Method of manufacturing porous filter elements

Claim 1

A method of manufacturing a porous filter element comprising superimposing upon one another a plurality of filter discs of woven wire having similar or dissimilar aperture size, or a number of layers of non-woven metal fabric, metallic skeletal material or a fill of macerated wire, compressing the filter discs together at high pressure so thatthe individual filter discs lose their initial forms and aperture sizes and are converted into a porous filter element, the porosity of the element being determined by the magnitude of the pressure. 2. A method according to claim 1, including the step of sintering the porous filter element. 3. A method according to claim 1 or claim 2, wherein the plurality of filter discs are initially laid in an open metal frame and, after the compression under high pressure, the upper edge of the metal frame is folded over onto the porous filter element to close the frame. 4. A method of manufacturing a porous filter element as claimed in claim 1 and substantially as hereinbefore described. 5. A porous filter element formed by the method of anyone of the preceding claims. t Printed for Her Majesty's Stationery Office, by Croydon Printing Company Limited, Croydon Surrey, 1980. Published by the Patent Office, 25 Southampton Buildings, London, WC2A l AY, from which copies may be obtained. 1. X,c i W