Recent trends in Paint Booth regulations and filter manufacturing have created some confusion in what type of filters are actually needed for paint booth exhaust. Too often we find that operators are using old style filters that perform poorly compared to more modern styles. With the costs associatiated with changing and disposing of paint booth exhaust filters, and non-compliance issues with State and Federal regulations it pays to take the time to periodically review what you are using and why. Here are 4 of the top trends currently impacting industrial coating filtration:1) Paints & Regulations Are Changing. Not Earth-Shattering or shocking information here, but it is the single biggest change to the industry. It wasn't that long ago filters we now label as "low-efficiency" like fiberglass, polyester, and slit-expanded paper products were all you needed to capture enough of the coating to keep the fans and ducts clean, and keep regulators from issuing citations or warnings. Advances like "nanocoating" or incorperating nano-particles into paints have made for beneficial end-user experiances but they have also ratched up the air permit regulations as the EPA (and most people I think would agree) doesn't want facilities to be pumping vast amounts of nano-particale sized titanum dioxide, chromates, etc into the air.
2) Fiberglass Media is Disappearing. Once the standby in industrial paint booths of all sizes and uses, the traditional roll or pad of fiberglass paint overspray media is quickly becoming a thing of the past. Your supplier may not have told you about this yet but it won't be long before even the largest suppliers stop offering this staple product. There are a couple reasons for this: First it is getting prohibitivly expensive to manufacture melt-blown glass, which when the basis for your existence is low-price negatively impacts the ability to compete. Higher costs on a low-cost item have forced all but the largest of manufactures to stop producing this filter media, meaning that some manufacturers that used to make their own fiberglass overspray media now buy it from a competitor. (It's a small world after all) Secondly, as mentioned before with changing paints and regulations the fiberglass media just doesn't capture enough small particles to be worthwile for a growning number of paint booth operators.
3) Explosion of Polyester Media. Quickly replacing the low-cost fiberglass rolls and pads is polyester media that can hold more paint and capture smaller particles, all at a narrowing price difference. Most of the applications we come across are better served by a low-cost polyester compared to a low-cost fiberglass. Polyester overpray media also offers the ability to "customize" the media itself by adding grooves or notches to increase surface area, making the media stiffer so it doesn't dog-ear as many pads do, and having a controlled progessive densitiy/needled media spacing through the depth of the filter. Some of these advances are more beneficial than others, most of these just sound good and make for pretty brochures and a unique sales pitch - so buyer beware of fancy/customized polyester overspray media.
4) NESHAP Systems. This is a topic that really deserves its own post, but I'll try to be brief here for an overview. There is no requirement that filters must be used as a 2-Stage NESHAP or 3-Stage NESHAP system in order to "pass" the environmental regulations. Anyone who insists that to be compliant in either an existing or new NESHAP booth you need to have 2, 3, or more stages of filtration just wants to sell you more filters than you need OR doesn't have access to newer filter technology. In fact, there is a manufacturer of paint booth exhaust filters that was awarded approval on a single-stage New Booth NESHAP product. The amount of labor, energy, disposal, and raw-cost savings that this product will bring to the industry is gigantic. However, it will be met with resistance from the "old-school" filter people who are more concerned about selling more volume and expensive filter combinations.
Understandably, reviewing your current filter use can seem like a waste of time, as most filter sales people are just that - sales people looking to spin their product in a way that seems best for you - But partnering with a knowledgeable specialist of paint booth exhaust filters can be overwhelmingly beneficial.