JP6677815B2 - Hollow resin plate - Google Patents

Description

  The present invention relates to a hollow resin plate having a plurality of hollow portions in an in-plane direction. More specifically, the present invention relates to a hollow resin plate subjected to terminal processing.

  Hollow resin sheets are not only lightweight and easy to handle, but also have excellent flexural rigidity and compressive strength, so they are used for logistics such as boxes and packing materials, architectural uses such as panel materials for walls and ceilings, and vehicles. It is used in a wide range of fields such as interior materials. In general, a hollow resin plate is cut into a predetermined size by cutting a long or large area, but in a logistics application such as a box material or a packing material, the end portion is kept cut. If so, whitening or deformation is likely to occur at the outer edge portion when bound by the packing band, and when the fastening speed is high, the packing band may be damaged by friction.

  Therefore, conventionally, in order to prevent deformation, discoloration, or displacement of the band when bound by the packing band, the outer peripheral cross section is formed to have a substantially vertical portion having an inclined portion and a bulging convex portion. A hollow resin plate has been proposed (see Patent Document 1). On the other hand, in order to enhance the handleability and the appearance, a hollow resin plate having an end portion sealed is also proposed (see Patent Documents 2 to 4).

  For example, the hollow resin plate described in Patent Literature 2 uses a heating die or an ultrasonic horn whose processing surface has a substantially semicircular shape in a side view, curves two surface materials, and joins the end surfaces to each other. Part is sealed. Further, in the end face processing method described in Patent Literature 3, the end is sealed using two disk-shaped rotating bodies. Further, the end face of the hollow resin plate described in Patent Document 4 is sealed over the entire circumference by a method of pressing while vacuuming using a mold.

JP 2010-058482 A JP 2006-103027 A JP 2007-237419 A JP 2013-240966 A

  The end processing of the hollow resin plate as described in Patent Documents 1 to 4 is expected to have a certain effect in reducing the deformation of the edge and the occurrence of whitening by the packing band, but with the expansion of the use of the hollow resin plate. Further improvement in performance is required.

  Therefore, an object of the present invention is to provide a hollow resin plate which is excellent in handleability and hardly deforms or whitens even when a local load is applied to the edge by a packing band or the like.

The hollow resin plate according to the present invention is a hollow resin plate having a plurality of hollow portions in the in-plane direction, at least one end, the outer shape is vertically symmetric, and the upper and lower edges in the thickness direction. hermetically so that sealing such as arc-shaped cross section, the resin density has become 150 to 240 percent higher than the other portions, the upper and lower edges, JIS B0601: maximum in the cross section curve defined in 2013 (P) And the minimum value is 0.5 mm or less, and the relationship between the radius of curvature R (mm) of the upper and lower edges and the plate thickness T (mm) satisfies the following formula 1.
The hollow resin plate of the present invention includes a core material composed of one or two resin sheets in which a plurality of convex portions and / or concave portions are formed in a matrix, and a surface material laminated on both surfaces of the core material. In this case, the sealed end has a part of the core material and / or the surface material wound inside.

  In the present invention, “vertical symmetry” means plane symmetry with respect to the center plane in the thickness direction, and includes the case of substantially symmetry. Further, “edge” indicates a boundary portion with the plane 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.

Another hollow resin plate according to the present invention is a hollow resin plate having a plurality of hollow portions in an in-plane direction, at least one end portion is vertically symmetrical in appearance, and has upper and lower edges in a thickness direction. The upper and lower edges are provided with an opening extending along the edge at the center in the thickness direction, and the upper and lower edges have an arcuate cross section. At the edge, the relationship between the radius of curvature R (mm) and the plate thickness T (mm) satisfies Equation 1 above.
In this case, the ratio (W / T) of the width W (mm) of the opening to the plate thickness T (mm) can be, for example, 0.4 or less.
In the hollow resin plate of the present invention, the entire plate including the hollow portion may have a vertically symmetric structure. The “vertical symmetric structure” here indicates a structure that is plane-symmetric with respect to the center plane in the thickness direction, and includes a substantially symmetric structure .
Also, the hollow resin plate of the present invention, a plurality of protrusions and / or the core material with a recess of one or two resin sheets are formed in a matrix, the surface material which is laminated on both surfaces of the core member It can also be composed of

  According to the present invention, the outer shape of the end portion is vertically symmetrical, 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 in a specific range. It is possible to realize a hollow resin plate which is excellent in property and hardly deforms or whitens even when a local load is applied to the edge.

1A to 1C are diagrams illustrating a configuration example of a hollow resin plate according to a first embodiment of the present invention, wherein A is a plan view, B is a cross-sectional view taken along line xx shown in A, and C is a curvature of upper and lower edges. FIG. 3 is a conceptual diagram illustrating a relationship between a radius R and a plate thickness T. FIG. 2 is an exploded perspective view illustrating a configuration example of a base material used for the hollow resin plate 10 illustrated in FIG. 1. It is an exploded perspective view showing other examples of composition of a substrate. It is an exploded perspective view showing other examples of composition of a substrate. It is an exploded perspective view showing other examples of composition of a substrate. It is the schematic which shows an example of terminal processing. It is a conceptual diagram which shows the winding of the edge part 2 by terminal processing. FIG. 1A is a diagram showing a configuration example of a hollow resin plate according to a second embodiment of the present invention, and corresponds to a cross-sectional view taken along line xx shown in FIG. 1A; It is a conceptual diagram which shows the relationship between width W of 21 and plate thickness T. It is a figure which shows the method of a local load test typically. It is a figure which shows the method of a creep resistance test typically.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below.

(First embodiment)
First, the hollow resin plate according to the first embodiment of the present invention will be described. 1A to 1C are diagrams showing a configuration example of a hollow resin plate of the present embodiment, FIG. 1A is a plan view, FIG. 1B is a cross-sectional view taken along the line xx shown in FIG. 1A, and FIG. FIG. 3 is a conceptual diagram illustrating a relationship between a radius R and a plate thickness T.

[overall structure]
As shown in FIGS. 1A and 1B, the hollow resin plate 10 of the present embodiment is a plate-shaped resin molded body having a hollow structure, and has a plurality of hollow portions 1a to 1c formed in an in-plane direction. The hollow resin plate 10 includes, for example, a core material 3 composed of one or two resin sheets in which a plurality of convex portions and / or concave portions are formed in a matrix, and surface materials 4 and 5 laminated on both surfaces thereof. Can be configured.

  Further, at least one end 2 of the hollow resin plate 10 of the present embodiment is vertically symmetrical in outer appearance, and the upper and lower edges 2a, 2b in the thickness direction are arc-shaped in cross section. Here, "vertical symmetry" indicates plane symmetry with respect to the center plane in the thickness direction, and includes not only complete symmetry but also substantially symmetry. Further, “edge” indicates a boundary portion with the plane 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.

[Hollow parts 1a to 1c]
The hollow portions 1a to 1c may be formed in a plurality in the in-plane direction, and their shapes and configurations 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 may be stacked in a plurality of stages in the thickness direction. Further, the hollow portion may be configured to be continuous in an arbitrary direction and have an open end, and such a continuous open hollow portion 1c and independent hollow portions 1a and 1b may be formed.

  Although FIG. 1B shows an example in which the independent hollow portions 1a and 1b are regularly arranged, the present invention is not limited to this, and the hollow portions 1a to 1c are irregularly arranged. It may be. Further, the shape of the independent hollow portion 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 columnar shape, and a substantially prismatic shape can be adopted.

[End 2]
When the cross-sectional shape of the upper and lower edges 2a and 2b of the end 2 is arc-shaped, even when a local load is applied by a packing band or the like, the stress is dispersed along the curved surface, and the stress is distributed to the upper and lower edges 2a and 2b. Deformation and whitening hardly occur. In addition, by making the external shape of the end portion 2 vertically symmetric, even when a local load is applied to either the upper edge portion 2a or the lower edge portion 2b, the occurrence of deformation and whitening is similarly suppressed. Is possible, and the handling is improved.

  However, even if the end 2 has the above-described shape, the relationship between the radius of curvature R (mm) and the plate thickness T (mm) of the upper and lower edges 2a and 2b shown in FIG. Then, deformation and whitening due to local load cannot be sufficiently prevented.

  Specifically, when the ratio (2R / T) of the curvature diameter 2R of the upper edge portion 2a and the lower edge portion 2b to the plate thickness T (2R / T) is less than 0.85, the end of the core material 3 is excessively formed during manufacturing. Buckling occurs, and the planar compressive strength of the hollow resin plate 10 is reduced, or a low density portion is formed at the end 2. As a result, when a local load is applied to the upper and lower edges 2a and 2b, deformation and whitening tend to occur, and the product life is shortened. Particularly, in the case where the curvature diameter 2R of the upper and lower edges 2a and 2b is smaller in relation to the plate thickness T (for example, 2R / T ≦ 0.60), the stress due to the local load cannot be dispersed, and the upper and lower edges 2a and 2b cannot be dispersed. 2b may be damaged or the packing band may be cut.

  On the other hand, when the ratio (2R / T) of the curvature diameter 2R of the upper and lower edges 2a, 2b to the plate thickness T (2R / T) exceeds 1.05, it is difficult to maintain the surface smoothness, and in the manufacturing process, , 2b, relatively large irregularities are likely to be formed on the surface, particularly at the boundary between the plane and the curved surface. If the upper and lower edges 2a and 2b have such irregularities, when the package is bound by the packing band, the load is concentrated on the irregularities, and the packing band is damaged by cutting or the like.

  In addition, processing is performed without laminating resin-based face materials such as a nonwoven fabric, a thermoplastic resin sheet, and a foamable sheet on the surface material, and (2R / T)> 1.05 and the ends are sealed. In order to obtain a hollow resin plate having such a structure, it is necessary to process a wide area up to the inner part. When such processing is performed, buckling occurs at the end portion, and end crush physical properties (vertical compressive stress) decrease. For example, when used on the side surface of a box or case, the end crush easily deforms when stacked. The “end crush” 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 is measured, for example, by a method specified in JIS Z0403 or the like. can do.

  Therefore, in the hollow resin plate 10 of the present embodiment, the outer shape of the end portion 2 is vertically symmetrical, and the upper and lower edges 2a, 2b are arc-shaped in cross section, and the curvature radius R (mm) is determined by the plate thickness. In relation to T, the range satisfies Equation 2 above. Thereby, the strength against a local load can be increased while maintaining the surface smoothness of the upper and lower edges 2a, 2b.

  The ratio (2R / T) between the curvature diameter 2R of the upper and lower edges 2a, 2b and the plate thickness T is preferably in the range of 0.90 to 0.98. Thereby, the appearance and surface smoothness of the end portion 2 are improved, and the strength against a local load can be further increased.

  Regarding the surface smoothness of the upper and lower edges 2a, 2b, it is preferable that 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. By setting the surface smoothness of the upper and lower edges 2a and 2b within this range, the effect of suppressing damage to the packing band can be further improved.

  In the hollow resin plate 10 of the present embodiment, all the ends are vertically symmetrical in appearance, and the upper and lower edges may have an arcuate cross-sectional shape, but at least a portion to which a local load is applied by a packing band or the like. May be the end 2 satisfying the above-mentioned requirements. For example, when a plurality of hollow resin plates 10 are used in combination, a local load due to a packing band or the like may be applied to only one end. In such a case, only at one end where a local load is applied, the external shape is vertically symmetrical, the upper and lower edges are arc-shaped in cross section, and the ratio (2R / T) between the curvature diameter 2R and the plate thickness T is 0. The end 2 may be 85 to 1.05.

[Internal structure]
The hollow resin plate 10 of the present embodiment is preferably vertically symmetric not only in the external shape of the end 2 but also in the internal structure. By making the entire hollow resin plate 10 including the hollow portions 1a to 1c into a vertically symmetric structure, a difference in strength between the front and back surfaces can be eliminated, so that the handleability 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 higher by 150 to 240% than other portions. By setting the resin density increase rate of the end portion 2 in this range, both the creep deformation resistance and the band breakage suppressing effect can be enhanced. When the rate of increase in the resin density of the end portion 2 exceeds 240% as compared with the portion other than the end portion 2, the resin is extruded outward at the time of terminal processing, and burrs and steps which cause band breakage are reduced. This may occur.

[Production method]
The hollow resin plate 10 of the present embodiment includes, for example, a core material made of a thermoplastic resin and a surface material made of a thermoplastic resin laminated on both surfaces thereof, and has a plurality of hollow portions in an in-plane direction. The material is obtained by terminal processing. Specifically, in the hollow resin plate 10 of the present embodiment, at least one end of the above-described substrate is vertically symmetrical in appearance, the upper and lower edges are arc-shaped in cross section, and the radius of curvature R (mm) is equal to the plate. It can be manufactured by processing into a shape whose relationship with the thickness T (mm) satisfies the above mathematical formula 2.

<Substrate>
The base material has, for example, a plate-like resin molded product in which a surface material is laminated on both surfaces of a core material formed of one or two resin sheets in which a plurality of convex portions and / or concave portions are formed in a matrix. Can be used.

  The material of the core material constituting the base material may be a thermoplastic resin, and its type and characteristics are not particularly limited. Specific examples of the thermoplastic resin include polyethylene (PE), polypropylene (PP), and polycarbonate (PC). Among them, low-density polyethylene, high-density polyethylene, linear Olefin-based resins such as low-density polyethylene, ultra-low-density polyethylene, homopolypropylene, random polypropylene and block polypropylene are preferred.

  On the other hand, the material of the surface material may be a thermoplastic resin, and its type and characteristics are not particularly limited, but from the viewpoint of processability and the like, a polyolefin-based resin is preferable, like the core material described above. . The material of the surface material and the material of the core material may be the same or different. Further, the thickness of the surface material is not particularly limited, and can be appropriately set according to the use or purpose. 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 plate 10. Specifically, as shown in the base material 6 shown in FIG. 2, two resin sheets 31 and 32 in which a plurality of hollow convex portions 31a and 32a are formed in a matrix are formed by joining the tips of the hollow convex portions 31a and 32a to each other. Are welded so as to abut each other to form a core material 3 and surface materials 4 and 5 are laminated on both surfaces thereof.

  Alternatively, like a base material 7 shown in FIG. 3, a surface material is provided on both surfaces of a resin sheet (core material 11) having a honeycomb structure in which regular hexagonal column-shaped hollow portions 11 a are regularly arranged in a vertical direction and a horizontal direction. What laminated | stacked 4 and 5 can also be used. When a material having a vertically symmetric structure such as the base material 6 shown in FIG. 2 or the base material 7 shown in FIG. 3 is used, there is no difference in strength on the back surface, and the hollow is excellent in surface smoothness over the entire plate surface. A resin plate can be manufactured.

  On the other hand, surface materials 4 and 5 are laminated on both surfaces of one resin sheet (core material 12) in which convex portions 12a and concave portions 12b are alternately formed adjacent to each other as in a base material 8 shown in FIG. Things can also be used. Further, as in the case of the base material 9 shown in FIG. 5, a resin sheet (core material 13) in which the convex portions 13a and the concave portions 13b are formed in a groove shape is used by laminating the surface materials 4 and 5 on both surfaces. Can also.

  The method of laminating the surface materials 4 and 5 on the core materials 3 and 11 to 13 is not particularly limited. In addition to heat fusion, a known method such as ultrasonic fusion, adhesion with an adhesive, or lamination may be used. Can be applied. The base material used when manufacturing the hollow resin plate 10 of the present embodiment may be formed into a long or large area and then cut into a predetermined size.

  In addition, the base material used for the hollow resin plate 10 of the present embodiment is not limited to the configuration illustrated in FIGS. 2 to 5 described above, and may be any resin plate having a plurality of hollow portions in an in-plane direction. . The base material used for the hollow resin plate 10 of the present embodiment includes, on the surface materials 4 and 5, a thermoplastic resin sheet, a thermosetting resin sheet, a foam sheet, a nonwoven fabric, a paper or a woven fabric. May be laminated.

<Terminal processing>
The end processing of the base material is performed, for example, in a desired end surface shape, that is, the appearance is vertically symmetric, the upper and lower edges are arc-shaped in cross section, and the relationship between the radius of curvature R (mm) and the plate thickness T (mm) is as described above. It can be performed using a mold having a concave portion having a shape corresponding to the shape satisfying Expression 2. FIG. 6 is a schematic view showing an example of a method for processing a terminal of a base material. As shown in FIG. 6, when performing the terminal processing on the base material 6 using the mold 30 having the U-shaped concave portion 30 a in a side view, the heated mold 30 is pressed onto the end of the base material 6. Then, the shape of the concave portion 30a is transferred.

At this time, the pressing distance of the mold 30 (the pressing distance to the base material) is set to 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 are joined. Thereby, the upper surface member 4 and the lower surface member 5 are joined without completely crushing the hollow portions 1a to 1c, and the hollow resin plate 10 having the sealed end 2 is formed. When the end portion 2 is sealed in this way, the density of the joined portion is increased, and the basis weight (mass per unit area) of the end surface is increased as compared with before the processing, so that the strength of the end portion is improved.

When the terminal processing is performed, a part of the ends of the core material 3 and the surface materials 4 and 5 are wound inside. FIG. 7 is a conceptual diagram showing the winding of the end 2 by terminal processing. In the hollow resin plate 10 of the present embodiment, the length a of a portion to be processed (a portion forming an arc-shaped cross-sectional end face) of the base material 6 before processing shown in FIG. The difference (ab−2) from the length b is defined as the length (involved amount L) that is wound inward.

  In the terminal processing of the base material, it is preferable that the ratio (L / T) of the winding amount L and the plate thickness T be in the range of 0.1 to 0.5. By setting the ratio (L / T) between the entrainment amount L and the plate thickness T within this range, the resin density of the end portion 2 becomes 150 to 240% higher than the other portions, and the creep deformation resistance and band breakage suppressing effect are obtained. Is excellent in both cases. The ratio (L / T) of the winding amount L to the plate thickness T is more preferably in the range of 0.11 to 0.17, thereby further improving the creep deformation resistance and the effect of suppressing band breakage. be able to.

  In the above-described terminal processing, terminal processing conditions such as the time for pressing the mold 30 against the base material 6 and the heating temperature of the mold 30 can be appropriately set according to the material, structure, thickness, and the like of the base material. it can. In the manufacture of the hollow resin plate 10 of the present embodiment, a plurality of dies having the same shape may be prepared and operated at the same time to process all the ends at one time. The material can be processed several times.

  In the case of performing multi-axis machining, it is preferable to synchronize the press distance and the moving speed of the mold 30 and the time for pressing the substrate 6 between the axes using an electrically controlled servomotor. By using a servomotor, the synchronization accuracy between the axes can be improved compared to cylinder control using pneumatic or hydraulic pressure, eliminating load unevenness when pressing the mold and improving the surface properties and strength of the machined surface. Can be. In addition, when the terminal processing conditions are electrically controlled, overload and insufficient load on the base material 6 are less likely to occur, and the load and the position of the mold 30 can be kept constant. Variations between intervals and processing positions are also reduced.

  In addition, the method of processing the terminal of the base material 6 is not limited to the method using the heating mold described above, and for example, ultrasonic processing using an ultrasonic horn or a mold divided into a plurality of pieces may be used. Known resin processing techniques, such as the processing used, can be applied, and can be appropriately selected according to the thickness and shape of the base material 6. Also, in the case of performing multi-axis machining in ultrasonic machining or machining using a plurality of dies, it is preferable to electrically control each axis using a servomotor.

  As described in detail above, the hollow resin plate of the present embodiment has an external shape that is vertically symmetrical in appearance and has a circular cross section at the upper and lower edges in the thickness direction. Since it has an arc shape, and further, the radius of curvature R of the upper and lower edges is in a specific range in relation to the plate thickness T, deformation and whitening of the edge due to local load hardly occur. In addition, the hollow resin plate of the present embodiment does not have the concept of the front and back surfaces, and the whitening and deformation of the edge can be similarly suppressed even if a packing band is applied to either surface, so that the characteristics differ between the front and back surfaces. It is easier to handle than products.

  In addition, if there is a low density portion or a buckled portion of the core material at the end of the hollow resin plate, the edge may be damaged when an instantaneous load is applied. Hollow resin plates manufactured using a vertically symmetrical structure have no unevenness in density and have a large amount of resin at the joints, which prevents edge deformation and breakage even under momentary loads. it can. In addition to these, the hollow resin plate of the present embodiment is also excellent in safety because the end surface is formed with a curved surface, and when touching or hitting, there is a concern that other objects may be damaged. Few.

(Second embodiment)
Next, a hollow resin plate according to a second embodiment of the present embodiment will be described. Although the hollow resin plate of the first embodiment described above seals the ends by joining the edges of the core material and the surface material, the present invention is not limited to such a configuration. The end may be open.

  FIG. 8A is a diagram illustrating a configuration example of the hollow resin plate of the present embodiment, and corresponds to a cross-sectional view taken along line xx illustrated in FIG. 1A. FIG. 8B is a conceptual diagram showing the relationship between the width W and the plate thickness T of the opening 21 of the hollow resin plate 20 shown in FIG. 8A. 8A and 8B, the same components as those of the hollow resin plate 10 shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 8A, in the hollow resin plate 20 of the present embodiment, an opening 21 extending along the edges 22 a and 22 b is provided at the center in the thickness direction at the end whose upper and lower edges have an arc-shaped cross section. Have been. Note that the hollow resin plate 20 of the present embodiment is the same as the hollow resin plate 10 of the above-described first embodiment except that it has an opening 21. 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 a vertically symmetric outer shape, and the upper and lower edges 22a and 22b have an arc-shaped cross section. The relationship between the radius of curvature R (mm) of the upper and lower edges 22a and 22b and the plate thickness T (mm) satisfies the above equation (2).

  The strength of the end portion 22 of the hollow resin plate 20 of the present embodiment is lower than that of the hollow resin plate 10 of the above-described first embodiment, but the load applied to the end portion 22 at the time of terminal processing is small. The surface smoothness of 22a, 22b is improved. In addition, the hollow resin plate 20 of the present embodiment has a smaller buckling load than the hollow resin plate 10 because the amount of deformation of the core material during processing is small.

  However, if the width W of the opening 21 shown in FIG. 8B is large, the relationship between the radius of curvature R (mm) of the upper and lower edges 22a, 22b and the plate thickness T (mm) may not satisfy the above-described formula (2). . 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 at the time of terminal processing. The shape may be restored after processing. Then, the ratio (2R / T) between the curvature diameter 2R (mm) of the upper and lower edges 22a and 22b and the plate thickness T (mm) exceeds 1.05, and the upper and lower edges 22a and 22b are deformed by local load. Or whitening, or damage to the packing band.

  Therefore, when the opening 21 is provided at the end 22 as in the hollow resin plate 20 of the present embodiment, the ratio (W / T) of the width W (mm) of the opening 21 to the plate thickness T (mm) is determined. It is preferred to be 0.4 or less. Thereby, the surface smoothness of the edge can be improved without reducing the effect of preventing the deformation and whitening of the edge due to the local load.

  The hollow resin plate 20 of the present embodiment can be manufactured by the same method as the hollow resin plate 10 of the above-described first embodiment. For example, for the terminal processing, the hollow resin plate 20 having the opening 21 as shown in FIGS. 8A and 8B is formed by adjusting the pressing distance and the moving speed of the mold 30 and the pressing time to the base material 6. can get.

  FIGS. 8A and 8B show an example manufactured using the base material 6 shown in FIG. 2, but the present invention is not limited to this. It may be manufactured using a substrate having the above structure, and in that case, the same effect can be obtained. The base material used for the hollow resin plate 20 of the present embodiment includes, on the surface materials 4 and 5, a thermoplastic resin sheet, a thermosetting resin sheet, a foam sheet, paper, woven fabric, nonwoven fabric, A face material composed of a metal plate, a metal mesh body, a metal oxide plate and the like may be laminated.

  Other configurations and effects of the hollow resin plate of the present embodiment are the same as those of the above-described first embodiment.

  Hereinafter, the effects of the present invention will be specifically described with reference to Examples and Comparative Examples.

(First embodiment)
As the first example of the present invention, the hollow resin plates of Examples 1 to 10 and Comparative Examples 1 to 4 were manufactured by changing the base material or the terminal processing conditions, and the performance was evaluated.

<Example 1>
The hollow resin plate of the first embodiment described above was manufactured using the base material having the structure shown in FIG. At that time, the resin sheets 31 and 32 were made of polypropylene resin, the basis weight was 1500 g / m ² , the thickness was 0.75 mm, and the projections were 31a and 32a and the height was 20 mm. As the surface materials 4 and 5, a polypropylene resin sheet having a basis weight of 1000 g / m ² and a thickness of 1.00 mm was used.

  For the terminal processing, a mold having a concave portion having a curvature radius (R) of 19 mm is used. The mold temperature is 185 ° C., and the distance (press distance) of pressing the mold after the base material comes into contact is 14.5 mm. The speed at which the mold was brought close to the substrate was 30 mm / min, and the time (holding time) for holding the mold in contact with the substrate was 4.5 seconds.

The hollow resin plate of Example 1 produced by the method described above had a basis weight 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, a curvature diameter 2R and a plate thickness T. The ratio (2R / T) was 0.98.

<Example 2>
The hollow resin plate of the first embodiment described above was manufactured using the base material having the structure shown in FIG. At this time, the resin sheets 31 and 32 were made of a polycarbonate resin, the basis weight was 1500 g / m ² , the thickness was 0.72 mm, and the height of the projections 31a and 32a was 20 mm. As the surface materials 4 and 5, a polycarbonate resin sheet having a basis weight of 1000 g / m ² and a thickness of 0.92 mm was used.

  The terminal processing uses the same mold as in Example 1, the mold temperature is 310 ° C., the press distance is 14.5 mm, the speed at which the mold approaches the base material is 20 mm / min, and the mold holding time is 5. It was performed at 0 seconds.

The hollow resin plate of Example 2 produced by the method described above has a basis weight 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 T. The ratio (2R / T) was 0.98.

<Example 3>
Using the same base material as in Example 1, the above-described hollow resin plate of the first embodiment was manufactured. In Example 3, a mold having a concave portion with a radius of curvature (R) of 16 mm was used. The conditions for the terminal processing were a mold temperature of 190 ° C., a press distance of 15.0 mm, and a speed of bringing the mold closer to the base material at 20 mm / Minutes and a mold holding time of 4.5 seconds.

As a result, the hollow resin plate of Example 3 had a basis weight of 3500 g / m ² , a thickness of 20.5 mm, a curvature diameter 2R of the upper and lower edges of 17.4 mm, and a ratio (2R) between the curvature diameter 2R and the plate thickness T. / T) was 0.85.

<Example 4>
Using the same base material as in Example 1, a hollow resin plate having the structure shown in FIG. 1 was manufactured. In Example 4, a mold having a concave portion having a radius of curvature (R) of 22 mm was used. The conditions for the terminal processing were a mold temperature of 185 ° C., a press distance of 14.5 mm, and a speed of 30 mm / Minutes and a mold holding time of 4.5 seconds.

As a result, the hollow resin plate of Example 4 had a basis weight 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 ratio (2R) between the curvature diameter 2R and the plate thickness T. / T) was 1.05.

<Example 5>
Using the substrate having the structure shown in FIG. 3, the hollow resin plate of the first embodiment described above was produced. At that time, a core material made of a polypropylene resin, having a basis weight of 1500 g / m ² , a thickness of 0.75 mm, and a height of a hollow portion of 20 mm was used. As the surface materials 4 and 5, a polypropylene resin sheet having a basis weight of 1000 g / m ² and a thickness of 1.00 mm was used.

  For the terminal processing, the same mold as in Example 1 was used. The mold temperature was 185 ° C., the press distance was 14.0 mm, the speed at which the mold approached the base material was 30 mm / min, and the mold holding time was 4. The test was performed for 5 seconds.

The hollow resin plate of Example 5 produced by the method described above has a basis weight of 3500 g / m ² , a thickness of 20.2 mm, a curvature diameter 2R of the upper and lower edges of 19.7 mm, a curvature diameter 2R and a plate thickness T. The ratio (2R / T) was 0.97.

<Example 6>
The hollow resin plate of the first embodiment described above was manufactured using the base material having the structure shown in FIG. At this time, the resin sheets 31 and 32 were made of polypropylene resin, the basis weight was 1000 g / m ² , the thickness was 0.75 mm, and the height of the convex portions 31a and 32a was 9 mm. As the surface materials 4 and 5, a polypropylene resin sheet having a basis weight 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 at which the mold approaches the base material is 20 mm / min. Was performed with a holding time of 4.5 seconds.

The hollow resin plate of Example 6 produced by the method described above has a basis weight of 2500 g / m ² , a thickness of 10.0 mm, a curvature diameter 2R of the upper and lower edges of 9.7 mm, a curvature diameter 2R and a plate thickness T. The ratio (2R / T) was 0.97.

<Example 7>
The hollow resin plate of the first embodiment described above was manufactured using the base material having the structure shown in FIG. At that time, the resin sheets 31 and 32 were made of polypropylene resin, the basis weight was 1500 g / m ² , the thickness was 0.75 mm, and the height of the projections 31a and 32a was 12 mm. As the surface materials 4 and 5, a polypropylene resin sheet having a basis weight of 1000 g / m ² and a thickness of 1.00 mm was used.

  The terminal processing uses a mold having a concave part with a radius of curvature (R) of 13 mm, the mold temperature is 185 ° C., the press distance is 10 mm, the speed at which the mold approaches the base material is 15 mm / min, and the mold is held. The time was set at 4.5 seconds.

The hollow resin plate of Example 7 produced by the method described above has a basis weight of 3500 g / m ² , a thickness of 14.0 mm, a curvature diameter 2R of the upper and lower edges of 13.5 mm, a curvature diameter 2R and a thickness T. The ratio (2R / T) was 0.96.

<Example 8>
Using the same base material as in Example 1, the above-described hollow resin plate of the second embodiment was manufactured. In Example 8, the same mold as that in Example 1 was used, and the conditions of the terminal processing were a mold temperature of 175 ° C., a press distance of 12 mm, a speed of approaching the mold to the base material of 6.0 mm / min, and holding of the mold. The time was set to 3.0 seconds.

As a result, the hollow resin plate of Example 8 had a basis weight 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 ratio (2R) between the curvature diameter 2R and the plate thickness T. / T) was 0.97. The width W of the opening was 8.2 mm, and the ratio (W / T) of the width W of the opening to the plate thickness T was 0.4.

<Example 9>
Using the same base material as in Example 1, the above-described hollow resin plate of the second embodiment was manufactured. In Example 9, the same mold as that in Example 1 was used, and the conditions of the terminal processing were a mold temperature of 175 ° C., a press distance of 13.5 mm, a speed of approaching the mold to the base material of 6.0 mm / min, and a mold. Was 3.0 seconds.

As a result, the hollow resin plate of Example 9 had a basis weight 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 ratio (2R) between the curvature diameter 2R and the plate thickness T. / T) was 0.97. The width W of the opening was 6.15 mm, and the ratio (W / T) between the width W of the opening and the plate thickness T was 0.3.

<Example 10>
The hollow resin plate of the first embodiment described above was manufactured using the base material having the structure shown in FIG. At that time, the resin sheets 31 and 32 were made of polypropylene resin, the basis weight was 1500 g / m ² , the thickness was 0.75 mm, and the height of the projections 31a and 32a was 20 mm. As the surface materials 4 and 5, a polypropylene resin sheet having a basis weight of 1000 g / m ² and a thickness of 1.00 mm was used.

  The terminal processing uses a mold having a concave portion with a curvature radius (R) of 19 mm, a mold temperature of 185 ° C., a press distance of 9.0 mm, a speed of bringing the mold closer to the base material of 30 mm / min, and a mold. Was performed with a holding time of 5.0 seconds.

The hollow resin plate of Example 10 produced by the method described above has a basis weight 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, a curvature diameter 2R and a thickness T. The ratio (2R / T) was 0.98.

<Comparative Example 1>
Using the same base material as in Example 1, a hollow resin plate whose end was sealed was produced. In Comparative Example 1, a mold having a concave portion with a radius of curvature (R) of 16 mm was used. The conditions for the terminal processing were a mold temperature of 200 ° C., a press distance of 16.0 mm, and a speed of 30 mm / Minutes and a mold holding time of 4.5 seconds.

As a result, the hollow resin plate of Comparative Example 1 had a basis weight 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 ratio (2R) between the curvature diameter 2R and the plate thickness T. / T) was 0.84.

<Comparative Example 2>
Using the same base material as in Example 1, a hollow resin plate whose end was sealed was produced. In Comparative Example 2, a mold having a concave portion having a radius of curvature (R) of 22 mm was used, and the conditions of the terminal processing were set at a mold temperature of 200 ° C., a press distance of 16.0 mm, and a speed of bringing the mold closer to the base material at 30 mm / Minutes and a mold holding time of 4.5 seconds.

As a result, the hollow resin plate of Comparative Example 2 had a basis weight 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 ratio (2R) between the curvature diameter 2R and the plate thickness T. / T) was 1.06.

<Comparative Example 3>
Using the same base material as in Example 1, a hollow resin plate having an open end was manufactured. In Comparative Example 3, the same mold as that of Example 1 was used, and the conditions of the terminal processing were a mold temperature of 175 ° C., a press distance of 8.0 mm, a speed of approaching the mold to the base material of 6.0 mm / min, and a mold. Was 3.0 seconds.

As a result, the hollow resin plate of Comparative Example 3 had a basis weight 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 ratio (2R) between the curvature diameter 2R and the plate thickness T. / T) was 0.98. The width W of the opening was 12.3 mm, and the ratio (W / T) of the width W of the opening to the plate thickness T was 0.60.

<Comparative Example 4>
Using the same base material as in Example 1, a hollow resin plate whose end was sealed was produced. In Comparative Example 4, the same mold as in Example 1 was used, and the conditions of the terminal processing were a mold temperature of 200 ° C., a press distance of 7.0 mm, a speed of bringing the mold closer to the base material, 20.0 mm / min, and a mold. Was set to 1.0 second.

As a result, the hollow resin plate of Comparative Example 4 had a basis weight 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 ratio (2R) between the curvature diameter 2R and the plate thickness T. / T) was 0.60.

<Evaluation>
The hollow resin plates of Examples 1 to 10 and Comparative Examples 1 to 4 were evaluated by the following methods. For comparison, the same evaluation was performed as a reference example using a base material that had not been subjected to terminal processing.

(1) Local load test FIG. 9 is a diagram schematically showing a local load test method for the hollow resin plates of the examples and the comparative examples. The hollow resin plates of the examples and comparative examples and the base material of the reference example were cut into a width of 50 mm and a length of 170 mm to obtain a sample 50 for evaluation. Then, as shown in FIG. 9, a packing band 53 was arranged between the sample 50 and the pedestal 51, and was fixed by the clamp 52. As the packing band 53, a band made of polypropylene resin and having a width of 15 mm and a thickness of 0.6 mm was used.

  Next, the tip of the packing band 53 was attached to the load cell 54, the pulling speed was set to 20 mm / min, the packing band 53 was pulled upward, and a 150 N load was applied to the edge of the sample 50. At that time, when the load reached 150 N, the operation of the crosshead was stopped. Thereafter, the sample 50 was removed, and the state of the end was visually confirmed. As a result, x (impossible) was given when whitening or deformation occurred at the edge, and o (good) was given when neither whitening nor deformation occurred.

(2) Band breakage test A load was applied to the edge of the sample 50 in the same manner as in the above-mentioned local load test except that the pulling speed was set to 200 mm / min. After the test, the packing band 53 was broken. Was visually checked. As a result, those with breakage such as cutting were evaluated as x (impossible), and those without damage were evaluated as ○ (impossible).

(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, the tip of the packing band 53 is attached to the load cell 54, the pulling speed is set to 20 mm / min, and the packing band 53 is pulled upward until the end buckles (the load that has risen decreases. ). The maximum value of the load measured by this method was defined as the buckling strength.

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

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

  On the other hand, in the comparative example and the reference example shown in Table 2, when a local load was applied, whitening of the edges and breakage of the packing band occurred. Specifically, in Comparative Example 1, since the ratio (2R / T) between the curvature diameter 2R of the upper and lower edges and the plate thickness T (2R / T) was smaller than 0.85, the local load could not be dispersed, and Damage has occurred. On the other hand, in Comparative Example 2, since the ratio (2R / T) of the curvature diameter 2R of the upper and lower edges to the plate thickness T (2R / T) exceeded 1.05, unevenness was generated on the edge surface, and the edge was whitened and packed. Breakage of the band.

In Comparative Example 3 having an opening at the end, the ratio (W / T) of the width W of the opening to the plate thickness (W / T) exceeded 0.4. The ratio (2R / T) between the curvature diameter 2R and the plate thickness T was 1.4. As a result, the packing band was damaged. In Comparative Example 4 , since (2R / T) = 0.6, the local load could not be distributed, and the end face was deformed. In the reference example in which the terminal processing was not performed, whitening of the edge portion and breakage of the packing band occurred.

  From the above results, it was confirmed that according to the present invention, it is possible to realize a hollow resin plate which is excellent in handleability and hardly deforms or whitens even when a local load is applied to the edge by a packing band or the like.

(Second embodiment)
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. FIG. 10 is a diagram schematically showing a creep resistance test method. As shown in FIG. 10, the creep resistance was determined by fixing a packing band 53 on a sample 50 by a clamp 52 and attaching a 10 kg weight 55 to the tip thereof in a dry oven at 60 ° C. for 24 hours. Before and after the test, the thickness of the portion where a load was applied was measured, and the amount of deformation was determined.

  For comparison, the same evaluation was performed as a reference example using a base material that had not been processed. The results are shown in Table 3 below. It should be noted that a sample having a smaller amount of creep deformation has better 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 higher than the other portions by 150 to 240% than the other portions had excellent creep resistance. .

1a to 1c, 11a Hollow portion 2, 22 End 2a, 2b, 22a, 22b Edge 31, 32 Resin sheet 31a, 32a, 12a, 13a Convex portion 3, 11 to 13 Core material 4, 5 Surface material 6 to 9 Base material 10, 20 Hollow resin plate 12b, 13b Concave portion 21 Opening 30 Mold 50 Sample 51 Base 52 Clamp 53 Packing band 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, with the external shape is vertically symmetric, and the upper and lower edges in the thickness direction is locked so that sealing such as arc-shaped cross section, the resin density becomes 150 to 240% higher than the other portions Yes,
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 plate in which the relationship between the radius of curvature R (mm) of the upper and lower edges and the plate thickness T (mm) satisfies the following formula (I).

A core material composed of one or two resin sheets in which a plurality of convex portions and / or concave portions are formed in a matrix,
And a surface material laminated on both sides of the core material,
2. The hollow resin plate according to claim 1, wherein a part of the core material and / or the surface material is wound inside the sealed end portion. 3. A hollow resin plate having a plurality of hollow portions in the in-plane direction,
At least one end has an outer shape that is vertically symmetrical, and the upper and lower edges in the thickness direction are arc-shaped in cross section,
An opening extending along the edge at the center in the thickness direction is provided at an end of the upper and lower edges having an arc-shaped cross section,
The upper and lower edges having a circular arc cross section are hollow resin plates in which the relationship between the radius of curvature R (mm) and the plate thickness T (mm) satisfies the following formula (I).

The hollow resin plate according to claim 3 , wherein a ratio (W / T) of a width W (mm) of the opening to a plate thickness T (mm) is 0.4 or less. A core material composed of one or two resin sheets in which a plurality of convex portions and / or concave portions are formed in a matrix,
The hollow resin plate according to claim 3 or 4 , comprising a surface material laminated on both surfaces of the core material. The hollow resin plate according to any one of claims 1 to 5 , wherein the entire plate including the hollow portion has a vertically symmetric structure.

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