Patent attributes
A membrane support material is support material for adhering a membrane to a membrane attachment surface. A plurality of non-woven fiber sheets, which are three-dimensional fiber aggregates, are layered together and thermal and pressure processed to bond fibers of the non-woven fiber sheets and form a single sheet of support material. Each layer of non-woven fiber sheet has a different longitudinal-to-lateral tensile strength ratio (k), which is the ratio (f2/f1) of the tensile strength in the lengthwise direction (f2) to the tensile strength in the width direction (f1), and in the thermal and pressure processed state, the support material membrane attachment surface has curvature in the lateral (width) direction with an outward protruding (convex) center region.