Manufacturing method of decorative panels

Abstract

To provide a manufacturing method of a decorative plate capable of preventing an excess part of a sheet material from being left while preventing a corner part of a substrate from being exposed at a corner part of the decorative plate.SOLUTION: A manufacturing method of a decorative plate according to the invention comprises: a first adhesion step of adhering a decorative sheet 3A to lateral surfaces 2b, 2c of a substrate 2 by an adhesive agent while heating; a first removal step of removing an excess part of the decorative sheet 3A protruding to the outside than ends of the lateral surfaces 2b, 2c of the substrate 2; a second adhesion step of adhering a decorative sheet 3B different from the decorative sheet 3A to a back surface 2d of the substrate 2 and an end surface of the decorative sheet 3A by the adhesive agent while heating; a cure step of making a temperature of the heated decorative sheet 3B lower than a temperature of the decorative sheet 3A in the first removal step; and a second removal step of removing the excess part of the decorative sheet 3B protruding to the outside than the end surface of the decorative sheet 3A adhered to the lateral surfaces 2b, 2c of the substrate 2 after the cure step.SELECTED DRAWING: Figure 2

Description

Technical Field

[0006]

[0001] The present invention relates to a method for manufacturing a decorative board.

Background Art

[0002] Some decorative boards have a decorative sheet made of synthetic resin or paper adhered to a woody base material. Depending on the purpose of use, the number of surfaces to which the decorative sheet is adhered varies for decorative boards. For example, in the case of a flooring material, a decorative sheet is not required on the surface in contact with the ground, and decorative sheets are adhered to three surfaces, namely, the front surface (one board surface) and both side surfaces of the base material. Also, for example, in a staircase where a tread is supported on a stringer called a stringer staircase, since four surfaces, namely, the front and back surfaces (both board surfaces) and both side surfaces of the stringer and the tread are exposed indoors, decorative sheets are adhered to four surfaces of the base material.

[0003] In Patent Document 1 below, when manufacturing a decorative board to which thin paper is adhered to the front surface and end surfaces of a base material, in order to efficiently cut off the surplus portion of the thin paper that becomes soft due to the penetration of an adhesive, the surplus portion is cooled at a temperature lower than room temperature, and thus the applied adhesive is solidified.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Conventionally, when decorative sheets are adhered to four surfaces, namely, the front surface, back surface, and both side surfaces of a base material, one decorative sheet is adhered to the front surface and one side surface, and another decorative sheet is adhered to the back surface and the other side surface, and a total of two decorative sheets are used.

[0006] When the decorative sheet is attached to the substrate with adhesive, the width of the decorative sheet is greater than the combined width of the two sides of the substrate to which it is attached. As a result, the edges of the decorative sheet become excess material and protrude from the corners of the substrate. After the two decorative sheets are attached to the substrate, the excess portions of the two decorative sheets that protrude from the corners are cut off at both locations simultaneously.

[0007] When a decorative sheet is attached to a substrate, it is heated and pressed. If the excess portion of the decorative sheet is trimmed while it is still hot immediately after attachment, the sheet will shrink as its temperature decreases. As a result, after the decorative sheet is attached, the corners of the substrate may be exposed at the corners of the decorative panel.

[0008] Furthermore, as shown in Figure 6, when two decorative sheets 13 are attached to the base material so that the decorative sheets cover all four sides of the base material, the two adjacent decorative sheets 13 overlap near the corner, causing the decorative sheets 13 to be slightly lifted from the base material 12. If the two adjacent decorative sheets are cut simultaneously in this state, there is a possibility that excess portions of the decorative sheets 13 will remain, or that the corners of the base material 12 will be exposed. Therefore, it is difficult to cut the two decorative sheets 13 simultaneously without leaving any excess portions of the decorative sheets 13 and without exposing the corners of the base material 12.

[0009] The present invention has been made in view of these circumstances, and aims to provide a method for manufacturing decorative panels that prevents excess sheet material from remaining at the corners of the decorative panel and prevents the corners of the base material from being exposed. [Means for solving the problem]

[0010] The inventors discovered that when the temperature of the decorative sheet decreases and the decorative sheet shrinks, the amount of shrinkage is greater for the decorative sheet attached to the surface or back (board surface) of the base material than for the side surface of the base material. As a result, the board surface side of the base material at the corners of the decorative panel becomes exposed.

[0011] To solve the above problems, the manufacturing method of decorative panels according to the present invention employs the following means. In other words, the method for manufacturing a decorative panel according to the present invention comprises: a first bonding step of bonding a first sheet material to the side surface of a base material with an adhesive while heating it; a first cutting step of cutting off the excess portion of the first sheet material that protrudes outward from the edge of the side surface of the base material; a second bonding step of bonding a second sheet material different from the first sheet material to the first surface of the base material and the end surface of the first sheet material with an adhesive while heating it; a curing step of lowering the temperature of the heated second sheet material to a temperature lower than the temperature of the first sheet material in the first cutting step; and a second cutting step of cutting off the excess portion of the second sheet material that protrudes outward from the end surface of the first sheet material bonded to the side surface of the base material after the curing step.

[0012] In this configuration, the first sheet material is heated and attached to the side surface of the base material with adhesive, at which point the excess portion of the first sheet material protrudes beyond the edge of the side surface of the base material. Then, the excess portion of the first sheet material is cut off. The second sheet material is heated and attached to the first surface of the base material and the edge of the first sheet material with adhesive, at which point the excess portion of the second sheet material protrudes beyond the edge of the first sheet material attached to the side surface of the base material. Then, the heated second sheet material is cured so that its temperature drops below the temperature of the first sheet material when it is cut off. After this curing period, the excess portion of the second sheet material is cut off.

[0013] At this time, the excess portion of the second sheet material is cut off so as to conform to the surface of the first sheet material. Since the excess portion is cut off after the second sheet material has cooled and shrunk, the second sheet material does not shrink after the cut, and the exposure of the base material corners at the corners of the decorative panel can be prevented.

[0014] Furthermore, since the excess portions of the first and second sheet materials are removed at different times, the first and second sheet materials are removed in such a way that no excess sheet material remains at the corners of the decorative panel, and the corners of the base material are not exposed.

[0015] In the first bonding step of the above invention, the first sheet material may be bonded to the second surface of the substrate opposite to the first surface, and to the two sides of the substrate.

[0016] In this configuration, the first sheet material is attached to the second surface and two sides of the base material with adhesive, and at this time, the excess portion of the first sheet material protrudes from the edges of the two sides of the base material to which the first sheet material is attached.

[0017] In the first cutting step of the above invention, the excess portion of the first sheet material may be cut off while the temperature of the heated first sheet material is higher than room temperature.

[0018] With this configuration, the excess portion of the first sheet material is removed while the heated first sheet material is at a temperature higher than room temperature, without going through a curing period during which the temperature of the first sheet material decreases.

[0019] In the curing step of the above invention, another base material to which another first sheet material and another second sheet material are attached may be stacked on top of the second sheet material attached to the first board surface.

[0020] With this configuration, during the curing process, the excess portion of the second sheet material protrudes from the surface of the first sheet material attached to the side of the base material. Therefore, the excess portion of the second sheet material can be used to prevent interference with other base materials to which other first sheet materials and other second sheet materials are attached. [Effects of the Invention]

[0021] According to the present invention, at the corners of the decorative board, it is possible to prevent the surplus portion of the sheet material from remaining and to prevent the exposure of the corners of the base material.

Brief Description of the Drawings

[0022] [Figure 1] It is a cross-sectional view showing a decorative board according to an embodiment of the present invention. [Figure 2] It is an explanatory view showing a method for manufacturing a decorative board according to an embodiment of the present invention. [Figure 3] It is a partially enlarged cross-sectional view showing the base material and the decorative sheet of a decorative board according to an embodiment of the present invention. [[ID=​​​​​​​​​​​​​​​​​​​​​​​The base material 2 is, for example, a material in which MDF (medium-density fiberboard) is laminated to the front and back surfaces of LVL (laminated veneer lumber) or plywood. In addition, a synthetic resin edge material may be installed on the sides 2b and 2c of the base material 2. When plywood or MDF with rough surfaces 2b and 2c is used for the base material 2, the installation of the edge material makes it easier for the decorative sheet 3 to adhere to the side surface of the base material 2. The base material 2 may also be a material in which MDF is laminated to the front and back surfaces of laminated wood. In the example of the decorative panel 1 described above, the base material 2 is, for example, 4500 mm in length, 240 mm in width, and 60 mm in height.

[0026] The decorative sheet 3 is, for example, an olefin resin sheet or decorative paper. The decorative sheet 3 has dimensions that are larger than the base material 2 before being attached to the base material 2, and has an excess portion. By providing an excess portion, it is possible to prevent the base material 2 from being exposed if the decorative sheet 3 shrinks after being attached to the base material 2.

[0027] In the decorative panel 1, two decorative sheets 3 are attached, for example, decorative sheet 3A (first sheet material) and decorative sheet 3B (second sheet material). Decorative sheet 3A is attached to three surfaces of the base material 2: the surface 2a (second surface) and two sides 2b and 2c. Decorative sheet 3B is attached to the back surface 2d (first surface) of the base material 2. Note that the surface 2a and back surface 2d of the base material 2 are defined for the sake of explanation, and either one surface or the other surface of the base material 2 may be surface 2a or back surface 2d. Also, the surface area of ​​sides 2b and 2c is smaller than the surface area of ​​surface 2a or back surface 2d.

[0028] In the example of decorative panel 1 described above, the width of decorative sheet 3A (first sheet material) is 370 mm, which is the sum of the width of base material 2, twice the height of base material 2, and the excess portion. The width of decorative sheet 3B (second sheet material) is 250 mm, which is the sum of the width of base material 2 and the excess portion. In this example, the excess portion is 5 mm on each side of the width direction.

[0029] The adhesive used to join the base material 2 and the decorative sheet 3 to each other can be, for example, a solvent-based two-component urethane adhesive (moisture-curing type), a PUR-based hot-melt adhesive, or a vinyl acetate-based adhesive.

[0030] Next, with reference to Figure 2, the manufacturing method of the decorative panel 1 according to this embodiment will be described. First, adhesive is applied to the back of decorative sheet 3A. Then, as shown in Figure 2(A), with the surface 2a of the base material 2 facing upwards, the decorative sheet 3A, to which adhesive has been applied, is attached to a total of three surfaces of the base material 2: the surface 2a and the sides 2b and 2c (first attachment step). At this time, the excess portion of the decorative sheet 3A protrudes outward beyond the edges of the sides 2b and 2c of the base material 2.

[0031] The process of attaching the decorative sheet 3A to the base material 2 is carried out, for example, using a roll press device. During the attachment process of the decorative sheet 3A, at least the decorative sheet 3A is heated while being attached. Specifically, the rolls in the roll press device are set to a high temperature, or the adhesive, base material 2, or decorative sheet 3A are preheated before attachment, so that the temperature of the base material 2, adhesive, and decorative sheet 3A is elevated during attachment.

[0032] When a solvent-based two-component urethane adhesive (moisture-curing type) is used as the adhesive, the decorative sheet 3A, adhesive, and base material 2 are heated and bonded together by a roll press device set to a press temperature of approximately 70°C. Furthermore, before bonding, the base material 2 and the decorative sheet 2A with the adhesive applied are preheated by a heater. When a solid PUR-based hot-melt adhesive is used, the roll press device itself is not heated; instead, the adhesive is heated to, for example, 120°C, and is in a melted state when applied to the decorative sheet 3A. During bonding by the roll press device, the decorative sheet 3A is heated by the heat of the PUR-based hot-melt adhesive. To prevent the PUR-based hot-melt adhesive from solidifying due to temperature drop, the base material 2 and decorative sheet 3 are set to 35°C to 55°C by a heater before bonding.

[0033] After the decorative sheet 3A is attached to the surface 2a and sides 2b,2c of the base material 2, the decorative sheet 3A is cut, as shown in Figure 2(B), and the excess portion of the decorative sheet 3A that protrudes from the edges of the sides 2b,2c of the base material 2 is removed (first cutting step).

[0034] The process of cutting off the excess portion of the decorative sheet 3A may be performed while the temperature of the decorative sheet 3A is higher than room temperature (which varies depending on the season, but is higher than room temperature, for example, around 30°C), without waiting for the heated decorative sheet 3A to cool. The decorative sheet 3A bonded to the sides 2b and 2c shrinks less than the surface 2a and back surface 2d, and the decorative sheet 3A bonded to the surface 2a is constrained by the bonding on both sides of the sides 2b and 2c. Furthermore, as will be described later, the end face 3a of the decorative sheet 3A is attached to the end of the decorative sheet 3B with adhesive. Therefore, movement of the decorative sheet 3A due to shrinkage is less likely to occur, and even when cooled after cutting, the corners of the base material 2 are less likely to be exposed.

[0035] The excess portion may be removed by an operator using a cutter, or by the operation of a rotary blade or milling (cutting) process using a processing machine.

[0036] Next, adhesive is applied to the back of decorative sheet 3B. Then, as shown in Figures 2(C) and 3(A), the base material 2 to which the decorative sheet 3A is attached is inverted so that the back surface 2d of the base material 2 becomes the top surface, and the decorative sheet 3B to which adhesive has been applied is attached to the back surface 2d of the base material 2 and the end surface 3a of the decorative sheet 3A (second attachment step). At this time, the excess portion of the decorative sheet 3B protrudes outward from the end surface 3a of the decorative sheet 3A attached to the sides 2b,2c of the base material 2. The process of attaching the decorative sheet 3B to the base material 2 is performed, for example, using a roll press device. During the attachment process of the decorative sheet 3B, at least the decorative sheet 3B is heated while being attached. The heating method is the same as that used in the attachment process of the decorative sheet 3A described above.

[0037] The steps of applying adhesive to the decorative sheet 3A, attaching the decorative sheet 3A to the base material 2, removing excess portions of the decorative sheet 3A, applying adhesive to the decorative sheet 3B, and attaching the decorative sheet 3B to the base material 2 are all performed on a series of conveying lines.

[0038] Subsequently, the substrate 2 to which the decorative sheets 3A and 3B have been attached is removed from the conveyor line and cured at normal room temperature (curing process). Curing lowers the temperature of the decorative sheet 3B, which was heated during the application process of decorative sheet 3B. For example, it is desirable that the temperature of decorative sheet 3B be lower than the temperature of decorative sheet 3A when the excess portion of decorative sheet 3A is trimmed (approximately the same temperature as room temperature, depending on the season). The curing time is determined, for example, according to the curing time of the adhesive that joins the substrate 2 and the decorative sheet 3 together. The curing time is, for example, between 24 hours and 168 hours, and is set to, for example, 48 hours.

[0039] If the curing time is shorter than 24 hours, the adhesive may not harden sufficiently, potentially causing shrinkage of the decorative sheet 3, which could result in poor adhesion or exposure of the corners of the base material 2 due to shrinkage. On the other hand, if the curing time is longer than 168 hours, the amount of semi-finished products occupied in a corner of the factory or warehouse may increase, and production efficiency may decrease due to longer delivery times.

[0040] In the curing process of this embodiment, a cooling device is not required, and a normal conveyor line for manufacturing decorative panels can be used as is. Furthermore, in the manufacturing method according to this embodiment, the cooling time by a cooling device on the conveyor line does not affect the process, so the base material 2 and the like can be sequentially conveyed by the conveyor line at the same timing as in a normal manufacturing process, and production efficiency does not decrease.

[0041] After the decorative sheet 3B is attached to the back surface 2d of the base material 2 and cured, as shown in Figure 2(D), the excess portion of the decorative sheet 3B that protrudes outward from the end surface 3a of the decorative sheet 3A attached to the sides 2b,2c of the base material 2 is cut off (second cutting step). As shown in Figure 3(B), the end surface 3b of the decorative sheet 3B coincides with the surface of the decorative sheet 3A attached to the sides 2b,2c of the base material 2, that is, the outside of the end surface 3a of the decorative sheet 3A. Thus, the corners of the decorative panel 1 are finished in such a way that the corners of the base material 2 are not exposed.

[0042] The cutting operation can be performed in a location separate from the conveying line, and it is not necessary to return the base material 2 to the conveying line. The excess portion of the decorative sheet 3B may be cut off by an operator using a cutter, similar to the decorative sheet 3A, or it may be done by the operation of a rotary blade or milling (cutting) by a processing machine.

[0043] As shown in Figure 3(B), the end of the decorative sheet 3B is positioned to cover the end face 3a of the decorative sheet 3A. Since the end face 3a of the decorative sheet 3A is attached to the end of the decorative sheet 3B with adhesive, the bond between the decorative sheet 3A and the decorative sheet 3B at the corners becomes strong. Therefore, even if there are adhesion defects to the base material 2 after the excess portion of the decorative sheet 3A is cut off, the adhesion with the decorative sheet 3B restrains the decorative sheet 3A from shrinking, making it difficult for the corners of the base material 2 to be exposed.

[0044] Furthermore, since the process of removing excess portions of the decorative sheet 3B is performed after the curing period during which shrinkage of the decorative sheet 3B occurs, the decorative sheet 3B attached to the back surface 2d of the base material 2 does not shrink after the removal of excess portions, and the corners of the base material 2 are not exposed.

[0045] With the back surface 2d of the base material 2 facing upwards, a blade such as a cutter is inserted into the decorative sheet 3B from above. This cuts the decorative sheet 3B along the outside of the end surface 3a of the decorative sheet 3A attached to the sides 2b and 2c, that is, along the corner of the decorative panel 1 to be manufactured. Therefore, not only is it easy to position the blade during cutting, but the decorative sheet 3B is also easily cut so that it covers the end surface 3a of the decorative sheet 3A.

[0046] Furthermore, as shown in Figure 6, when two adjacent decorative sheets 13 overlap near a corner, it is difficult to simultaneously cut both decorative sheets 13 without leaving any excess material and without exposing the corners of the base material 12. In contrast, in this embodiment, as described above, the removal of the excess material of decorative sheet 3B is performed at a different timing than the removal of the excess material of decorative sheet 3A. Therefore, in each cutting process, the decorative sheet 3 is more easily cut to match the surface of the decorative panel 1. Thus, unlike when the two decorative sheets 13 are cut while overlapping, it is less likely that excess material of the decorative sheet 3 will remain at the corners of the decorative panel 1, and the corners of the base material 2 are less likely to be exposed.

[0047] As shown in Figure 2(D), the excess portion of the decorative sheet 3B is cut off to complete the decorative panel 1, which is then packaged in cardboard or the like.

[0048] Next, we will explain the curing process, which is part of the manufacturing method described above. In this embodiment, as shown in Figure 4, during the curing period described above, one base material 2 can be stacked with its back surface 2d facing upwards, and another base material 2 with another decorative sheet 3A, 3B attached to it can be stacked on top of the decorative sheet 3B attached to the back surface 2d of the base material 2, with its back surface 2d facing upwards. This allows the other base material 2 to be stacked on top of the base material 2 with the decorative sheets 3A, 3B attached, so that the excess portion of the decorative sheet 3B does not interfere with the other base material 2.

[0049] In the cured substrate 2, the decorative sheet 3B is attached to the back surface 2d of the substrate 2. As a result, the excess portion of the decorative sheet 3B protrudes from the surface of the decorative sheet 3A attached to the sides 2b and 2c of the substrate 2, and the excess portion of the decorative sheet 3B extends in the direction of extension of the back surface 2d. Therefore, as shown in Figure 4, when multiple substrates 2 are stacked vertically, the excess portion of the decorative sheet 3B of one substrate 2 does not interfere with other substrates 2. Consequently, the decorative sheet 3B attached to the substrate 2 is less likely to come into contact with other substrates 2, and the decorative sheet 3B is less likely to detach from the substrate 2. In addition, because the adhesive portion between the decorative sheet 3B and the back surface 2d is located away from other substrates 2, even if the adhesive is exposed at the corner on the back surface 2d side of the substrate 2 during curing, there is little possibility of it accidentally adhering to other substrates 2.

[0050] As described above, this embodiment is suitable for manufacturing decorative panels 1 such as stringers and treads used in stringer staircases. Furthermore, this embodiment is not limited to stringers and treads for stringer staircases, and is suitable for manufacturing decorative panels 1 in which decorative sheets 3 are attached to four surfaces of the base material 2: the front surface 2a, the back surface 2d (both panel surfaces), and the two side surfaces 2b and 2c.

[0051] According to this embodiment, the process of removing excess portions of the decorative sheet 3B is performed after the curing period during which shrinkage of the decorative sheet 3B occurs. Therefore, after the removal of excess portions, the decorative sheet 3B attached to the back surface 2d of the base material 2 does not shrink, and exposure of the corners of the base material 2 due to shrinkage can be prevented.

[0052] The decorative sheet 3A bonded to the sides 2b and 2c shrinks less than the surface 2a and back surface 2d. Furthermore, the decorative sheet 3A bonded to the surface 2a is constrained by the adhesion on both sides of the sides 2b and 2c. In addition, the end face 3a of the decorative sheet 3A is attached to the end of the decorative sheet 3B by adhesive. As a result, movement of the decorative sheet 3A due to shrinkage is less likely, and even after cooling following cutting, the corners of the base material 2 are less likely to be exposed. Moreover, as shown in Figure 3(B), the end face 3a of the decorative sheet 3A is attached to the end of the decorative sheet 3B by adhesive, resulting in a strong bond between the decorative sheet 3A and decorative sheet 3B at the corners. Therefore, even if there is poor adhesion to the base material 2 after cutting off the excess portion of the decorative sheet 3A, the adhesion to the decorative sheet 3B constrains the decorative sheet 3A, making it less likely to shrink and preventing the corners of the base material 2 from being exposed.

[0053] In the embodiments described above, the case where the corners of the base material 2 are 90 degrees was explained, but the present invention is not limited to this example. For example, as shown in Figure 5, the decorative panel 1 can also be manufactured by the manufacturing method described above even when the corners of the base material 2 have curved surfaces such as R surfaces.

[0054] Furthermore, although the above-described embodiment described a case in which the base material 2 is covered with two decorative sheets 3A and 3B, the present invention is not limited to this example. For example, four decorative sheets 3 may be attached to the base material 2. In this case, a different decorative sheet 3 is attached to each of the sides 2b and 2c, and after the excess portions of the decorative sheets 3 attached to each side 2b and 2c are cut off, decorative sheets 3 are attached to the surface 2a and back surface 2d, respectively. Even when four decorative sheets 3 are attached, the excess portions of the decorative sheets 3 on the board surface side, i.e., the decorative sheets 3 on the surface 2a and back surface 2d side, which shrink more than the decorative sheets 3 attached to the sides 2b and 2c, are cut off after curing. Therefore, after the excess portions are removed, the decorative sheets 3 attached to the surface 2a and back surface 2d of the base material 2 do not shrink, and exposure of the corners of the base material 2 due to shrinkage can be prevented. The decorative sheets 3 attached to the sides 2b and 2c shrink less than the surface 2a and back surface 2d. Furthermore, since the end face 3a of the decorative sheet 3 attached to the sides 2b and 2c is attached to the end face of the decorative sheet 3 attached to the surface 2a and back surface 2d by adhesive, the decorative sheet 3 on the side is less likely to shrink, thus preventing the corners of the base material 2 from being exposed. [Explanation of symbols]

[0055] 1: Decorative board 2: Base material 2a: Surface (second plate surface) 2b: Side 2c: Side 2d: Back side (first board side) 3: Decorative sheet 3A: Decorative sheet (first sheet material) 3B: Decorative sheet (second sheet material) 3a: End face 3b: End face 12: Base material 13: Decorative sheet

Claims

1. A first bonding step involves bonding a first sheet material to the side surface of the base material with an adhesive while heating it, A first cutting step involves cutting off the excess portion of the first sheet material that extends beyond the edge of the side surface of the base material, A second bonding step involves bonding a second sheet material, different from the first sheet material, to the first plate surface of the substrate and the end surface of the first sheet material using an adhesive while heating. A curing step in which the temperature of the heated second sheet material is lowered to a level lower than the temperature of the first sheet material in the first cutting step, After the curing step, a second cutting step is performed to cut off the excess portion of the second sheet material that extends beyond the end face of the first sheet material attached to the side surface of the base material, A method for manufacturing decorative panels.

2. The method for manufacturing a decorative panel according to claim 1, wherein in the first bonding step, the first sheet material is bonded to the second surface of the substrate opposite to the first surface and to the two sides of the substrate.

3. The method for manufacturing a decorative panel according to claim 1, wherein in the first cutting step, the excess portion of the first sheet material is cut off while the temperature of the heated first sheet material is higher than room temperature.

4. The method for manufacturing a decorative panel according to claim 1, wherein in the curing step, another base material to which another first sheet material and another second sheet material are attached is stacked on top of the second sheet material attached to the first panel surface.

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