Powder coating of aluminium
A wide offer of Final S.A. allows for tailoring services based on various technologies to the customer’s needs, thanks to which aluminium profiles become more durable and are often used in decorations. One of such technologies is powder coating of aluminium, which is carried out by Final in a modern powder coating shop equipped with a vertical profiles hanging and transport system. The advanced technical level of the powder coating shop equipment allows us to provide powder coating at best quality, as well as to obtain high output. Modern line allows for and guarantees:
- coating profiles up to 7,500 mm long with a maximum rectangular cross-section of 120x250 mm
- output at the level of 1000 m2 per hour.
Powder coating - equipment and technical stations
Modern aluminium powder coating shop uses various innovative equipment and many technological stations. The most important ones are:
- profile hanging station which consists of a feeding table, profile guides allowing for the shifting from horizontal feeding to vertical hanging on the conveyor
- conveyor with a lubrication system and furnace for hooks devarnishing
- chemical processing tunnel
- composite construction of a drier and a polymerization furnace
- spray booth
- profiles discharging station which consists of an outfeed table for profiles and profiles separator allowing for shifting from vertical to horizontal position on the outfeed table
- auxiliary equipment: demineralised water station, heat recovery installations, air handling unit, sewage pumping station, compressor room
Chemical processing is executed by spraying preparations and water on the surface of aluminium profiles. To form a conversion layer, which is a protection layer, best quality polymer preparations are used, which ensure safety and best results. Spraying installation in the powder coating shop of Final allows for using chrome-free preparations.
The sequence of the aluminium powder coating processes is as follows:
- acid bath, degreasing and pickling of profiles surfaces
- acid pickling
- water bath
- demineralised water bath
- chrome-free passivation
- demineralised water bath
Ecological powder coating of aluminium
Innovative processes of aluminium powder coating are connected with pro-ecological approach to every day life. Powder coating of aluminium for which Final is responsible is carried out according to applicable Directives of the European Union which aim at maximum elimination of preparations consisting chrome that are used for chemical processing of aluminium. Additionally, the use of chrome-free polymer preparations contributes to easier sewage processing and decreases related expenses.
Final stages of powder coating of aluminium
After chemical processing, aluminium profiles are transferred to a drier, and then a special conveyor transports them to an automatic spray booth. The powder is applied in a selected colour by two modern OFB4 discs, instead of standard electrostatic guns. In addition, the double omega shaped route of the conveyor is another innovative solution which allows for a uniform application of powder (quality and thickness) on the entire circumference of coated profile. It is possible thanks to an optimum angle of aluminium profiles positioning against the disc. The advanced technology used by Final ensures high quality thanks to dispersion of powder coating between 5–10 µm. In horizontal coating the dispersion can reach tens of µm.
The automatic spray booth, in which powder coating of aluminium profiles is carried out, is equipped with a feeding system, pre-treatment system, and powder recovery system, as well as an immediate booth cleaning system used while changing pigments. An interesting solution is the application of moving walls while the booth is being cleaned.
The polymerization process, in a result of which particles react with one another, is performed in an open-ended continuous furnace with a U-shaped conveyor with a double loop. The process is performed in compliance with the parameters recommended by powder paints manufacturers. Quick setting of the furnace parameters is possible thanks to a multi-point temperature measurement system and an automatic control system which allows for faster and more efficient process of polymerisation.