End capped fibrous filter making
AssigneePall Corporation
InventorsRaymond T. Friel, Colin F. Harwood
Life of this patent
Estimating the term…
Abstract
Bonded end capped tubular or cylindrical filter elements are formed by fusing a fibrous mass of non-woven, intertwining, mechanically entangled, synthetic polymeric, microfibers possessing a temperature of dimensional heat instability and end caps formed from a dynamic vulcanizate comprising ethylene-propylene-diene-monomer (EPDM) rubber particles dispersed in a polypropylene matrix wherein the fused end capped filter exhibits minimal fiber pull back.
Claims23
A method for manufacturing end capped, cylindrical, fibrous, filter elements formed from a lofty, fibrous mass of microfibers composed from a synthetic polymer having a selected temperature of dimensional/conformational heat instability and end caps formed from a dynamic rubber vulcanizate, the method comprising the steps of:
- generating sufficient heat energy in the end cap to soften a selected portion thereof to induce bonding of the microfibers in the selected portion between the end cap to the fibrous mass of microfibers and filter element but insufficient to melt or cause substantial dimensional instability in the microfibers outside of the bonding zone;
- contacting the fibrous element with the end cap in a manner to fuse the end cap and the fibrous mass to a selected depth substantially in the selected portion;
- and
- cooling the selected portion to solidify the end cap material and to bond the portion of the fibrous mass in contact therewith in a manner to prevent fiber pull back of said fibrous mass and to establish a unitary, integrated filter element.
A method of end capping a fibrous filter cartridge comprising a mass of intertwined and mechanically entangled, non-woven, synthetic, polymeric microfibers possessing a particular temperature of dimensional heat instability and supported on a core to an end cap formed of a polypropylene rubber blend having a selected softening temperature, the method comprising the steps of
- rotating the end cap at a high rotational rate;
- pressing the filter cartridge into the end cap at sufficient pressure and for a sufficient number of revolutions to induce frictional heating of the end cap portion in contact with the filter cartridge to generate heat energy sufficient to soften the end cap portion;
- embedding the end of the filter cartridge in the heated end cap portion where the heat energy is insufficient to induce dimensional heat instability of the fibers outside of the embedded end but sufficient to fuse the mass of microfibers of the embedded end to the end cap where fiber pull back is prevented and the structural integrity of the filter cartridge is preserved;
- and
- cooling the end cap to provide an integrated, unitary end capped filter cartridge.
A method for manufacturing a filter cartridge comprising:
- providing a filter element having microfibers;
- providing a filter end cap made from a dynamic vulcanizate;
- and
- embedding said microfibers into said end cap.
Dependencies are inferred from the claim text.