What is the processing technology and performance of wood-plastic composite materials? Many people are curious about this, let us introduce it to you.The technical feature of wood-plastic materials is to mix two different types of materials with each other. That is, wood and plastic are combined into a composite material.
Wood flour (or fiber powder of crops) as an organic filler for plastics has a wide range of sources, low price, low density, good insulation and other excellent properties that many other inorganic fillers can’t match, but it does not get the same as inorganic fillers. widely used. The main reasons are: first, poor compatibility with the matrix resin; second, poor dispersion in melt-separated thermoplastics, resulting in poor fluidity and difficulty in extrusion molding.
Because the main component of wood flour is cellulose. Contains a large number of hydroxyl groups, these hydroxyl groups form intermolecular hydrogen bonds or intramolecular hydrogen bonds to make wood flour have water absorption. And the polarity is very strong. The thermoplastics are mostly non-polar and have fluidity, so the compatibility between the two is poor, and the adhesion of the interface is very small. It is necessary to modify the surface of the plastic and wood powder by additives. Improve the affinity of the interface between them. The modified wood flour has reinforcing properties and can well transmit the stress between the filler and the plastic, thereby achieving the effect of enhancing the strength of the composite material.
Extrusion molding,hot press molding, and injection molding are the main molding methods for processing wood-plastic composite materials. Due to the short processing cycle and high efficiency of extrusion molding, the extrusion molding method is a more commonly used process route.
From the perspective of the technical characteristics of wood-plastic composite materials, there are mainly the following categories:According to the raw materials, the plastic raw materials used in the first category are pure plastics or commercial grade plastics; the other is the use of single-component waste plastics with certain characteristics. . According to the processing technology. One is the two-step molding method. That is, the plastic and wood powder are mixed directly and processed directly.
From the perspective of forming mechanism, one type is physical forming. That is, the use of thermal barrier adhesives. In the molding process, plastic and wood powder are bonded together; the other is physical and chemical molding. That is, by adding additives. Under the control of pressure and temperature. The raw material mixture and the relatively low-molecular additives are transformed into a high-molecular network fiber material. Materials made using this process. The internal structure is completely reborn after fusion, and has better flexural, compressive, and impact strength than wood-plastic products produced by other processes.