Pollution Prevention Case Study

Gehl Company

Using Plastic Media Blasting to
Strip Paint from Parts

Standard Industrial Classification (SIC) Agricultural Equipment Manufacturer/3523
Process Paint Stripping
Type of Waste Sodium hydroxide contaminated with stripped paint
Strategies Process Modification - Plastic Media Blasting
Material Substitution - Plastic Media
Background Gehl Company is a manufacturer of trailed agricultural implements headquartered in West Bend, Wisconsin. Gehl strips paint from parts rejected by quality control before remanufacturing them. The parts were soaked in a 300 gallon hot sodium hydroxide bath to strip the paint. The paint stripping was a batch process that operated about 30% of the time.
Motivation This paint stripping method generated up to 19,000 pounds per year of sodium hydroxide contaminated with paint. The waste was classified as hazardous due to a high pH and disposal costs were about $36,000 annually.
Changes Implemented Gehl replaced its troublesome sodium hydroxide paint stripping bath with a plastic media blasting cabinet. Plastic media blasting systems fire small plastic particles at a surface. The abrasive action of the particles striking the surface strips the paint without damaging the surface texture.
Problems Encountered A non-hazardous solid waste is now generated. This waste is currently disposed of in a landfill. At this time no potential reuse for the paint waste has been identified.
Material/Energy Balance Original Process

Feedstock
Sodium hydroxide

Waste
Paint-contaminated sodium hydroxide
19,000 lbs/yr (1989)

Disposal
Managed by third party at a cost of $36,000/yr

Pollution Prevention Approach

Feedstock
Plastic blast media
4000 lbs/yr used at $2.00/lb (1991)

Waste
Paint chips and spent blast media

Disposal
Landfill

Economics Capital Cost
$8000 for the plastic media blasting unit.

Operating/Maintenance Cost
Not available

Payback Period
3 month payback based on an estimated annual waste disposal savings of $32,000.

Company Address Gehl Company
143 Water Street
West Bend, WI 53095-0179
Contact Person Larry Lang
Phone: 414/334-6608
Additional Publications Available From Pollution Prevention Clearinghouse Reduction of Total Toxic Organic Discharges and VOC Emissions from Paint Stripping Operations Using Plastic Media Blasting
EPA Project Summary
Pollution Prevention Resources Free, On-site Technical Assistance
University of Wisconsin Extension
Solid and Hazardous Waste Education Center
Milwaukee area: 414/475-2845
Remainder of state: 608/262-0385

Pollution Prevention Clearinghouse
Wisconsin Department of Natural Resources
Hazardous Waste Minimization Program
608/264-8852, 608/267-9523 or 608/267-3763

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Bureau of Cooperative Environmental Assistance
Wisconsin Department of Natural Resources
P.O. Box 7921
Madison, WI   53707
608/267-9700

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