Development of PVC Co-Extrusion Decking
As a green environmental protection material, the development and application of wood plastic composite decking materials have become a research hotspot in recent years, and PVC wood-plastic composite materials products, especially Co-extrusion decking products, have completely overcome the shortcomings of logs and make up for the shortage of logs. It retains the unique woody feel of the logs. The Co-extrusion decking has waterproof and fireproof functions, so it can also be used for decoration in indoor high-humid areas such as kitchens and bathrooms. At the same time, PVC wood-plastic composite materials can produce imitation wood products of different grades, different specifications and different colors according to different wood species and colors. PVC wood plastic composite decking materials have a rapid development speed in the field of architectural decoration.
Defects in PVC Wood Plastic Composite Decking
Although PVC wood-plastic composite materials have many advantages, they are used as structural materials such as outdoor façades and stencils, which have the disadvantages of being easily deformed by heat and having low mechanical strength. This limits the expansion of its application to a certain extent. Therefore, it is a hot research and difficult point to further prepare PVC-based wood-plastic composite materials with high strength, high modulus and high heat distortion temperature. The industry has conducted many researches and practices on this difficulty.
Development of PVC Co-Extrusion Decking
For example, chlorinated polyvinyl chloride (CPVC) is a product of further chlorination of PVC, which has better heat resistance and mechanical properties than PVC, and can be used as a blending modifier for PVC. The appropriate amount of inorganic mineral fillers, such as calcium carbonate, attapulgite, muscovite, etc., can further improve the strength, modulus and heat resistance of the composite. Some studies have proved that PVC wood-plastic composites are modified with CPVC resin to obtain the optimized ratio of PVC/CPVC. On the basis of this, two kinds of inorganic rigid particles, muscovite and attapulgite, were used to modify PVC/CPVC wood-plastic composite materials. Based on the test results of heat resistance and mechanical properties, combined with microscopic morphology analysis, two kinds of particles were applied to PVC/CPVC. The wood plastic composite has a good modification effect. First, CPVC significantly improved the heat deformation resistance and mechanical properties of PVC wood-plastic composites. When the ratio of PVC/CPVC is 50/50, the heat distortion temperature reaches above 80 °C, and the tensile strength and bending strength of the composite material are remarkably improved. Second, after the addition of inorganic rigid particles, the heat resistance and mechanical properties of the PVC/CPVC wood-plastic composite material are further improved. When the amount of muscovite and attapulgite is 3 parts, the heat distortion temperature is increased by 14.3 °C and 19.7 °C, respectively; at the same time, the mechanical properties of the composite are better. Compared with muscovite, attapulgite has a more significant effect on the heat resistance and mechanical properties of the composite.
