We have the largest PMDA production lines in China andcan provide sublimed and crystallization Pyromellitic Dianhydride(PMDA). Well-equipped test and analysis measures guarantee thestable and reliable product quality. We can also control the heavymetal content. PMDA is produced in several grades to meet thespecific market requirements. Currently, our factory has appliedthe patent for heavy metal control in PMDA production (Patent No.is 201210398252-5). Now this product has been sold to South Korea,Japan, the United States, Taiwan and the middleeast.