JPS6145948B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry method for manufacturing a wood composite board in which the composite board is manufactured in a dry state without using impregnated paper, resin liquid, or the like.

Conventionally, when manufacturing a composite board by laminating a fibrous surface material to plywood or hardboard that has unevenness due to conduit grooves, cracks, intersecting fibers, etc., the following wet manufacturing method using impregnated paper has been known. It is being The conventional manufacturing method is to first immerse the base paper in an impregnating liquid bath filled with a thermosetting resin such as melamine resin, urea resin, or phenol resin, to impregnate the base paper with the resin, and then completely cure or completely cure the resin. A semi-cured impregnated paper is made, and the impregnated paper is heat-pressed onto a substrate to make a composite board.

However, such conventional methods have disadvantages in terms of manufacturing process, such as not only is it not easy to manufacture and handle the impregnated paper, but also the process of manufacturing the impregnated paper and the process of pasting must be performed separately and independently. That is,
The production of impregnated paper involves a process of immersing paper in an impregnating liquid and heating and drying the impregnating liquid to completely cure or semi-cure it, which requires large equipment such as an impregnating liquid tank and a drying oven. Furthermore, since the paper is used as is from the beginning, it is not easy to handle. In addition, even if the resin impregnation rates are different, each of them has the following disadvantages. That is, impregnated papers include low-density impregnated paper with a resin impregnation rate of 20% or less of the base paper weight, medium-density impregnated paper with a resin impregnation rate of 20 to 60%, and high-density impregnated paper with a resin impregnation rate of 100 to 120%. Here, low or medium density impregnated paper is brittle and easily cracked because the impregnated resin is completely cured in preparation for being attached to a substrate using an adhesive. On the other hand, with high-density impregnated paper, the impregnated resin is semi-cured in order to be attached to the substrate by thermocompression bonding without using adhesives, so it is easy to block, and to prevent this, release paper is placed between the impregnated papers. must intervene. Furthermore, since storage stability in a semi-cured state is required, the resins to be used must be limited.

The present invention eliminates all the above-mentioned disadvantages of the conventional wet manufacturing method by using a pine-like fiber instead of the impregnated paper and bonding it to the substrate in a dry state. , its structure is to form a fiber mat by intertwining thermoplastic resin fibers with vegetable fibers and/or mineral fibers and attaching a thermosetting resin to the fiber body, and then heat the thermoplastic resin fibers to form a fiber mat. It is characterized in that the composite plate is manufactured by heat-pressing bonding to a substrate via an adhesive at a temperature at which the thermosetting resin melts and hardens.

The present invention will be explained in detail below along with examples.

In the method of the present invention, first, in the first step, a fiber material consisting of vegetable fibers obtained by defibrating pulp, paper, waste paper, etc., or mineral fibers such as asbestos, glass fiber rock wool, etc., alone or mixed in any proportion, is used. A mat-like fibrous body is formed by felting a composition in which a thermoplastic resin fiber and a thermosetting resin are uniformly mixed or applied to a fibrous material.

In this case, in order to have the strength to withstand winding of the pine and to maintain the shape of the pine, the amount of the thermoplastic resin fiber and thermosetting resin to be mixed is determined based on 100 parts by weight of the pine fiber body. It is preferable to use 5 to 40 parts by weight of fiber and 5 to 40 parts by weight of thermosetting resin. Here, the thermosetting resin may be liquid or powdery. In the case of liquid resin, it is best to spray it onto the fiber body. As a result, the above-mentioned fibrous body becomes a state in which the fibers of the thermoplastic resin are entangled with the plant mineral fibers, and the thermosetting resin is attached to the fiber surface, so that when the fibrous body is touched, the viscosity of the thermosetting resin slightly increases. It becomes a dry fibrous body that can be felt. In addition, the use of thermoplastic resin fibers acts as a binder when the above-mentioned mat-like fiber body is manufactured in the first step, and is sufficient for various handling purposes such as cutting and transporting the low specific gravity hardened mat that is an intermediate product. It can exhibit durable mechanical strength. The length of the thermoplastic resin fiber is preferably about 3 to 30 mm. Generally, cellulose fibers have a maximum fiber length of about 3 to 5 mm, and when felted by a dry method, the fibers are less entangled, have poor strength, and are easily damaged during handling. Therefore, by adding thermoplastic resin fibers having a fiber length of about 3 to 30 mm, which is longer than cellulose fibers, it is possible to help the fibers intertwine with each other and prevent breakage during handling. Note that polyolefin fibers such as polyethylene and polypropylene can be used as the thermoplastic resin fibers, and phenol resins can be used as the thermosetting resin.

Further, by using a thermosetting resin, the thermosetting resin is cured when the fiber mat is compressed in the next second step, thereby increasing the physical strength and water resistance of the composite board. As the above-mentioned thermosetting resin, phenolic resin is most suitable from the viewpoint of physical and mechanical properties and cost.

As described above, the plant mineral fibers, thermoplastic resin fibers, and thermosetting resin are uniformly mixed and felted to form a mat-like fiber body, and then the fiber body is heated at a temperature at which the thermoplastic resin fibers are melted. death,
Cool to form a fiber mat. By this heat treatment, the thermoplastic resin fibers are partially welded to each other while being entangled with the plant mineral fibers, thereby improving shape retention and forming a fiber mat having a low specific gravity of about 0.02 to 0.2.

Next, in the second step, the above-mentioned fiber mat is laminated with an adhesive on the surface of a wood substrate such as a glued veneer or plywood, particle board, hardboard, etc. and other substrates when manufacturing plywood, and then the above-mentioned heat is applied. The fiber mat is pressed onto the substrate surface by heating and pressurizing at a temperature where the plastic resin fibers are thermally melted and the thermosetting resin is cured, thereby producing a wood composite board with a smooth surface. At this time, the thermoplastic resin fibers are melted while being entangled with the plant mineral fibers to firmly bond these fibers, and also easily enter the recessed holes on the substrate surface so that the fiber mats easily fill these recesses. This improves adhesion to the substrate. Furthermore, after cooling and solidifying, the fibrous portion on the surface is made denser to improve water resistance. Furthermore, the physical strength and water resistance of the entire fibrous body portion are increased by curing the thermosetting resin.

In addition, in the second step, when hot-pressing molding, if necessary, a decorative plastic sheet, cloth, decorative paper, etc. is laminated on the top surface of the fiberboard, and a call board with an embossed pattern is used on top of it. An embossed decorative board can be manufactured by hot-pressing molding.

The manufacturing method of the present invention described above has the following advantages.

Since waste fibers such as plywood waste and waste paper can be used, manufacturing costs can be reduced.

When the intermediate fiber mat is crimped onto the substrate surface, the thermoplastic resin fibers are tangled and melted, so the entire fiber mat easily fills small recesses on the plywood surface, resulting in a wood composite board with a smooth surface.

Embossing is done at the same time as the crimping of the fiber mat, so it is easy to process the fiber mat and improves the wood grain.
Patterns of any design can be easily embossed on bricks and the like.

When manufacturing plywood, the fiber mats can be crimped at the same time as the veneer is heat-pressed, so there is no need for equipment and processes for separately crimping the fiber mats.

Since the intermediate fiber matte is manufactured by dry method,
Unlike the previous wet method using impregnated paper, the yield of cellulose fibers, adhesives, etc. is good.

In addition, since the low specific gravity pine is manufactured using a dry method, the pine specific gravity is as low as 0.2 or less, and the hot air passes through the dryer in the first step easily, reducing the amount of heat energy required during pine manufacturing.

Next, examples of the present invention will be shown.

Example 1 Softwood ground pulp crushed into small pieces using a crusher
83% by weight, 5% by weight of polyethylene synthetic pulp (SWP manufactured by Mitsui Zerapack Co., Ltd.), 10% by weight of powdered phenolic resin (Gunei RP), 2% by weight of zinc stearate, and the pulp was completely decomposed into single fibers using a defibrating machine. After the fibers are woven, a uniform mat-like fiber body of 800 g/m ² is formed using a mat forming device. Further, this mat-like fiber body is passed through a hot air circulation heating furnace and heat-treated at a heating temperature of 140° C. for 1 minute to melt the synthetic pulp, and then cooled to form a fiber mat with an apparent density of 0.06.

Next, the fiber mat and the plywood veneer glued in a separate process are laminated in the order of fiber mat 1, core material 2, core material 3, core material 4, and back board 5 from above as shown in FIG. After cold pressing for 10 minutes at a pressure of 10 kg/cm ² , hot pressing was performed at a pressure of 15 kg/cm ² at a temperature of 150° C. for 4 minutes. As a result, as shown in FIG. 2, a composite board was obtained in which the fiber mat was crimped at the same time as the veneers were joined, and the fibrous portion 6 and the plywood portion 7 were integrated. Furthermore, the obtained wood composite board had a smooth surface and had sufficient performance as a high-grade decorative board base plate.

Example 2 Instead of the softwood ground pulp of Example 1, a composition was prepared in which 80% by weight of waste paper pulp obtained by coarsely crushing newspaper, 8% by weight of polyethylene synthetic pulp, 10% by weight of powdered phenolic resin, and 2% by weight of zinc stearate were mixed. After defibrating the material using a defibrator, a mat-like fibrous body having a uniform texture of 500 g/m ² is formed using a mat forming device. This mat-like fibrous body is then heat-treated at 140℃ for 1 minute in a hot air circulation heating furnace to melt the synthetic pulp and then cooled to determine the apparent density.
Forms a fiber mat of 0.08. Next, in a separate process, the fiber mat was superimposed on the surface of 3-ply 5.5 mm plywood whose surface had been coated with adhesive, and then a cloth wallpaper coated with 200 g/m ² of vinyl acetate emulsion was placed on top of it. Heat and pressure treatment is performed using a caul board with an embossed pattern at a temperature of 160°C and a pressure of 15 kg/cm for ² hours and 3 minutes.

As a result, a composite board is obtained in which the decorative sheet portion 8, the fibrous portion 9, and the plywood portion 10 are integrated with each other, as shown in FIG. It had an embossed pattern and had sufficient performance as a high-grade plywood.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams of the manufacturing method according to the present invention. Figure 1 is an explanatory diagram showing the laminated state of fiber mat and plywood, and Figures 2 and 3 are after the fiber mat is crimped. It is an explanatory view showing a composite board of.
In the drawing, 1 is a fiber mat, 2 is a core material, 3 is a core material, 4 is a core material, 5 is a back plate, 6 and 9 are fibrous parts, 7, 1
0 is a plywood part, 8 is a decorative sheet, and 11 is an embossed pattern.

Claims (1)

[Scope of Claims] 1. A fiber mat is formed by intertwining thermoplastic resin fibers with vegetable fibers and/or mineral fibers and attaching a thermosetting resin to the fiber body, and then the fiber mat is mixed with the thermoplastic resin fibers. A method for manufacturing a wood composite board, characterized in that the composite board is manufactured by heat-pressing bonding to a substrate via an adhesive at a temperature at which the thermosetting resin is thermally melted and the thermosetting resin is hardened. 2. In the manufacturing method described in claim 1,
A method for manufacturing a wood composite board, characterized in that the amount of thermoplastic resin fiber and thermosetting resin mixed is 5 to 40 parts by weight, respectively, per 100 parts by weight of vegetable fiber and/or mineral fiber. 3. In the manufacturing method according to claim 1 or 2, the fiber mat is made into a mat by uniformly mixing plant fibers and/or mineral fibers, thermoplastic resin fibers, and thermosetting resins, and then felting the fiber mat to form a mat, A method for producing a wood composite board, further comprising heating the wood composite board at a temperature at which the thermoplastic resin fibers melt.