base material 14 is not limited to a non-woven fabric, but may be a woven fabric, a knitted fabric, a wire net, or the like. Further, as the material thereof, appropriate natural fiber, synthetic resin, inorganic material, metal or the like can be used.

When manufacturing the core material 10, first, the nonwoven fabric 14 is aligned with both ends of the cell wall of the core material body 12. Next, the core material body 12 is heated and pressed at a temperature of about 150 degrees Celsius from above and below with a flat plate-shaped heating plate (not shown). The heat of the heating plate is transferred to the core body 12 via the nonwoven fabric 14. Then, when the transmission temperature slightly exceeds 100 degrees Celsius, the polyethylene, which is the material of the core body 12, begins to melt. Since polyethylene has a low thermal conductivity, it melts conveniently only in the area in contact with the hot platen. Then, heating and pressing are performed until polyethylene having a cell column height of about 1.3 mm is melted. The melted polyethylene flows into the openings of the porous nonwoven fabric 14 and entangles with the fibers, gradually closing the openings (see FIG. 3). Further heating reduces the opening area of the cell 16,
The thickness of the edge gradually increases. After that, the core material body 12 is solidified by natural cooling. As a result, the core material body 12 and the nonwoven fabric 14 are firmly integrated to complete the core material 10.

As shown in FIG. 2, when a face material 18 made of an appropriate material is adhered to the core material 10, it can be used as a sandwich panel 20. The face material 18 is, for example, a wood fiber board having a thickness of 2.5 mm. To apply the face material 18, first, an adhesive 22 such as ethylene vinyl acetate emulsion (water-based general-purpose product) is applied to one surface of the face material 18. Next, the face material 18 and the non-woven fabric 14 are aligned so that the side coated with the adhesive 22 faces the non-woven fabric 14. When a predetermined pressure is applied to the face material 18 from above and below in this state, the adhesive 22 starts to permeate the nonwoven fabric 14. The adhesive 22 that has permeated then flows into the back surface side through the thick portion at the cell end. By the so-called anchoring effect, the face material 18 is indirectly and surely bonded to the core body 12 via the nonwoven fabric 14. Completed wood panel 20
Is ideal for partitions and doors around water such as bathrooms and washrooms.

FIG. 4 is a partial perspective view showing an enlarged core material according to another embodiment of the present invention.

As shown in the figure, the core material 30 has a polypropylene core material body 32 and a porous base material 34. A large number of rectangular cells 36 defined by cell walls 35 arranged in a grid pattern are adjacently extended in substantially the same direction. The melting point of polypropylene, which is the material of the core body 32, is about 160 degrees Celsius. In this embodiment, a stainless steel wire net is used as the base material 34 instead of the non-woven fabric. Its thickness is 0.09 mm. The cross-sectional shape of the core material is not limited to the corrugated shape or the grid shape, and may be an appropriate shape including various polygons.

In manufacturing the core material 30, first, the wire mesh 34 as the base material is applied to both ends of the cell wall 35 of the core material body 32. From this state, the core body 32 is heated and pressed from above and below with a heating plate (not shown) heated to about 170 degrees Celsius. The heat of the heating plate is transferred to the polypropylene core material body 32 through the wire net 34. When this transmission temperature reaches around 160 degrees Celsius, polypropylene, which is the material of the core body 32, melts and gradually begins to coat the wire net 34. Since polypropylene also has low thermal conductivity like polyethylene, the resin locally melts. In the embodiment shown in FIG. 4, polypropylene surrounds each wire forming the wire netting 34 at a ratio of 90% or more.

To manufacture a sandwich panel using this core material 30, an epoxy resin is applied to one surface of a stainless steel surface material (not shown) having a thickness of 0.7 mm, for example.
Then, when the applied side is aligned with the core material 30 and a predetermined pressure is applied, the face material is firmly adhered to the core material. By the way, when the sandwich panel manufactured as described above was subjected to a fracture (tensile) test, 100% fracture was found in the core material (the panel of this construction is particularly useful for non-structural panels of automobiles). .

In the embodiments of FIGS. 1 to 4, the base material is fused to one end or both ends of the cell wall of the core material, but the base material may be fused to one flat surface of the core material.

In the embodiment shown in FIG. 5, the core material 40 is
It has a polyethylene core material body 42 with a thickness of about 5 mm. The core main body 42 is composed of two thin upper and lower flat plates 42a having a thickness of about 0.3 mm, and a large number of cell walls 42b having the same thickness provided between the flat plates 42a perpendicular to the flat plates 42a. Then, the flat plate 42a and the cell wall 42b define a large number of cells 44 having a rectangular cross section. On the surface side of the flat plate 42a,
The base material forming a part of the core material 40 has a thickness of about 0.
A 1 mm polyester non-woven fabric 46 is fused.
A wire mesh (not shown) is used to fuse the non-woven fabric 46 to the surface of the flat plate 42a. That is, on the surface of the flat plate 42a, about 0.
A 1 mm square wire mesh is placed, and the wire mesh is pressed against the surface by heating means such as a heating plate. The heating temperature at this time is about 150 degrees Celsius, and the surface of the flat plate 42a has an appropriate thickness, for example, 0.3.
After melting for 0.5 mm, the pressure is stopped and the mixture is cooled and solidified. As a result, the non-woven fabric 46 is fused to the flat plate 42a at the position where the wire mesh partially cuts into the flat plate 42a. In FIG. 6, the non-woven fabric 46 is a flat plate 42 at a place where there is no trace of the wire mesh.
Not fused to a. Then, a part of the non-fused non-woven fabric 46 works effectively when adhering to the face material. When a sandwich panel is manufactured using a face material made of an appropriate material, the adhesive used for bonding the face material penetrates into the non-fused non-woven fabric 46 and surrounds the fiber for good adhesion. Be effective. The permeation of the adhesive is positively performed because the nonwoven fabric 46 is porous and has high wettability.

In the above embodiment, the wire mesh is used to promote the fusion bonding of the non-woven fabric 46. However, the heat roller is provided with an embossing or groove of an appropriate shape so that the surface of the flat plate 42a as shown in FIG. Can also be formed.

In another embodiment shown in FIG. 7, a core material 50
Has a polypropylene core body 52 having a thickness of about 5 mm. Similarly to the above embodiment, the core material main body 52 also includes two thin upper and lower flat plates 52a, for example 0.3 mm, and a flat plate 52.
It has the same thickness as a and is composed of a large number of cell walls 52b provided between the flat plate 52a and the flat plate 52a in a manner orthogonal to each other. And
The flat plate 52a and the cell wall 52b define a cell 54 having a rectangular cross section. The core material 50 further includes a punching metal 56 made of aluminum that is fused to at least one surface of the flat plate 52a.
Having. As shown in FIG. 8, this punching metal 5
6 is after making a small cut in a rectangular metal sheet,
It is expanded to form a number of parallelogrammatic openings 58.
The cell wall (slanting piece) 60 defining the opening 58 has a thickness of about 1.5 mm and a cell size of about 2.8 mm, and is inclined at an angle of, for example, 70 degrees.

To fuse the expanded punching metal 56 to the core body 52, first, the punching metal 56 is placed on the surface of the flat plate 52a of the core body 52. After mounting, the punching metal 56 is pressed against the flat plate 52a by an appropriate heating means (not shown) such as a smooth heat roller. The heating temperature of the heating means at this time is about 180 degrees Celsius. And
For example, when heating and pressing at a pressure of about 0.5 kgf / cm ² for about 20 to 30 seconds, the inclined piece 60 of the punching metal 56 is partially immersed in the surface of the molten flat plate 52a. When the punching metal is immersed in an appropriate amount, the heating and pressing operation is stopped and the core material body 52 is solidified by natural cooling.

As shown in FIG. 7, when a channel material 62 made of, for example, aluminum is adhered to a core material 50 composed of a core material body 52 and a punching metal 56 using an adhesive 64 having a large cohesive force, such as an epoxy resin. The adhesive 64 surrounds a portion where the punching metal is not embedded and exerts a good adhesive function. Of course, it is also possible to adhere a metal face material to the entire surface of the flat plate. When strength is required for punching metal, stainless steel should be used as the material.

[0025]

EFFECT OF THE INVENTION Since the core material and sandwich panel of the present invention use polyethylene or polypropylene as the main material, they are excellent in water resistance and chemical resistance, and when a face material is attached, a base material is used. Since it indirectly adheres via the interposition, it is possible to surely and easily adhere to various kinds of face materials. Incidentally, since polyethylene and polypropylene are supplied in large quantities as by-products of the petrochemical industry, there is an advantage that the material can be easily secured and the unit price is low.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a core material according to an embodiment of the present invention.

FIG. 2 is a perspective view of a wood panel manufactured using the core material of FIG. In order to make it easier to see the internal structure, some materials such as face materials are cut away.

FIG. 3 is a partially enlarged view showing a fusion state of a core material and a non-woven fabric used for the core material of FIG.

FIG. 4 is an enlarged perspective view showing a part of a core material according to another embodiment of the present invention.

FIG. 5 is a perspective view showing a core member according to still another embodiment of the present invention.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is a perspective view of a stretch punching metal used to form irregularities on one surface of the core body shown in FIG.

FIG. 8 is a perspective view showing a core material according to another embodiment of the present invention.

[Explanation of symbols]

 12 core material main body 14 non-woven fabric (base material) 16 cell 18 face material 20 wood panel 22 adhesive 32 core material main body 34 wire mesh (base material) 35 cell wall 36 cell 42 core material main body 44 cell 46 non-woven fabric 52 core material main body 54 cell 56 Expanded punching metal 60 Cell wall (inclined piece)

Claims (12)

[Claims] 1. A core material main body made of polyethylene or polypropylene having a large number of adjacent cells extending in substantially the same direction, and a melting point higher than that of polyethylene or polypropylene, and fused to at least one surface of the core material main body. A core material for a sandwich panel having a porous base material. 2. The core material for a sandwich panel according to claim 1, wherein the base material is fused to the cell opening side of the core material body. 3. The core material for a sandwich panel according to claim 1, wherein the base material is a woven cloth, a non-woven cloth, a knitted cloth, or a wire mesh. 4. The core material for a sandwich panel according to claim 1, wherein the base material is made of natural fiber, synthetic resin, inorganic material or metal. 5. The core material body has at least one flat plate having irregularities formed on one surface thereof, and the base material is fused to one surface of the flat plate on the side provided with the irregularities. 1
The core material for sandwich panels described in. 6. The core material body has at least one flat plate, and the base material is an expanded punching metal having inclined pieces, and the core is partially buried in one surface of the flat plate. The sandwich panel core material according to claim 1, which is fused to the material body. 7. The core material for a sandwich panel according to claim 1, wherein the core material main body has a cross section of a ladder shape, a grid shape, a honeycomb shape, or a corrugated board shape. 8. A method of manufacturing a core material for a sandwich panel, which comprises using polyethylene or polypropylene as a material, producing a core material body having a large number of cells extending adjacent to each other in substantially the same direction, and polyethylene. Alternatively, a method for producing a core material for a sandwich panel, comprising a step of fusing a porous base material having a higher melting point than polypropylene to at least one surface of the core material body, and a step of cooling and solidifying the core material body after the fusion . 9. The method of manufacturing a core material for a sandwich panel according to claim 8, wherein, in the step of fusing, the core material main body is heated and pressed to make the ends of the cell walls thick. 10. A core material main body made of polyethylene or polypropylene having a large number of cells extending in substantially the same direction and adjacent to each other, and having a melting point higher than that of polyethylene or polypropylene and being fused to at least one surface of the core material main body. A sandwich panel having a porous base material and a face material adhered to at least one surface of the core material body via the base material. 11. A method for manufacturing a sandwich panel, which comprises using polyethylene or polypropylene as a material to produce a core material body having a large number of cells extending adjacent to each other in substantially the same direction; A step of fusing a porous base material having a high melting point to at least one surface of the core material body, a step of cooling and solidifying the core material body after the fusion, and a step of applying the base material to at least one surface of the core material body. A method of manufacturing a sandwich panel, which comprises a step of adhering the face material with an adhesive via the interposition. 12. The method of manufacturing a sandwich panel according to claim 11, wherein the adhesive surrounds at least a part of the base material.