17 MEMBRANES IN FORM OF HOSES, TUBES, HOLLOW FIBERS, FLAT FOILS AND HOSE FOILS FOR FILTERING OF UNDISSOLVED OR EMULSIFIED SUBSTANCES FROM LIQUIDS OF ALL TYPES AS WELL AS FOR SEPARATION OF DISSOLVED SUBSTANCES FROM LIQUIDS OF ALL TYPES BY A SELECTIVE PERMEATION, ALL FOR USE IN THE CHEMICAL, FOOD STUFF, BEVERAGE, WATER, AND BIOTECHNOLOGY INDUSTRIES