Filter cartridge

A filter cartridge for separating particles from fluid flowing inwardly through the cartridge, wherein the improvement consists essentially of:

• an inner tubular perforated core member;
• a pre-formed needle punched mat of non-woven fibrous filtering material having a width substantially equal to the length of said core member and wrapped in a continuous spiral layer around only said core member and itself, to form a roll of said mat;
• and a strand wound in a criss-cross open weave pattern around only the outer periphery of said roll and itself to form an open mesh network containing said roll;
• said cartridge, following formation thereof, being impregnated with resin to make the fibers of said roll more rigid without appreciably affecting the permeability of said cartridge.

A process for making a filter cartridge for separating particles from fluid flowing inwardly through the cartridge wherein the improvement consists essentially of the steps of:

• mounting a tubular perforated core member on a mandrel;
• rotating the core member and mandrel together;
• wrapping a pre-formed needle punched mat of non-woven unbonded fibrous filtering material having a width substantially equal to the length of said core member in a continuous spiral layer around only said core member and itself, to form a roll of said mat;
• and winding a strand in a criss-cross open weave pattern around only the outer periphery of said roll and itself, to form an open mesh network containing said roll.