JPH0631766A - Manufacture of composite molded product - Google Patents

Abstract

PURPOSE:To obtain a composite molded product superior in an external appearance, which generates neither creases nor a breaking on a corner part nor leaking of injection synthetic resin on the surface even if a ligneous decorative sheet is molded into a deep form. CONSTITUTION:A corner part of a ligneous decorative sheet which is to be premolded is cut into a developed form of a molded product beforehand and a corner cut part 5 is formed. Then after the same is premolded, a backing material 8 is stuck onto a corner part of a rear member side. Then the same is arranged within a cavity 10 of an injection molding tool 9 so that the rear member side faces on inward of the cavity 10 and synthetic resin is injection- molded on the rear member side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite molded article composed of a wooden decorative board having a wooden layer on its surface and a synthetic resin core material. The shape of the preformed wooden decorative board is used as a developed shape of the molded article. By preforming this, and then pasting the backing material to the corner abutting part on the back member side, by arranging this so that the back member side faces the inside of the cavity in the cavity of the injection mold, It is possible to manufacture a composite molded product with an excellent appearance, in which wrinkles and tears do not occur on the corner surface of the deep-formed product and the synthetic resin for injection molding does not leak to the surface. is there.

[0002]

2. Description of the Related Art Conventionally, as a high-grade furniture material or an interior material for a high-class passenger car, a composite molded article composed of a wood decorative board having a wood layer on its surface and a synthetic resin core material has been used. In order to obtain such a composite molded article, prepare a wood decorative board having a wood layer on the surface, press it so as to form a curved portion, preform it, and place it in an injection mold. Then, a method of injection molding a synthetic resin on the back side of the wooden decorative board has been performed.

However, when a wooden decorative board is drawn into a deep shape having corners (end face corners) having a small radius of curvature, wrinkles and tears occur at the corners, and when the synthetic resin is injection-molded, this The synthetic resin leaks to the surface of the wooden decorative board from the breakage, and the appearance of the composite molded product becomes ugly.

[0004]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to prevent wrinkles and tears on the surface at the corners (end face corners) even when the wood decorative board is formed into a deep shape in the production of a composite molded article. It is intended to provide a method for producing a composite molded article which is excellent in appearance without causing the occurrence of synthetic resin for injection molding and leaking to the surface.

[0005]

[Means for Solving the Problems] This problem is that the corners of the wooden decorative board to be preformed are cut in advance so as to have a developed shape of the molded product, and this is preformed.
Then, after applying a backing material on the corner portion on the back member side, this is solved by disposing the backing material in the cavity of the injection mold so that the back member side faces the inside of the cavity.

The present invention will be described in detail below. Figure 1
FIG. 3 is a vertical cross-sectional view showing an example of a wooden decorative board 1 used in the method for producing a composite molded article of the present invention, in which reference numeral 2 is a reinforcing plate. A wood veneer 3 is laminated on one surface of the reinforcing plate 2 and a back member 4 is laminated on the other surface of the reinforcing plate 2 by an adhesive to form a three-layered wood decorative board 1. Also,
The backing member 4 is not limited to a single layer and may be used by laminating two or more layers.

The reinforcing plate 2 is made of a metal thin plate or a resin thin plate. As the metal thin plate, metals such as aluminum, aluminum alloy, stainless steel, carbon steel can be used.
A thin plate having a thickness of about 01 to 0.5 mm can be used. The thickness of this metal sheet is especially 0.0
It is preferable to set it in the range of 5 to 0.3 mm, and if it is less than 0.01 mm, the effect of reinforcing the wood veneer 3 on the surface portion cannot be obtained, and if it exceeds 0.5 mm, the rigidity is too high. Instead, it is possible to use a material having a thickness equal to or larger than this thickness, if necessary. Further, it is desirable to use a thin metal plate that has been subjected to a chemical conversion coating treatment in order to improve the corrosion resistance, the adhesiveness and the like.

As the resin thin plate, a phenol resin-impregnated paper laminated cured sheet or the like is used. The thickness of this resin thin plate is preferably in the range of 0.1 to 1 mm. If it is less than 0.1 mm, the effect of reinforcing the wood veneer 3 on the surface portion cannot be obtained, and if it exceeds 1 mm, the rigidity is too high. However, the thickness is not limited to this, and it is possible to use a layer having a thickness larger than this, if necessary.

The wood veneer 3 constitutes the surface of the wood veneer 1, and is made of American walnut, rosewood, mahogany or the like having a beautiful grain pattern on the surface. The thickness of the wood veneer 3 is preferably 0.15 to 0.5 mm, especially about 0.2 mm, and if it is less than 0.15 mm, it causes difficulty in appearance and strength. The followability is reduced, and it becomes difficult to mold a molded product having a complicated shape. Further, this thickness is not limited to these ranges and can be changed depending on the material and thickness of the back member 4.

The back member 4 is made of a porous material or a fibrous material and constitutes the back surface of the wooden decorative board 1. As the porous material, a wood veneer or a foamable resin plate (open cells) made of polyurethane foam or the like is used. As the fibrous material, a non-woven fabric such as a smar mat made of acrylic resin or vinylon fiber or the like having a basis weight of about ²⁰ to 200 g / m ² , cloth, paper, a glass fiber mat or the like is used. The thickness of these back members 4 can be arbitrarily set within a range that does not deteriorate the shape followability of the wooden decorative board 1. By using such a back member 4 on the back surface portion of the wooden decorative board 1, when the synthetic resin is injection-molded, the small holes of the porous material or the fibrous material are impregnated with the synthetic resin to obtain an anchor effect. Thus, the wooden decorative board and the synthetic resin core material obtained by injecting the synthetic resin are firmly joined.

Next, a method for producing a composite molded article using such a wooden decorative board 1 will be described. First, as shown in FIG. 2, the shape of the corner portion to be deep-drawn in the preformed wooden decorative board is preliminarily cut into the developed shape of the molded product to form the cut portion 5. The shape to be cut is almost determined from the design drawing, but there is elongation of the material due to press molding, so it is arbitrarily set in consideration of these.

Next, the wooden decorative board 1 is pressed to preform it. This preforming, using a normal mold,
It is performed using a press machine. By this preforming, the wooden decorative board 1 does not return to the original state in which the shape after molding is kept as it is due to the plastic deformation of the metal thin plate or the resin thin plate of the reinforcing material 2, and therefore the almost finished product. Can take the form of. In addition, the corners are in a state in which the materials have abutted from the left and right.

Then, as shown in FIG. 3, the backing material 8 is attached to the corner abutting portion of the preform 7 obtained by the preforming on the back member 4 side by using an adhesive. By sticking the backing material 8 here, there is an effect of preventing the synthetic resin for injection molding from leaking out to the surface side of the wooden decorative board from the gap of the corner abutting portion. The backing material 8 used here is the same material as the wood veneer 3 or the wood veneer 3
It is desirable to use a wood veneer that is similar in color to the surface color of. This is because the backing material that can be seen from the gap between the corners is conspicuous unless the colors are similar.

The backing material 8 is a thin plate-like material, and its thickness is preferably 0.15 to 0.5 mm. If it is less than 0.15 mm, the synthetic resin is injection-molded. The effect of preventing leakage of this synthetic resin is not obtained, and 0.5
This is because the shape-following property deteriorates when the thickness exceeds mm. Further, the thickness is not limited to these ranges, and can be changed depending on the material of the synthetic resin used for injection molding and the depth of the cut 5. The thickness of such a backing material 8 is 0.
Since it is as thin as 15 to 0.5 mm, the surface of the wooden decorative board 1 is shaped like a mold even if a curved portion on the back member side of the preform 7 is pasted and then synthetic resin is injection-molded on the back member side. It does not become stepped because it follows. On the other hand, the lengths of the backing material 8 in the vertical and horizontal directions must be such that the synthetic resin does not leak from the abutting dimension.

As the adhesive used here, it is desirable to use an adhesive colored in the same color as the surface color of the wood veneer 3 so that the adhesive seen from the gap between the butts is not conspicuous.

Next, as shown in FIG. 4, the preform 7 to which the backing material 8 is attached is placed in the cavity 10 of the injection mold 9 so that the back member 4 side faces the inside of the cavity 10. The shape of the cavity 10 matches the shape of the outer shape of the final molded product. Then, when a synthetic resin is injection-molded on the back member 4 side of the preform 7, the synthetic resin and the preform 7 are integrated. Then, when this is taken out from the injection molding die 9, a composite molded product 12 including the preformed product 7 and the synthetic resin core material 11 as shown in FIG. 5 is obtained. The synthetic resin used here includes ABS resin, polycarbonate resin, modified PPO resin and the like.

As described above, according to the method for producing the composite molded article of the present invention, the corners of the preformed wooden decorative board are cut so as to have the developed shape of the molded article, preformed, and then cut. Since the backing material is attached to the corner abutting part on the back member side, wrinkles and tears do not occur at the corners of deep molded products, and the synthetic resin for injection molding soaked into the back member Since it is possible to prevent leakage from the butting to the surface of the wooden decorative board, a composite molded article having an excellent appearance can be obtained.

[0018]

Example: 0.3 mm in thickness, 0.2 mm in thickness on one surface of an aluminum thin plate treated with chromium phosphate conversion coating
The American walnut veneer of No. 2 was laminated on the other surface with a 0.2 mm thick birch veneer using an adhesive to integrate the veneer veneer to form a three-layered wooden decorative board. At this time, a cross-linked urethane dispersion was used as the adhesive, and the coating amount was 100 g / m ² , the temperature was 150 ° C., and the pressure was 10 kg / cm ² .
Pressed for minutes to bond.

Then, after the corners of the wooden decorative board to be preformed are cut into the expanded shape of the molded product, the wooden decorative board is pressed to preform.

Then, an American walnut veneer having a length of 15 mm, a width of 5 mm and a thickness of 0.2 mm was attached to the corner abutting portion on the back member side of the preform using an adhesive. At this time, cyanoacrylate (instantaneous adhesive) was used as an adhesive material, and several drops were spot-coated and pressed for 1 minute for adhesion. After that, this is arranged in the cavity of the injection mold so that the foamable resin plate side faces the inside of the cavity, and the ABS resin is injection-molded on the foamable resin plate side of this preform to obtain a synthetic resin core material. Integrated with the preform,
Then, this was taken out from the injection molding die to obtain a composite molded article. The thus obtained composite molded article has no wrinkles or tears in the curved portion of the wooden decorative board,
Furthermore, the synthetic resin for injection molding did not leak to the surface, and the appearance was excellent.

[0021]

As described above, according to the method for producing a composite molded article of the present invention, after the corner portions of the wood decorative board to be preformed are cut and formed into the expanded shape of the molded article, this is preformed and then After the backing material is pasted on the corner abutting part on the backing material side, it is placed inside the cavity of the injection molding die so that the backing material side faces the inside of the cavity, so the wooden decorative board is deep Even if it is molded into the above shape, it is possible to prevent wrinkles and tears on the surface at the corners of deep-molded products and prevent synthetic resin for injection molding from leaking to the surface, resulting in a composite molded product with an excellent appearance. To be

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of a wooden decorative board used in the present invention.

FIG. 2 is a plan view showing an example in which a corner cut portion is formed on a wooden decorative board used in the present invention.

FIG. 3 is a perspective view showing an example in which a backing material is attached on a corner abutting portion on the back member side of the preform used in the present invention.

FIG. 4 is a vertical cross-sectional view showing an example in which a preform having a backing material attached thereto is arranged in a cavity of an injection mold.

FIG. 5 is a perspective view showing an example of a composite molded article obtained by the manufacturing method of the present invention.

[Explanation of symbols]

1 ... Wooden decorative board, 2 ... Reinforcement board, 3 ... Wooden veneer, 4 ...
Back member, 5 ... Corner cut part, 7 ... Preform, 8
... Backing material, 9 ... Injection mold, 10 ... Cavity,
12: Composite molded product

Claims (1)

[Claims] 1. A wood decorative board in which a wood veneer is laminated on one surface of a reinforcing plate and a back member is laminated and integrated on the other surface,
Then, after placing this preform in the cavity of the injection mold so that the back member side faces the inside of the cavity, the shape of the wooden decorative board to be preformed in the method of manufacturing a composite molded article in which a synthetic resin is injection molded. To the developed shape of the molded product, preform it, and then attach the backing material to the back side of the abutting part of the corner, and then put this inside the cavity of the injection mold so that the back member side is inside the cavity. A method for producing a composite molded article, which is characterized by arranging so as to face each other.