JP2006035761A - Resin extrusion molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin extruded body having a more genuine grain.
SOLUTION: A base material 1 and a surface material 2 thereof are provided, the base material 1 is a resin composition containing 50% by weight or more of wood powder, and the surface material 2 contains 5 to 20% by weight of wood powder and A resin composition having an embossed grain pattern 4 on the surface, wherein the base material and the surface material are extruded at the same time.
[Selection] Figure 1

Description

  The present invention relates to a resin extrusion molded body resembling wood.

In recent years, due to a decrease in wood resources, the use of extruded products of resin or aluminum instead of wood has been increasing. In a resin extrusion molded body, it is known that a wood texture can be obtained by mixing wood powder with a thermoplastic resin. In Patent Document 1, by forming a surface layer made of a thermoplastic resin compatible with the resin of the base material on the surface of the base material made of thermoplastic resin and wood powder, the linear expansion coefficient and rigidity of the material are formed. It describes improving hygroscopicity and weather resistance.
JP 2002-338699 A

  When using resin-extruded bodies as building materials instead of wood, more than that, the consumer wants the appearance to look more like natural wood. In conventional products, the surface layer is mixed with colored pellets and extruded to create a wood-like striped pattern that looks like wood. It is only far from the appearance of the tree. Therefore, it is also possible to form unevenness on the surface by crafting the extrusion mold or polishing after extrusion molding, but this method can only form streak-like unevenness parallel to the longitudinal direction of the member So it was not enough to make it look like a real wood grain. In view of such circumstances, the present invention aims to provide a resin extrusion molded body having a more authentic grain.

  In order to achieve the above object, a resin extrusion molded article according to the invention of claim 1 includes a base material and a surface material thereof, and the base material is a resin composition containing 50% by weight or more of wood flour, The surface material is a resin composition containing 5 to 20% by weight of wood powder and embossed with a grain pattern on the surface, and the base material and the surface material are extruded simultaneously.

  The invention according to claim 2 is characterized in that the depth of the groove by embossing is 100 to 400 μm.

  In the resin extrusion molded article according to the first aspect of the invention, the grain is expressed not by a simple color difference but by the shading caused by the unevenness of the groove by embossing, and the pattern can be freely formed to resemble natural wood, It is possible to easily produce a high-product-value resin extrusion molded body that has an appearance close to wood. In addition, an excellent anti-slip effect can be obtained by embossing. A good wood texture can be obtained by including 50% by weight or more of wood powder in the base material, and by providing a surface material with a wood powder ratio of 5 to 20% by weight around the base material, hygroscopicity, Weather resistance and dimensional stability are improved, and it can be used for a wide range of indoor and outdoor applications. Wood flour can be used for building waste, thinned wood, wood chips from timber factories, etc., and can contribute to recycling of wood resources and preservation of the global environment.

  When the depth of the groove by embossing is set to 100 to 400 μm as in the invention of claim 2, a clear shadow that can be recognized as a grain is obtained by the unevenness of the groove, and an excellent anti-slip effect is obtained. It is obtained and suitable for use as a member that is difficult to slip, such as a deck material.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the resin extrusion molded article of the present invention. This resin extrusion molded body 3 is formed in a strip shape, and is used as, for example, a flooring. This resin extrusion molded body 3 has a base material 1 and a surface material 2 surrounding the entire circumference of the base material 1, embossing is performed after the extrusion molding, and a three-dimensional wood grain pattern 4 is added to the surface material 2. It looks like a natural tree. The base material 1 and the surface material 2 are integrally formed by extrusion at the same time.

  The base material 1 is a composition mainly composed of a thermoplastic resin and wood powder, and the ratio of the wood powder is 50 to 90% by weight. As the thermoplastic resin, polyethylene resin, polypropylene resin, ABS resin, polyvinyl chloride resin, copolymers of these resins and other resins, mixtures of these resins and other resins, and the like can be used. Wood powder can use various kinds of wood such as hardwoods and conifers, but if you use building waste, thinned wood, or wood chips from wood factories, you can reduce material costs and effectively use wood resources. Considering the characteristics of recycled products, it will be friendly to the global environment. The base material 1 is provided with a plurality of hollow portions 5 that are continuous in the longitudinal direction, thereby reducing the weight of the member, improving the bending rigidity in the longitudinal direction, and surface curvature due to the difference in cooling rate between the inside and outside during extrusion molding. There is an effect such as prevention.

  Similarly to the base material, the surface material 2 is a composition mainly composed of a thermoplastic resin and wood powder, but the ratio of the wood powder is less than that of the base material and is 5 to 20% by weight. The thickness of the surface material 2 is 0.5 to 2 mm, more preferably 1.0 to 1.5 mm. Thus, by covering the entire circumference of the base material 1 with a surface material with a small proportion of wood powder and a large proportion of thermoplastic resin, the hygroscopicity is kept low, the weather resistance is improved, and it can be used outdoors. And dimensional stability is also improved. The thermoplastic resin uses a resin compatible with the base material, such as polyethylene resin, polypropylene resin, ABS resin, polyvinyl chloride resin, copolymers of these resins with other resins, these resins and other resins. A mixture with resin can be used. Further, if a weather-treated resin is used, the weather resistance is further improved. The surface material 2 can be mixed with a pigment as appropriate to obtain a color tone resembling various kinds of wood. If the surface material is not provided, or if the ratio of the surface material wood powder is out of the range of 5 to 20% by weight, problems occur in any of hygroscopicity, weather resistance and dimensional stability, making it unsuitable for actual use. .

  As a method of extruding the base material 1 and the surface material 2 simultaneously, for example, the resin composition for the base material and the resin composition for the surface material are respectively melt-kneaded with a resin extruder and hollowed into the base material 1 through a multilayer multiple die. While forming the part 5, the resin for surface material is merged so that the surface of the base material 1 may be thinly coated, and coextruded from the die mold. If necessary, the extruded molded body can be passed through a forming die to improve dimensional accuracy.

  As shown in FIG. 2, the embossing is performed by pressing an embossing roll 6 sculpted with natural wood grain irregularities on the surface of a cylindrical mold against the surface of the resin extrusion 3 while being heated with oil. The wood grain pattern 4 is continuously transferred to the surface material 2 by rotating the surface material 2. If the concave-convex pattern 7 on the surface of the embossing roll 6 is formed by reversing the natural wood grain pattern and the concave and convex portions, the natural wood grain pattern irregularity is transferred as it is to the surface material. The processing conditions for embossing vary depending on the type of resin of the surface material 2, but in the case of polyethylene resin, the surface temperature of the embossing roll 6 is 100 to 110 ° C., the molding speed is 3 m / min, and the pressing load is resin extrusion. The distance between the embossing rolls 6 and 6 is appropriately adjusted according to the thickness of the molded body 3. The grain pattern 4 by embossing may be formed on both sides of the resin extrusion molded body 3, but may be formed only on one side.

  The resin extrusion molded body of the present invention expresses a grain of wood by shading produced by unevenness due to embossing, and it is considered that a certain groove depth is necessary to be recognized as a grain of wood. Table 1 summarizes the comparison of visual appearance when the embossing groove depth is varied. As can be seen from this table, if the groove depth is 100 μm or more, the grain is recognized. In particular, when one or two grooves of 200 to 400 μm or more were mixed in a groove having a depth of 100 to 180 μm, a good appearance closer to that of natural wood was obtained. When the groove depth is 400 μm or more, the resin melts and sticks to the embossing roll and cannot be processed well.

  Table 2 is a comparison of the coefficient of static friction (relative to rubber) between the resin extruded product according to the present invention in which irregularities are formed on the surface material by embossing, the resin extruded product subjected to polishing treatment, and natural wood. . In general, the static friction coefficient is considered to be safe if it is 0.5 or more, and if it is 0.6 or more, it is said that there is sufficient safety even in the inclined part. The value was considerably large as 05, which was larger than the value of natural wood (0.79) measured for reference. Thus, since the resin extrusion molding of this invention has the outstanding slip prevention effect, it is suitable for using as a location where slipping difficulty is especially calculated | required, for example, an outdoor deck material.

  The present invention is not limited to the embodiments described above. The resin extrusion molded body is not limited to a plate shape, and can be formed in a column shape, and the method of providing the hollow portion of the substrate is arbitrary. In the surface material, pigment pellets may be mixed at the time of extrusion molding, and the grain may be expressed in terms of color. However, even a concavo-convex pattern obtained by embossing is sufficiently recognized as a grain, so it is not always necessary.

It is a perspective view which shows one Embodiment of the resin extrusion molding of this invention. It is explanatory drawing which shows the method of embossing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Surface material 3 Resin extrusion molding 4 Wood grain pattern 5 Hollow part

Claims (2)

  A base material and a surface material thereof are provided, the base material is a resin composition containing 50% by weight or more of wood powder, and the surface material contains 5 to 20% by weight of wood powder and has a grain pattern embossed on the surface. A resin extruded product, wherein the base material and the surface material are extruded at the same time. The depth of the groove | channel by embossing is 100-400 micrometers, The resin extrusion molding of Claim 1 characterized by the above-mentioned.

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