Choosing the best filter for your paint/varnish booth is essential, because it is the most important item in terms of consumable costs and maintenance time. In this article we will compare the different existing filters for extracting the mist generated during gun spraying in industrial paint booths.
Filter characteristics
In order to characterize and compare the advantages and disadvantages of the different types of filters, we have determined 4 main criteria:
1- Lifespan : retention capacity (kg/m²): this is the quantity in kilograms that a filter can contain per square meter. This will have a direct impact on the frequency of filter changes. It depends on the density and nature (dry or sticky) of the particles to be filtered.
2- Filtration efficiency (%): it is necessary to protect the fan and ducts downstream of the extraction filter, as well as limit discharges into the external environment. The filtration level must be optimal. However, this can have an impact on the lifespan of the filter. Recommended applications: floor vacuuming if space is limited – flat varnish robots
3- Evolution of pressure loss curve: the operating principle of a filter constitutes the way in which it will fill and clog. This therefore has an impact on the pressure loss of the filter (measured in pascals or millimeters water column), that is to say how a media will slow down the flow when the air flow passes through it. The slower and more progressive the curve, the better. Conversely, it can be abrupt and exponential, which will reduce the lifespan of the filter.
4- Cost/efficiency ratio: a consumable filter is a cost due to its unit purchase price, and especially due to the frequency with which you will have to change it. It is important to take into account the purchasing budget, and also cabin intervention times and therefore loss of production.
The different types of extraction filters
There are several types of filters for capturing and filtering mist in paint booths. The filter can be made of fibers or paper/cardboard material. There are also filters combining several materials.
1- Fiberglass filter : also called “Paintstop”. This is the least capacitive and also the least expensive filter on the market. It can be adapted to spraying very small quantities of paint (in bodywork for example), but will tend to clog very quickly in an industrial environment. It therefore generates significant maintenance costs. The other defect of this filter lies in its raw material, which consumes energy during manufacturing and is irritating during handling (gloves and mask recommended).
–Recommended applications: preparation booth – small volume of paint or in addition to a pleated cardboard filter
–Sectors of activity: bodywork – spraying of small series
2- Honeycomb filter : filter made up of several layers of paper, and sometimes an additional layer of polyester media. It can have a longer lifespan than the fiberglass filter.
–Recommended applications: floor vacuuming if space is restricted – flat varnish robots
–Sectors of activity: wood varnish
3- Progressive synthetic fiber: this is a filter based on the principle of a Paintstop, but made from polyester fibers, giving it better filtration efficiency, and handling without gloves.
–Recommended applications: filtration of dry and fine particles – UV varnish – chrome VI – ideal in addition to a pleated cardboard filter
–Sectors of activity: finishing on plastics – cosmetics
4- Diamond filter : this filter is also made of synthetic fiber and has the particularity of being made up of a top layer with retention pockets, giving it a better lifespan.
–Recommended applications: filtration of dry and fine particles – UV varnish – chrome VI – ideal in addition to a pleated cardboard filter
–Sectors of activity: floor suction – chrome VI – UV varnish – aeronautics
5- Pleated cardboard filter – Standard : also called accordion filter, this is the most used filter in industrial environments in the world, due to its retention capacity 5 times greater than fiberglass.
–Recommended applications: large paint volume – wet and sticky particles
–Sectors of activity: all industrial sectors
6- Pleated cardboard filter – with Media : a layer of fine polyester filter is added to the back of the pleated cardboard filter in order to improve its filtration fineness, but this has an impact on its lifespan.
–Recommended applications: filtration of fine and dry particles (varnish) when the cabin cannot be modified or space is restricted
–Sectors of activity: wood varnish
7- Pleated cardboard filter – High Capacity : this filter has a retention capacity up to 70% greater than a standard cardboard filter. This is an important advance for all industrial environments spraying significant quantities of paint every day.
–Recommended applications: large paint volume – sticky and heavy particles
–Sectors of activity: all industrial sectors
8- Cube Filter : filter in cardboard box with a very high retention capacity. There are several models on the market depending on the structure inside the cardboard. Used mainly in the automotive and aeronautical industries.
–Recommended applications: spraying paint in large quantities
–Sectors of activity: metal – wood
COMBINATION OF FILTERS: this is the secret to taking advantage of the characteristics of several filters and significantly reducing the cost of filter consumables and maintenance time.
The different applications of extraction filters
In this article, we have discussed all the types of filters designed for the filtration of mist generated during the spraying of liquid or sticky products in suction cabins.
Here are the different industrial sectors concerned and examples of application:
- WOOD: Varnish / Lacquers / Hard base for Carpentry / Cabinetmaking / Framing / Kitchens
- METAL: Painting on small and medium-sized parts / Metal framework
- PLASTICS: Painting / Metallization / UV varnish on plastics for Cosmetics / Prototypes / Models / 3D printing
- COMPOSITES: Spraying of Polyester Resins / Gelcoat / Simultaneous projection for the manufacture of shower trays, swimming pools, aeronautical and automobile parts
- GLASS: Painting on glass / Decoration / Bottles for Cosmetics / Perfumery / Decoration
- SKINS/LEATHERS: Pigmentation / Finishing in Tanneries and Tanneries / Luxury leather goods
The secret: combine several filters
You will have understood, each filter has its specificities which can allow it to adapt to each profession and product sprayed.
However, it will be necessary to carefully study the nature and quantity of product sprayed in order to choose the right filter combining lifespan and filtration efficiency.
In an industrial environment, the combination of 2 to 3 filters may be the best way to minimize the frequency of change, as well as the annual consumable filter budget.
The implementation of a new type of filtration may require a slight modification of the cabin. Technicis Filtration supports you in the study and tailor-made manufacturing of the necessary supports.
Consult us for a precise study of your installations and evaluation of possible improvements and gains in terms of costs and productivity.
Technicis Filtration in a few words
Since 1992, TECHNICIS FILTRATION has been the leading French manufacturer of pleated cardboard filters for paint booths.
Expert in filtration of overspray and mist generated in industrial spraying and surface treatment booths, we design and market a complete range of filters adapted to all processes related to finishing on wood, metal, plastic, composite, glass or leather, for all brands of installations.
In addition, we design and produce custom-made suction boxes and walls to effectively capture and filter overspray and spray mist in an industrial environment.
Our expertise and commitment to quality allow us to meet the specific needs of our customers in various industrial sectors.
