JPS6073808A - Method of molding woody synthetic molded item - Google Patents

Abstract

PURPOSE:To let a molded item have both the woody characteristic and the resin characteristic, by mixing a relatively fine wood flour or the like as a molding aggregate with a synthetic resin material such as a vinyl chloride resin, and press molding, extruding, or injection molding the mixture. CONSTITUTION:A cellulosic material such as a fine powder obtained from wood chips or pulp material is further pulverized to produce an aggregate. The water content in the material is to be up to 15%, and the material is heated to be dried and is broken to have a particle diameter of 100-150 mesh, during which the composition of the material is broken, thereby causing the water content thereof to be 3-5%. 20-50wt% Aggregate are mixed with a powder of a thermoplastic resin such as vinyl chloride resin, then a urea type synthetic resin powder in an amount required for neutralizing the wood acid gas that will be released from the mixed aggregate is added thereto, and after stirring the mixture, the mixture is molded. As the material is heated, the urea type resin powder adheres to the mixed aggregate and hardens so that it is present as an aggregate having a special function in the melted resin material such as vinyl chloride resin.

Description

Detailed Description of the Invention This invention involves mixing relatively fine wood flour etc. as a molding aggregate into a synthetic resin material such as vinyl chloride resin and performing press molding, extrusion, injection molding, etc. The purpose of this invention is to provide a synthetic molded product that has the following characteristics.

Therefore, one of the main objectives expected in the present invention is to improve the molding properties by adding characteristics to the mixed aggregate and also mixing urea resin powder, so that it can be used in extrusion or injection cylinders during molding. It eliminates inconveniences such as partial wear and damage to the die, as well as roughness on the surface of the molded product, and also improves the compatibility between the mixed aggregate and resin material, and prevents the formation of cavities on the surrounding surface of the aggregate. It was designed to provide the following benefits.

Another objective of the present invention is to impart characteristics to the mixed aggregate, and to mix urea-based resin powder with the aggregate to easily produce a relatively large amount of aggregate.
In other words, it is possible for the resin to be mixed in on the molding work surface and on the familiar surface of the molded resin material, thereby reducing cooling shrinkage strain and eliminating distortion and warpage. Furthermore, the modulus of elasticity is more than three times that of ordinary vinyl chloride molded products, and the hard melon on the surface is also sufficiently hard to provide a composite piece.

Furthermore, one of the other main objectives anticipated in the present invention is to press, extrude, and
Alternatively, it can be easily mass-produced and provided by molding it into any shape by injection molding or the like.

Another main objective of the present invention is that it has superior abrasion resistance compared to the characteristics of the material to be molded, has no shrinkage due to molding shrinkage, and is more durable than wood in actual use. The aim is to make it possible to provide products that have the same surface characteristics as those of the above, that is, color tone, texture, and can be painted, bonded, laminated, etc.

The method for molding a composite piece carving according to the present invention is intended to achieve various desired effects in an urgent manner. The means are predetermined.

Next, a typical method for forming a composite piece for building materials or fittings according to the present invention will be explained in detail.

First, the materials to be prepared are vinyl chloride, ABS resin,
These are a thermoplastic resin material such as polystyrene, a mixed aggregate based on wood flour, a charcoal-brewed calcium powder stabilizer, a coloring agent, etc., which are added as necessary.

The thermoplastic resin materials used are determined and used based on the selection criteria that satisfy the various needs required for molded articles, and in the case of building materials, fitting materials, etc. In particular, vinyl chloride resin was used due to its hardness and other factors.

The aggregate to be used next is a cellulosic material such as crushed wood chimp powder, pulp material powder, or rice husk powder, and the crushing and pulverization treatment methods are appropriate. 15% moisture content in the material
By drying within 100 minutes, the composition of the material is destroyed, and the particle size is reduced to 100% by heating, drying, and crushing.
~150 mesh, with a water content of 3 to 5%, preferably zero water content. By specifically positioning the aggregate under unique conditions, the following resin molding was made possible.

The urea-based resin material prepared together with the aggregate and the molding resin material is in powder form, and it reliably captures and neutralizes the wood acid gas induced during the heat molding of the aggregate, as well as heat molding. It hardens in the process and either adheres to the aggregate or forms the aggregate independently.

20 to 50 wt% of aggregate is mixed with the thermoplastic resin powder of vinyl chloride q. prepared in step 2, and urea-based synthetic resin powder is added to the powder, and wood acid produced from the mixed aggregate is added. The mixture is mixed in an amount within a range that neutralizes the gas, and after sufficiently stirring and mixing, the resin is molded using a conventional molding method.

In such resin molding, as the material is heated, the urea-based resin powder hardens into the mixed aggregate, which is another solid substance (= 1 piece), and then melts into the melted resin material such as PVC. It is mixed as an aggregate with a unique function.In particular, wood acid gas is neutralized by binding to the surrounding surface of the aggregate where a large amount of wood acid scum is expected to be generated. Aggregates with a pH of about 5 are adjusted to a pH value of about 6 to 7 during molding.Also, since the urea resin is hardened and bonded to the surrounding surface of the aggregate, The frictional resistance of the aggregate, such as extrusion resistance, is significantly reduced, allowing easy extrusion and other shaping.

In addition, the aggregate used in the process is heated to reduce the water content in the aggregate to a maximum of 13
%, ideally within 3 to 5%, and even as much as possible to O%, to eliminate any room for water vapor to occur in the subsequent resin molding with aggregate mixed in, and to reduce the amount of wood acid contained. This prevents dissociation and volatilization and eliminates the possibility of generating acidic gas.

In addition, the aggregate used is subject to expansion and expansion of the aggregate during heating and drying in the pulverization process of the aggregate, that is, wood chips.
In the case of wood powder, pure wood powder, agglomerates during the forming process, or formed granular aggregates, appropriate drying means may be applied to achieve the degree of drying required separately. It is separated.

In addition, the aggregate used is mainly composed of the above-mentioned urea-based resin, and the wood acid contained in the wood flour, especially acetic acid scum, is , 75 dispersion, neutralization y
Therefore, in the subsequent process of molding the aggregate into the resin material by 8Q, more room for acidic gas to be generated is effectively provided than the aggregate used.

In addition, most of the moisture contained in the aggregate is dispersed by the heating and drying process applied during the molding of the aggregate, which prevents the generation of water vapor, which is considered to be a problem in resin molding using molded aggregate. There is no room for foaming, cavities, rough skin, etc. to occur in the molded product. In addition, the removal of this water content has a significant effect on the volatilization of wood acid contained in wood flour, and the wood acid contained in aggregates such as wood flour usually has H2O groups. Since dissociation and volatilization occur only after reaction, this is effectively suppressed. Therefore, it is more effective to eliminate the wood acid produced in the process of curing and binding the thermosetting resin powder and to suppress the generation of residual wood acid gas from the aggregate.

Usually, when wood acid gas is generated during resin molding, the cylinder screw of the press, extruder, or injection machine used for resin molding, or the inner wall surface of the molding tie or mold is oxidized and corroded, reducing its service life. This extremely reduces the molding efficiency and also causes the problem of molding defects due to uneven extrusion and injection pressures.

In addition, unlike the usual pure wood flour, in the case of diagonal aggregate,
By adding a hardening resin to the aggregate, the surface resistance value is extremely reduced, and when molded as an aggregate into a resin material, the extrusion and injection pressure is almost equal to that of ordinary resins. It's a close one. On the other hand, in the past, when wood flour was mixed in, the wood flour slid into contact with the inner circumferential surface of cylinders, ties, etc., causing frictional resistance, and when extrusion or injection was performed, cylinders, ties, etc. This causes scratches, wear, or damage on the inner circumferential surface of the hat.

Furthermore, the bond R of the urea resin material to the aggregate is l
This ensures good compatibility with the mixed resin material, ensures uniform mixing of aggregate, and eliminates as much as possible the voids that occur around the aggregate in the molded product, ensuring that the molded product has the desired quality. This makes it possible to provide this service.

The calcium carbonate powder prepared next is necessary to prevent the molded product from deforming during extrusion, etc., and to set the unit price of the molded product low since calcium carbonate itself is particularly cheap. It was used accordingly.

A separate attempt was made to prepare stabilizers such as lead along with these materials to prevent deterioration in the molded product and to reduce as much as possible the frictional resistance that occurs during extrusion 1-1. .

Furthermore, when the molded product is to be colored, a corresponding coloring agent is prepared. For example, when the molded product is made white, titanium oxide is mixed in.

The materials detailed above are t, 17. In some cases, it is provided in the form of pellets by pre-mixing with a resin material such as vinyl chloride resin, and in other cases, it is provided in a form similar to jμ, which is mixed into a resin powder such as vinyl chloride resin. They are selectively supplied and used depending on the type of resin molding machine used.

Therefore, when making pellets, first mix the above-mentioned aggregate within 50wt% with resin powder, and add urea-based resin powder and calcium carbonate as necessary within the range of Lout%. Then, necessary stabilizers, lubricants and colorants are mixed in and heated under cross-wire heating to obtain pellets for molding. The molded phase pellet yi thus obtained
The desired composite carving was obtained using the same method as in ordinary resin molding.

Another method that will be planned next is to use a method similar to that used for making pellets, but to directly produce a molded product by putting the various materials into a molding machine, kneading them, and molding them by heating.

In addition, since the above-mentioned aggregates are planned to be mixed, the main molding methods for resin molded products are press molding, extrusion molding, or injection molding, with extrusion foam molding being used in some cases. It was planned.

The amount of aggregate to be mixed is determined according to the resin molding method and the characteristics of the molded product, and is 20% to 20%.
It is approximately determined within a range of about 50 wt%.

In addition, the processing temperature is within the range of about 110°C to 170'C depending on the resin material used, the amount of aggregate, the molding method, etc.
It is expected to have a specific effect on the above-mentioned characteristics,
This makes it possible to provide a composite piece that combines the advantages of wood and plastic.

In particular, it is now possible to easily mold various molded products that were previously considered almost impossible to mold due to the fact that the wood powder mixed in with the wood powder produces wood acid gas, or that the wood powder has particularly high slip resistance. It could have been done.

In addition, the molded product is compatible with the resin material used due to the characteristics of the mixed aggregate, and resin molded products with good quality characteristics can be provided using normal molding methods and normal molding efficiency. It could have been done.

In addition, due to the characteristics of the aggregate, it does not induce excessive frictional resistance or cylinder pressure in the molding machine itself, and the roughness of the inner peripheral surfaces of the cylinder and die is prevented, making it easy to use the equipment. The attrition rate is particularly low compared to other types.

As mentioned above, the molded product thus provided has a woody feel, excellent water resistance, abrasion resistance, and impact resistance, and has a hard surface.

In addition, molding distortion due to sink marks during molding, distortion, warping, cracking, etc. after molding are reliably prevented, and the elastic modulus is also particularly good.

In addition, it has a low thermal deformation rate, and has excellent machinability, paintability, adhesiveness,
It has nailing characteristics, etc., and is said to have particularly good construction characteristics.

It should be noted that the wood used can be either softwood or broadleaf, as the cellulose fibers are made into fine powder without crushing the wood.

The method of molding the wood-like composite shape according to the present invention is described below, and the molded products include architectural components, door frame materials, window frame materials, surrounding edging materials, Skirting boards, curtain bonks, edge edges, angles, test pieces, wood, wall materials, thresholds, lintels, doorstops, etc., as well as fittings such as barrier frames, doors, stile doors, louvers, etc., for furniture, automobiles, etc. A wide range of uses are planned, including for commercial use, ships, household utensils, various cabinets, sinks, and more.

Claims (2)

[Claims] (1) A mixture of a thermoplastic synthetic resin powder and a cellulose-based fine dry aggregate such as wood flour, pulp powder, or rice husk powder with a particle size of 100 to 150 mesh and a moisture content of 5% or less contains urea. A method for molding a wood-like composite piece, characterized in that resin powder is added and mixed and heat molded. (2) The method for forming a wood-like composite carved article according to claim 1, characterized in that the amount of the aggregate mixed is 20 to 50 wt%.