Dissolve Filter Disposal Problems

Paint booth overspray filters are critical to safe, efficient operation and quality finishes. By capturing paint overspray, they make the booth environment safer for operators and reduce the chance of contamination on painted surfaces.

Users can choose from several types of filter materials—fiberglass, paper, or composite, to name a few—but conventional filter elements suffer from a couple of drawbacks. First, air volume and velocity decrease to varying degrees as the filter elements load with paint, leading to reduced filtration efficiency and low air flow in the booth. And, when it’s time for disposal, the loaded filter elements must often be dealt with as hazardous waste. Depending on the specific type of paint being used, stored filter elements can even present a fire hazard.

Enter the Super Baffler, an overspray filter element produced from expanded polystyrene. It’s essentially the same stuff as the packaging material seen in shipping boxes and cartons for countless products, but the design of the filters is said by manufacturer Polyfoam Corp. (Northbridge, MA) to provide filtration efficiency greater than 98% per standard Air Filter Testing Laboratories (AFTL) paint arrestor filtration performance testing.

In the booth, the elements are said to offer 5–7× longer life than conventional filter elements. They are designed to provide an air-tight fit without grids—instead, filters fit directly into the frame. They also will not pull down as some other filter elements do, the company says. And the elements’ white color increases visibility in the booth.

But the real payoff comes at the end of life, according to Polyfoam. Super Baffler EPS filters can be disposed of simply by dissolving them in the same solvent used to thin paints, such as acetone. The solvent can then be handled as normal, the company says. Storage before disposal is also safer, because the filter elements have reduced static resistance, are non-combustible and meet all UL1 standards.

Polyfoam says the filters may make sense even for some paint shops that don’t use a lot of solvent. They can also be reused by simply brushing off accumulated paint from the filter surfaces.

The idea of EPS overspray filters is not exactly new—Polyfoam says the filter elements were first developed more than 20 years ago as a possible alternative to paper and fiberglass paint filters. But the concept languished until Polyfoam, which manufactured the filter elements for customer Bay State Enterprises, purchased Bay State earlier this year and decided to push the filter idea. Now the company, which currently manufactures the elements to fit standard 20-inch square frames, is considering a possible line expansion to handle other frame sizes as well.