Patent ID: 8827085
Filing Date: 2014-09-09
Classification: B01D,B29C,B29K

Abstract:
1. An outside-in hollow fiber asymmetric membrane comprising, a tubular flexible braid of monofilament embedded as a monolayer in a tubular film of membrane polymer infiltrating the braid so as to form and reinforce the membrane's lumen, the braid, free of multifilament yarn, comprising, from 6 to 24 separate monofilaments in the range from 25-250 denier (g/9000 meters), woven in a spiral open weave having an air permeability greater than 10 cc/sec/cm 2 at 1.378 kPa, to provide contiguous rhomboid areas of the membrane polymer bounded by monofilaments, the rhomboid areas having a pair of opposed acute included angles, and the spiral weave being woven with filaments at axially oppositely directed spiral angles in the range from 20°-60° from the longitudinal axis, so as to be free of a restricting circumferential filament allowing the braid and membrane to be biaxially distensible under pressure from within, prior to being damaged; such that the asymmetric membrane is adapted for use as a microfiltration or ultrafiltration liquid separation membrane.