1. Internal quality inspection items: width deviation, mass deviation rate per unit area, mass variation coefficient per unit area, breaking strength, elongation at break, bursting strength, equivalent pore diameter, vertical permeability coefficient, thickness
2. Appearance quality inspection items: holes, bad trimming, color difference, joints, frits, foreign matters, poor auxiliary network and soft folds
3. Optional test items: Dynamic perforation, puncture strength, longitudinal and transverse strength ratio, in-plane water flow, wet screen aperture, friction coefficient, UV resistance, acid-base resistance, oxidation resistance, temperature resistance, wear performance, creep performance, flame retardant performance, splicing strength, oil drainage performance, constant load elongation, constant elongation load Elongation at break, etc