Abstract: Various embodiments disclose filtration apparatuses and processes for filtering particles from a particle-laden air stream. In one embodiment, a filter is provided with a front face layer, in which at least one impaction nozzle is formed, is to accelerate an air stream onto an interior substrate to capture large particle sizes with a calculated fractional efficiency. The interior substrate is formed within the filter. The filter further includes a rear face layer in which at least one opening is formed to exhaust the air stream. A filter media material may be placed between the front face layer and rear face layer. Other apparatuses and processes are disclosed as well.

Abstract: A method and apparatus for evaluating a paint filter. The apparatus includes a duct, air supply, spray gun, target, filter holder and particle sensing device. The spray gun and target are disposed within the duct to simulate actual paint spraying conditions, including production of overspray. The filter holder maintains a test filter downstream of the target such that overspray interacts with the test filter. The particle sampling device is associated with the filter holder and is configured to sense and provide information indicative of paint filter efficiency and preferably includes a time-of-flight particle measurement instrument. During use, the spray gun sprays paint particles at the target. Overspray from the target interacts with the test filter. The particle sampling device senses data upstream and downstream of the filter, from which a filter evaluation is made.