Cuno, Inc.

Mark W Schimmel

Richard D Sale

Richard A Prince

Norbert Roessler

Wei-Chih Chen

Katharine L K Faye

A process for manufacturing wet-felted and thermally bonded porous structures is provided to produce formed porous media for use in filters with improved filtration performance. The process includes the steps of forming a slurry with a primary media consisting of natural or synthetic fibers, a wet strength agent consisting of fibrillated fibers, and a binding agent; vacuum forming the slurry to produce a formed media; drying the formed media using a gas at a temperature below the melting temperature of the binding agent; bonding the formed media using a gas at a temperature above the melting temperature of the binding agent; and cooling the formed media using a gas at ambient temperature. The process produces a formed porous media with improved bonding which results in improved filtration performance.

Process for manufacturing wet-felted and thermally bonded porous structures and porous structures formed by the process

A method for sealing the edges of a filter sheet (,) with wax to create a fluid-impermeable wax seal (,) enclosing a non-sealed portion (,). The method includes applying melted wax to the edges of the filter sheet, heating the treated filter sheet such that the wax permeates through the edges thereof, and then allowing the filter sheet to cool such that the wax congeals. The wax of the fluid-impermeable wax layer (,) has a durometer reading of about 75 to about 100 Shore A hardness at 25&deg; C. and 85&deg; C., a melt point of about 110&deg; C. to about 180&deg; C., a viscosity of less than about 100 cp at 155&deg; C. and preferably includes ethylene bis stearamide. The wax layer increases the useful life of the filter sheet while providing a sheet which is easily released from a filter press and which retains integrity along the seal during repeated hot water sanitations.

Method for sealing the perimeter of a filter sheet

A filter sheet positioned between plates (14) of a filter press has a fluid-impermeable wax layer (11) sealing the sheet's perimeter. The wax preferably comprises ethylene bis stearamide and has a durometer reading of about 75 to about 100 Shore A hardness at 25.degree. C. and 85.degree. C., a melt point of about 110.degree. C. to about 180.degree. C., and a viscosity of less than about 100 cp at 155.degree. C. The wax layer increases the useful life of the filter sheet while providing a sheet which is easily released from a filter press and which retains integrity along the seal during repeated hot water sanitations.

Growing community of inventors

Stafford Springs, CT, United States of America

Mark W Schimmel