Nonwoven batt mfd. from filaments - has high uniformity as defined by light transmission measurements

摘要

A non-woven batt of 250-950 g/m2 is made from filaments and has a uniformity, as measured by the light transmission of 20 samples, of 25 mm x 36.4 mm with 99.9% confidence limits, described by the relationship wi=0.19w+b where wi = batt non-uniformity in g/m2 w = mean batt density in g/m2 b = a constant between 55 and 90 g/m2 The batt can be made by depositing filaments and/or filament bundles which have been opened by air jets into single filaments, very uniformly on to a moving surface and bonding by needle punching. The uniformity is determined by measuring the light transmission with a digitising scanning camera with 512 x 512 pixels. The light transmission is measured by taking 10 sample areas from each side. The system is calibrated by taking light measurements without the batt and applying the Beer-Lambert equation for absorption coefficients. USE/ADVANTAGE - Partic. uniform non-woven batt made from glass, polyamide, polyester, polypropylene or bi-component fibres is obtd.