According to the national "Ninth Five-Year Plan" development plan and the long-term goal of "using plastic substitute wood, plastic substitute steel, Ethylene-Vinyl Acetate,resource conservation, and environmental protection" in 2010, the Institute of Plastics Machinery and Plastics Engineering, Beijing University of Chemical Technology and Shanghai Chad After many years of research and research, the plastic products cooperation company successfully developed new production technologies for PVC/wood powder composite materials and their products.
Formolon Pvc Resin is characterized by adding 30-50% of wood fiber fillers (wood powder) and various processing auxiliaries such as stabilizers, modifiers, lubricants, and foaming agents to PVC plastic raw materials, and mixing them with a high speed mixer. The special pelletizing extruder is used to prepare wood-plastic pellets of different specifications and grades. Finally, various types of PVC wood-plastic composite micro-foaming decorative profiles are produced using a molding extruder, a die and different processes. The key technology is to ensure a high loading of wood flour, in order to achieve a lower production cost and a higher use performance of the product. At the same time, due to the surface treatment of the wood flour, it can be well-wet by the Pvc Pipe Resin. , to achieve the best combination of interface. The project is in line with the national new project to focus on development of materials, energy conservation, and safety, meet market needs, fill the gaps in domestic demand, and comply with the long-term technical national policy of “plastic substitute wood” and “plastic substitute steel”.
The development of PVC/wood flour composites is fast, and its advantages of high toughness and low cost are gradually replacing traditional wood products. However, the compounding of Sg 5 Pvc Resin and wood flour has lower ductility and impact resistance, and the material is more brittle and the density is nearly 2 times higher than traditional wood products. These factors limit its wide use. In order to eliminate the above disadvantages, impact modifiers are generally added to improve their impact properties, but this approach is almost ineffective in improving the ductility and density of the products. In recent years, the direction of R&D has turned to micro-foam molding technology. After foamed PVC/wood powder composites have a good cell structure, they can passivate the crack tip and effectively prevent the expansion of cracks, thereby significantly increasing the resistance of the material. Impact properties and ductility, but also greatly reduces the density of the product. Extrusion micro-foaming has become the main method for forming foamed plastics because of its advantages of low cost, high efficiency, short time-consuming and easy industrialization.
Second, PVC / wood flour composite micro-foam new material characteristics
PVC/wood flour composite extruded micro-foamed products combine the excellent properties of wood and plastics. Products achieve the effect of real wood. The production cost is also lower than wood products. Its emergence will bring a revolution to the wood products industry,Sodium Hexametaphosphate. Especially in the shortage of resources and the soaring price of raw materials, it brings new vitality to the plastics processing industry. Its characteristics are as follows:
1, with waterproof
The water absorption of the wood itself is as high as 8-10%, but after the surface treatment of the wood flour, a layer of polymer film is formed on the surface, and the wood powder is also tightly coated by the polymer material. The test result shows that the water absorption rate of the material is less than 2 %, with a certain degree of waterproof performance.
2, with flame retardant
This is related to the molecular structure of polyvinyl chloride in the material, because the content of chlorine in the molecular structure of PVC is as high as 56%. Chlorine itself has a self-extinguishing function away from the fire. Generally, the oxygen index of the material is as high as 35 or more.
3, good anti-mildew properties
Because the wood flour is surface-treated and coated with polymer materials at the same time, it lacks a breeding environment for mold. At the same time, during the processing of wood flour, the surface has adsorbed the anti-mold agent, Melamine Powder also improves the anti-mildew properties of the product.
4, strong sense of wood
Because the content of wood flour in this material can reach 30-50%, at the same time through the micro-foaming, the product density can be controlled between 0.6-1.0g/cm, very close to the density of the wood, the internal structure is more loose, with natural wood Texture. Can be equipped with various colors and shapes, eliminating color troubles.
5, strong practicality
With all the safety of solid wood: nail, planing, can be painted (optional paint). Especially suitable for large-scale, factory-based rapid decoration, fast and convenient.
6, corrosion resistance:
Wood powder itself has poor corrosion resistance, but after being coated with a polymer material, polyvinyl chloride itself has good acid-base inertness, so this material has good corrosion resistance.
7, good electrical insulation properties.
Third, application prospects
With the improvement of people’s living standards and the development of homestay projects, the market for home improvement is getting larger and larger, and the demand for decoration materials is gradually increasing, and the quality requirements are getting higher and higher. As a high-grade decorative decoration material, wood-plastic composite decorative profiles have great market potential. As a new type of wood substitute, it can be widely used in architectural decoration and packaging, such as edge lines, shavings, curtains, lintels, floors, fences, skirting boards, art boards, shutters, frames, photo frames, windows. Boxes, toys and general furniture products, interior doors, etc., the vast majority of indoor and outdoor decorative building materials can be made of PVC wood plastic materials. It is particularly worth pointing out that the use of wood processing and decorative materials in addition to bringing fire hazards, but also easy to mildew and insects, bringing security risks. The PVC wood completely abandons the defects of the logs, improves the lack of logs, and retains the unique woody feel of the logs. Compared with wood, wood-plastic materials have waterproof and fireproof functions and can be used for decoration of kitchens, toilets, and the like. At the same time, PVC wood-plastic materials can produce products of different grades, different specifications and different colors according to different wood species and colors. As the production process adopts extrusion molding, it can realize automatic continuous production and the length is arbitrarily determined, which is beyond the limit of logs. Wood-plastic products have now attracted international attention, known as new green materials, will have broad prospects for development.
Fourth, the conclusion
In recent years, the global forest resources are increasingly depleted, and the awareness of social environmental protection has been rising day by day, and higher requirements have been put forward for the application of wood. Wood-plastic materials belong to basic industrial raw materials and can produce a wide range of architectural decoration materials that can replace wood, which can save forest resources and protect the environment. This material has the advantages of small specific gravity, high strength, weather resistance, corrosion resistance, heat insulation, and other excellent properties, and is rich in raw materials, variety of species, color adjustable, texture close to wood, simple maintenance, significant economic and social benefits, therefore, developed This new type of green and environmentally friendly material has extremely realistic and far-reaching significance.
