What is Polyvinyl butyral (PVB)?
Polyvinyl butyral (PVB) is a clear, colourless, amorphous thermoplastic obtained by condensation reaction of polyvinyl alcohol and butyraldehyde. The resin is known for its excellent flexibility, film forming, and good adhesion properties as well as outstanding UV resistance.
What is PVB used for?
One of the major uses of PVB film is in safety glass. Due to its good adhesion to glass most of the splinters of fractured glass will adhere to the surface of the PVB film and thus prevent personal injury by large and sharp glass fragments. PVB laminated glass also offers an improved sound barrier, good impact resistance, and almost 100% absorption of UV light. The latter is important for the protection of interiors from fading due to UV exposure.
The problems associated with high humidity and the use of PVB film
PVB film is highly susceptible to moisture. During storage and manufacturing, the film is required to be kept at less than 18.0°Cdb at no more than 25% relative humidity. Failure to maintain these conditions, will result in imperfections in the final product and in some cases will lead to catastrophic failure of the product.
Desiccant dehumidification is the best technology to use for controlling air at low relative humidity.
Due to the air dewpoint required for the storage and use of PVB film being equivalent to that of below freezing point the utilisation of refrigerant based technologies is not practical and will lead to inefficient and unstable conditions during defrost cycles. Desiccant dehumidification systems have the ability to work constantly at both low temperatures and dewpoints. Our desiccant dehumidification systems are the most efficient and practical method to maintaining the required conditions in any area with low relative humidity requirements.