KR102363756B1 - hollow resin plate - Google Patents

Abstract

Provided is a hollow resin board that has excellent handling properties and is hardly deformed or whitened even when a local load is applied to the edge portion by a band for packing or the like. With respect to the hollow resin plate 10 having a plurality of hollow portions 1a to 1c in the in-plane direction, at least one end portion 2 is vertically symmetrical in appearance, and the cross section of the upper and lower edges in the thickness direction is a circular arc. Let it be a shape and let the ratio (2R/T) of the curvature diameter (2R) (mm) of an upper and lower edge part and board thickness (T) (mm) be the range shown by the following formula (I).

Description

hollow resin plate

The present invention relates to a hollow resin plate having a plurality of hollow portions in the in-plane direction (direction perpendicular to the thickness direction). More specifically, it relates to a hollow resin board subjected to terminal processing (端末加工).

Since the hollow resin board is lightweight and easy to handle, as well as excellent in flexural and compressive strength, it is used for distribution purposes such as box materials and packing materials, wall or It is used in a wide range of fields, such as architectural applications such as ceiling panel materials, and vehicle interior materials. In general, hollow resin boards are cut to a predetermined size by cutting those formed in a long shape or a large area. Whitening and deformation are easy to occur at the outer edge when the band is bound with the back packing band, and if the fastening speed is fast, the packing band may be damaged by friction. .

Therefore, in order to prevent deformation, discoloration, or misalignment of the band when it is conventionally bound with a band for packing, a hollow resin whose outer peripheral cross-section is composed of a substantially vertical part having an inclined part and a protruding convex part. A plate has been proposed (see Patent Document 1). On the other hand, in order to improve handleability and aesthetics, a hollow resin board in which a sealing (sealing) process is applied to the end has also been proposed (see Patent Documents 2 to 4).

For example, the hollow resin board described in Patent Document 2 is a heating type having a substantially semicircular processing surface when viewed from the side, or curved two surface materials using an ultrasonic horn. The end is sealed by joining the end faces to each other. Moreover, in the end surface treatment method described in patent document 3, the edge part is sealed using two disk-shaped rotating bodies. Moreover, the end surface of the hollow resin board described in patent document 4 is sealed over the whole periphery by the method of pressing while vacuum processing using a metal mold|die.

Japanese Patent Laid-Open Publication No. 2010-058482 Japanese Patent Laid-Open Publication No. 2006-103027 Japanese Patent Laid-Open Publication No. 2007-237419 Japanese Patent Laid-Open Publication No. 2013-240966

End processing of hollow resin boards such as those described in Patent Documents 1 to 4 can be expected to have a certain effect on reducing the occurrence of whitening and deformation of the edge portion due to the band for packing, but hollow resin Along with the expansion of the use of the plate, the performance improvement is further demanded.

Then, an object of this invention is to provide the hollow resin board which is excellent in handling property, and deformation|transformation or whitening hardly occurs even when a local load is applied to the edge part by a band for packing etc.

A hollow resin board according to the present invention is a hollow resin board having a plurality of hollow portions in an in-plane direction, wherein at least one end portion has an outer shape symmetrical and upper and lower edges in the thickness direction are arc-shaped in cross section.圓弧狀), and the relationship between the radius of curvature (R) (mm) and the plate thickness (T) (mm) of the upper and lower rims satisfies Equation 1 below.

[Number 1]

In the present invention, "up-down symmetry" means that it is planar-symmetric with respect to the central plane in the thickness direction, and includes a case of substantially symmetrical shape. In addition, "edge portion" indicates a boundary portion with the flat portion and a curved surface portion in the vicinity thereof, and "arc cross-section" indicates that the cross section in the thickness direction is arc-shaped.

In the hollow resin board of the present invention, an opening extending along the edge may be formed at an end of the upper and lower edge portions having an arc-shaped cross section, and at a central portion in the thickness direction.

In that case, the ratio (W/T) between the width W (mm) of the opening and the plate thickness T (mm) can be, for example, 0.4 or less.

In the hollow resin board of the present invention, the entire board including the hollow part may have a vertical symmetry structure. In addition, the "up-down symmetrical structure" as used herein indicates that the structure is planar symmetric with respect to the central plane in the thickness direction, and includes a substantially symmetrical structure.

Alternatively, in the hollow resin plate of the present invention, the upper and lower edge portions may be sealed at the ends having arc-shaped cross-sections. In that case, the sealed end portions can have a resin density 150 to 240% higher than that of the other portions.

In addition, the hollow resin board of the present invention may be composed of a core material comprising one or two resin sheets in which a plurality of convex portions and/or concave portions are formed in a matrix shape, and a surface material laminated on both surfaces of the core material.

According to the present invention, since the external shape of the end is symmetrical, and the upper and lower edges in the thickness direction are arc-shaped in cross section, and the relationship between the radius of curvature and the plate thickness is within a specific range, handling is excellent. , it is possible to realize a hollow resin board that is hardly deformed or whitened even when a local load is applied to the edge portion.

1A to 1C are diagrams showing a configuration example of a hollow resin board according to a first embodiment of the present invention, where A is a plan view, B is a cross-sectional view taken along the line X-X shown in A, and C is the radius of curvature of the upper and lower edges ( It is a conceptual diagram showing the relationship between R) and the plate thickness (T).
FIG. 2 is an exploded perspective view showing a configuration example of a base material used for the hollow resin board 10 shown in FIG. 1 .
3 is an exploded perspective view showing another configuration example of the substrate.
4 is an exploded perspective view showing another configuration example of the substrate.
Fig. 5 is an exploded perspective view showing another configuration example of the substrate.
6 is a schematic diagram showing an example of terminal processing.
Fig. 7 is a conceptual diagram showing the curling of the end 2 by terminal processing.
Fig. 8A is a diagram showing a configuration example of a hollow resin plate according to a second embodiment of the present invention, which corresponds to a cross-sectional view taken along the line x-x shown in Fig. 1A, and B is a hollow resin plate 20 shown in A. It is a conceptual diagram showing the relationship between the width (W) of the opening part 21 and the plate thickness (T).
9 is a diagram schematically showing a method of a local load test.
Fig. 10 is a diagram schematically showing a method of a creep resistance test.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail with reference to attached drawing. In addition, this invention is not limited to embodiment demonstrated below.

(First embodiment)

First, a hollow resin board according to a first embodiment of the present invention will be described. 1A to 1C are views showing a configuration example of a hollow resin board of this embodiment, FIG. 1A is a plan view, FIG. 1B is a cross-sectional view taken along the x-x line shown in FIG. 1A, and FIG. 1C is a radius of curvature of the upper and lower edges ( It is a conceptual diagram showing the relationship between R) and the plate thickness (T).

[Entire configuration]

As shown in Figs. 1A and B, the hollow resin plate 10 of this embodiment is a plate-shaped resin molded body having a hollow structure, and a plurality of hollow portions 1a to 1c are formed in the in-plane direction. has been The hollow resin board 10 includes, for example, a core material 3 comprising one or two resin sheets in which a plurality of convex portions and/or concave portions are formed in a matrix shape, and a surface material 4 laminated on both surfaces thereof; 5) can be configured.

Further, at least one end portion 2 of the hollow resin plate 10 of the present embodiment has an external shape symmetrical, and the upper and lower edge portions 2a and 2b in the thickness direction are formed in an arc-shaped cross section. Here, "up-down symmetry" means that it is planar-symmetric with respect to the central plane in the thickness direction, and includes not only perfectly symmetrical cases but also substantially symmetrical cases. In addition, "edge portion" indicates a boundary portion with the flat portion and a curved surface portion in the vicinity thereof, and "arc cross-section" indicates that the cross section in the thickness direction is arc-shaped.

[Hollow part (1a to 1c)]

A plurality of hollow portions 1a to 1c may be formed in the in-plane direction, and the shape and configuration thereof are not particularly limited. For example, a plurality of independent hollow portions may be formed adjacent to each other in the in-plane direction, or they may be laminated in a plurality of stages in the thickness direction. In addition, the hollow part may be continuous in any direction and may have a structure with an open end, and both of these continuous open hollow part 1c and independent hollow part 1a, lb may be formed.

In addition, although FIG. 1B shows an example in which the independent hollow parts 1a and lb are regularly arranged, the present invention is not limited thereto, and the hollow parts 1a to 1c may be arranged irregularly. In addition, the shape of the independent hollow part is not limited to the substantially truncated cone shape shown in FIG. 1B, and various shapes such as a substantially truncated pyramid shape, a substantially cylindrical shape, and a substantially prismatic shape may be employed.

[End (2)]

If the cross-sectional shape of the upper and lower edge portions 2a, 2b is arc-shaped with respect to the end portion 2, the stress is dispersed along the curved surface even when a local load is applied by a packing band or the like, and the upper and lower edge portions 2a, 2b ), deformation and whitening are less likely to occur. Furthermore, by making the external shape of the end portion 2 symmetrical up and down, it becomes possible to suppress the occurrence of deformation and whitening similarly even when a local load is applied to either of the upper and lower borders 2a and 2b. , handling is improved.

However, even if the end portion 2 has the above shape, the relationship between the radius of curvature R (mm) and the plate thickness T (mm) of the upper and lower edge portions 2a and 2b shown in FIG. 1C satisfies the following Equation 2 Otherwise, deformation or whitening due to local load cannot be sufficiently prevented.

[Number 2]

Specifically, when the ratio (2R/T) of the curvature diameter (2R) and the plate thickness (T) of the upper edge part 2a and the lower edge part 2b is less than 0.85, the core material 3 at the time of manufacture The end portion is excessively buckled, and the plane compressive strength of the hollow resin plate 10 is lowered, or a portion having a low density is generated at the end portion 2 . As a result, when a local load is applied to the upper and lower edge portions 2a and 2b, deformation or whitening tends to occur, and the product life is shortened. In particular, in the case where the curvature diameter 2R of the upper and lower edge portions 2a and 2b is smaller in relation to the plate thickness T (for example, 2R/T≤0.60), the stress caused by the local load is not dispersed. Failure to do so may result in damage to the upper and lower edge portions 2a and 2b or cutting of the band for packing.

On the other hand, when the ratio (2R/T) of the curvature diameter (2R) and the plate thickness (T) of the upper and lower edge portions 2a and 2b exceeds 1.05, it is difficult to maintain surface smoothness, and the upper and lower edge portions in the manufacturing process (2a, 2b) relatively large irregularities are likely to be formed on the surface, particularly at the boundary between the flat surface and the curved surface. And if the upper and lower edge portions 2a, 2b have such irregularities, the load is concentrated on the irregularities when they are bound with the wrapping band, and damage such as cutting occurs in the wrapping band.

In addition, processing is performed without laminating a resin-based face material such as a nonwoven fabric, a thermoplastic resin sheet, and a foamable sheet on the surface material, and (2R/T)>1.05, to obtain a hollow resin board having a sealed structure For this purpose, it is necessary to perform processing in a wide range up to the inner part. When such processing is performed, buckling occurs at the ends and the physical properties (vertical compressive stress) of end crashes are lowered. In addition, "end crash" is an index indicating the breaking strength when a plate-like material such as a corrugated cardboard sheet is erected vertically and a load is applied from the end, and can be measured, for example, by a method prescribed in JIS Z 0403 or the like.

Therefore, in the hollow resin board 10 of the present embodiment, the external shape of the end portion 2 is symmetrical, and the upper and lower edge portions 2a and 2b are arc-shaped in cross section, and the radius of curvature R ( mm) in the relationship with the plate thickness (T), within the range satisfying the above expression (2). Accordingly, it is possible to increase the strength against a local load while maintaining the surface smoothness of the upper and lower edge portions (2a, 2b).

Moreover, it is preferable that the ratio (2R/T) of the curvature diameter (2R) of the upper and lower edge parts (2a, 2b) to the plate|board thickness (T) sets it as the range of 0.90-0.98. Accordingly, the appearance and surface smoothness of the end portion 2 can be improved, and the strength against a local load can be further increased.

Moreover, about the surface smoothness of the upper and lower edge parts 2a, 2b, it is preferable that the difference between the maximum value and the minimum value in the cross-sectional curve P prescribed|regulated to JIS B0601:2013 is 0.5 mm or less. By making the surface smoothness of the upper and lower edge portions 2a and 2b within this range, the effect of inhibiting damage to the band for packing can be further improved.

The hollow resin board 10 of this embodiment may have all the ends in a shape that is vertically symmetrical in appearance and that the upper and lower edges are arc-shaped in cross section, but at least the portion to which a local load is applied by a band for packing, etc. meets the above requirements. What is necessary is just to set it as the edge part 2 which satisfies. For example, when a plurality of hollow resin boards 10 are used in combination, a local load by a band for packing or the like may be applied to only one end portion. In such a case, only one end to which a local load is applied has an external shape symmetrical, the upper and lower edges are arc-shaped in section, and the ratio (2R/T) of the diameter of curvature (2R) to the thickness (T) is 0.85 to 1.05. What is necessary is just to set it as the edge part (2).

[Internal structure]

It is preferable that the hollow resin board 10 of this embodiment is vertically symmetrical not only in the external shape of the edge part 2 but also in internal structure. Since the difference in strength between the front and back surfaces can be eliminated by making the entire hollow resin plate 10 including the hollow portions 1a to 1c into a vertically symmetrical structure, handling can be further improved.

[Resin Density]

As shown in Fig. 2, when the end portion 2 has a sealed structure, it is preferable that the resin density of the end portion 2 is 150 to 240% higher than that of the other portions. By setting the resin density increase rate of the end portion 2 within this range, both the creep deformation resistance and the band breakage suppression effect can be improved. In addition, when the increase rate of the resin density of the end portion 2 exceeds 240% compared to the portion other than the end portion 2, the resin is extruded to the outside during terminal processing, and a burr that causes band breakage ) or a step difference may occur.

[Manufacturing method]

The hollow resin board 10 of this embodiment is composed of, for example, a core material made of a thermoplastic resin, and a surface material laminated on both sides thereof and made of a thermoplastic resin, and a base material having a plurality of hollow portions in the in-plane direction, the terminal; It can be obtained by processing. Specifically, the hollow resin plate 10 of the present embodiment has at least one end of the above-described base material, the outer appearance is symmetrical, the upper and lower edges are arc-shaped in cross section, and the radius of curvature (R) (mm) and It can be manufactured by processing into a shape in which the relation with the plate thickness (T) (mm) satisfies Equation 2 above.

<Reference>

As the base material, for example, a plate-shaped resin molded body having a structure in which a surface material is laminated on both sides of a core material comprising one or two resin sheets in which a plurality of convex portions and/or concave portions are formed in a matrix shape. can be used

The material of the core material constituting the base material may be a thermoplastic resin, and the type and characteristics thereof are not particularly limited. Specific examples of the thermoplastic resin include polyethylene (P), polypropylene (P), and polycarbonate (P C). Among them, low-density polyethylene, high-density polyethylene, linear low-density from the viewpoint of processability, etc. Olefinic resins, such as polyethylene, ultra-low-density polyethylene, homo polypropylene, random polypropylene, and block-shaped polypropylene, are preferable.

On the other hand, the material of the surface material may also be a thermoplastic resin, and the type and characteristics are not particularly limited, but from the viewpoint of workability and the like, a polyolefin-based resin is preferable similarly to the above-described core material. Further, the material of the surface material and the material of the core material may be the same or different. In addition, the thickness of a surface material is not specifically limited, According to a use or purpose, it can set suitably. However, when it is necessary to seal the end portion, it is preferable that the thickness of the surface material be 500 μm or more in order to secure the adhesive strength of the sealing portion and the rigidity of the end portion.

2 to 5 are exploded perspective views showing a configuration example of a base material used for the hollow resin board 10. As shown in FIG. Specifically, as in the base material 6 shown in Fig. 2, two resin sheets 31 and 32 having a plurality of hollow convex portions 31a and 32a formed in a matrix shape are formed into the hollow convex portions 31a and 32a. It is possible to use the core material 3 by welding so that the tip ends face each other, and the structure in which the surface materials 4 and 5 are laminated on both surfaces thereof can be used.

Or, as in the base material 7 shown in Fig. 3, on both surfaces of the resin sheet (core material 11) of a honeycomb structure in which the hollow portions 11a in the shape of regular hexagonal columns are regularly arranged in the longitudinal and transverse directions, the surface material ( 4 and 5) may be laminated. When the substrate 6 shown in Fig. 2 or the substrate 7 shown in Fig. 3 has a vertical symmetric structure, there is no difference in strength between the front and back surfaces and a hollow resin plate excellent in surface smoothness over the entire plate surface. can be manufactured.

On the other hand, as in the base material 8 shown in FIG. 4, the surface material 4, 5) may be laminated. Further, as in the base material 9 shown in Fig. 5, surface materials 4 and 5 are laminated on both sides of a resin sheet (core material 13) having convex portions 13a and concave portions 13b formed in a groove shape. you can also use

The method of laminating the surface materials 4 and 5 on the core materials 3, 11 to 13 is not particularly limited, and, in addition to heat sealing, known methods such as ultrasonic welding, adhesion by an adhesive, and lamination may be applied. can The substrate used when manufacturing the hollow resin board 10 of the present embodiment may be formed into a long shape or a large area and then cut to a predetermined size.

In addition, the base material used for the hollow resin board 10 of this embodiment is not limited to the structure shown to the above-mentioned FIGS. In addition, in the base material used for the hollow resin board 10 of this embodiment, a face material made of a thermoplastic resin sheet, a thermosetting resin sheet, a foam sheet, a nonwoven fabric, paper or woven fabric, etc. is further laminated on the surface materials 4 and 5. good.

<Terminal processing>

The terminal processing of the substrate is, for example, the target end surface shape, that is, the external appearance is symmetrical, the upper and lower edges are arc-shaped in section, and the radius of curvature (R) (mm) and the plate thickness ( This can be done by using a mold having a concave portion having a shape corresponding to a shape whose relation with T) (mm) satisfies the above expression (2). Fig. 6 is a schematic diagram showing an example of the terminal processing method of the substrate. As shown in Fig. 6, when terminal processing is performed on the base material 6 using a mold 30 having a U-shaped concave portion 30a when viewed from the side, the end of the base material 6 is The heated mold 30 is pressed to transfer the shape of the concave portion 30a.

At this time, the press distance of the mold 30 (the press-fit distance with respect to the base material) is a length at which the ends of the core material 3 and the surface materials 4 and 5 are curved toward the center in the thickness direction and joined. Accordingly, the upper surface material 4 and the lower surface material 5 are joined to each other without completely crushing the hollow portions 1a to 1c, and the hollow resin plate 10 having the sealed end portion 2 is formed. When the end portion 2 is sealed in this way, the density of the joint portion increases, and the weight per unit area (mass per unit area) of the end surface increases compared to before processing, so that the strength of the end portion is improved.

When terminal processing is performed, a part of the end portions of the core material 3 and the surface materials 4 and 5 is rolled inward. Fig. 7 is a conceptual diagram showing the curling of the end 2 by terminal processing. In the hollow resin board 10 of the present embodiment, the length (a) of the portion to be processed (the portion constituting the arc-shaped end surface of the cross-section) in the base material 6 before processing shown in Fig. 7, and the end surface after processing Let the difference (ab/2) with the length (b) of the arc in a cross section be the length (curling amount (L)) rolled inward.

And in the terminal processing of the base material, it is preferable that the ratio (L/T) of the curling amount (L) to the plate thickness (T) is in the range of 0.1 to 0.5. By setting the ratio (L/T) of the curling amount (L) to the plate thickness (T) within this range, the resin density of the end part 2 is 150 to 240% higher than that of the other parts, and the creep deformation resistance and band breakage suppression effect are improved. Together, an excellent hollow resin board is obtained. Moreover, it is more preferable that the ratio (L/T) of the amount of curl (L) to the plate thickness (T) is in the range of 0.11 to 0.17, whereby the effect of creep deformation resistance and band breakage suppression can be further improved.

In the terminal processing described above, the terminal processing conditions such as the time for pressing the mold 30 to the substrate 6 and the heating temperature of the mold 30 can be appropriately set according to the material, structure, thickness, etc. of the substrate. Further, in the production of the hollow resin board 10 of the present embodiment, a plurality of molds of the same shape may be prepared and operated at the same time to process all the ends at once, but one substrate may be processed multiple times. .

In the case of multi-axis machining, it is preferable to synchronize the pressing distance and moving speed of the mold 30, the pressing time to the substrate 6, and the like between the respective axes by using an electrically controlled servomotor. By using a servomotor, it is possible to increase the synchronization precision between the shafts compared to the cylinder control by pneumatic or hydraulic pressure. In addition, if the terminal processing conditions are electrically controlled, overload or insufficient load on the substrate 6 is less likely to occur, and since the load and the position of the mold 30 can be kept constant, the processing quality is improved and the lot ( The non-uniformity between lot) and each processing position is also reduced.

The method of terminal processing of the base material 6 is not limited to the method using the above-described heating mold, for example, a known resin processing technique such as ultrasonic processing using an ultrasonic horn or processing using a mold divided into a plurality of pieces. It can be applied, and it can select suitably according to the thickness, shape, etc. of the base material 6 . Also in ultrasonic machining or machining using a plurality of molds, in the case of multi-axis machining, it is preferable to use a servomotor to electrically control each axis.

As described in detail above, in the hollow resin board of this embodiment, the end portion to which a local load is applied by a packing band or the like is symmetrical in appearance, and the cross section of the upper and lower edges in the thickness direction is in an arc shape, In addition, since the radius of curvature R of the upper and lower edges is set within a specific range in relation to the plate thickness T, deformation or whitening of the edges due to a local load is unlikely to occur. Furthermore, since the hollow resin board of this embodiment has no concept of the front and back surfaces, whitening and deformation of the rim can be suppressed equally even if a packing band is hung on either surface. castle is excellent

In addition, if there is a portion with low density or a portion where the core material is buckled at the end of the hollow resin board, there is a risk that the edge portion may be damaged when an instantaneous load is applied. Since the hollow resin board, which is a structure, has no unevenness in density and a large amount of resin at the joint, it is possible to prevent deformation or damage of the edge portion even for an instantaneous load. In addition, since the hollow resin board of this embodiment is formed with a curved end surface, it is excellent also in the point of safety|security, and there is little possibility of damaging another thing when it touches or collides.

(Second Embodiment)

Next, a hollow resin board according to a second embodiment of the present embodiment will be described. In the hollow resin board of the first embodiment described above, the edges of the core material and the surface material are joined to seal the ends. However, the present invention is not limited to this configuration, and the edges may be open.

Fig. 8A is a diagram showing a configuration example of the hollow resin board of the present embodiment, and corresponds to a cross-sectional view taken along the line x-x shown in Fig. 1A. Fig. 8B is a conceptual diagram showing the relationship between the width W of the opening 21 of the hollow resin plate 20 and the plate thickness T shown in Fig. 8A. In Figs. 8A and 8B, the same reference numerals as those of the hollow resin board 10 shown in Fig. 1 are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

As shown in Fig. 8A, in the hollow resin plate 20 of this embodiment, an opening 21 extending along the rims 22a and 22b is formed in the central portion in the thickness direction at the end of the upper and lower rims having an arc-shaped cross-section. has been In addition, the hollow resin board 20 of this embodiment is the same as the hollow resin board 10 of the above-mentioned 1st embodiment except that it is provided with the opening part 21. As shown in FIG. That is, the hollow resin plate 20 also has a plurality of hollow portions in the in-plane direction, and at least one end portion 22 has an outer shape symmetrical, and the upper and lower edge portions 22a and 22b are arc-shaped in cross section, The relationship between the radius of curvature R (mm) of the upper and lower edge portions 22a and 22b and the plate thickness T (mm) satisfies the above expression (2).

In the hollow resin plate 20 of this embodiment, compared with the hollow resin plate 10 of the first embodiment described above, the strength of the end 22 is lowered, but the load applied to the end 22 during terminal processing is small. Therefore, the surface smoothness of the edge portions 22a and 22b is improved. In addition, the hollow resin board 20 of this embodiment has a small amount of deformation of the core material during processing, so that the bucking load is higher than that of the hollow resin board 10 .

However, when the width W of the opening 21 shown in FIG. 8B is wide, the relationship between the radius of curvature R (mm) of the upper and lower edge portions 22a and 22b and the plate thickness T (mm) is expressed by the above formula 2 may not be satisfied. Specifically, when the ratio (W/T) of the width W (mm) of the opening 21 to the plate thickness T (mm) exceeds 0.4, the core material is not sufficiently deformed during terminal machining and after machining The shape may be restored. Then, the ratio (2R/T) of the curvature diameter 2R (mm) and the plate thickness T (mm) of the upper and lower edge portions 22a and 22b exceeds 1.05, and the upper and lower edge portions 22a due to local load , 22b), deformation or whitening may occur, or damage may occur to the packing band.

Therefore, when the opening 21 is formed in the end 22 as in the hollow resin plate 20 of the present embodiment, the width W (mm) of the opening 21 and the plate thickness T (mm) are It is preferable to set the ratio (W/T) to 0.4 or less. Accordingly, it is possible to improve the surface smoothness of the edge portion without reducing the effect of preventing deformation or whitening of the edge portion due to a local load.

The hollow resin plate 20 of this embodiment can be manufactured in the same way as the hollow resin plate 10 of the first embodiment described above. For example, in terminal processing, the hollow resin having the opening 21 as shown in Figs. 8A and 8B is adjusted by adjusting the pressing distance and moving speed in the mold 30 and the pressing time to the substrate 6 . A plate 20 is obtained.

8A and B show an example manufactured using the substrate 6 shown in FIG. 2, but the present invention is not limited thereto, and even if manufactured using a substrate having a different structure as shown in FIGS. good, and in that case, the same effect is obtained. In addition, in the base material used for the hollow resin board 20 of this embodiment, a thermoplastic resin sheet, a thermosetting resin sheet, a foam sheet, paper, woven fabric, a nonwoven fabric, a metal plate, a metal mesh body, and a metal oxide on the surface materials 4 and 5. Face materials made of plates or the like may be further laminated.

Configurations and effects other than the above in the hollow resin board of this embodiment are the same as those of the above-described first embodiment.

[Example]

Hereinafter, an Example and a comparative example are given and the effect of this invention is demonstrated concretely.

(Example 1)

As a first example of the present invention, the hollow resin boards of Examples 1 to 10 and Comparative Examples 1 to 4 were manufactured by changing the substrate or terminal processing conditions, and their performance was evaluated.

<Example 1>

The hollow resin board of 1st Embodiment mentioned above was produced using the base material of the structure shown in FIG. At this time, as the resin sheets 31 and 32, those made of polypropylene resin and having a weight per unit area of 1500 g/m ² , a thickness of 0.75 mm, and a height of the convex portions 31a and 32a of 20 mm were used. In addition, as the surface materials 4 and 5, a polypropylene resin sheet having a weight per unit area of 1000 g/m ² and a thickness of 1.00 mm was used.

Terminal processing uses a mold having a concave portion with a radius of curvature (R) of 19 mm, a mold temperature of 185°C, a distance (press distance) at which the mold is pressed after contact with the substrate is 14.5 mm, and the mold is close to the substrate It was implemented by setting the speed to make 30 mm/min, and the time (holding time) of maintaining the metal mold|die in the state which made the base material contact with 4.5 second.

The hollow resin board of Example 1 produced by the above method had a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a diameter of curvature (2R) of the upper and lower edges of 20.1 mm, a diameter of curvature (2R) and a thickness ( The ratio (2R/T) with T) was 0.98.

<Example 2>

The hollow resin board of 1st Embodiment mentioned above was produced using the base material of the structure shown in FIG. At this time, as the resin sheets 31 and 32, those made of polycarbonate resin and having a weight per unit area of 1500 g/m ² , a thickness of 0.72 mm, and a height of the convex portions 31a and 32a of 20 mm were used. In addition, as the surface materials 4 and 5, a polycarbonate resin sheet having a weight per unit area of 1000 g/m ² and a thickness of 0.92 mm was used.

The terminal processing was performed using the same mold as in Example 1, a mold temperature of 310 ° C., a press distance of 14.5 mm, a speed of bringing the mold close to the substrate at 20 mm/min, and a holding time of the mold at 5.0 seconds.

The hollow resin board of Example 2 manufactured by the above method had a weight per unit area of 3500 g/m ² , a thickness of 20.3 mm, a curvature diameter (2R) of the upper and lower edges of 19.9 mm, a curvature diameter (2R) and a plate thickness ( The ratio (2R/T) with T) was 0.98.

<Example 3>

A hollow resin board of the above-described first embodiment was produced using the same substrate as in Example 1. In Example 3, a mold having a concave portion having a radius of curvature (R) of 16 mm is used, and the conditions of terminal processing are: a mold temperature of 190° C., a press distance of 15.0 mm, a speed of bringing the mold close to the substrate 20 mm/min, the mold The holding time was set to 4.5 seconds.

As a result, the hollow resin board of Example 3 has a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a diameter of curvature (2R) of the upper and lower edges of 17.4 mm, and a diameter of curvature (2R) and the thickness (T) of the The ratio (2R/T) was 0.85.

<Example 4>

A hollow resin board having the structure shown in Fig. 1 was manufactured using the same substrate as in Example 1. In Example 4, a mold having a concave portion having a radius of curvature (R) of 22 mm is used, and the conditions of terminal processing are: a mold temperature of 185° C., a press distance of 14.5 mm, a speed of bringing the mold close to the substrate 30 mm/min, the mold The holding time was set to 4.5 seconds.

As a result, the hollow resin board of Example 4 has a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a curvature diameter (2R) of the upper and lower edges of 21.5 mm, and a diameter of curvature (2R) and a thickness (T) of The ratio (2R/T) was 1.05.

<Example 5>

Using the base material of the structure shown in FIG. 3, the hollow resin board of 1st Embodiment mentioned above was produced. At this time, as the core material, a polypropylene resin having a weight per unit area of 1500 g/m ² , a thickness of 0.75 mm, and a hollow portion having a height of 20 mm were used. In addition, as the surface materials 4 and 5, a polypropylene resin sheet having a weight per unit area of 1000 g/m ² and a thickness of 1.00 mm was used.

The terminal processing was performed using the same mold as in Example 1, a mold temperature of 185° C., a press distance of 14.0 mm, a speed of bringing the mold close to the substrate at 30 mm/min, and a holding time of the mold at 4.5 seconds.

The hollow resin board of Example 5 produced by the above method had a weight per unit area of 3500 g/m ² , a thickness of 20.2 mm, a diameter of curvature (2R) of the upper and lower edges of 19.7 mm, a diameter of curvature (2R) and a thickness ( The ratio (2R/T) with T) was 0.97.

<Example 6>

The hollow resin board of 1st Embodiment mentioned above was produced using the base material of the structure shown in FIG. At this time, as the resin sheets 31 and 32, a polypropylene resin having a weight per unit area of 1000 g/m ² , a thickness of 0.75 mm, and a height of the convex portions 31a and 32a of 9 mm were used. In addition, as the surface materials 4 and 5, a polypropylene resin sheet having a weight per unit area of 750 g/m ² and a thickness of 0.75 mm was used.

The terminal processing uses a mold having a concave part with a radius of curvature (R) of 9 mm, the mold temperature is 185 ° C, the press distance is 7.0 mm, the speed of bringing the mold close to the substrate is 20 mm / min, and the holding time of the mold is It was implemented by setting it as 4.5 sec.

The hollow resin board of Example 6 produced by the above method had a weight per unit area of 2500 g/m ² , a thickness of 10.0 mm, a diameter of curvature (2R) of the upper and lower edges of 9.7 mm, a diameter of curvature (2R) and a thickness ( The ratio (2R/T) with T) was 0.97.

<Example 7>

The hollow resin board of 1st Embodiment mentioned above was produced using the base material of the structure shown in FIG. At this time, as the resin sheets 31 and 32, those made of polypropylene resin and having a weight per unit area of 1500 g/m ² , a thickness of 0.75 mm, and a height of the convex portions 31a and 32a of 12 mm were used. In addition, as the surface materials 4 and 5, a polypropylene resin sheet having a weight per unit area of 1000 g/m ² and a thickness of 1.00 mm was used.

Terminal processing uses a mold having a concave portion with a radius of curvature (R) of 13 mm, a mold temperature of 185 ° C, a press distance of 10 mm, a speed of bringing the mold close to the substrate by 15 mm/min, and a mold holding time of 4.5 It was carried out in seconds.

The hollow resin board of Example 7 produced by the above method had a weight per unit area of 3500 g/m ² , a thickness of 14.0 mm, a diameter of curvature (2R) of the upper and lower edges of 13.5 mm, a diameter of curvature (2R) and a thickness ( The ratio (2R/T) with T) was 0.96.

<Example 8>

A hollow resin board of the above-described second embodiment was produced using the same substrate as in Example 1. In Example 8, the same mold as in Example 1 was used, and the terminal processing conditions were a mold temperature of 175° C., a press distance of 12 mm, a speed of bringing the mold close to the substrate 6.0 mm/min, and a holding time of the mold of 3.0 seconds.

As a result, the hollow resin board of Example 8 has a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a curvature diameter (2R) of the upper and lower edges of 19.9 mm, and a curvature diameter (2R) of The ratio (2R/T) was 0.97. In addition, the width (W) of the opening was 8.2 mm, and the ratio (W/T) of the width (W) of the opening to the thickness (T) was 0.4.

<Example 9>

A hollow resin board of the above-described second embodiment was produced using the same substrate as in Example 1. In Example 9, the same mold as in Example 1 was used, and the conditions of terminal processing were: a mold temperature of 175° C., a press distance of 13.5 mm, a speed of bringing the mold close to the substrate 6.0 mm/min, and a holding time of the mold of 3.0 seconds.

As a result, the hollow resin board of Example 9 has a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a curvature diameter (2R) of the upper and lower edges of 19.9 mm, and a curvature diameter (2R) of The ratio (2R/T) was 0.97. In addition, the width (W) of the opening was 6.15 mm, and the ratio (W/T) of the width (W) of the opening to the thickness (T) was 0.3.

<Example 10>

The hollow resin board of 1st Embodiment mentioned above was produced using the base material of the structure shown in FIG. At this time, as the resin sheets 31 and 32, those made of polypropylene resin and having a weight per unit area of 1500 g/m ² , a thickness of 0.75 mm, and a height of the convex portions 31a and 32a of 20 mm were used. In addition, as the surface materials 4 and 5, a polypropylene resin sheet having a weight per unit area of 1000 g/m ² and a thickness of 1.00 mm was used.

The terminal processing uses a mold having a concave part having a radius of curvature (R) of 19 mm, a mold temperature of 185 ° C, a press distance of 9.0 mm, a speed of bringing the mold close to the substrate 30 mm/min, and a holding time of the mold. It was implemented by setting it as 5.0 second.

The hollow resin board of Example 10 produced by the above method had a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a radius of curvature (2R) of the upper and lower edges of 20.1 mm, a diameter of curvature (2R) and a thickness ( The ratio (2R/T) with T) was 0.98.

<Comparative Example 1>

A hollow resin plate with a sealed end was manufactured using the same substrate as in Example 1. In Comparative Example 1, a mold having a concave portion having a radius of curvature (R) of 16 mm is used, and the conditions for terminal processing are: a mold temperature of 200° C., a press distance of 16.0 mm, a speed of bringing the mold close to the substrate 30 mm/min, the mold The holding time was set to 4.5 seconds.

As a result, the hollow resin board of Comparative Example 1 had a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a curvature diameter (2R) of the upper and lower edges of 17.2 mm, and a curvature diameter (2R) of The ratio (2R/T) was 0.84.

<Comparative Example 2>

A hollow resin plate with a sealed end was manufactured using the same substrate as in Example 1. In Comparative Example 2, a mold having a concave portion having a radius of curvature (R) of 22 mm is used, and the conditions for terminal processing are: a mold temperature of 200° C., a press distance of 16.0 mm, a speed of bringing the mold close to the substrate 30 mm/min, the mold The holding time was set to 4.5 seconds.

As a result, the hollow resin board of Comparative Example 2 had a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a curvature diameter (2R) of the upper and lower edges of 21.7 mm, and a The ratio (2R/T) was 1.06.

<Comparative Example 3>

A hollow resin board with an open end was produced using the same substrate as in Example 1. In Comparative Example 3, the same mold as in Example 1 was used, and the terminal processing conditions were a mold temperature of 175° C., a press distance of 8.0 mm, a speed of bringing the mold close to the substrate 6.0 mm/min, and a holding time of the mold of 3.0 seconds.

As a result, the hollow resin board of Comparative Example 3 has a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a curvature diameter (2R) of the upper and lower edges of 20.1 mm, and a The ratio (2R/T) was 0.98. In addition, the width (W) of the opening was 12.3 mm, and the ratio (W/T) of the width (W) of the opening to the thickness (T) was 0.60.

<Comparative Example 4>

A hollow resin plate with a sealed end was manufactured using the same substrate as in Example 1. In Comparative Example 4, the same mold as in Example 1 was used, and the terminal processing conditions were a mold temperature of 200° C., a press distance of 7.0 mm, a speed of bringing the mold close to the substrate 20.0 mm/min, and a holding time of the mold of 1.0 second.

As a result, the hollow resin board of Comparative Example 4 has a weight per unit area of 3500 g/m ² , a thickness of 20.5 mm, a curvature diameter (2R) of the upper and lower edges of 12.3 mm, and a The ratio (2R/T) was 0.60.

<Evaluation>

The hollow resin boards of Examples 1 to 10 and Comparative Examples 1 to 4 were evaluated in the following manner. Moreover, for comparison, the same evaluation was performed using the base material which was not terminal-processed as a reference example.

(1) Local load test

9 is a diagram schematically showing a method of a local load test of a hollow resin board of Examples and Comparative Examples. The hollow resin boards of Examples and Comparative Examples and the base material of Reference Examples were cut to a width of 50 mm and a length of 170 mm to obtain a sample for evaluation (50). And as shown in FIG. 9, the band 53 for packing was arrange|positioned between the sample 50 and the pedestal 51, and it fixed with the clamp 52. The band 53 for packing was made of polypropylene resin, and the thing of width 15mm and thickness 0.6mm was used.

Next, attach the tip of the band 53 for packing to the load cell 54, pull the band 53 for packing in the upward direction at a tensile speed of 20 mm/min, and load 150 N on the edge of the sample 50 was added At that time, when the load reached 150N, the movement of the crosshead was stopped. After that, the sample 50 was removed, and the state of the edge part was confirmed visually. As a result, a case in which whitening or deformation occurred in the edge portion was denoted as × (impossible), and a case in which neither whitening nor deformation occurred was denoted as ○ (probable).

(2) Band breakage test

A load was applied to the edge of the sample 50 in the same manner as in the local load test, except that the tensile speed was set to 200 mm/min. Confirmed. As a result, the thing which damage|disconnection etc. generate|occur|produced was set to x (impossibility), and the thing which did not generate|occur|produce was made into (circle) (a).

(3) End buckling strength

The end buckling strength was measured using the same sample and device as in the local load test described above. Specifically, attach the tip of the band 53 for packing to the load cell 54, pull the band 53 for packing in the upward direction at a tensile speed of 20 mm/min, until the end buckles (rising and rising) load) was applied until the existing load changed to descending. And the maximum value of the load measured by this method was taken as the buckling strength.

The above results are summarized in Tables 1 and 2 below.

As shown in Table 1, in the hollow resin boards of Examples 1 to 10 produced within the scope of the present invention, even when a local load was applied, whitening of the edge portion or damage to the packing band did not occur. Among the Examples, those in which the ratio (2R/T) of the curvature diameter (2R) of the upper and lower edge portions to the plate thickness (T) was in the range of 0.90 to 0.97 was particularly excellent in appearance and surface smoothness of the edges.

On the other hand, in the comparative example and reference example shown in Table 2, when a local load was applied, the whitening of the edge part and breakage of the band for packing generate|occur|produced. Specifically, in Comparative Example 1, since the ratio (2R/T) of the curvature diameter (2R) of the upper and lower edges to the plate thickness (T) was smaller than 0.85, the local load could not be dispersed and the band for packing was damaged. . On the other hand, in Comparative Example 2, since the ratio (2R/T) of the curvature diameter (2R) and the plate thickness (T) of the upper and lower edge portions exceeds 1.05, irregularities occur on the surface of the edge portion, resulting in whitening of the edge portion and of the band for packing. damage has occurred.

In Comparative Example 3 having an opening at the end, since the ratio (W/T) of the width (W) to the plate thickness (W/T) of the opening exceeds 0.4, the shape is restored after processing, and the curvature diameter (2R) of the upper and lower edges and the plate The ratio (2R/T) to the thickness T was 1.4. As a result, damage generate|occur|produced in the band for packing. In Comparative Example 4, since (2R/T) = 0.6, the local load could not be dispersed and deformation occurred on the end surface. Moreover, in the reference example in which terminal processing was not performed, the whitening of the edge part and the damage|damage of the band for packing generate|occur|produced.

From the above results, it was confirmed that, according to the present invention, it was possible to realize a hollow resin board that was excellent in handling properties and hardly deformed or whitened even when a local load was applied to the edge portion by a band for packing or the like.

(Example 2)

As a second example of the present invention, creep resistance was evaluated for Examples 1 to 7 and 10 in which the ends were sealed. It is a figure which shows typically the method of a creep resistance test. As shown in Fig. 10, in terms of creep resistance, a packing band 53 is fixed on the sample 50 by a clamp 52 and a 10 kg weight 55 is attached to the tip of the sample 50 dried at 60°C. It was left still in the oven for 24 hours, and the amount of deformation was calculated by measuring the thickness of the place where the load was applied before and after the test.

For comparison, the same evaluation was performed using a non-terminated substrate as a reference example. The results are shown in Table 3 below. Moreover, the sample with a small creep deformation amount is excellent in creep resistance.

As shown in Table 3, the hollow resin plates of Examples 1 to 7, in which the resin density of the sealed end portion was 150 to 240% higher than that of the other portions, had excellent creep resistance.

1a~1c, 11a hollow part
2, 22 end
2a, 2b, 22a, 22b border
31, 32 resin sheet
31a, 32a, 12a, 13a projections
3, 11 to 13 core material
4, 5 surface material
6 to 9
10, 20 hollow resin plate
12b, 13b recesses
21 opening
30 mold
50 samples
51 pedestal
52 clamp
53 band for packing
54 load cell
55 weight

Claims (6)

A hollow resin plate having a plurality of hollow portions in the in-plane direction,
At least one end portion is sealed so that the external shape is symmetrical and the upper and lower edges in the thickness direction are arc-shaped in cross section, and the upper and lower edges are arc-shaped in cross section. is, the resin density is 150 to 240% higher than that of the other parts,
Regarding the surface smoothness of the upper and lower edges, the difference between the maximum value and the minimum value in the cross-sectional curve P specified in JIS B0601:2013 is 0.5 mm or less,
A hollow resin board in which the relationship between the radius of curvature (R) (mm) and the plate thickness (T) (mm) of the upper and lower edges satisfies the following formula (I).

According to claim 1,
A core material comprising one or two resin sheets in which at least one of a plurality of convex portions and concave portions is formed in a matrix shape;
It consists of a surface material laminated on both sides of the core material,
The sealed end is a hollow resin plate in which a portion of at least one of the core material and the surface material is rolled inward.
A hollow resin plate having a plurality of hollow parts in the in-plane direction,
At least one end portion has an external shape symmetrical, and the upper and lower edges in the thickness direction are formed in a cross-sectional arc shape,
An opening extending along the edge is formed in the central portion in the thickness direction at the end of the upper and lower edges having an arc-shaped cross-section,
A hollow resin board whose relationship between the radius of curvature (R) (mm) and the plate thickness (T) (mm) satisfies the following formula (I) for the upper and lower edges of the arc-shaped cross section.

4. The method of claim 3,
A hollow resin plate in which a ratio (W/T) between the width (W) (mm) of the opening and the plate thickness (T) (mm) is 0.4 or less.
5. The method of claim 3 or 4,
A core material comprising one or two resin sheets in which at least one of a plurality of convex portions and concave portions is formed in a matrix shape;
A hollow resin board composed of a surface material laminated on both sides of the core material.
4. The method of claim 1 or 3,
A hollow resin plate in which the entire plate, including the hollow part, has a top-down symmetrical structure.

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