Classification of WPC Boards and selection of raw materials
According to different applications, the production of wood-plastic panels is generally divided into three types: hollow, solid and structural. Hollow ones can be used on the surface of trestle bridges and fences with small loads, and ordinary solid wood-plastic panels can be used on facilities with heavy loads. The use of wood in the production of wood-plastic panels also has certain restrictions, such as temperature treatment and moisture content issues. Nevertheless, compared with other substrates, such as mineral materials, the degree of wear of the equipment for processing and handling the board is reduced. Compared with traditional wood products, wood-plastic panels have many advantages as follows. They can be painted as needed. Water resistance is strong and durable, and they will not be easily bent, broken or broken. Wood-plastic panels made of recycled materials can still be recycled. It is an environmentally friendly material with the same processing ability as wood products and low maintenance workload. The disadvantage is that compared with other materials, the production cost is higher. The finished board is about twice as heavy as wood. The density of wood-plastic board is 0.95-1.46, while the density of solid wood is 0.35-0.59; the content of wood determines the weight of wood-plastic board. The degree of corrosion resistance, that is, the more wood content, the higher the degree of corrosion resistance. Compared with the production of pure wood products, its disadvantages are reflected in the following aspects: the energy consumption is twice as high, and it cannot be used as a structural material. Ultraviolet radiation will reduce the service life. In order to ensure that wood-plastic panels meet the use standards and user requirements, the selection and preparation of raw materials become very important. It is worth noting that no special raw materials are designated as the necessary raw materials for wood-plastic panels. The choice of raw materials must be determined by availability, economic factors and market demands of the product. For example, the polymer of wood-plastic board can be high or low density polyethylene or polypropylene, and the wood can be wood powder or fiber of different materials. But the stability of wood and plastic is very important, such as cleanliness, physical properties and moisture content. The technical problems encountered in the production of wood-plastic panels with clean raw materials and waste raw materials will be different, because the performance of raw materials is greatly affected by the type, waste treatment method and newness.