Paints and Solvents: Waterbased Finishing Systems
Celebrate Success: Automated Building Components (ABC) in Chanhassen has a system to prevent defect parts from being coated. ABC successfully converted to a waterbased finishing system and uses high transfer efficiency spray equipment with automated and manual spray finishing stations.
Overspray on the automated finishing line is collected and reused. Old product is consumed first, to minimize the need for disposal of old and obsolete paints. In two years, the company succeeded in reducing their toluene use by 16,990 pounds and volatile organic compounds by 48,200 pounds. All hazardous waste generation was eliminated in 1996.
US Postal Service Switches Paint
by Lisa Mlinarcik
The US Postal Service (USPS) not only sets high standards for getting your mail to you, they go the extra mile for the environment too. At its Minneapolis Vehicle Maintenance Facility, the post office is making environmental strides. For the last three years, a team of employees has been working with a painting supplier to develop a waterbased paint system with an epoxy primer and urethane top coat.
This initiative is part of a larger USPS environmental management goal to eliminate 17 targeted chemicals that are harmful to people and the environment. The new paint and primer—used on roughly 600 to 800 vehicles a year—eliminates the chemicals chromium, lead, methyl ethyl ketone, toluene and xylene.
By eliminating these chemicals the Minneapolis facility saw a number of benefits:
- It significantly reduced hazardous waste and air emissions which will save disposal and permitting costs.
- Switching to the waterbased paints should eliminate the need for an air emissions permit and allow reclassification of the facility to a very small quantity generator of hazardous waste.
- The risk of fire was greatly reduced because the new paints are not flammable and are thinned with water. These changes will reduce the time employees spend on hazardous material and safety training.
- The new product costs $60 more a gallon, but as production volumes increase the cost will go down. Glenn Caffrey, supervisor of Vehicle Supplies said, “It’s going to save a lot of money.”
By working with coating and equipment suppliers, facility staff easily addressed obstacles. Together they determined the best tip size and spray gun for the new product. When troubleshooting is needed the coating supplier is working on the problem within 20 minutes according to Caffrey.
“Training was our biggest challenge,” said Caffrey. “It’s a totally different system and employees had to learn a new spray technique.” The coating supplier provided step-by-step training for the painters.
“So far everything is running great. The paint comes out perfect on every job.” Overall Caffrey says they’re “more than satisfied” with the new system which is now also being tested in Albany, Kansas City and Milwaukee. Future plans include working with the paint supplier to reduce the paint’s dry time.
The new products meet the USPS’s quality standards and are easy to work with. If testing continues to go well, the post office may adopt the waterbased paint nationwide and it could become commercially available for fleet maintenance.
Paint and Solvent Tips
- Improve efficiency by training painters to mix correct amounts and properly prepare surfaces.
- Use high transfer efficiency application equipment—like HVLP and air-assisted airless—and keep it well maintained.
- Explore biochemical alternatives to paint stripping such as terpenes, d-limonene, and dimethylsulfoxide (DMSO) from natural raw wood lignin.
- Check into abrasive stripping processes that use natural materials such as wheat starch, walnut hulls and carbon dioxide.
- Reuse or recycle cleaning solvents.
- Evaluate waste generation to identify opportunities for minimizing waste. Adjust purchasing, equipment cleaning schedules and inventory systems accordingly.