The fastest development and the most representative is polyvinyl butyral (PVB) in polyvinyl acetal products. It is a products which is made of polyvinyl alcohol with n-butyl aldehyde condensation under acid catalysis. PVB film has high tensile strength, impact resistance, transparent, elasticity and etc. It is mainly used as the middle of the membrane for the sandwich of safety glass and the solar cell encapsulation. PVB resin is also widely used in the special coatings, adhesives, ceramic printing paper, aluminum foil, etc. Applicable PVA: 100-27, special material for PVB.