As the wood fiber filler used in PTFE board composites […]
As the wood fiber filler used in PTFE board composites generally can withstand the highest processing temperature of 200 ℃, PTFE board composites usually use thermoplastic resins such as PE, PP, and PVC with relatively low processing temperatures, The matrix resin is different, its performance is quite different. The conical twin-screw extruder has received much attention in recent years. Its ability to mix materials is stronger than that of a single screw extruder, and it also has the characteristics of large material compression ratio. This is an outstanding advantage of the machine for the extrusion processing of PTFE board composites with low raw material bulk density. . However, there are advantages and disadvantages. In terms of mixing efficiency, the conical twin-screw extruder is far inferior to the parallel twin-screw extruder.
The stiffness and tensile strength of PE are small. Compared with other polymers, PE has excellent properties of flexibility, water resistance, chemical resistance and low temperature flexibility, good processing performance, and low price. Among them, HDPE has higher tensile strength, surface hardness and rigidity than LDPE. With the continuous improvement of people's living standards, people's requirements for the performance and texture of PTFE board composites are also increasing. Therefore, HDPE resin is currently used The composite material of PTFE board as the matrix occupies the majority and is generally used for outdoor components. PP melt has low viscosity, low temperature sensitivity and good processing performance. Compared with HDPE, it has higher tensile strength, surface hardness, tensile yield strength and stiffness, but it is easy to brittle at low temperature. The weather resistance of PP-based PTFE board composites is not as good as that of PE-based PTFE board products, which limits its application range.
PVC has the advantages of high rigidity, high strength, low price, good adhesion and colorability, but its cold resistance, aging resistance and thermal stability are poor, and processing performance is poor. These shortcomings can be improved by adding additives , Such as plasticizers, stabilizers, lubricants, ACR impact resistance additives. PVC melt has high strength and can be used to prepare polytetrafluoroethylene board foamed composite materials. PVC-based PTFE board composite materials are mainly used in interior decoration materials.