Product technology and classification of pvc films
According to different functional requirements, the weight of the coating should be between 400 and 1 500g/m². The thickness of the PVC film material should be greater than 0.5mm. The surface layer should have stable anti-corrosion, anti-ultraviolet eroding ability and self-cleaning performance during the warranty period. When the PVC film material reaches the melting point in a fire environment, a molten hole will appear, and the boundary of the molten hole will burn and spread, but no open flame will be produced. According to my country's GB 8624 "Classification Method for the Combustion Performance of Building Materials", PVC membrane materials are classified as Class B1 flame-retardant materials.
The surface treatment of PVC coated membranes was first coated with acrylic to improve antifouling properties. However, after a few years, it will be discolored, stained, and deteriorated. In order to improve the weather resistance of PVC membrane materials, fluorine-based resin coating materials have been developed in recent years to improve their weather resistance and antifouling properties. The most common are the following two:
(1) PVDF is the abbreviation of Polyvinylidene Fluoride. The material coated with PVDF resin on the surface of PVC film is called PVDF film. Compared with ordinary PVC membranes, PVDF membranes have a service life of 10-15 years. In addition, adding a thin layer of titanium dioxide treatment on PVDF can greatly improve the self-cleaning properties of the membrane material, thereby making it free of maintenance and cleaning.
(2) PVF is an abbreviation for Polyvinyl Fluoride. PVF membrane material is processed by using PVF resin as a film-like laminate on the surface treatment of PVC membrane material, which has better durability than PVDF membrane and has the advantage of anti-contamination. However, the application is limited because of poor processability, construction and fire resistance.
pvc films is considered to be the most standard product in membrane construction. Polyester fiber has high tensile strength and good elasticity. Before the tensile yield, the fiber has a large elongation deformation capacity, so that it can be adjusted during installation. However, sunlight will cause the polyester fiber to age and reduce the mechanical properties such as elasticity and strength. At the same time, the fire resistance and durability are not as good as PTFE and ETFE membranes, so the price is relatively low. But it is precisely this characteristic that pvc films materials are widely used in temporary exhibition buildings and still achieve good results.