... fiberglass filter media / glass fiber filter cloth / fiberglass air filter/ glass fiber felt fiberglass filter media 1. 450- ... testing of our fabric, such as weight, thickness, air permeability, tensile strength, etc.PROFESSIONAL ENGINEERSTo ensure our products ... Chemical index test, strength test, abrasion test, fiber analysis, air permeability, water & oil repellent test, fine dust test, single ...