In recent years, my country's wood-plastic composite materials industry has developed strongly, especially the co-extruded wood-plastic composite materials coated with functional materials on the surface are booming.Co-extruded wood-plastic composite material is a kind of wood-plastic composite material processed by co-extruding technology to coat one or more layers of materials with specific functions on the surface of ordinary wood-plastic composite materials.Its anti-water absorption performance, anti-aging performance and other properties are far superior to non-co-extruded wood-plastic composite materials.Since co-extrusion technology is currently a relatively advanced wood-plastic composite molding processing technology,Therefore, there is no current standard for co-extruded wood-plastic composite products at home and abroad, and the quality inspection of most products is mainly carried out with reference to the relevant non-co-extruded wood-plastic product standards.If the co-extruded wood-plastic floor is classified into the finished wood-plastic floor, use GB/T 24508-2020 "wood-plastic floor" for quality inspection and control.
Due to the differences in production process and product structure between co-extruded wood-plastic composite materials and non-co-extruded wood-plastic composite materials, the performance characteristics of the two types of products are different.If the non-co-extruded wood-plastic composite material expands when it encounters water, it will expand and deform as a whole, without obvious local expansion and deformation.However, the co-extruded wood-plastic composite material can well prevent moisture from entering from the front by virtue of its surface co-extrusion layer. Usually, moisture can only enter from the cutting end.In turn, the expansion and deformation of the end part after long-term immersion in water is obviously larger than that of the middle part. Therefore, using the relevant standards for non-co-extruded wood-plastic composite materials to carry out quality control and inspection of co-extruded wood-plastic composite materials may have problems such as inappropriate test methods and quality requirements.
Water absorption performance and dimensional stability are important properties of wood-plastic composite materials. According to the testing methods in the commonly used inspection standards for wood-plastic composite materials, the water absorption performance and dimensional stability of co-extruded and non-co-extruded wood-plastic composite materials are mainly compared and analyzed. , aiming to analyze a suitable testing method for the water absorption performance of co-extruded wood-plastic composites, which can be used as a reference for the quality control and inspection of co-extruded wood-plastic composites and the formulation and revision of related standards.