We have the largest PMDA production lines in China and can provide sublimed and crystallization Pyromellitic Dianhydride (PMDA). Well-equipped test and analysis measures guarantee the stable and reliable product quality. We can also control the heavy metal content. PMDA is produced in several grades to meet the specific market requirements. Currently, our factory has applied the 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 middle east.