polyvinyl butyral, the English abbreviation PVB resin.
PVB (polyvinyl butyral) is currently not widely used in China, and it is mainly a polymer material-PVB intermediate film that is plasticized and extruded by a plasticizer. Due to the complex processing  technology of PVB diaphragms, only a few international multinational companies such as the United States,Japan and Germany have this technology in the world. It’s not that there are no PVB manufacturers in China,but the main reason is that the technology in equipment and production process has not reached the levelof foreign countries. Therefore, there is still a certain distance in product quality. There are no less
than 20 PVB film manufacturers in China. Among these more than 20 manufacturers, very few are made entirely of resin powder. Because PVB film is a recyclable material. Therefore, in order to seek huge profits, most manufacturers use PVB scraps and sub-brand products of foreign manufacturers to produce. Regenerated PVB film varies greatly in quality stability and product weather resistance. Therefore, many well-known glass  companies use imported PVB film.