JPH0573858B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a bent plate material and a method for manufacturing the same.

[Prior art] In the past, attempts have been made to bend wood, plywood, particle board, and insulation board as substrates, but these substrate materials have directional fibers and high specific gravity. They were either too small or too rigid, too strong or too weak, and were easily broken, making it impossible to bend them.

In other words, when bent in a direction perpendicular to the fiber direction,
It breaks easily and causes hangnails. In addition, if it is bent in a direction parallel to the fiber direction, it is likely to be folded in the fiber direction, and hangnails are also likely to occur.

Therefore, the productivity is poor and the yield is extremely low.

In addition, in order to alleviate this tendency to bend, a sheet-like material such as vinyl chloride is pasted on the front side of the board, a cut is made from the back side over the entire thickness of the board, and this cut part is bent. Attempts were also made to bend and process the material.

[Problems to be Solved] However, in this method of manufacturing a bent plate material, it is necessary to attach a sheet-like material to a substrate in advance, which makes the manufacturing process complicated and the productivity low. Furthermore, the finished bent material has a sheet-like material attached to it, and its commercial value is extremely low.

Furthermore, since the fibers have directionality, it is not easy to cut the fibers, resulting in a significant decrease in yield.

[Means for Solving the Problems] In order to solve the above-mentioned conventional problems, the present invention uses a so-called "medium-density fiberboard" with a specific gravity of 0.4 to 0.8 and no directionality of fibers as the substrate 1, and Directly connect the V-shaped groove 2 to the V-shaped groove 2 without attaching anything to the surface side.
The cut is made leaving the remaining base 3 between the groove apex 2b and the surface of the plate material.

The V-shaped groove 2 has an isosceles triangle with an apex 2b and both leg ends 2a, 2a.

After softening the structure of the remaining base 3 with a softening agent, the V-shaped groove 2 is bent around the apex 2b, the substrate 1 is bent to the back side, and both leg ends 2a, 2a are bent.
are joined on the back side to form a bent plate.

[Function] Medium-density fiberboard is produced by Noda Plywood Co., Ltd. and Kitashin Plywood Co., Ltd. The fibers have no directionality, and because the fibers are long, the fibers are tightly intertwined and have a specific gravity of 0.4~
It is a 0.8 board. Therefore, despite its light specific gravity, it has the advantage of being a strong material. On the other hand, since the V-groove 2 can be cut easily since there is no directionality of the fibers, the remaining base portion 3 will not break when bent.

By the way, hardboard has a specific gravity of 0.8 or more, and particle board has almost the same specific gravity as medium-density fiberboard, but the fiber direction is quite strong.

In addition, since insulation board has a specific gravity of less than 0.4, the material is too weak and cannot be bent.

[Explanation of Examples] A so-called medium density fiberboard with a specific gravity of 0.4 to 0.8 is used as the substrate 1.
shall be.

Medium-density fiberboard can be obtained from any of the following: softwood fiberboard using softwood wood fibers, hardwood fiberboard using hardwood forest wood fibers, and fiberboard using a mixture of softwood wood fibers and hardwood forest wood fibers. It will be done.

A V-shaped groove 2 is formed on the back side of the substrate 1 to be bent using a processing machine such as a multi-axis running saw.

The V-shaped groove 2 leaves about 0.5 to 5 mm on the surface side of the substrate to form a remaining base portion 3.

If the specific gravity of substrate 1 is less than 0.4, it will be too flexible,
When processed with a V-groove, it breaks easily, and when the specific gravity is 0.8 or more, the rigidity is strong, and after processing the V-groove, it is difficult to bend.
Difficult to bend.

In addition, when the remaining base portion 3 is formed to leave 0.5 mm or less, the tensile strength of the remaining substrate 1 becomes low, so that the remaining substrate 1 is easily cut at the V-shaped groove portion during bending.

If it is formed to leave 5 mm or more, on the other hand, the tensile strength is strong and it tends to break during bending, making it impossible to bend the radius of curvature to a small value.

In addition, there is a rectangular protrusion 4 between the V-shaped grooves 2, 2...
will be formed.

The remaining base 3 is then coated or sprayed with hot water, steam, or an activator to soften the tissue. These softeners are applied or sprayed from between the V-shaped grooves 2, 2... and from the surface of the substrate 1.

Next, the V-shaped groove 2 is filled with adhesive or the adhesive is applied to the side surfaces of the comb teeth, and the substrate 1 is bent to the back side around the apex 2b of the V-shaped groove 2, and both leg ends 2a, 2a are joined together, held and fixed with a predetermined holder, the adhesive is dried and solidified, and then bent.

In this way, a bent plate having the desired curved surface is obtained.

Next, if necessary, please refer to Figures 3, 4, and 5.
As shown in the figure, reinforcing materials 4a, 4b, and 4c having a triangular shape, a strut shape, or a filler shape on the back side may be attached to the back side.

[Effects of the present invention] Since a so-called medium-density fiberboard with a specific gravity of 0.4 to 0.8 is used as the substrate 1, the fiberboard itself has appropriate rigidity and flexibility, is a homogeneous material, has no fiber directionality, and has no fiber orientation. Since the grooves 2 can be easily processed and the bending process is easy, there is no need to attach a sheet-like material to the surface.

Therefore, it is possible to obtain a bent wood board material that is low in cost and has high commercial value.

For example, if hardboard is used as the wood fiber board, it has a specific gravity of 0.8 or more and is hard, so cracks are likely to occur when it is bent.

Furthermore, when particle board is used, the length of the fibers is shorter than that of medium-density fiberboard, so the entanglement of the fibers is not sufficient, and the fibers have strong directionality, making it easy for cracks to occur during arrow bending.

Insulation board has a specific gravity of less than 0.4, so the material is too weak.

As described above, the present invention selects a medium-density fiberboard and obtains a bent plate material that does not cause cracks even without attaching a sheet-like material to the surface side.

[Brief explanation of drawings]

Figure 1: A front view of the substrate 1 from which the plate material of the present invention is obtained, Figure 2: A front view of the plate material of the present invention, Figures 3 and 4.
Figure 5: Reinforcing materials 4a, 4b, 4 on the plate material of the present invention
Front view when c is pasted, 1... board, 2... V-shaped groove, 2a... both leg ends,
2b: apex, 3...remaining base.

Claims (1)

[Claims] 1. A non-directional medium-density fiberboard with a specific gravity of 0.4 to 0.8 is used as the substrate 1, and the back side of the substrate 1 has a thickness of 0.5 to 5 m/cm on the front side.
A V-shaped groove 2 is cut in such a way as to leave a residual base 3 of 1.m, and the substrate 1 is bent toward the back side around the apex 2b of the V-shaped groove 2, and its two leg ends 2a, 2a are bent.
are joined to each other, and the remaining base portion 3 forms a curved surface on the front side. 2 A medium-density fiberboard with a specific gravity of 0.4 to 0.8 and no fiber direction is used as the substrate 1, and a V-shaped groove 2 is formed on the back side of the substrate 1 so as to leave a residual base 3 of 0.5 to 5 m/m on the front side. Then, after softening the tissue of the remaining base 3 with a softening agent, the substrate 1 is bent to the back surface side around the apex 2b of the V-shaped groove 2, and the two leg ends 2a, 2a are joined to each other. A method for manufacturing a bent plate material, characterized in that the remaining base portion 3 forms a curved surface on the front side.