... 1.polyester needle felt 2.good alkali resistance 3.stable physical dimension 4.good air permeability 5.easy cake release Polyester needle feltMaterial: ... ): 150-350Surface treatment: singeing, calendaring, heat settingBrief Introduction:polyester needle felt adopt nonwoven workmanship, with the property of stable physical dimension ... and ideal material to purrify and filter gas., Polyester needle felt