METHOD DETERMINING AIR PERMEABILITY OF VOLUMETRIC MATERIALS Russian patent published in 2001 - IPC

FIELD: study of materials for light industry, investigation of structure and properties of materials. SUBSTANCE: for test of domestic and technical fabrics ( materials ) there are used devices determining air permeability as volume of air passed through specified area of tested material per time unit with definite rarefaction under point sample. Given method of test provides for pressing of material against testing table over perimeter of round hole of specified area with pressure effort being constant. As with growth of diameter area of contact of pressure ring with sample increases then pressure on sample changes which does not provide for generation of comparable stable results and leads to impossibility of comparison of indices of air permeability of various materials. Testing unit makes it feasible to determine air permeability of volumetric materials having thickness up to 200 mm under different pressure, to avoid air ingress through side surface of point sample, to distribute pressure evenly over surface of point sample but not over perimeter, to check thickness of point sample in process of test, to determine air permeability of volumetric materials with due account of thickness of point sample, pressure on this sample and air pressure differential. EFFECT: increased informativity with generation of comparable stable results. 2 dwg