# US 5,702,516 A · Method of using water soluble foamed starch for reclaiming paint over-spray particles

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,702,516 A
- Document ID: US5702516A
- Status: Granted
- Kind: A
- Application number: 08/768,825
- Filed: 1996-12-17
- Granted: 1997-12-30
- Earliest claimed: 1996-12-17
- Assignees: Caterpillar Inc.
- Inventors: John M. Spangler
- Web page: https://patentgrep.com/patent/US5702516A

## CPC

- C08J 11/00: Recovery or working-up of waste materials (recovery of plastics B29B17/00; polymerisation processes involving purification or recycling of waste polymers or their depolymerisation products C08B, C08C, C08F, C08G, C08H)
- B01D 39/1676: {of synthetic origin}
- B01D 46/10: Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
- C09D 7/71: {Paint detackifiers or coagulants, e.g. for the treatment of oversprays in paint spraying installations (chemical paint removers C09D9/00)}
- B05B 14/43: by filtering the air charged with excess material
- B05B 14/462: and separating the excess material from the washing liquid, e.g. for recovery
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- B05B: SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES (spray-mixers with nozzles B01F25/72; processes for applying liquids or other fluent materials to surfaces by spraying B05D)

## Abstract

A method of using water soluble foamed starch for reclaiming paint overspray particles from air includes the steps of passing a stream of air containing paint overspray particles through an air filter assembly having a filtration element. The filtration element consists essentially of water soluble foamed starch. The paint overspray particles are collected on the filtration element. The filtration element containing the collected paint overspray particles is deposited in a vessel containing water. The filtration element is dissolved in the water and an aqueous solution of starch in water is formed. The paint overspray particles are separated from the aqueous solution of starch dissolved in water.

## Claims

### Claim 1

A method of using water soluble foamed starch for reclaiming paint overspray particles from air, comprising the steps of:
passing a stream of air containing paint overspray particles through an air filter assembly having a filtration element, said filtration element consisting essentially of water soluble foamed starch;
collecting said paint overspray particles on said filtration element;
depositing said filtration element containing said collected paint overspray particles in a vessel containing water;
dissolving said filtration element in said water and forming an aqueous solution of starch in water; and
separating said paint overspray particles from said aqueous solution of starch dissolved in water.

### Claim 2 (depends on 1)

A method of using water soluble foamed starch, as set forth in claim 1, wherein subsequent to separating said paint overspray particles from the aqueous solution of starch dissolved in water, the separated paint particles are pulverized and used as a base to form a recycled paint product.

### Claim 3 (depends on 1)

A method of using water soluble foamed starch, as set forth in claim 1, wherein said step of dissolving said filtration element in water includes at least one of heating said water, adding an alkaline composition to said water, adding an oxidizing agent to said water, and ozonation.

### Claim 4 (depends on 1)

A method of using water soluble foamed starch, as set forth in claim 1, wherein subsequent to separating said paint overspray particles from the aqueous solution of starch dissolved in water, said method further comprises the steps of:
washing the separated paint particles to remove substantially all starch from the particles;
filtering the washed paint particles;
drying the filtered paint particles to less than 1% moisture content;
pulverizing the dried paint particles to a nominal size less than 20 microns; and
blending said pulverized paint particles with binder, solvent and other materials sufficient to form a paint composition.

### Claim 5 (depends on 1)

A method of using water soluble foamed starch, as set forth in claim 1, wherein said filtration element consists essentially of at least about 99% water soluble foamed starch and no more than about 1% of a hydrophobic agent.

### Claim 6 (depends on 5)

A method of using water soluble foamed starch, as set forth in claim 5, wherein said hydrophobic agent is hydrophobic silica.

### Claim 7 (depends on 5)

A method of using water soluble foamed starch, as set forth in claim 5, wherein said water soluble foamed starch is chemically unmodified.

### Claim 8 (depends on 5)

A method of using water soluble foamed starch, as set forth in claim 5, wherein said water soluble foamed starch has a porous interconnecting open cell structure capable of trapping paint particles carried by a stream of air passing through said filtration element.

### Claim 9 (depends on 5)

A method of using water soluble foamed starch, as set forth in claim 5, wherein said water soluble foamed starch has a nonporous closed cell structure capable of trapping paint particles carried by a stream of air impinging upon the surface of the filtration element.