In every spray booth two or three stages of air filtration are usually at work:
- Pre-filters (where present)
- Ceiling filter blankets
- Paint exhaust or over spray floor air filters
The following are some important tips for the frequent use and proper maintenance of a downdraft paint spray booth, regardless of booth make or model. We compiled these tips from professionals in the field, equipment suppliers, paint suppliers and spray booth air filter maintenance companies from around the globe. As a leading supplier of air filter materials to spray booth professionals and automotive assembly plants worldwide, FILTRAIR, through Peregrine Industries Pty. Ltd., their sole Australian Distributor would like to contribute this valuable experience to everyone.
Efficient and long-lasting use of FILTRAIR materials assures a world-class finish on the customer’s prized automobile.
PRE-FILTERS
When pre-filters in pads, panels or pocket filters are used, sufficient care must be taken to ensure a perfect airtight seal between the filter and the holding frame.
When a gasket is in use, check it for deterioration, and replace if required.
Panel filters and pads of media should be properly gasketed and clamped.
When installing the filters, take great care to ensure that the airstream is directed from the dirty air side to the clean air side (downstream) of the air filter.
FILTRAIR air filter media are constructed with an inherent graduated media density so that the imprinted identification on the media is on the clean air side (downstream) of the media. Thus, always place the writing side facing the clean air side (air entering the booth)
CEILING FILTER BLANKETS
Always remove the old filters with great care to avoid soiling the interior of the spray booth.
Clean the outer plenum of the spray booth above the filter, if appropriate. Be careful using solvents, since they can dissolve gaskets (rubber compounds and the like) and loosen them.
Gasket tape should be replaced regularly to avoid air leaks.
Detergent should be avoided as detergent residues can enter the air stream when the booth is put back into operation, leading to high concentrations of unwanted solvents in the booth during the initial hours of operation.
The FILTRAIR ceiling filter mats, which can be cut to size by your authorised FILTRAIR supplier, have received the worldwide recognition by Automotive manufacturers and repairers alike as the replacement product of choice for your spray booth.
The correct size of pad for your spray booth is extremely critical, thus when measuring your ceiling media pads remember that if they are slightly too big they can be easily cut down, but if they are ordered too small then they will not be able to do the job properly.
When removing the FILTRAIR pads from their packaging, note that the fibres from the air entry side of the spray booth ceiling media may have stuck to the scrim side (air exit) of |
the pad when unrolled. These fibres could also have lodged on the air exit side of the ceiling media during the cutting or packaging process.
All fibres in a FILTRAIR air filter mat for spray booth ceiling filters are fully impregnated with a non-drying sticky adhesive coating. All fibres inside the filter media, even between the top and bottom (scrim) side of the filter blanket, are fully coated with adhesive, unlike many other “dry in the centre” or surface coated media available on the market.
Dirty hands, tables or floating dust particles will adhere to the air filter very quickly, which makes quick and hygienic installation of the filter, after unwrapping a “must do”.
The proper sealing of the air filter medium in the spray booth ceiling filter framing system must always be inspected. Any air leakage due to incomplete seals, folds in the media or other forms of air bypass will lead to paint damaging dust particles ending up in the paint finish.
After installing the air filters any loose fibres will be blown off when the paint spray booth is put back into operation under the air flow pressure from the blower. The fibres will follow the air stream and disappear in the exhaust airflow in the floor grids.
Depending on the air stream it is sometimes possible (in the initial hour of operation) that such fibres do not release right away.
We recommend that you to blow out (run) the spray booth for approximately two to four hours prior to starting your first spray-painting job, to “wash out” the system.
The “washing” process of the filters can be accelerated by carefully brushing off the filters on the scrim (air exit) side. However, when doing this, take great care so as to not damage the media or transplant any dust particles onto the clean air side of the filters and always use a clean brush.
PAINT EXHAUST OR OVER SPRAY FLOOR FILTERS
Commonly a paint arrester or paint stop medium is installed in the floor of the paint spray booth under the open floor grid.
This medium is usually made up of an open mesh fibreglass mat of approximately 50mm (2 inches) in thickness. Open synthetic fibre mats filters may also be applied, however these media tend to load up more quickly and require more frequent changing.
Be aware that the floor filters need frequent replacement; failure to do so can cause
- Imbalance in the spray booth air flow and static pressure,
- Major turbulence in the airstream creating cross-flows and up-flows and with that,
- Major dust problems by stirring up any dust that may have entered the spray booth through the doors etc.
- Insufficient airflow through the spray booth which can put the health and safety of the operator at risk.
Paint over spray filters are often changed monthly or more frequently when the equipment experiences constant and heavy use.
Paint exhaust filters operate most efficiently at an airflow rate not exceeding 2,800 cubic metres of air per hour per square metre (equal to 155 cfm per sq.ft.). |
