... of sealing: 1,good elastic-plastic 2,chemical stability impermeable 3,lower coefficient of friction high quality PTFE Packing for sealing 1 ... GB/T28001-2001,SGS test. 2.Characteristics: It has good elastic plastic, chemical stability, impermeable, lower coefficient of friction, wear ... , sewage treatment, paper etc. We will offer you the high grade quality, considerate service, competitive price.