Method for manufacturing a hollow structure board

Abstract

To provide a method for manufacturing a hollow structural plate capable of suppressing the occurrence of folds and wrinkles and stably and continuously producing the plate.SOLUTION: There is provided a method for manufacturing a hollow structural plate including: a hollow structural part containing a thermoplastic resin in which a plurality of hollow parts separated by vertical walls are formed at intervals; and one or more surface materials and / or skin materials containing a thermoplastic resin laminated on at least one surface of the hollow structural part. The method includes: a hollow structural part producing step of producing the hollow structural part from a sheet containing the thermoplastic resin; and a lamination step of laminating the surface materials and / or skin materials on the hollow structural part. In the hollow structural part producing step, a non-processed part where the plurality of hollow parts are not formed is removed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a hollow structured board. More specifically, it relates to a method for manufacturing a hollow structured board comprising a hollow structure portion containing a thermoplastic resin in which a plurality of hollow portions separated by vertical walls are formed at intervals, and one or more sheets of a surface material and / or a skin material containing a thermoplastic resin laminated on at least one surface of the hollow structure portion.

Background Art

[0002] Hollow structured boards made of resin are excellent in impact resistance, compressive strength, etc., and are easy to handle. Therefore, they are used in a wide range of applications such as building materials, packaging cases, containers such as passage boxes, surface protection packaging materials, partition boards, and decorative materials constituting the interior of vehicles (see, for example, Patent Document 1 and Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the manufacturing process of the hollow structured board, there has been a problem that folds and wrinkles occur in the hollow structure portion forming the hollow structured board, making it difficult to stably and continuously produce the hollow structured board.

[0005] Therefore, the main object of the present invention is to provide a method for manufacturing a hollow structured board that can suppress the occurrence of folds and wrinkles and enable stable and continuous production.

Means for Solving the Problems

[0006] As a result of the inventor of the present application conducting intensive experimental studies, paying attention to the step of creating the hollow structure portion during the manufacturing process of the hollow structure board, and removing the non-processed portion in this step, it was found that the occurrence of breakage and wrinkles can be suppressed and stable continuous production is possible, leading to the completion of the present invention.

[0007] That is, in the present invention, a method for manufacturing a hollow structure board comprising a hollow structure portion containing a thermoplastic resin in which a plurality of hollow portions separated by vertical walls are formed at intervals, and one or a plurality of surface materials and / or skin materials containing a thermoplastic resin laminated on at least one surface of the hollow structure portion, the method comprising at least a hollow structure portion manufacturing step of creating the hollow structure portion from a sheet containing a thermoplastic resin, and a lamination step of laminating the surface material and / or skin material on the hollow structure portion, wherein in the hollow structure portion manufacturing step, a method for manufacturing a hollow structure board is provided in which non-processed portions where the plurality of hollow portions are not formed are removed. In the present invention, in the hollow structure portion manufacturing step, the sheet may be vacuum formed to create the hollow structure portion. In the present invention, the removal of the non-processed portion in the hollow structure portion manufacturing step may be performed after the sheet in a molten state or a softened state has solidified. In the present invention, it may further have a pelletizing step of pelletizing the non-processed portion after removal. In the present invention, it may further have a winding step of winding up the non-processed portion after removal. In the present invention, the basis weight of the hollow structure portion is 300 g / m 2 or more.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a method for manufacturing a hollow structure board capable of suppressing the occurrence of breakage and wrinkles and enabling stable continuous production. Note that the effects described here are not necessarily limited, and may be any of the effects described in this specification.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0010] 1. Hollow structure board 1 Hereinafter, the hollow structure board 1 manufactured by the manufacturing method according to the present invention will be described in detail. The hollow structure board 1 is composed of a hollow structure portion 11 and a surface material and / or a skin material (12, 13).

[0011] The hollow structure board 1 manufactured by the manufacturing method according to the present invention is, as shown in the examples described later, suppressed from generating folds and wrinkles, and has good surface properties and appearance.

[0012] The basis weight of the hollow structure board 1 is not particularly limited, but it is preferably 200 g / m 2 or more and 6000 g / m 2 or less, and more preferably 300 g / m 2 or more and 4000 g / m 2It is more preferable to do as follows. By doing so, the weight reduction of the hollow structure plate 1 can be achieved.

[0013] The end face of the hollow structure plate 1 can be processed into any shape. Specifically, for example, the end face may be left as it is, or the end face may be processed into a C shape or the like, sealed to be a vertical end face, or sealed into an R shape. Further, in the present invention, in order to impart functionality to the end face of the hollow structure plate 1, an edge material or the like can also be bonded to the end face.

[0014] (1) The hollow structure portion 11 The hollow structure portion 11 includes a thermoplastic resin in which a plurality of hollow portions 111 separated by standing walls are formed at intervals. Further, on at least one surface of the hollow structure portion 11, a surface material and / or a skin material (12, 13) including one or a plurality of thermoplastic resins are laminated. In the present invention, there may be a slightly small gap partially between the hollow structure portion 11 and the surface material and / or the skin material (12, 13). Also, in the present invention, the number of the surface material and / or the skin material (12, 13) laminated on the hollow structure portion 11 is not particularly limited.

[0015] The angle (tilt angle) θ1 (refer to U in FIG. 7) formed by the virtual horizontal plane and the standing wall in the hollow structure portion 11 is not particularly limited. However, when a load is applied from the outside of the hollow structure plate 1, it is preferable that the standing wall has a tilt angle in order to obtain sufficient strength. When the standing wall has a tilt angle, the tilt angle θ1 is preferably 45° or more. By setting the tilt angle θ1 to 45° or more, further sufficient strength can be obtained. Also, the tilt angle θ1 is preferably less than 80°. By setting the tilt angle θ1 to less than 80°, when the hollow structure portion 11 is vacuum formed or the like, it is possible to prevent the thickness of the hollow structure portion 11 from becoming too thin and to prevent the standing wall from being formed into a film, so that sufficient strength can be obtained.

[0016] Further, the inclination angle θ1 is more preferably 50° or more and less than 75°. Thereby, the rigidity of the hollow structure plate 1 can be enhanced. Also, deformation due to buckling or the like can be prevented, and the shape retention of the hollow structure plate 1 can be improved. In the hollow structure plate 1, the inclination angle θ1 does not always have to be constant, and the standing wall may have an asymmetrical shape with respect to the central axis.

[0017] The height h of the standing wall (see U in FIG. 7) is not particularly limited, but is preferably 1 mm or more. By setting the height h of the standing wall to 1 mm or more, a hollow structure plate 1 with high rigidity can be obtained. Also, the height h of the standing wall is preferably 50 mm or less. By setting the height h of the standing wall to 50 mm or less, when a hollow convex portion described later is adopted as the hollow portion 111, it is possible to prevent the side wall portion of the convex portion from becoming too thin and to prevent deformation of the hollow structure portion 11.

[0018] The thickness of the standing wall is not particularly limited either, but is preferably 0.1 mm or more. By setting the thickness of the standing wall to 0.1 mm or more, deformation such as buckling can be prevented, and the shape retention of the hollow structure plate 1 can be improved. Also, in the present invention, a step or a wave may be provided on a part or all of the standing wall.

[0019] The material of the hollow structure portion 11 is made of a thermoplastic resin. Also, if necessary, in order to improve moldability and mechanical properties, an inorganic substance may be added to the thermoplastic resin. When an inorganic substance is contained, it can be appropriately blended with the thermoplastic resin at a desired content ratio (for example, 0.5% by mass or more) by a conventionally known method. Further, in the present invention, for the thermoplastic resin forming the hollow structure portion 11 and the surface material described later, a dispersant, an antioxidant, an ultraviolet absorber, an antistatic agent, a conductive agent, an antibacterial agent, a flame retardant, a light stabilizer, a lubricant, etc. may be appropriately added in order to improve flame retardancy, conductivity, wettability, slipperiness, weather resistance, etc.

[0020] Examples of the thermoplastic resin include polyethylene, polypropylene, polystyrene, polyurethane, polycarbonate, polymethyl methacrylate, polyacetal, etc. In the present invention, among these, particularly from the viewpoints of cost, moldability, weight, and physical properties, polyolefin resins such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene, ultra-low-density polyethylene, polypropylene homopolymer, polypropylene random copolymer, polypropylene block copolymer, etc. are preferred. Further, in order to obtain high rigidity, engineering plastics such as ABS resin and polycarbonate can also be used. Further, it may be appropriately colored as necessary using a colorant such as a pigment.

[0021] Examples of the inorganic substance include silicates, sulfates, carbonates, phosphates, borates, oxides, or hydrates thereof, inorganic fibers, etc. of magnesium, aluminum, calcium, titanium, iron, zinc, etc. Specifically, for example, clays such as talc and kaolin, calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, calcium silicate, aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica sand, carbon black, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium sulfite, sodium sulfate, potassium titanate, bentonite, wollastonite, dolomite, graphite, glass fiber, micro glass, carbon fiber, ceramic fiber, rock wool, etc. These inorganic substances may be prepared by a synthetic method or may be of natural origin. Further, one or more of these inorganic substances may be selected and used.

[0022] Note that the hollow structure portion 11 and the surface material and / or skin material (12, 13) described later may be formed of the same material, or may be formed of different materials within the range where heat fusion is possible.

[0023] The specific structure of the hollow structure portion 11 is not particularly limited. For example, it may be a structure composed of a single thermoplastic resin sheet having a plurality of hollow convex portions as the hollow portions 111 formed on at least one surface (see A to C in FIGS. 4 and 5), a structure composed of a thermoplastic resin sheet having a plurality of honeycomb-structured hollow portions 111 (see D in FIG. 5), or a structure composed of two thermoplastic resin sheets having a plurality of hollow convex portions as the hollow portions 111 formed on at least one surface (see E in FIG. 6). In the present invention, among these, a structure composed of one or two thermoplastic resin sheets having a plurality of hollow convex portions as the hollow portions 111 formed on at least one surface is particularly preferable. In the present invention, a structure in which a flow path exists in a part of the hollow structure portion 11 can also be adopted. In this case, the shape of the flow path, the cross-sectional structure of the flow path, the formation direction of the flow path, etc. are not particularly limited.

[0024] The specific shape of the convex portion 111 is not particularly limited as long as it has at least the upper surface portion 112 and the opening portion 113 as shown by U in FIG. 7, and can be freely designed. Specifically, for example, it can be designed into various shapes such as a frustum of a cone shape, a frustum of an elliptical cone shape, a frustum of a triangular pyramid shape, a frustum of a quadrangular pyramid shape, a frustum of a pentagonal pyramid shape, etc., and further, a cylindrical shape, an elliptical column shape, a polygonal column shape, a polygonal star column shape, a polygonal star frustum shape, etc. Also, the shapes of the plurality of convex portions 111 may all be the same shape, or may be a combination of these shapes described above. Furthermore, it is also possible to provide steps or waves on the side surfaces, upper surface portions 112, or opening portions 113 of some or all of the convex portions 111.

[0025] In the present invention, in order to reduce the starting points and improve the peel strength from the surface material and / or the skin material (12, 13) when the surface material and / or the skin material (12, 13) described later is laminated on the hollow structure portion 11, the corners such as the frustum of a polygonal pyramid shape or the polygonal column shape may be designed to be rounded.

[0026] As the shape of the convex portion 111, among those described above, it is particularly preferable to adopt any one or more shapes selected from the group consisting of a frustum of a cone shape, a frustum of an elliptical cone shape, and a frustum of a polygonal pyramid shape. Thereby, in addition to facilitating the design in the manufacturing process, when molding the convex portion 111 using a mold, the manufacturing cost of the mold can also be reduced. Further, as the shape of the convex portion 111, a shape having a taper at least in part as shown by U in FIG. 7 is preferable, and specifically, a frustum of a cone shape and / or a frustum of an elliptical cone shape is preferable, and a frustum of an elliptical cone shape is particularly preferable. Thereby, the bending rigidity of the hollow structure board 1 can be improved and the compressive strength can be maintained.

[0027] When the convex portion 111 is designed to have a frustum of a cone shape and / or a frustum of an elliptical cone shape, the length of the diameter or major axis of the upper surface portion 112 is not particularly limited, but it is preferably 1 mm or more and 10 mm or less. Thereby, the compressive strength in the thickness direction of the hollow structure board 1 can be improved. Further, the length of the diameter or major axis of the opening portion 113 is not particularly limited, but it is preferably 3 mm or more and 20 mm or less. Thereby, the compressive strength in the thickness direction of the hollow structure board 1 can be improved.

[0028] The arrangement form of the plurality of convex portions 111 is not particularly limited, and they can be arranged in a square lattice pattern, a staggered pattern, or irregularly. In the present invention, among those described above, it is particularly preferable to arrange them in a square lattice pattern or a staggered pattern. Further, the arrangement form of the plurality of convex portions 111 includes a form in which adjacent convex portions 111 are arranged alternately when viewed along a predetermined reference direction.

[0029] When the convex portions 111 are arranged in a staggered pattern, the angle θ2 (see T in FIG. 7) formed by the line connecting the centers of the convex portions 111 in the horizontal direction and the line connecting the centers of the convex portions 111 in the diagonal direction is not particularly limited, but it is preferably θ2 = about 60°. Thereby, the rigidity of the hollow structure board 1 can be improved. Note that the "square lattice pattern" means an arrangement when θ2 = about 90°.

[0030] The shortest distance L (refer to T in FIG. 7) between the openings 113 of the convex portions 111 is not particularly limited, but is preferably 0.2 mm or more and 8 mm or less. By setting the shortest distance L to 0.2 mm or more, it is possible to prevent the thickness of the liner portion (the portion where the convex portion 111 does not exist when the convex portion 111 is viewed from a certain direction) from becoming too thin, and thus avoid a decrease in compressive strength. Further, by setting the shortest distance L to 8 mm or less, it is possible to avoid the distance between the convex portions 111 becoming too long and the number of convex portions 111 per unit area decreasing too much, so that the bending rigidity of the hollow structure board 1 can be maintained at a certain level or higher. In the present invention, the shortest distance L does not necessarily have to be constant at all times.

[0031] In the present invention, the structure composed of a single thermoplastic resin sheet having a plurality of hollow convex portions formed on at least one of the above-described surfaces specifically means, for example, a structure composed of a single thermoplastic resin sheet having a plurality of convex portions in the shape of a truncated elliptical cone formed on one surface as shown in FIG. 1. By adopting this structure, it is possible to provide the hollow structure board 1 which is excellent in workability while maintaining the planar compressive strength.

[0032] The lower limit value of the basis weight of the hollow structure portion 11 is not particularly limited, but is preferably 300 g / m 2 or more. By setting the basis weight to 300 g / m 2 or more, it is possible to further suppress the occurrence of breakage and wrinkles in the hollow structure portion 11. Further, the upper limit value of the basis weight of the hollow structure portion 11 is not particularly limited, but is preferably 1500 g / m 2 or less. By setting the basis weight to 1500 g / m 2 or less, it is possible to reduce the weight of the hollow structure board 1.

[0033] Although the thickness of the hollow structure portion 11 is not particularly limited, it is preferably 1.5 mm or more and 55 mm or less. By setting it to 1.5 mm or more, it is possible to prevent the thickness of the hollow structure board 1 from becoming too thin and to produce a hollow structure board 1 with maintained flexural rigidity. Further, by setting it to 55 mm or less, it is possible to control the height of the standing wall in the hollow structure portion 11. When the above-described hollow convex portion is adopted as the hollow portion 111, it is possible to prevent the thickness of the side wall from being drafted and becoming too thin, and thus it is possible to produce a hollow structure board 1 in which deformation such as buckling hardly occurs.

[0034] (2) Surface material and / or skin material (12, 13) The surface material and / or skin material (12, 13) is laminated on at least one surface of the hollow structure portion 11 in one or more layers. Further, the surface material contains a thermoplastic resin. In the present invention, a skin material may be laminated on the surface material. Further, when there are a plurality of surface materials and / or skin materials (12, 13), the thickness, basis weight, etc. of the plurality of surface materials and / or skin materials (12, 13) may all be the same or different.

[0035] In FIGS. 4 to 6, for convenience, the surface material and / or skin material laminated on the upper side of the hollow portion (convex portion) 111 is referred to as the "upper surface material and / or skin material 12", and the surface material and / or skin material laminated on the lower side (opening side) of the hollow portion (convex portion) 111 is referred to as the "lower surface material and / or skin material 13". However, in the hollow structure board 1 which is an actual product, it is assumed that there is no such distinction.

[0036] The material of the surface material is, for example, made of a thermoplastic resin. Further, if necessary, in order to improve moldability and mechanical properties, it may contain an inorganic substance. When containing an inorganic substance, it can be appropriately blended into the thermoplastic resin at a desired content ratio (for example, 0.5 mass% or more) by a conventionally known method. Since the thermoplastic resin and the inorganic substance are the same as those described above, the description thereof is omitted here. Among the above-mentioned ones, polyolefin-based resins are particularly preferable as the thermoplastic resin. Also, in order to obtain high rigidity, engineering plastics such as ABS resin and polycarbonate can also be used. Further, it may be appropriately colored as needed using a colorant such as a pigment.

[0037] The thickness of the surface material is not particularly limited, but it is preferably 0.1 mm or more and 2.0 mm or less. By setting it to 0.1 mm or more, the rigidity of the hollow structure board 1 can be maintained. Also, by setting it to 2.0 mm or less, cost reduction can be achieved.

[0038] The basis weight of the surface material is not particularly limited, but it is preferably 100 g / m 2 or more and 2000 g / m 2 or less. By setting the basis weight to 100 g / m 2 or more, it is possible to prevent the surface material from becoming too thin and breaking when laminating the surface material to the hollow structure portion 11. Also, by setting the basis weight to 2000 g / m 2 or less, the weight reduction of the hollow structure board 1 can be achieved.

[0039] The skin material can be laminated on the hollow structure portion 11 and / or the surface material, but preferably, it is laminated on the surface material. By laminating the skin material, various characteristics according to various applications such as design, sound absorption characteristics, and heat insulation characteristics can be imparted to the hollow structure board 1.

[0040] The material of the skin material is not particularly limited, and generally, a material that can be used as the skin material of a hollow structure board can be appropriately selected and used according to the intended application and the like. Specifically, for example, a thermoplastic resin sheet, a woven fabric made of resin, a non-woven fabric, a laminated fabric, a knitted fabric, a metal sheet made of stainless steel, aluminum, copper, etc., an organic or inorganic porous sheet, a decorative sheet, etc. can be mentioned.

[0041] 2. Manufacturing method of the hollow structure board 1 Figs. 1 to 3 are diagrams schematically showing each embodiment of the manufacturing method according to the present invention. The manufacturing method according to the present invention is the manufacturing method of the above-described hollow structural board 1, and includes at least a hollow structure portion manufacturing step and a lamination step. Further, if necessary, a winding step, a pelletizing step, a sizing step, or the like may be performed. Hereinafter, each step will be described in detail with reference to the drawings.

[0042] (1) Hollow structure portion manufacturing step The hollow structure portion manufacturing step is a step of manufacturing the hollow structure portion 11 from a sheet containing a thermoplastic resin.

[0043] As a method of manufacturing the hollow structure portion 11 from a sheet containing a thermoplastic resin, for example, a method of vacuum forming the sheet can be mentioned. More specifically, as shown in FIGS. 1 and 3, using a vacuum forming apparatus in which one or more forming rollers 101 having a plurality of convex pins projecting from the surface are arranged, a molten or softened thermoplastic resin sheet extruded from an extruder provided with a T-die at the tip is injected into the groove of the forming roller 101 and formed by being held in contact with the forming roller 101. The forming rollers 101 are each installed in a decompression chamber, and the decompression chamber is provided with suction holes for sucking and holding the hollow structure portion 11.

[0044] After the hollow portion 111 is formed, it is taken up by a take-up roller 102 as it is, having non-processed portions (see the X portions of S and T in FIG. 7), for example, as shown in FIGS. 1 to 3. By providing the take-up roller 102, the formability can be improved.

[0045] In the present invention, the portion where the non-processed portion is formed is not particularly limited, and examples thereof include both end portions in the TD direction (a direction substantially perpendicular to the MD direction) continuous in the MD direction (machine flow direction). This non-processed portion serves as a seal at the end, especially when performing vacuum forming, and by reducing the holding of decompression and pressure fluctuations, a hollow structure portion 11 with a stable shape can be obtained.

[0046] As another method for producing the hollow structure portion 11 from a sheet containing a thermoplastic resin, for example, a method using a mold can be mentioned. Specifically, as shown in FIG. 2, a molten or softened thermoplastic resin sheet extruded from an extruder provided with a T-die at the tip is injected into the grooves of a pair of molds 106 having a desired shape on the surface, and is molded by pressing from both sides. In this case as well, since the non-processed portion serves as a seal at the end, a hollow structure portion 11 with a stable shape can be obtained.

[0047] However, when there is a non-processed portion, the process passing tension becomes non-uniform due to this, folds and wrinkles occur in the hollow structure portion 11, and it was difficult to stably and continuously manufacture the hollow structure plate. The occurrence of folds and wrinkles is particularly likely to occur in the substantially MD direction, and is also prominent when the rigidity of the hollow structure portion 11 is low (for example, when the basis weight of the hollow structure portion 11 is 500 g / m 2 in the following cases, etc.). Furthermore, when the sizing process described later is performed, it becomes more prominent when the process passing resistance increases.

[0048] Note that the "folds" and "wrinkles" referred to in this specification are those that occur in the hollow structure portion 11 and cause continuous or intermittent dents, protrusions, grooves, ribs, etc. that are reflected or generated on the surface of the hollow structure plate 1 after the surface material and / or skin material (12, 13) are bonded.

[0049] On the other hand, in the present invention, in the hollow structure portion manufacturing process, it is characterized by removing non-processed portions in which a plurality of hollow portions 111 are not formed. Thereby, it is possible to prevent the non-uniformity of the process passing tension caused by the presence of the non-processed portion, and suppress the occurrence of folds and wrinkles.

[0050] The method for removing the non-processed portion is not particularly limited, and either a contact type or a non-contact type method may be used. In the case of the contact type, for example, cutting with a blade such as a cutter blade, mechanical shearing method, press shearing method, etc. can be mentioned. In the case of the non-contact type, for example, cutting by laser irradiation or laser heating can be mentioned. In the present invention, among these, particularly from the viewpoints of cost and handleability, cutting with a blade such as a cutter blade is preferable.

[0051] When cutting a blade, the material for forming the blade is not particularly limited, and conventionally known materials such as SK (carbon tool steel) materials, stainless steel, titanium, and ceramics can be used. Also, the thickness of the blade is not particularly limited, but for example, it can be 0.3 mm or more and 5 mm or less. If the thickness of the blade is less than 0.3 mm, the blade is likely to break. If the thickness of the blade exceeds 5 mm, the cutting resistance increases, and the mounting space also increases. The blade can be fixedly arranged at a predetermined position, and may be penetrated through the hollow structure portion 11 at the fixed position.

[0052] In this step, the timing for removing the unprocessed portion is not particularly limited, but it is preferably performed after the thermoplastic resin sheet in a molten state or a softened state has solidified. If the solidification of the sheet is not sufficient, there is a risk of leading to removal defects or molding defects. Specifically, it is preferable that the sheet is formed into the hollow structure portion 11 and solidified, and a relatively early timing after solidification is preferred. More specifically, as shown in FIGS. 1 to 3, it is preferable to install a cutting tool 103 at a position immediately after the take-up roller 102 of the hollow structure portion 11 (for example, a position within 1 m from the center of the take-up roller). The closer the timing of removing the unprocessed portion is to the next lamination step, the more difficult it is to eliminate the influence of folding and wrinkles of the hollow structure portion 11 before removing the unprocessed portion.

[0053] (2) Lamination step The lamination step is a step of laminating the surface material and / or the skin material (12, 13) on the hollow structure portion 11 produced in the hollow structure portion production step.

[0054] The lamination step can be performed by a conventionally known method. For example, as shown in FIGS. 1 to 3, on both sides of the hollow structure portion 11, a surface material and / or a skin material (12, 13) composed of a thermoplastic resin sheet extruded from an extruder provided with a T-die at the tip is heat-bonded by a flat roller 105.

[0055] (3) Rewinding step The winding process is a process of winding the unprocessed part after removal. In the manufacturing method according to the present invention, the winding process is not essential, but by performing the winding process, the removed unprocessed part can be efficiently recovered, leading to space saving.

[0056] The method of winding the unprocessed part is not particularly limited. For example, a method of winding the unprocessed part around one or a plurality of rotating rollers 104 can be mentioned. The installation position of the rotating roller is not particularly limited. For example, as shown in FIGS. 1 to 3, it is preferably installed on the upper surface side of the take-up roller 102. In this case, the surface of the unprocessed part being wound and the surface of the hollow structure part 11 form an angle of approximately 90°. Thereby, space saving can be achieved.

[0057] (4) Pelletizing process The pelletizing process is a process of pelletizing the unprocessed part after removal. As used herein, "pelletizing" means processing the unprocessed part into a pellet shape or cutting it to a pellet size. When the winding process is performed, the pelletizing process is preferably performed after the winding process. In the manufacturing method according to the present invention, the pelletizing process is not essential, but by performing the pelletizing process, the removed unprocessed part can be reused, contributing to the solution of the waste plastic problem and the achievement of SDGs.

[0058] The pelletizing method is not particularly limited and can be performed by a conventionally known method using a pelletizer or the like.

[0059] (5) Sizing process The sizing process is a process of bringing the surface material and / or the skin material (12, 13) into close contact with at least one sizing former 107 as shown in FIG. 3 before the surface material and / or the skin material (12, 13) solidifies. In the manufacturing method according to the present invention, the sizing process is not essential, but by performing the sizing process, the surface smoothness of the hollow structure board 1 can be improved. Also, in the present invention, breaks and wrinkles that are likely to occur when the sizing process is performed can be suppressed.

[0060] As used in this specification, the "sizing former" refers to a mold used for purposes such as obtaining surface smoothness while the extruded product has not completely cooled in extrusion molding or the like. Conventionally known sizing formers can be used in this step, and the material, performance, shape, size, etc. are not particularly limited. The sizing former is usually made of a material with high thermal conductivity (for example, aluminum, iron, etc.), and the temperature can be adjusted by bringing a refrigerant or a heat medium into contact, thereby enabling efficient heat exchange with the substance in contact with the sizing former (in the present invention, the surface material and / or the skin material (12, 13)).

[0061] Also, the method of closely adhering the surface material and / or the skin material (12, 13) to the sizing former is not particularly limited, and it can be carried out by a conventionally known method such as vacuum suction or reduced-pressure suction. When adhering by reduced-pressure suction, the negative pressure is not particularly limited, but it is preferably 5 Kpa or more and 80 Kpa or less.

[0062] In the present invention, if necessary, after closely adhering the surface material and / or the skin material (12, 13) to the sizing former, it is also possible to control the temperature with a temperature-controlled pressing roller (not shown).

Examples

[0063] Hereinafter, the present invention will be described in more detail based on examples. It should be noted that the examples described below show an example of a typical example of the present invention, and the scope of the present invention is not construed narrowly thereby.

[0064] First, hollow structural boards of Examples 1 to 12 shown in Tables 1 and 2 below and Comparative Examples 1 to 12 shown in Tables 3 and 4 below were manufactured. The shapes of the respective hollow structural boards are also shown in Tables 1 to 4 below. The hollow structural boards of Examples 1 to 12 were manufactured based on the manufacturing method shown in FIG. 1 when a sizing former was not used, and were manufactured based on the manufacturing method shown in FIG. 3 when a sizing former was used. Further, the hollow structural boards of Comparative Examples 1 to 12 were manufactured based on the same manufacturing method as the manufacturing method shown in FIG. 1 except that the unprocessed portion was not removed in the hollow structure portion manufacturing process when a sizing former was not used, and were manufactured based on the same manufacturing method as the manufacturing method shown in FIG. 3 except that the unprocessed portion was not removed in the hollow structure portion manufacturing process when a sizing former was used. In Tables 1 to 4 below, "PP" indicates polypropylene, and "inorganic high-filled PP" indicates polypropylene containing 4% by mass of talc, which is an inorganic substance, in the hollow structure portion and 20% by mass in the surface material.

[0065] [Table 1]

[0066] [Table 2]

[0067] [Table 3]

[0068] [Table 4]

[0069] Next, the following evaluations were performed on each of the hollow structural boards. The following evaluation results are also shown in Tables 1 to 4 above.

[0070] [Evaluation of bending] Each hollow structural board was cut into five pieces with a size of approximately 1 m in length and 1.3 m in width. Then, each piece was visually inspected to check for any breaks. If there was a break at even one location, it was judged as "with break". Also, even if the degree of break was slight, it was judged as "with break". The evaluation criteria for breaks are shown below. A: None of the hollow structural boards had a break. B: One hollow structural board had a break. C: Two hollow structural boards had breaks. D: Three hollow structural boards had breaks. E: Four hollow structural boards had breaks. F: Breaks were found in all the hollow structural boards.

[0071] [Evaluation of wrinkles] Each hollow structural board was cut into five pieces with a size of approximately 1 m in length and 1.3 m in width. Then, each piece was visually inspected to check for any wrinkles. If there was a wrinkle at even one location, it was judged as "with wrinkle". Also, even if the degree of wrinkle was slight, it was judged as "with wrinkle". The evaluation criteria for wrinkles are shown below. A: None of the hollow structural boards had a wrinkle. B: One hollow structural board had a wrinkle. C: Two hollow structural boards had wrinkles. D: Three hollow structural boards had wrinkles. E: Four hollow structural boards had wrinkles. F: Wrinkles were found in all the hollow structural boards.

[0072] [Comprehensive evaluation] If both the evaluation of breaks and the evaluation of wrinkles were B or above, it was judged as "qualified"; otherwise, it was judged as "unqualified".

[0073] It was found that the hollow structural boards of Examples 1 to 12 had less breakage and wrinkling compared to the hollow structural boards of Comparative Examples 1 to 12. Therefore, it has been found that in the process of manufacturing the hollow structure part, by removing the non-processed part where a plurality of hollow parts are not formed, it is possible to provide a method for manufacturing a hollow structure board that can suppress the occurrence of breakage and wrinkles and enable stable continuous production.

Industrial Applicability

[0074] According to the present invention, it is possible to provide a method for manufacturing a hollow structure board that can suppress the occurrence of breakage and wrinkles and enable stable continuous production. The hollow structure board manufactured by this manufacturing method is useful in a wide range of fields such as building materials, containers such as packing cases and passage boxes, surface protection packaging materials, partition boards, and decorative materials constituting the interior of vehicles.

Explanation of Signs

[0075] 1: Hollow structure board 11: Hollow structure part 111: Hollow part (protrusion) 112: Upper surface part 113: Opening 12: Upper surface material and / or skin material 13: Lower surface material and / or skin material 101: Forming roller 102: Take-up roller 103: Blade 104: Rotating roller 105: Flat roller 106: Mold 107: Sizing former h: Height of the vertical wall L: Shortest distance between the openings 113 of the protrusions 111 X: Non-processed part θ1: Inclination angle θ2: Angle formed by the line connecting the centers of the protrusions 111 in the horizontal direction and the line connecting the centers of the protrusions 111 in the diagonal direction

Claims

1. A method for manufacturing a hollow structure board comprising a hollow structure portion made of a thermoplastic resin in which a plurality of hollow portions separated by vertical walls are formed at intervals, and one or more sheets made of a thermoplastic resin laminated on at least one surface of the hollow structure portion and / or a skin material, a hollow structure portion manufacturing step of manufacturing the hollow structure portion from a sheet containing a thermoplastic resin, a lamination step of laminating the surface material and / or the skin material on the hollow structure portion, having at least, In the hollow structure portion manufacturing step, a method for manufacturing a hollow structure board, wherein a non-processed portion where a plurality of the hollow portions are not formed is removed.

2. The method for manufacturing a hollow structure board according to claim 1, wherein in the hollow structure portion manufacturing step, the sheet is vacuum formed to manufacture the hollow structure portion.

3. The method for manufacturing a hollow structure board according to claim 1 or 2, wherein the removal of the non-processed portion in the hollow structure portion manufacturing step is performed after the sheet in a molten state or a softened state has solidified.

4. The method for manufacturing a hollow structure board according to any one of claims 1 to 3, further comprising a pelletizing step of pelletizing the non-processed portion after removal.

5. The method for manufacturing a hollow structure board according to any one of claims 1 to 4, further comprising a winding step of winding up the non-processed portion after removal.

6. The basis weight of the hollow structure part is 300 g / m ２ or more. The method for manufacturing a hollow structure board according to any one of claims 1 to 5.

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