What are paint booth filters?
The paint room ventilation system consists of three filters, and These filters are shaped like cotton, also called filter cotton. And distribution is primary filtering cotton, roof filtering cotton, and paint mist filtering cotton.
These three filter cotton are called paint booth filters or spray booth filters.
Why need paint booth filters?
Paint booths are mainly used to paint various products that need to be painted.
To strictly control the quality of painting, ventilation and filtration systems with filters are generally used.
The paint booth filters can well filter the air dust impurities entering the paint booth, adsorb the paint mist particles in the paint booth, and purify the air pollutants discharged from the paint booth.
Paint booth filters can ensure excellent air quality in the spray booth.
As we all know, the quality of the air entering the spray booth affects the quality of the workpiece painting. The atmosphere contains a lot of dust, flying insects, flotsam, and so on, which can affect the painting quality at any time.
Therefore, it is necessary to set up a few filtering cottons in the air inlet of the painting room to block the outside air pollution.
What’s the paint booth?
The paint booth is a closed painting environment specially set up for products that need surface painting.
Compared with the traditional painting environment, the overall painting effect of the products in the paint booth has been improved, and the quality of the products is undoubtedly improved.
Wet and dry wet paint room
The paint spraying room is divided into wet and dry wet. Wet and dry wet is relative to the treatment of paint mist generated during the spraying process.
Wet paint booths mainly use water curtains to remove the overspray paint mist and use paint mist flocculant to trap the paint mist particles in the water, which wastes many water resources.
The dry spray booth mainly uses glass fiber filtering cotton to trap the overspray paint mist particles. Then the exhaust gas is treated with activated carbon to reach the emission standard. So we also called glass fiber filtering cotton as exhaust filters.
Each of the two ways of dealing with paint mist has advantages and disadvantages.
We will discuss the paint booth filters mainly used in dry paint spray booths.
Pollutants from paint booths
The paint spraying room will produce many waste gas, including benzene, toluene, xylene, etc. This VOC is quite serious to environmental pollution.
Let’s first understand what the wastes produced by spray painting are.
The first is the suspended paint mist particles produced during the spraying process.
The second is oil-based paint: water droplets carrying paint particles; water-based paint: water droplets of dissolved paint particles.
The third is the odor of the raw material of the paint itself in the vaporized state, the odor emitted by the thinner (room temperature paint curing agent), and the odor released during the reaction and curing process.
Knowing that the spraying process will produce those harmful substances, we will target the solution and discuss how to deal with paint mist and the materials used in the dry spray booth.
Filters for dry paint booths
Two kinds of paint mist filters are used in dry paint spray booths: the filtering cotton or air filter for filtering paint mist particles and the filtering cotton for removing harmful gases.
The filter options for paint mist include glass fiber filter cotton, organ filter paper, honeycomb filter paper, etc.
The paint mist filter effectively intercepts the paint mist particles produced by spray painting, and the paint mist filter is replaced frequently.
Glass fiber filter cotton must be replaced in a dozen hours or so in case of a high volume of spraying operation.
Paint mist filter cotton effectively protects the service life of the latter activated carbon filter.
After the paint mist particles are filtered, the remaining exhaust gas must be filtered with an activated carbon filter. The exhaust gas filtered by the activated carbon filter can generally meet emission standards.
Three types of paint booth filters
According to the location of use, there are three types of paint booth filtering cotton.
Primary filter cotton
The first air inlet filter cotton is called air inlet cotton, primary filter cotton, nonwoven filter cotton, and so on. It can be classified as disposable filter cotton and washable filter cotton.
The primary filter cotton mainly works as primary filtration, trapping the large dust and particles and letting the fresh air into the second filter.
The central role of the primary filter cotton is only one, blocking particles above 5 microns.
Air inlet filter cotton not only filters large particles of dust but also effectively protects the next level of the medium-effect pocket filter or medium-effect filter cotton to extend the service life of the back channel filter or filter cotton.
Generally, the primary filter cotton replacement cycle is 2-3 months. Of course, this replacement time needs to be decided according to local working conditions.
It is best to regularly check the air inlet filter cotton in some more severe pollution areas and test the air inlet pressure difference.
When the final resistance reaches the theoretical value, replacing the air inlet filter cotton is necessary.
Inlet filter cotton is not recommended for reuse.
Cleaning them will more or less affect the filtering effect.
Rather than reuse the inlet filter cotton to save costs, it is better to replace it regularly to effectively protect the next filter or filter cotton life, which is the actual cost savings.
Roof filter cotton
Roof filter cotton is installed on the roof and is the second filter for the paint room.
The roof filter cotton filters the air and is then sent into the working room by the fan, making the air inside the working room form positive pressure, ensuring the effective emission of paint pollution in the paint room.
The clean air that is filtered comprehensively spreads evenly in the paint booth, forming a laminar flow state, thus helping the painting to achieve optimal results.
Roof filter cotton is divided into two kinds of mesh and cloth surface.
There are surface spray glue roof filter cotton and three-dimensional impregnated roof filter cotton.
Glue filter cotton can more effectively block 1-10 microns of particles.
The thickness of the roof filter cotton is generally 2-2.3 cm or so, is made of grade-by-grade encryption of polyester fiber heat laminated, and then compound cloth or mesh surface to increase its strength.
Then after the surface of the spray glue or three-dimensional dipping process, the filter cotton can effectively intercept dust and other particles to improve the filtration efficiency.
The roof filter cotton’s replacement time is generally about three months – half a year.
The specific situation also depends on the actual working conditions to decide if the location of the high quality of air, then the roof filter cotton’s replacement cycle can also be up to 9-12 months ranging.
Paint mist filtering cotton.
Paint mist filtering cotton is Also called paint mist felt, glass fiber felt, or ground cotton because it is placed under the grid at the bottom of the paint booth. Also, it’s used in the air outlet of the paint booth.
Paint mist filtering cotton is the final filtration of the paint room.
The primary function of ground cotton is to filter the paint mist in the air, reduce airborne paint levels and odors, and reduce the pollution discharged into the atmosphere.
The fluffiness of glass fiber filtering cotton is perfect, and the thickness is between 50-100mm.
After being compressed into a volume, even after a long time of transportation and storage, it can still return to its original thickness after opening.
When the glass fiber filter cotton has trapped a certain amount of paint mist, it will not be flattened because of the increase in dust capacity. However, it can still maintain its original shape, and its processing air volume is more prominent, which is a good paint mist filter material.
The glass fiber filter cotton is green and white, and the green side is the windward side of the air.
Materials and features of paint booth filters
Primary filter cotton
The composition of air filter cotton is three-dimensional hollow polyester staple fiber. It has a good curl degree, which can make the yarn and fiber more closely together to play a better barrier effect.
Polyester fiber characteristics are weak acid and alkali resistance and continuous temperature resistance of up to 100 degrees Celsius;
In the conventional environment, it has good physical and chemical properties, the fiber and the fiber of close combination without losing fluffiness so that dust particles and other substances through the filter cotton are effectively blocked.
The good resilience ensures it will not collapse under high dust holding capacity.
It’s suitable for filters requiring frequent cleaning and air filtration system pre-filter or intake filters.
The usual production method for filtering cotton is hot air and needle punching.
Roof filter cotton
It is made of a high-performance hot fusion method composed of break-resistant organic synthetic fibers; Incremental structure, using gradually encrypted multi-layer technology.
The fiber density gradually increases in the direction of pure air. With higher filtration efficiency, various sizes of dust can be blocked at different density levels, which is more effective in accommodating more dust.
A layer of square mesh or cloth is added to the air outlet side of the roof filter cotton to strengthen the shape.
This structure makes the filter cotton maintain a good filtration effect and high dust capacity and can extend the service life.
In addition to ensuring good filtration quality, the filter media has a relatively low resistance, so it can also save system operating costs.
Paint mist filtering cotton
Fiberglass filter cotton is made of glass fibers with a progressively denser structure.
The increasing density of the fiber structure from the air inlet side to the air outlet side ensures that dust particles are kept at a deeper level, thus increasing the dust-holding capacity.
Because of the low compressibility of the material, there is no crushing of the filter media when the incoming air is impacting, so the different density levels can effectively contain the dust.
Fiberglass filters can meet some unique needs, like filter paint mist in the spray booth as booth filters or customized high-temperature filters in some specific industries.
Features:
- Glass fiber filter cotton consists of high-strength continuous monofilament glass fibers with incremental structure and a high capture rate.
- Good compression performance can keep its appearance unchanged, and its filter fiber is conducive to the storage of lacquer dust.
- The filter cotton is green and white, the green side is the air inlet, and the white side is the air outlet.
- With elasticity and low-pressure loss, it has an excellent effect of trapping and filtering for paint fog, and the filtration efficiency is G3-G4.
- Strong humidity resistance can reach the relative humidity of the humidity resistance.
- High-temperature resistance 170℃.
- Available in rolls or slices. Customized in lengths and widths.
Overall overview of filter cotton
The range of filter cotton is relatively wide. Usually, filter cotton generally refers to air filtration.
The filter cotton can be made into rolls, pads, or cut pieces, which can be cut according to the size of the air inlet, or custom sizes can be made.
It can be washed after adding waterproof treatment.
It can be used for an automatic roll filtering unit after applying mesh on one side and adding a paper tube to the roll.
Filter cotton can also be divided according to different filtration efficiency: primary filter cotton and medium-effect filter cotton.
Application of filter cotton
- For large dust filtration, pre-filtration and air conditioning systems return air filtration.
- They are used in various industrial applications, such as pollution prevention, the air conditioning industry, industrial waste gas, processing fog, etc.
- Especially suitable for pre-filtration of paint spraying system, paint spraying workshop.
- It can be processed into primary effect plate type or primary effect bag type filter according to customer’s demand.
- Especially for paint spraying systems, paint shop end fine filtration is a prerequisite for a high-value baking process and high-quality baking paint.
- It was installed in automotive assembly, painting, and baking workshops as roof filter cotton.
- It was installed on the roof of paint spraying and baking rooms in automotive surface finishing departments as the final air supply filter cotton for ventilation equipment.
- Installed as a last air supply filter in production and paint booths where high gloss and polished products are required.
Paint booth filters replacement
When replacing the filter cotton, first remove the air inlet, ceiling, and floor filters, clean the ventilation ducts, dark corners, and dusty places carefully, then close the door of the paint room and open the fan to blow for about 1 hour.
The filter cotton and the frame, frame, and surroundings shall not leave any gap to ensure filtration efficiency when installing the filter cotton.
First, the roof and the air inlet filter cotton were installed, and then open the fan air blew for about 4 hours.
After another cleaning work, install the ground cotton before using the paint booth.
