In the automotive industry, filtration challenges are numerous. The fluids used (water, oils, gases, etc.) must be purified to be used without damaging the production lines along which they are implemented. The challenge is significant, as the processes (cutting, welding, painting, polishing, washing, buffing, etc.) generate pollutants of varying nature and size, often harmful to operators, capable of damaging equipment and compromising production quality. Issues encountered, filtration solutions: Pemflow takes stock.
Filters in hydraulic systems
The automotive manufacturing sector, like other major mechanical industries, relies on numerous hydraulic systems. For these systems to operate optimally, it is essential to use effective filters. Particles present in cooling, lubrication, cutting, or washing fluids must be removed using high-performance industrial filters. These ensure a high level of fluid cleanliness and extend fluid service life. Filtration devices are also used in plastic injection molding machines.
Filtering process oils
To produce, for example, transmissions and other hot-forged and hot-rolled components, automotive equipment manufacturers use synthetic oil baths to cool and lubricate forging machines. The oil used must be free of any metallic particles. The selected filtration devices must be suitable for use with high-viscosity fluids, at relatively high temperatures, and capable of withstanding significant differential pressures. Depth filtration cartridges are particularly well suited for this application.
Discover an example of oil filters used in the automotive industry
Filters for treating process water
The processes implemented in the automotive industry use large quantities of water. Before being used, this water must be purified of microorganisms and any sediments it may contain, whether it comes from groundwater pumping or from storage tanks. Depending on the case, bag filters or cartridge filters are used. Depending on the required level of purity, an ultrafiltration stage may be necessary.
Discover a practical example of wash fluid filtration
Air quality and welding
Welding operations release fumes into the environment that are harmful to workers’ health. These fumes can penetrate deep into the lungs, where they may cause serious damage and spread into the bloodstream. Exposure to welding fumes is a risk factor in the development of pulmonary, renal, and central nervous system disorders, etc.
The metal dust particles emitted are also problematic: they can cause eye irritation, upper respiratory tract irritation, as well as headaches. Like fumes, welding dust must therefore be removed from the ambient air.
More generally, the machining of mechanical parts generates metal particles during polishing, buffing, or cleaning, which must also be filtered. This operation is often delicate, as the metal fragments produced are generally projected at high speed. It is then necessary to use properly positioned extraction hoods to collect them.
If you would like to learn more about air filtration in the automotive industry, feel free to read the following articles:
Everything you need to know about industrial air filtration
Learn more about industrial dust collection
Discover an example of the implementation of AHU filters in the automotive industry
Filtration and painting
In the automotive industry, vehicle painting is carried out by cataphoresis, also known as cationic electrodeposition. This technique consists of immersing the body components in a water-soluble paint bath, placing the part to be treated as the cathode, and causing the paint particles suspended in the bath to migrate by means of an electric current, from the anode toward this cathode. The paint particles then deposit uniformly over the entire surface of the immersed part. Paint deposition is monitored throughout the process using a coulombmeter or a timer, which makes it possible to stop the process when the optimal paint thickness has been reached. The paint is then drained before being polymerized in an oven.
Filters play an essential role in pretreatment operations, degreasing, and in the electrophoretic painting process itself. The surfaces of parts coming from manufacturing units (machining, welding, stamping, etc.) may be contaminated by oils, welding metal splatter, and other particles. These contaminants must therefore be removed by filtration. Filtration operations are also required to maintain the quality of the rinse water and that of the phosphate pretreatment solution used during cataphoresis.
Filtration of the cataphoresis bath is also a critical step, allowing recovery of poorly dispersed paint, cured resins, and all insoluble particles that may contaminate the bath. The filters used here must provide high particle removal efficiency, reproducible and consistent over time. They must also be capable of retaining any oil residues.
The liquid effluents generated by painting processes must also be filtered using ultrafiltration membranes. To protect these membranes, it is recommended to implement upstream filtration, which will limit fouling and extend their service life.
Discover a practical example of paint filtration
Expert advice
Caution: at these stages, it is imperative to use filters completely free of silicone (which generates significant bodywork defects). Remember to ask your supplier to ensure that each filter is supplied with its “silicone-free” certificate.
Sealants: filtering high-viscosity fluids
In the automotive industry, sealants and waxes are used to prevent water ingress and delay joint corrosion. These products have very high viscosities (70,000 to 100,000 cP) and must therefore be applied using high-pressure spray guns. To prevent nozzle clogging, pre-filtration is essential. It is therefore necessary to use highly specific, high-strength filters capable of operating at pressures of up to 350 bar.
Eliminating oil mists
During the metallurgical processes used to manufacture automobiles, oils and emulsions are employed to cool or lubricate metal components. When these metallurgical fluids escape into the air, they form an aerosol: oil vapor is generated upon contact with the hot machined surface, evaporates, and then condenses into microscopic particles. This oil mist settles as a greasy film, making floors and work surfaces slippery. These microscopic droplets can also damage electrical or electronic equipment present along production lines or in workshops.
Oil mist also poses health risks for operators. For example, there are established links between exposure to oil mists and an increased risk of bladder cancer.
These oil mists must therefore be filtered using cartridge filters, bag filters, or demisting or electrostatic filters.
In Air Handling Units (AHUs), bag filters are often used to treat high oil loads in the air.
To learn more about oil mist elimination
Discover an example of cutting oil filtration
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