... 4.good air permeability 5.easy cake release Polyester needle felt Material: polyester fiberweight:400~600g/m2bursting strength :warp ... treatment: singeing, calendaring, heat setting Brief Introduction: polyester needle felt adopt nonwoven workmanship, with the property of stable physical ... mixed with acid and alkali,water and oil.Needle-punched felt are widely used in metallurgy,chemical industry , ...