3021 is impregnated with phenolic resin by drying by hot pressing of laminated cardboard impregnated paper insulation. This product is suitable for high performance requirements of electrical machinery and electrical equipment as insulating structural parts, and can be used in transformer oil. 3021 phenolic cardboard processing Which is better? Yi Industrial Co., Ltd. Shanghai Giant is your choice! Class products, first-class service, first-class after-sales, will not let you down, please call us. Contact: Manager Ma Tel: 021-39879312 / 18917950198 Website: www.zgjuyi.com