JP2021035730A - Hollow structure plate and production method thereof - Google Patents

Abstract

To provide a hollow structure plate comprising excellent flatness and fitting property in coupling time and capable of being easily detached.SOLUTION: A hollow structure plate 1 comprises a hollow protrusion molding sheet which has a plurality of hollow protrusions formed on at least one surface and is formed of one or two thermoplastic resins. The hollow structure plate 1 comprises a pair of recess parts which have different height on at least one end, and the pair of recess parts are adjacent in an orientation where the recess parts are in parallel. A first recess part 20a of the pair of recess parts extends to a second recess part 20b whose height is lower than that of the first recess part, and a difference between a height of the first recess part and a height of the second recess part is 40-70% or smaller with respect to a total thickness of the hollow structure plate, and the height of the second recess part is 15% or greater with respect to a total thickness of the hollow structure plate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hollow structural plate and a method for producing the same. More specifically, the present invention relates to a hollow structural plate having a hollow convex portion molded sheet made of one or two thermoplastic resins having a plurality of hollow convex portions formed on at least one surface, and a method for producing the same.

Hollow structural boards made of resin are lightweight, have excellent chemical resistance, water resistance, heat insulation, sound insulation and resilience, and are easy to handle. Therefore, they are used for logistics, construction such as panel materials, and more. Is used in a wide range of fields such as automotive applications. For example, in Patent Document 1, a corrugated member made of a synthetic resin material in which an uneven waveform is repeated at a predetermined pitch between two sheets made of a synthetic resin material arranged in parallel at a predetermined interval. A hollow structural plate in a sandwiched state is disclosed.

Further, for example, in Patent Document 2, a so-called twin cone (registered trademark) type hollow structure having a structure in which a plurality of convex portions protruding from two thermoplastic resin sheets are heat-sealed in a state of being abutted against each other. The board is disclosed. Since this twin cone (registered trademark) type hollow structure plate is excellent in bending performance and compression performance, it is used in various fields such as automobile interior materials, logistics materials, and building materials.

A plurality of such hollow structural plates may be connected and used to form a partition or the like. For example, Patent Document 1 discloses a technique for connecting hollow plates to each other by using a structural material attached to the edge of the hollow plate.

Japanese Unexamined Patent Publication No. 2003-170515 Japanese Unexamined Patent Publication No. 2008-260309 Japanese Unexamined Patent Publication No. 2016-56859

Conventionally, it has been possible to connect a plurality of hollow structure plates by heat-bonding them to each other, but once the hollow structure plates are heat-bonded, it is difficult to return to the individual state again. Further, if the size of the hollow structure plate to be manufactured is made larger than the conventional size, it becomes difficult to store and carry the hollow structure plate. Further, by using a conventionally known structural material or the like, when the hollow structural plates are connected to each other, the thickness of the connecting portion of the structural material or the like is larger than the thickness of the plate, so that the flatness is deteriorated. There was a problem.

Therefore, it is a main object of the present invention to provide a hollow structure plate which has excellent flatness and consistency at the time of connection and is easy to remove, and a method for manufacturing the same.

That is, in the present invention, the hollow structure plate has a hollow convex portion molded sheet made of one or two thermoplastic resins having a plurality of hollow convex portions formed on at least one surface, and the hollow structural plate is , At least one end has a pair of recesses having different heights, the pair of recesses are adjacent to each other in a direction parallel to each other, and the first recess of the pair of recesses has a height higher than that of the first recess. It is extended to a lower second recess, and the difference between the height of the first recess and the height of the second recess is 40% or more and 70% or less with respect to the total thickness of the hollow structure plate, and the first recess. (Ii) Provided is a hollow structure plate in which the height of the recess is 15% or more with respect to the total thickness of the hollow structure plate.
The hollow structure plate according to the present invention may be formed by laminating one or more surface materials and / or skin materials on at least one surface of the hollow convex portion molded sheet.
Further, the hollow convex portion forming sheet is composed of two thermoplastic resin sheets in which a plurality of frustum-shaped convex portions are formed on one surface, and the two thermoplastic resin sheets abut the convex portions against each other. It may have a structure that is melted in a state of being melted.

Further, in the present invention, the hollow structural plate has a hollow convex portion molded sheet made of one or two thermoplastic resins having a plurality of hollow convex portions formed on at least one surface, and the hollow structural plate is a hollow structural plate. , At least one end has a pair of recesses having different heights, the pair of recesses are adjacent to each other in a direction parallel to each other, and the first recess of the pair of recesses has a height higher than that of the first recess. It is extended to a lower second recess, and the difference between the height of the first recess and the height of the second recess is 40% or more and 70% or less with respect to the total thickness of the hollow structure plate, and the first recess. (Ii) In the method for manufacturing a hollow structure plate in which the height of the recesses is 15% or more with respect to the total thickness of the hollow structure plate, the pair of recesses are formed by semi-crushing to manufacture the hollow structure plate. It also provides a method.

According to the present invention, there is provided a hollow structure plate which has excellent flatness and consistency at the time of connection and is easy to remove.
The effects described here are not necessarily limited, and may be any of the effects described in the present specification.

It is a schematic perspective view which shows an example of the structure of the hollow structure plate 1 which concerns on this invention. It is a schematic cross-sectional view which shows an example of the structure of the hollow structure plate 1 which concerns on this invention. A to D are schematic cross-sectional views showing an example of the structure of the hollow structure plate 1 according to the present invention, omitting the internal structure, and E is a structure of the hollow structure plate (comparative example) not included in the present invention. It is a schematic cross-sectional view which omitted the internal structure which shows an example. A is a schematic plan view showing a state in which the two hollow structure plates 1 are combined, and B is a schematic cross-sectional view of the combined portion of the two hollow structure plates 1. It is a schematic conceptual diagram which shows an example of the manufacturing method of the hollow structure plate 1 which concerns on this invention.

Hereinafter, suitable embodiments for carrying out the present invention will be described in detail with reference to the drawings.
It should be noted that the embodiments described below show an example of typical embodiments of the present invention, and the scope of the present invention is not narrowly interpreted by this.

1. 1. Hollow structure plate 1
FIG. 1 is a schematic perspective view showing an example of the structure of the hollow structure plate 1 according to the present invention. The hollow structure plate 1 according to the present invention has a hollow convex portion molded sheet 2 made of one or two thermoplastic resins having a plurality of hollow convex portions formed on at least one surface thereof, and has a height at least one end thereof. It has a pair of recesses 20a and 20b different from each other.

Further, in the present invention, the pair of recesses 20а and 20b are adjacent to each other in parallel directions, and the first recess 20a of the pair of recesses 20а and 20b is lower in height than the first recess 20a. It is characterized in that it extends to the second recess 20b.

In the present invention, by adopting the above structure, the hollow structural plates 1 can be connected to each other without using a conventionally known structural material or the like. Further, by connecting the plates with a structural material or the like, the thickness of the connecting portion does not become larger than the thickness of the plates, so that the flatness can be maintained. Furthermore, since no structural material or the like is used, it can be easily removed and can be used repeatedly.
In addition, when two hollow structure plates 1 are put together, for example, each hollow structure plate 1 can adopt a structure having a pair of recesses 20a and 20b at one end thereof. For example, in the case where three or more hollow structure plates 1 are assembled with each other, each hollow structure plate 1 may have a structure having a plurality of a pair of recesses 20a and 20b at its ends. ..

Further, in the present invention, the difference between the height of the first recess 20a and the height of the second recess 20b is 40% or more and 70% or less with respect to the total thickness of the hollow structure plate 1, and the first. (Ii) The height of the recess 20b is 15% or more with respect to the total thickness of the hollow structure plate 1.

When the difference between the height of the first recess 20a and the height of the second recess 20b (hereinafter, also simply referred to as “X”) exceeds 70% with respect to the total thickness of the hollow structure plate 1, the second recess 20b Since the height (hereinafter, also simply referred to as “Y”) is less than 15% of the total thickness of the hollow structure plate 1 and the second recess 20b becomes too thin, the durability of the hollow structure plate 1 is improved. Problems arise. Further, if X is less than 40% of the total thickness of the hollow structure plate 1, the catching area at the mating portion becomes small, and the fitting property deteriorates.
Therefore, by controlling X and Y within the above-mentioned specific numerical range, it is possible to obtain the hollow structure plate 1 having excellent durability while maintaining the consistency.

In the present invention, the upper limit of the height of the second recess 20b is not particularly limited, but it is preferably 30% or less with respect to the total thickness of the hollow structure plate 1.

In the present invention, the specific numerical range of X is not particularly limited, but it is preferably 0.6 mm or more and 38.5 mm or less. Further, the specific numerical range of Y is not particularly limited, but it is preferably 0.23 mm or more and 16.5 mm or less.

3A to 3D are schematic cross-sectional views showing an example of the structure of the hollow structure plate 1 according to the present invention, omitting the internal structure. In the present invention, the structure of the pair of recesses 20a and 20b is not particularly limited, but for example, the structures A to D in FIG. 3 can be used, and the structure A in FIG. 3 is particularly preferable from the viewpoint of ease of formation. .. Note that X and Y when each structure is adopted are shown in the figure.

In the present invention, as shown in B of FIG. 3, in the hollow structure plate 1 having a plurality of pairs of recesses 20a and 20b, the structures of the pair of recesses 20a and 20b do not necessarily have to be the same. Further, as shown in D of FIG. 3, the structure may be such that when the hollow structure plates 1 are put together, a partial gap is provided.

Is not particularly limited total weight of the hollow plate 1, it is preferable that the 200 g / ^{m 2} or more 6000 g / ^{m 2} or less, more preferably to 500 g / ^{m 2} or more 3000 g / ^{m 2} or less, 800 g / ^{m 2} It is particularly preferable that the amount is 2000 g / m ^{2 or more.} As a result, the weight of the hollow structure plate 1 can be reduced.

The total thickness of the hollow structure plate 1 is also not particularly limited, but is preferably 1.5 mm or more and 55 mm or less, more preferably 2 mm or more and 25 mm or less, and particularly preferably 3 mm or more and 15 mm or less. By setting the thickness to 1.5 mm or more, it is possible to prevent the thickness of the hollow structure plate 1 from becoming too thin, and to manufacture the hollow structure plate 1 in which the bending rigidity is maintained. Further, by setting the thickness to 55 mm or less, the height of the convex portion 21 in the hollow convex portion forming sheet 2 can be controlled, and the thickness of the side wall of the convex portion 21 can be prevented from being drafted and become too thin, so that deformation (for example, buckling) can be prevented. Etc.) can be produced easily.

Further, in the hollow structure plate 1, the end face on which the pair of recesses 20а and 20b are not formed may be processed into an arbitrary shape. Specifically, for example, the end face may be left uncut, but the end face may be processed into a C shape or the like, sealed to a vertical end face, or sealed to an R shape. Further, in the present invention, in order to impart functionality to the end face of the hollow structure plate 1, an edge material can be bonded to each other via an adhesive or the like.

<Hollow convex molded sheet 2>
The hollow convex portion forming sheet 2 is made of one or two thermoplastic resins in which a plurality of hollow convex portions 21 are formed on at least one surface. The hollow structure plate 1 according to the present invention may be formed only from the hollow convex portion forming sheet 2, but at least one surface material 3 and / or the skin on at least one surface of the hollow convex portion forming sheet 2. It is preferable that the materials 4 are formed by laminating the materials 4. In the present invention, there may be a slight gap partially between the surface material 3 and the skin material 4 laminated on the hollow convex portion forming sheet 2 and the hollow convex portion forming sheet 2.

As shown in FIG. 2, the specific shape of the hollow convex portion 21 is not particularly limited as long as it has at least the upper surface portion 211 and the opening portion 212, and can be freely designed as appropriate. Specifically, for example, a truncated cone shape such as a truncated cone shape or an elliptical pyramid shape, a triangular pyramid shape, a quadrangular pyramid shape, a pentagonal pyramid shape, and a cylindrical shape shown in FIGS. It can be designed into various shapes such as an elliptical column shape, a polygonal column shape, a polygonal star column shape, and a polygonal truncated cone shape. Moreover, you may design by combining these shapes as appropriate.

Further, in the present invention, when the surface material 3 and / or the skin material 4 described later is laminated on the hollow convex portion forming sheet 2, the starting point is reduced to increase the peel strength from the surface material 3 and / or the skin material 4. In order to improve the shape, the corners such as a polygonal pyramid shape and a polygonal prism shape may be designed to be rounded.

The shape of the convex portion 21 is preferably any one or more selected from the group consisting of a truncated cone shape, an elliptical truncated cone shape, and a polygonal truncated cone shape. As a result, in addition to facilitating the design in the manufacturing process, when the convex portion 21 is molded using the mold, the manufacturing cost of the mold can be reduced. Further, the shape of the convex portion 21 is preferably a shape having a taper at least partially, and particularly preferably a truncated cone shape and / or an elliptical frustum shape. As a result, the bending rigidity of the hollow structure plate 1 can be improved, and the compressive strength can be maintained.

When the convex portion 21 is designed to have a truncated cone shape and / or an elliptical truncated cone shape, the length of the diameter of the upper surface portion 211 is not particularly limited, but is preferably 1 mm or more and 10 mm or less. As a result, the compressive strength of the hollow structure plate 1 in the thickness direction can be improved.

When the convex portion 21 is designed to have a truncated cone shape and / or an elliptical truncated cone shape, the length of the diameter of the opening 212 is not particularly limited, but is preferably 3 mm or more and 15 mm or less. As a result, the compressive strength of the hollow structure plate 1 in the thickness direction can be improved.

The convex portions 21 may all have the same shape, or two or more types of shapes may be freely selected and combined. Further, in the present invention, a step may be provided or a wave may be provided in the middle of the convex portion 21.

The arrangement form of the convex portions 21 is not particularly limited and can be arranged in a square grid pattern, a staggered pattern, or irregularly, and among these, it is particularly preferable to arrange the convex portions 21 in a square lattice pattern or a staggered pattern. In addition, in this specification, the staggered arrangement includes a state in which adjacent convex portions 21 are arranged so as to be staggered when viewed along a predetermined reference direction.

When the convex portions 21 are arranged in a staggered pattern, the angle θ2 formed by the line connecting the centers of the convex portions 21 in the lateral direction and the line connecting the centers of the convex portions 21 in the diagonal direction is not particularly limited. It is preferable that θ2 = about 60 °. Thereby, the rigidity of the hollow structure plate 1 can be improved. The “square grid” means an array when θ2 = about 90 °.

The shortest distance L between the openings 211 of the convex portion 21 is not particularly limited, but is preferably 0.2 mm or more and 8 mm or less. By setting the shortest distance L to 0.2 mm or more, it is possible to prevent the thickness of the liner portion (the portion where the convex portion 21 does not exist when the convex portion 21 is viewed from a certain direction) from becoming too thin, so that the compression strength is reduced. Can be avoided. Further, by setting the shortest distance L to 8 mm or less, it is possible to prevent the distance between the convex portions 21 from becoming too long and the number of the convex portions 21 per unit area from decreasing too much. It can be kept above a certain level. In the hollow structure plate 1 according to the present invention, the shortest distance L does not have to be constant at all times.

The angle (inclination angle) θ1 (see FIG. 2) formed by the imaginary horizontal surface and the convex portion 21 in the hollow convex portion forming sheet 2 is not particularly limited, but is sufficient when a load is applied from the outside of the hollow structure plate 1. It is preferable to have an inclination angle in order to obtain sufficient strength. When it has an inclination angle, the inclination angle θ1 is preferably 45 ° or more. Further sufficient strength can be obtained by setting the inclination angle θ1 to 45 ° or more. Further, the inclination angle θ1 is preferably less than 80 °. By setting the inclination angle θ1 to less than 80 °, it is possible to prevent the hollow convex portion forming sheet 2 from becoming too thin when the hollow convex portion forming sheet 2 is vacuum-formed, and to form the convex portion 21 into a film. Can also be prevented, so sufficient strength can be obtained.

Further, the inclination angle θ1 is more preferably 50 ° or more and less than 75 °. Thereby, the rigidity of the hollow structure plate 1 can be increased. In addition, deformation due to buckling or the like can be prevented, and the shape retention of the hollow structure plate 1 can be improved. In the hollow structure plate 1, the inclination angle θ1 does not have to be constant, and the convex portion 21 may have an asymmetrical shape with respect to the central axis.

The height h of the convex portion 21 (see FIG. 2) is not particularly limited, but is preferably 1 mm or more. By setting the height h of the convex portion 21 to 1 mm or more, the hollow structure plate 1 having high rigidity can be obtained. Further, the height h of the convex portion 21 is preferably 50 mm or less. By setting the height h of the convex portion 21 to 50 mm or less, it is possible to prevent the side wall portion of the convex portion 21 from becoming too thin and prevent the hollow convex portion molded sheet 2 from being deformed.

The thickness of the convex portion 21 is also not particularly limited, but is preferably 0.1 mm or more. By setting the thickness of the convex portion 21 to 0.1 mm or more, deformation such as buckling can be prevented and the shape retention of the hollow structure plate 1 can be improved.

Further, in the present invention, it is also possible to adopt a structure in which a flow path exists in a part of the hollow convex portion forming sheet 2. In the present invention, the shape of the flow path, the structure of the cross section, the formation direction of the flow path, and the like are not particularly limited.

In the present invention, as shown in FIGS. 1 and 2, the structure of the hollow convex portion forming sheet 2 is composed of two thermoplastic resin sheets in which a plurality of frustum-shaped convex portions are formed on one surface, and the above 2 It is preferable that the thermoplastic resin sheet has a structure in which the convex portions 21 are melted in a state of being butted against each other. In this case, the truncated cone shape is preferably a truncated cone shape and / or an elliptical truncated cone shape. By adopting this structure, the flatness can be further improved and the bending rigidity is also excellent.

The material of the hollow convex portion forming sheet 2 is not particularly limited as long as it is a thermoplastic resin, and one or two or more kinds of thermoplastic resins that can be usually used for the hollow structure plate can be appropriately selected and used.
Examples of the thermoplastic resin include polyethylene (PE), polypropylene (PP), polystyrene (PS), polyurethane, polycarbonate (PC), polymethylmethacrylate (PMMA), polyacetal (POM) and the like.

Among these, the material of the hollow convex molded sheet 2 is low-density polyethylene, high-density polyethylene (HDPE), linear low-density polyethylene, and ultra-low-density polyethylene from the viewpoints of workability, cost, weight, and physical properties. , Polypropylene homopolymers, polypropylene random copolymers, polypropylene block copolymers and other olefin resins are preferred. Further, in order to obtain higher rigidity, engineering plastics such as ABS resin and polycarbonate can also be used.

In the present invention, fillers such as talc, mica and calcium carbonate, chopped strands such as glass fiber, aramid fiber and carbon fiber are added to the thermoplastic resin forming the hollow convex molded sheet 2 and the surface material 3 described later. Alternatively, a modifier, a colorant such as a pigment, or the like for improving flame retardancy, conductivity, wettability, slipperiness, weather resistance, etc. may be added.

The hollow convex portion forming sheet 2 and the surface material 3 described later may be formed of the same material, or may be formed of different materials within a range in which heat fusion is possible.

The basis weight of the hollow convex portion forming sheet 2 is not particularly limited ^{, but is preferably 300 g / m 2} or more and 600 g / m ² or less, and more preferably 350 g / m ² or more and 500 g / m ² or less. By setting the basis weight to 300 g / m ² or more, the shape retention of the convex portion 21 can be improved. Further, by setting the basis weight to 600 g / m ² or less, the weight of the hollow structure plate 1 can be reduced.

The thickness of the hollow convex portion forming sheet 2 is also not particularly limited, but is preferably 1.5 mm or more and 55 mm or less. By setting the thickness to 1.5 mm or more, it is possible to prevent the thickness of the hollow structure plate 1 from becoming too thin, and to manufacture the hollow structure plate 1 in which the bending rigidity is maintained. Further, by setting the thickness to 55 mm or less, the height of the convex portion 21 in the hollow convex portion forming sheet 2 can be controlled, and the thickness of the side wall of the convex portion 21 can be prevented from being drafted and become too thin, so that deformation (for example, buckling) can be prevented. Etc.) can be produced easily.

<Surface material 3>
The surface material 3 is made of, for example, a thermoplastic resin, and is laminated on the hollow convex portion forming sheet 2 to form the hollow structure plate 1 together with the hollow convex portion forming sheet 2.

When the material of the surface material 3 is a thermoplastic resin, one type or two or more types of thermoplastic resins that can be usually used for the hollow structure plate can be freely used.
Since the thermoplastic resin is the same as the hollow convex portion molded sheet 2, the description thereof is omitted here.

The thickness of the surface material 3 is not particularly limited, but is preferably 0.1 mm or more. By setting the thickness to 0.1 mm or more, the rigidity of the hollow structure plate 1 can be maintained.

The basis weight of the surface material 3 is not particularly limited ^{, but is preferably 200 g / m 2} or more and 800 g / m ² or less, and more preferably 300 g / m ² or more and 600 g / m ² or less.

<Skin material 4>
The skin material 4 constitutes the hollow structure plate 1 together with the hollow convex portion forming sheet 2 and / or the surface material 3 directly on the hollow convex portion forming sheet 2 or laminated on the surface material 3. By laminating the skin material 4, it is possible to impart properties such as designability, sound absorption property, and heat insulation property to the hollow structure plate 1 according to various uses.

The material of the skin material 4 is not particularly limited, and a material that can be usually used as the skin material of the hollow structure plate can be freely selected and used depending on the intended use and the like.
Specific examples thereof include thermoplastic resin sheets, resin woven fabrics, non-woven fabrics, braided fabrics, knitted fabrics, metal sheets made of stainless steel, aluminum, copper and the like, organic or inorganic porous sheets, decorative sheets and the like. Be done.

2. Manufacturing Method of Hollow Structure Plate 1 FIG. 5 is a schematic view showing an example of a manufacturing method of the hollow structure plate 1.
Hereinafter, the method for manufacturing the hollow structure plate 1 according to the present invention will be described with reference to FIG. 5, but the present invention is not limited to this. That is, in the production of the hollow structure plate 1 according to the present invention, the method usually used for producing the hollow structure plate can be freely selected and used as appropriate.

In the manufacturing method shown in FIG. 5, first, the hollow convex portion forming sheet 2 is manufactured. The hollow convex portion forming sheet 2 uses a vacuum forming apparatus in which two forming rollers R1 having a plurality of convex pins projected on the surface thereof are arranged so that their rotation axes are parallel to each other. Manufactured by injecting a molten thermoplastic resin sheet P extruded from an extruder 101 provided with a T-die 102 at the tip into a groove of R1 and molding the convex portions 21 in a state of being butted against each other. To.
In this production example, the two forming rollers R1 are installed in the decompression chambers 103a and 103b, respectively, and the hollow convex forming sheet 2 and the surface material 3 are sucked and held in the decompression chambers 103a and 103b, respectively. Suction holes 104a and 104b are provided for this purpose.
In the present invention, as the hollow convex portion forming sheet 2, a prefabricated hollow convex portion may be used. Further, the hollow convex portion forming sheet 2 may be produced by injecting a molten thermoplastic resin sheet P into a pair of dies or the like and pressing the sheets from both sides without using the forming roller R1.

Next, the surface material 3 in the molten state or the softened state extruded from the extruder 101 is laminated on each surface of the hollow convex portion forming sheet 2.
In the present invention, the surface material 3 may be a prefabricated one.

After that, the first concave portion 20a and the second concave portion 20b are produced by pressing one end of the hollow convex portion forming sheet 2 on which the surface material 3 is laminated by the pressing machine 105 from the same direction, according to the present invention. Obtain the hollow structure plate 1. The pressing machine 105 may have a heating function, a temperature control function, and the like. In this production example, the heights of the first recess 20а and the second recess 20b are controlled by, for example, adjusting the shape, pressure, and the like of the pressing machine 105.

In the present invention, the method for producing the pair of recesses 20a and 20b is not limited to the above-mentioned semi-crushing process, and may be produced by, for example, punching, but in the present invention, the pair of recesses 20a and 20b are formed. , It is preferably formed by semi-crushing.
When the hollow structure plate 1 is half-crushed, the cross section of the hollow structure (see the Z portion in FIG. 1) becomes rough, and the shape differs depending on the place where the half-crushing process is performed. These rough cross sections serve as resistance, resulting in good integration.

Further, although not shown in FIG. 5, in the present invention, the skin material 4 is directly laminated on the hollow convex portion forming sheet 2, or the surface material 3 laminated on the hollow convex portion forming sheet 2 is further laminated. It is also possible to stack the skin material 4.

Hereinafter, the present invention will be described in more detail based on Examples.
It should be noted that the examples described below show an example of a typical example of the present invention, and the scope of the present invention is not narrowly interpreted by this.

First, the hollow structural plates of Examples 1 to 9 and Comparative Examples 1 to 4 shown in Tables 1 and 2 below were prepared.
The hollow structural plates of Examples 1 to 6 and Comparative Examples 1 to 3 had a cross-sectional shape of A shown in FIG. 3, and were manufactured by the manufacturing method shown in FIG.
The hollow structure plate of Example 7 had a cross-sectional shape of B shown in FIG. 3, and was manufactured by the manufacturing method shown in FIG.
The hollow structure plate of Example 8 had a cross-sectional shape of C shown in FIG. 3, and was manufactured by the manufacturing method shown in FIG.
The hollow structure plate of Example 9 has a cross-sectional shape of D shown in FIG. 3, and was manufactured by the manufacturing method shown in FIG.
The hollow structure plate of Comparative Example 4 had a cross-sectional shape of E shown in FIG. 3, and was manufactured by the manufacturing method shown in FIG.

Next, the flatness, consistency, and durability of each of the produced hollow structural plates were evaluated. The evaluation results are also shown in Tables 1 and 2 above.

[Flatness]
First, the thicknesses of the two hollow structural plates to be fitted were measured at five points in the direction along the combined cross section, and the average value was calculated. Next, the two hollow structure plates were fitted together, and the thickness of the connecting portion of the hollow structure plate formed into one plate was measured at five points, and the average value was calculated. Then, the absolute value (| а |) of the difference between the average value of the thickness of the hollow structure plate and the average value of the thickness of the connecting portion was calculated. The evaluation criteria in Examples 1 to 9 and Comparative Examples 1 to 4 are shown below.
(Evaluation criteria)
⊚: ｜ a ｜ ≦ 0.2
◯: 0.2 << a | ≤ 0.4
×: 0.4 << a |
a = (average value of hollow structure plate thickness)-(average value of connecting portion thickness)

[Consistency]
The two hollow structure plates that were combined were dropped from a height of 1000 mm with respect to the aluminum plate at n = 5, and it was visually confirmed whether the combination was removed and the two hollow structure plates were separated. .. The evaluation criteria in Examples 1 to 9 and Comparative Examples 1 to 4 are shown below.
(Evaluation criteria)
⊚: Number of separations is 0 〇: Number of separations is 1 ×: Number of separations is 2 or more

[durability]
First, the two hollow structural plates were put together. Then, it was removed and the appearance of the Z portion shown in FIG. 1 was visually confirmed. The evaluation criteria in Examples 1 to 9 and Comparative Examples 1 to 4 are shown below.
(Evaluation criteria)
◎: No abnormality 〇: Whitening is seen in a part of the hollow structure plate ×: A part of the hollow structure plate is bent or deformed

The hollow structural plates of Examples 1 to 9 were flat at the time of connection and excellent in conformability, and were not bent or deformed at the time of removal. On the other hand, in Comparative Examples 1 and 2, the consistency was poor and the durability was also problematic as compared with Examples 1 to 9. Further, in Comparative Examples 3 and 4, although no problem was observed in the durability at the time of removal, the consistency was poor.
Therefore, the hollow structure plate according to the present invention is flat at the time of connection and has excellent conformability, and is not bent or deformed at the time of removal, and there is a problem even if it is used repeatedly. It turned out not.

According to the present invention, it is possible to provide a hollow structure plate which has excellent flatness and consistency at the time of connection and is easy to remove. Therefore, the hollow structural board according to the present invention is useful in a wide range of fields such as automobile interior materials, distribution materials, interior or exterior building materials, and the like.

1: Hollow structure plate 2: Hollow convex molded sheet 20а: First concave 20b: Second concave 21: Convex 211: Upper surface 212: Opening 3: Surface material θ1: Virtualized from the opening 212 of the convex 21 Angle formed by the horizontal surface and the convex portion 21: Height of the convex portion 21 R1: Molding roller R2: Flat roller 101: T die 102: Extruder 103a, 103b: Decompression chamber 104a, 104b: Suction hole 105: Pressing machine P: Thermoplastic resin sheet in a molten state

Claims (4)

A hollow structure plate having a hollow convex portion molded sheet made of one or two thermoplastic resins having a plurality of hollow convex portions formed on at least one surface thereof.
The hollow structure plate has a pair of recesses having different heights at least at one end.
The pair of recesses are adjacent to each other in a direction parallel to each other.
Of the pair of recesses, the first recess extends to the second recess, which is lower in height than the first recess.
The difference between the height of the first recess and the height of the second recess is 40% or more and 70% or less with respect to the total thickness of the hollow structure plate, and
A hollow structure plate in which the height of the second recess is 15% or more with respect to the total thickness of the hollow structure plate. The hollow structural plate according to claim 1, wherein one or a plurality of surface materials and / or skin materials are bonded to at least one surface of the hollow convex portion molded sheet. The hollow convex portion forming sheet is composed of two thermoplastic resin sheets in which a plurality of frustum-shaped convex portions are formed on one surface.
The hollow structure plate according to claim 1 or 2, wherein the two thermoplastic resin sheets have a structure in which the convex portions are butted against each other and melted. A hollow structure plate having a hollow convex portion molded sheet made of one or two thermoplastic resins having a plurality of hollow convex portions formed on at least one surface, and the hollow structure plate has a height at least at one end. The pair of recesses are adjacent to each other in a direction parallel to each other, and the first recess of the pair of recesses extends to a second recess having a height lower than that of the first recess. The difference between the height of the first recess and the height of the second recess is 40% or more and 70% or less with respect to the total thickness of the hollow structure plate, and the height of the second recess is In the method for manufacturing a hollow structure plate, which is 15% or more of the total thickness of the hollow structure plate.
A method for manufacturing a hollow structural plate, in which the pair of recesses are formed by semi-crushing.