Manufacturing method of wooden board member

Abstract

To provide a manufacturing method of a wooden board member, being capable of preventing whitening thereof.SOLUTION: A manufacturing method of a wooden board member 20 provided with a substrate 21 including a woody material and a waterproof film 22 having waterproofness to cover at least one of surfaces of the substrate 21 includes a hot-press molding process hot-pressing a laminated body made by laminating the substrate 21 and the waterproof film 22, wherein the waterproof film 22 has a plurality of holes 23 penetrating from its front surface to its rear surface, and diameters of the plurality of holes 23 of the waterproof film 22 before the hot-press molding process are within a range of 0.2 to 2.5 mm.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a method for manufacturing a wood board member. [Background technology]

[0002] Conventionally, a known wood-based board member is described in, for example, Patent Document 1 below. Patent Document 1 describes a wood-based board covered on one or both sides with a moisture-proof sheet. Since wood-based boards are likely to lose strength or emit odors when wet, such a waterproof layer is provided on the surface to improve waterproofing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-227112 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there are cases where the texture and feel of the base material of a wood-based board itself is utilized as a design element, and in such cases, a transparent layer is used as a layer that covers the base material.

[0005] However, when the surface of the substrate is covered with a transparent layer having waterproof properties, gases such as water vapor generated from the wood material during the heat molding of the substrate can get between the substrate and the transparent waterproof layer, causing whitening of the finished board component, which leads to a deterioration in appearance and makes it difficult to use the product.

[0006] The technology disclosed in this specification was developed based on the above circumstances, and aims to provide a method for manufacturing a wood-based board member that is less susceptible to whitening. [Means for solving the problem]

[0007] The technology disclosed in this specification, which was completed to solve the above-mentioned problems, is a manufacturing method for a wood-based board component comprising a base material containing a wood material and a waterproof film having waterproof properties covering at least one side of the base material, and includes a hot press molding process in which a laminate formed by laminating the base material and the waterproof film is hot pressed, the waterproof film has a plurality of holes penetrating from the front to the back, and the diameters of the plurality of holes in the waterproof film before the hot press molding process are within the range of 0.2 to 2.5 mm.

[0008] According to the above manufacturing method, even when the wood-based board component is manufactured using a process that includes a hot press molding process, gases such as water vapor generated from the wood material when heated can easily escape through holes provided in the waterproof film, thereby preventing gas from accumulating between the base material and the waterproof film and causing whitening of the wood-based board component.

[0009] Furthermore, if the diameter of the hole is less than 0.2 mm, the hole is easily crushed during the hot press molding process, and whitening is likely to occur. If the diameter of the hole is more than 2.5 mm, the waterproofness of the finished wood board member is reduced, and the board is likely to have a water-wet odor and lose strength.

[0010] The plurality of holes may be arranged in a first row aligned in a straight line and a second row adjacent to and parallel to the first row, and the first holes constituting the first row and the second holes constituting the second row among the plurality of holes may be arranged alternately in the row direction.

[0011] By arranging the first hole portions and the second hole portions alternately in the row direction, the waterproof film is less likely to tear even when force is applied in the direction in which the waterproof film stretches during the hot press molding process, compared to when adjacent hole portions are arranged in a vertically and horizontally aligned state. Effect of the Invention

[0012] According to the technology disclosed in this specification, it is possible to provide a method for manufacturing a wood-based board member that is less susceptible to whitening. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a front view of a door trim according to an embodiment; [Diagram 2] Cross-section of an ornament board [Diagram 3] An explanatory diagram showing the waterproof film application process [Figure 4] An explanatory diagram showing the ornament board molding process (mold open) [Diagram 5] An explanatory diagram showing the ornament board molding process (mold closed) [Figure 6] Illustrative diagram of bending evaluation test [Figure 7] Explanation of the tear evaluation test [Figure 8] An explanatory diagram showing the change in holes when a pre-board with a waterproof film is heated and pressed (wave-like arrangement) [Figure 9] An explanatory diagram (linear arrangement) showing the change in holes when a pre-board with waterproof film is heated and pressed. [Figure 10] Table showing various test evaluation results of Examples and Comparative Examples DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment will be described with reference to Fig. 1 to Fig. 10. In this embodiment, a manufacturing method of an ornament board 20 provided in a door trim 10 used as an interior material for a vehicle will be illustrated. The door trim 10 constitutes the interior side of a vehicle side door and is attached to the door inner panel from the interior side of the vehicle. The door trim 10 is mainly composed of a trim board 11 having a generally rectangular shape, and in addition to the trim board 11, various functional parts such as an inside handle 12, an armrest 13, a door pocket 14, and a speaker grill 15 are provided on the trim board 11 (see Fig. 1).

[0015] The trim board 11 is made up of a plurality of board members assembled together, and is mainly composed of an upper board 17, a lower board 18, an ornament board 20, and an armrest board 19. Of these, the ornament board 20 is a wood-based board member of this embodiment, and is disposed above the armrest 13 provided on the trim board 11. The interior surface of the ornament board 20 is not covered with a skin material such as synthetic leather, genuine leather, or fabric, and is configured to utilize the texture and feel of a base material 21 described later as a design. Note that the board members other than the ornament board 20 are configured such that the surfaces of plate-shaped base materials are covered with skin materials.

[0016] The ornament board 20 is a plate-like member having a predetermined thickness. As shown in Fig. 2, the ornament board 20 includes a plate-like base material 21 and a transparent or semi-transparent waterproof film 22 that covers an interior surface 21A (design surface side) of the base material 21.

[0017] The base material 21 contains vegetable fibers (an example of a wood material) and a thermoplastic resin. Examples of vegetable fibers contained in the base material 21 include bast vegetable fibers such as kenaf, and vegetable fibers obtained by unweaving fibrous wood. The base material 21 is obtained by hot press molding a fiber mat in which vegetable fibers and thermoplastic resin fibers are mixed, and the thermoplastic resin functions as a binder that binds the vegetable fibers. Examples of thermoplastic resins contained in the base material 21 include polyolefin resins (polypropylene, polyethylene, etc.), polyester resins (aliphatic polyester resins such as polylactic acid and polycaprolactone, and aromatic polyester resins such as polyethylene terephthalate), and the like.

[0018] In this embodiment, the base material 21 contains plant fibers obtained from kenaf and polypropylene, but the material of the base material 21 is not limited to these and can be changed as appropriate.

[0019] The transparent or translucent waterproof film 22 has waterproof and odor-resistant properties, and protects the surface of the base material 21 while exerting an effect similar to that of a clear coating, thereby enhancing the design of the base material 21. An example of the waterproof film 22 is a three-layer film of polyethylene-nylon-polyethylene (each layer is not shown).

[0020] The waterproof film 22 is provided with a plurality of holes 23 penetrating the front and back of the film throughout. As shown in FIG. 8, the holes 23 include a first column C1 arranged in a straight line and a second column C2 arranged parallel to the first column C1 adjacent to the first column C1, and the first holes 23A constituting the first column C1 and the second holes 23B constituting the second column C2 among the holes 23 are arranged alternately in the row direction. Such first columns C1 and second columns C2 are arranged repeatedly in a row, so that a large number of holes 23 are provided throughout the waterproof film 22. Hereinafter, an arrangement in which adjacent holes 23 are arranged alternately in the row direction will be referred to as a wavy arrangement.

[0021] Next, a description will be given of an example of a manufacturing method for the ornament board 20. The manufacturing method for the ornament board 20 in this embodiment sequentially includes a pre-board forming process for forming a pre-board 21P, a waterproof film attachment process for attaching a waterproof film 22 to the surface of the pre-board 21P, and an ornament board forming process (an example of a hot press forming process) for producing the ornament board 20 by heating and press-forming the pre-board 21P covered with the waterproof film 22.

[0022] <Pre-board molding process> In the pre-board molding process, first, a fiber mat made of vegetable fibers and thermoplastic resin fibers is heated and pressed by a pair of flat press dies. As a result, the fiber mat is compressed and the thermoplastic resin contained in the fiber mat melts and mixes with each other at the contact surface. After that, the thermoplastic resin contained in the fiber mat is cooled and solidified, and the pre-board 21P is molded.

[0023] <Waterproof film application process> Next, the pre-board 21P is heated again by a heater (not shown) to melt the thermoplastic resin on its surface, and then, as shown in Fig. 3, is placed between a pair of flat forming dies (cooling dies) 30. At this time, the waterproof film 22 is placed between the upper plate surface of the pre-board 21P and the upper die 31. At this time, the diameter of the hole 23 of the waterproof film 22 alone is set to be within a range of 0.2 to 2.5 mm.

[0024] Thereafter, the upper die 31 is brought close to the lower die 32, and the molding die 30 is closed to cool and compress the pre-board 21P and the waterproof film 22. When the thermoplastic resin contained in the pre-board 21P cools and solidifies, the thermoplastic resin that has seeped out of the pre-board 21P adheres the waterproof film 22 to the upper surface of the pre-board 21P, thereby obtaining a pre-board 21F with a waterproof film.

[0025] <Ornament board molding process (an example of the hot press molding process)> In the ornament board molding process, first, the pre-board 21F with the waterproof film is heated by a heater (not shown). This causes the pre-board 21F with the waterproof film to be in a softened state. Thereafter, as shown in FIG. 4, the softened pre-board 21F with the waterproof film is placed between a pair of molding dies 40 (upper die 41 and lower die 42). Next, as shown in FIG. 5, the upper die 41 and the lower die 42 are closed, and the pre-board 21F with the waterproof film is press-molded by the molding surfaces 41A, 42A of the upper die 41 and the lower die 42. This causes the pre-board 21F with the waterproof film to assume a shape that matches the shape of the molding space, and the ornament board 20 is molded.

[0026] Next, the effects of the present embodiment will be described. This embodiment is a method for manufacturing an ornament board 20 including a base material 21 containing vegetable fibers and a waterproof film 22 having waterproof properties and covering at least one surface of the base material 21, and includes an ornament board forming step of hot pressing a pre-board 21F with a waterproof film in which the base material 21 and the waterproof film 22 are laminated, the waterproof film 22 has a plurality of holes 23 penetrating from the front to the back, and the diameter of the plurality of holes 23 of the waterproof film 22 before the ornament board forming step is within a range of 0.2 to 2.5 mm.

[0027] According to the above manufacturing method, even when the ornament board 20 is manufactured using a process including a hot press molding process, gases such as water vapor generated from the plant fibers when heated can easily escape through the holes 23 provided in the waterproof film 22, thereby preventing gas from accumulating between the base material 21 and the waterproof film 22 and causing whitening of the ornament board 20.

[0028] Furthermore, if the diameter of the hole 23 is less than 0.2 mm, the hole 23 is easily crushed and whitened during the hot press molding process. If the diameter of the hole 23 is greater than 2.5 mm, the waterproofness of the completed ornament board 20 decreases, and the ornament board 20 is likely to have a water-wet odor and lose strength.

[0029] The multiple holes 23 form a first column C1 arranged in a straight line and a second column C2 adjacent to the first column C1 and arranged parallel to the first column C1, and among the multiple holes 23, the first hole portion 23A forming the first column C1 and the second hole portion 23B forming the second column C2 are arranged alternately in the row direction.

[0030] By arranging the first hole portion 23A and the second hole portion 23B alternately in the row direction, the waterproof film 22 is less likely to tear even when force is applied in the direction in which the waterproof film 22 stretches during the hot press molding process, compared to when adjacent hole portions 23 are arranged in a vertically and horizontally aligned state. EXAMPLES

[0031] The technology disclosed in the present specification will be described in more detail below with reference to examples. Note that the technology disclosed in the present specification is not limited to these examples.

[0032] Example 1 A pre-board 21F with a waterproof film was produced by using a waterproof film 22 to be attached to a pre-board 21P, in which a plurality of first hole portions 23A arranged in a straight line to form a first column C1 and a plurality of second hole portions 23B arranged in a straight line adjacent to the first column C1 to form a second column C2 are arranged in a wavy pattern alternately in the row direction across the entire waterproof film 22 (see Figure 8).

[0033] The diameter of each hole 23 in the waterproof film 22 of the first embodiment is 2.5 mm, and the number of holes is 6 per cm. 2 The hole distance (n5 average) is 3.5 mm.

[0034] Example 2 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 1, except that the hole diameter of each hole 23 was 2.0 mm and the distance between holes was 4.1 mm.

[0035] Example 3 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 1, except that the hole diameter of each hole 23 was 1.5 mm and the distance between holes was 4.4 mm.

[0036] Example 4 The diameter of each hole 23 is 1.0 mm, and the number of holes is 25 / cm 2 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 1, except that the hole distance was 2.1 mm.

[0037] Example 5 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 4, except that the hole diameter of each hole 23 was 0.5 mm and the distance between holes was 2.4 mm.

[0038] Example 6 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 4, except that the hole diameter of each hole 23 was 0.3 mm and the distance between holes was 2.6 mm.

[0039] Example 7 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 4, except that the hole diameter of each hole 23 was 0.2 mm and the distance between holes was 2.8 mm.

[0040] Example 8 A pre-board 21F with a waterproof film was produced using a waterproof film 22 to be attached to a pre-board 21P, in which a plurality of first hole portions 23A are arranged in a straight line to form a first column C1, and a plurality of second hole portions 23B are arranged in a straight line adjacent to the first column C1 to form a second column C2, the plurality of second hole portions 23A being aligned in the row direction across the entire waterproof film 22 (see Figure 9).

[0041] The diameter of each hole 23 of the waterproof film 22 in Example 8 is 1.0 mm, and the number of holes is 25 / cm. 2 The hole distance (n5 average) is 1.6 mm.

[0042] Example 9 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 8, except that the hole diameter of each hole 23 was 0.5 mm and the distance between holes was 1.9 mm.

[0043] Example 10 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 8, except that the hole diameter of each hole 23 was 0.3 mm and the distance between holes was 2.2 mm.

[0044] Example 11 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 8, except that the hole diameter of each hole 23 was 0.2 mm and the distance between holes was 2.4 mm.

[0045] Comparative Example 1 A waterproof film without holes was used for application to the pre-board 21P.

[0046] Comparative Example 2 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 1, except that the hole diameter of each hole 23 was 3.0 mm and the distance between holes was 3.1 mm.

[0047] Comparative Example 3 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 4, except that the hole diameter of each hole 23 was 0.1 mm and the distance between holes was 2.9 mm.

[0048] Comparative Example 4 The diameter of each hole 23 is 0.1 mm, and the number of holes is 100 / cm 2 A pre-board 21F with a waterproof film was produced using the same waterproof film 22 as in Example 4, except that the hole distance was 1.1 mm.

[0049] The pre-boards 21F with waterproof film of the above-mentioned Examples 1 to 11 and Comparative Examples 1 to 4 were evaluated for the following items.

[0050] <Evaluation 1: Whitening> Each test piece of Preboard 21F with waterproof film, made to be 250 x 200 mm, was hot-pressed in a flat mold at 235 degrees for 90 seconds, raising the internal temperature of the test pieces to 170 degrees, and after cooling, the surface of each test piece was visually inspected for any whitened areas. ·Bleaching evaluation criteria "〇": No bleaching was observed "X": Bleaching was confirmed

[0051] <Rating 2: Wet smell> 100cm 2 A waterproof film-covered Preboard 21F was sprayed with 11.9 ml of water (equivalent to the amount of water used by four umbrellas), and the odor was evaluated after 30 and 60 minutes. Water odor evaluation criteria "〇": No water smell was detected "X": Water smell was detected

[0052] <Evaluation 3: Bending (rigidity) test> Waterproof film pre-board 21F 50×150mm (75cm 2 ) test piece S1 was taken in the longitudinal and transverse directions, which are roughly parallel and crossing the extension direction of the kenaf fiber, and 8.9 ml of water was poured over it, and it was left for 60 minutes under standard conditions (23°C, 50-60% RH). After that, the test piece was hung between two support plates arranged vertically so that the plate distance L1 was 100 mm, and a pressure plate arranged in the direction parallel to the extension direction of the kenaf fiber from above the test piece was lowered at a speed of 50 mm / min to apply a load (see Figure 6), and the bending elasticity gradient (rigidity) was calculated from the slope of the ss curve where the test piece was cut. The end faces of the support plate and the pressure plate were curved with R = 3.2.

[0053] <Rating 4: Torn> A test piece S2 of 50 x 150 mm was taken from the pre-board 21F with waterproof film in the lengthwise and crosswise directions, which are the directions roughly parallel and crossing the extension direction of the kenaf fiber, and was clamped in the direction crossing the extension direction of the kenaf fiber with a chuck distance L2 of 100 mm, and pulled at a speed of 10 mm / min while heated to 100°C in a hot air oven (see Figure 7). It was pulled to a stroke of 50 mm (elongation rate of 150%), and visually confirmed whether the waterproof film 22 was torn. · Evaluation criteria for tears "〇": No tear occurred "X": Tearing occurred

[0054] The results of the above-mentioned evaluations 1 to 4 are shown in the table of FIG. 10. As shown in the table, no whitening occurred in the test pieces of Examples 1 to 11 in which the hole diameter was in the range of 0.2 to 2.5 mm, and Comparative Example 2 in which the hole diameter was 3.0 mm. That is, it is considered that the gas generated from the substrate 21 was released from the hole 23. In contrast, whitening occurred in Comparative Example 1 in which the hole 23 was not provided, and Comparative Examples 3 and 4 in which the hole diameter was 0.1 mm. That is, the gas generated from the substrate 21 was stored between the substrate 21 and the waterproof film 22. Since whitening occurred in Comparative Example 4 despite the number of the hole 23 being sufficiently increased, it is considered that the whitening occurred in Comparative Examples 3 and 4 because the hole diameter was too small and the hole 23 was crushed by the heat press during the waterproof film attachment process.

[0055] Furthermore, although no whitening occurred in Comparative Example 2, a water-wet odor occurred, which did not occur in Examples 1 to 11. This is believed to be because the pore size was too large, allowing water to penetrate through pores 23 to the base material 21 side.

[0056] Moreover, as shown in the table, the rigidity of Examples 1 to 11 in which the waterproof film 22 was provided with the hole 23 was almost the same as that of Comparative Example 1 in which the hole 23 was not provided. In other words, it can be said that the provision of the hole 23 caused almost no decrease in rigidity.

[0057] Furthermore, in Examples 1 to 7 in which the holes 23 were arranged in a wavy pattern, no tears occurred in the tear test. In contrast, in Examples 8 to 11 in which the holes 23 were arranged in a linear pattern, tears occurred. For this reason, when the pre-board 21F with waterproof film is significantly stretched or subjected to strong stress during hot press molding, it can be said that it is preferable to use a waterproof film in which the holes 23 are arranged in a wavy pattern that is less likely to tear.

[0058] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, and for example, the following embodiments are also included within the technical scope.

[0059] (1) In the above embodiment, the substrate 21 is made of vegetable fiber and thermoplastic resin, but the substrate is not limited to the above embodiment. For example, the technology disclosed in this specification can be applied to a wood-based board member having a substrate made of wood chips or strand pieces, which are thermocompressed together with an adhesive.

[0060] (2) In the above embodiment, a form is shown in which a pre-board 21F with a waterproof film is produced by directly laminating a waterproof film 22 onto the surface of a substrate 21, but a form in which, for example, a colored spunbond is interposed between the substrate and the waterproof film is also included in the technical scope.

[0061] (3) In the above embodiment, the waterproof film 22 has a three-layer structure, but the waterproof film is not limited to the above embodiment, and a single layer, two layers, or four or more layers may be used.

[0062] (4) In the above embodiment, an ornamental board 20 is shown in which only one side of the base material 21 is covered with a waterproof film 22, but depending on the application, it can also be a wood-based board component in which both the front and back sides of the base material are covered with a waterproof film.

[0063] (5) In the above embodiment, the ornament board 20 of the door trim 10 for a vehicle was given as an example of a wood-based board component. However, the technology disclosed in this specification is not limited to the ornament board 20 and can be applied with various modifications to other vehicle interior materials such as pillar garnishes, ceiling materials, console boxes, dashboards, various instrument panels, deck trim, etc., as well as vehicle interior materials for trains, airplanes, ships, etc., and applications other than vehicle interior materials. [Explanation of symbols]

[0064] 20: ornament board (wood-based board member), 21: base material, 22: waterproof film, 23: hole portion, 23A: first hole portion, 23B: second hole portion, C1: first row, C2: second row

Claims

1. A substrate including a wood material; A method for manufacturing a wood-based board member comprising: a waterproof film having waterproof properties covering at least one surface of the base material; A hot press molding process is included in which a laminate in which the base material and the waterproof film are laminated is hot pressed, The waterproof film has a plurality of holes penetrating the front and back of the film, A method for manufacturing a wood-based board member, wherein the diameter of the holes in the waterproof film before the hot press molding process is within a range of 0.2 to 2.5 mm.

2. The plurality of holes form a first row arranged in a straight line and a second row arranged parallel to the first row and adjacent to the first row, 2. A method for manufacturing a wood board component as described in claim 1, wherein among the plurality of holes, the first holes constituting the first column and the second holes constituting the second column are arranged alternately in the row direction.

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