US 6,712,939 B2 · Process for manufacturing wet-felted and thermally bonded porous structures and porous structures formed by the process

Abstract

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.

Claims30

Dependent claims

A process for making fibrous felted porous structures, comprising the steps of:

(a) preparing a slurry containing a primary media, a wet strength agent and a binding agent;
(b) vacuum forming the slurry to produce a formed media;
(c) drying the formed media at a temperature below the binding temperature of the binding agent, until substantially all water is removed from the formed media;
(d) bonding the formed media by heating the formed media to a temperature above the binding temperature of the binding agent;
and
(e) cooling said formed media at ambient temperature.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application

09/793,174Filed 26 Feb 2001

Published

US 2002/0119299 A129 Aug 2002

Granted

30 Mar 2004

Term ends

Not estimatedThe source records don’t support an estimate.

Classification12 codes

B29C 41/16
For making articles of definite length, i.e. discrete articles: slip casting, i.e. applying a slip or slurry on a perforated or porous or…
B01D 39/1607
Of organic material, e.g. synthetic fibres: the material being fibrous
B01D 39/20
Other self-supporting filtering material ; Other filtering material: of inorganic material, e.g. asbestos paper, metallic filtering material of…
B29K 2105/0854
Of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns: in the form of a non-woven mat

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

Life of this patent

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

Life of this patent

Abstract

Claims30