JPH0410405B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the disclosure of a method for forming a wood-like resin plate material by combining roll kneading and press processing, and in particular, it is concerned with the disclosure of a method for forming a wood-like resin plate material by combining roll kneading and press processing, and in particular, it is concerned with the disclosure of a method for forming a wood-like resin board material by combining roll kneading and press processing. In addition to reliably preventing wear and tear on the molding machine, it also prevents the surface of the molded product from roughening of the inside surface of the molding machine, extrusion friction resistance due to mixed wood flour, and various gases generated from wood flour. The purpose is to prevent rough skin and provide mass production of wood-like resin board materials at low cost.

Conventionally, this type of wood board material was molded by resin molding by mixing wood powder and resin powder in an extruder, injection machine, etc., as shown in, for example, Japanese Patent Publication No. 52-26534. As a result, the molding machine itself suffered extremely severe wear and tear, and the quality of the molded product itself was extremely poor, making it insufficient to provide plate materials that could withstand use. .

In particular, in such conventional methods, first, the extrusion pressure or injection pressure in the molding machine is extremely increased by the mixed wood powder, which drastically reduces the number of molding shots and often causes die loss. This also caused roughening of the inner wall surface of the molding machine.

In addition, in such a molding method, the mixed wood powder causes corrosion of the inner wall surface of the molding machine due to wood acid gas, water vapor, etc. generated during heating processing, and the surface of the molding machine becomes rough due to gas bubbles and fleshy parts. This is accompanied by the formation of foam nests.

Therefore, molded products are subject to quality problems due to gases generated, wear in the die, rough skin, excessive molding pressure, etc. In particular, extreme variations in molding pressure are particularly problematic in terms of quality. Shrinkage distortion is likely to occur after molding, and this has been considered the main cause of warpage and distortion.

In this regard, the conventional method inevitably assumed quantitative and qualitative constraints on the mixed wood flour, and this created an initial woody state in the formed board. This makes molding difficult or extremely expensive.

In other words, the smaller the amount of wood flour mixed in, the more its properties become extremely similar to those of vinyl chloride, which makes it useless to mix wood flour as a lubricant, and with a slight increase in the amount, the properties become more similar to those of vinyl chloride. Because of the inconvenience caused, there was no point in intentionally mixing wood flour.

In addition, when increasing the amount of wood flour is mixed into a wood-like resin plate material that can withstand sufficient use, as mentioned above, the molding machine itself may be worn out, especially damage to the die, and damage to the liner or cavity. As a result, the molding speed was drastically reduced and a larger molding machine was required, which definitely increased the molding cost.

The method for molding a wood-like resin board according to the present invention includes:
It was specially devised in view of the inconveniences of the conventional synthetic composite material, and it is made by making the mixed wood powder itself have a certain quality, that is, the particle size is 80 mesh or more, ideally about 150 mesh. , in a so-called extremely dry state with a moisture content of 4% or less, to eliminate some of the inconveniences in molding caused by mixed wood flour itself, and knead the molding itself with kneading rolls, By spreading and molding using a press, we were able to eliminate the inconveniences of the above-mentioned molding method,
The gist of its composition is that the mixed molding material obtained by mixing and kneading 50 to 70 wt% of wood flour with a moisture content of 4% or less and a particle size of 80 mesh or more into thermoplastic resin powder is sequentially passed through a heating rotating roll. The material was melted and kneaded to a predetermined thickness, then cut to a fixed width and pressed.

In addition to the outline of such a configuration, a corresponding method, so-called equivalent means, has been separately planned, and the following specific examples and a corresponding detour method are planned. It is something that

Hereinafter, a typical embodiment of the present invention will be described in detail with reference to the accompanying drawings.Firstly, the wood flour used as the aggregate is usually obtained by crushing wood chips, cutting sawdust, etc.
Polishing powder for various wood moldings or synthetic wood moldings, cellulose scraps from sludge, and other various wood powders to be supplied as needed are planned, and these are first thoroughly dried and ground. The particle size is set to 80 mesh or more, usually 120 mesh or more, ideally 150 mesh, to improve the slippage as an aggregate and eliminate the generation of wood acid gas and water vapor during hot molding. It is something.

In particular, the disadvantage of slip resistance in wood flour is minimized by making the particle size extremely fine, and the degree of mixing with vinyl chloride powder is made more intimate.

In addition, wood acid, which is a characteristic of wood flour itself, is generally a gas, which affects the mixed vinyl chloride resin as an acidic gas, or corrodes the inner wall of the molding machine. By keeping the acetic acid in an extremely dry state, any room for such acetic acid gas to be generated is wiped out.

Next, when wood flour is mixed in, urea-based resin powder is mixed in with the wood flour. This is added as an aggregate element during the wood flour kneading process and as an element to neutralize the generated wood acid gas, and its characteristics are that of a so-called thermosetting resin, and that it is a urea-based resin. That is, it is placed in a position where it can neutralize acids.

In addition, foamed and various inorganic aggregates can be used as additives.
Optional addition of thickeners, pigments, etc. is planned.

Next, the vinyl chloride resin agent used as the main material is basically prepared as a powder, but resin, pellets, etc. may be used or used in combination if necessary.

50-70wt% of wood powder and urea resin
10wt% is mixed into vinyl chloride resin, and in a sufficiently mixed state, it is sent sequentially to heating rotating rolls 1 to 1, melted and kneaded, and in a sufficiently melted and kneaded state, it is transferred to cooling rolls 2 to 1. After being fed into a hot press 3 and subjected to a predetermined cooling and shape retention, it is provided as a plate, and then pressed and heated again in a hot press 3.
The molding is performed by cooling and demolding. In addition, in the forming described above, rotating roll 1
〜1 directly supplies the material w to the hot press 3,
It is also possible to omit the cooling roll 2, and the molding can be appropriately selected depending on the type of molded plate material.

Further, the press 3 is usually a hot press type, but in the case where the material w is directly supplied to the press 3 from a kneading roll, the press 3 is also planned to be a molding press. This made it possible to shorten mold release time and enable even greater mass production.

In addition, these presses 3 can freely create various mold surface shapes and patterns to match the molded plate material, and unlike conventional extrusion molded materials, etc., they can quickly adapt to various shapes. This makes it possible to freely provide plate materials.

The forming method according to the present invention uses the above-mentioned rolls and press in combination, and by setting certain restrictions on the degree of drying and particle size of the aggregate used, it is better than the conventional method. This eliminates these inconveniences and makes it possible to mass-produce wood-like resin board materials at low cost.

In other words, as mentioned above, the generation of wood acid gas and water vapor can be suppressed by regulating the moisture content in aggregate, and even if these gases are generated, This is the so-called open type, and there is no possibility that all of it evaporates between the heated rotating rolls 1 and 1 and remains in the material or in the machine, causing the above-mentioned inconvenience.

Also, it eliminates dies, liners, cavities, etc.
By adopting a simple kneading roll structure, setting certain restrictions on the particle size of the wood flour used, and mixing urea resin powder, we achieved good slip resistance during molding, and these sliding contacts This eliminates the conventional inconveniences associated with resistance, and allows the amount of wood flour to be mixed in at will, making it possible to mix in enough wood flour to have the desired wood properties.

The method for molding wood-like resin board materials according to the present invention has the characteristic structure, functions, and effects described above, and can provide materials for a wide range of purposes such as various building materials, furniture materials, equipment parts, etc. This makes it possible to provide an extremely innovative board material that has both the advantages of wood and resin materials.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a typical embodiment of the molding method according to the present invention, and FIG. 2 is a perspective view showing an embodiment of the same molded product. In the figure, 1 indicates a heating rotating roll, 2 indicates a cooling roll, and 3 indicates a hot press.

Claims (1)

[Claims] 1 Wood flour with a moisture content of 4% or less and a particle size of 80 mesh or more is added to thermoplastic resin powder with a moisture content of 50 to 50 mm.
The mixed molding material obtained by mixing and kneading 70wt% is sequentially melted and kneaded using heated rotating rolls to form a predetermined thickness, which is then cut to a fixed width and subjected to press processing. A method for forming wood-like resin board materials.