High-quality coating requires pretreatment of the surface. The parts must be degreased and, in case of higher corrosion requirements, also chemically treated. Preparatory work on surfaces is conducted by water solutions of chemical agents, which are subsequently rinsed away. Each pretreatment technology is designed, together with the degreasing agent supplier, according to specific customer requirements in order to achieve the optimal parameters of the work baths and quality of rinsing while reducing the amount of rinsing water as much as possible.
Fully automated surface pretreatment is ensured by passage-through spraying machines. As a standard, these machines are equipped with degreasing units and several stages of rinsing with pre-rinsing frames, work bath dosing, measurement of rinsing conductivity with automatic monitoring and setting of conductivity values within the defined limits, and regulation of the heated baths temperature. All operating parameters are managed automatically, effectively eliminating the need for permanent operator. The passage-through spraying machines are delivered in stainless-steel or plastic version with complete accessories, i.e. bath heating, inlet water treatment, waste water treatment, and retention, sludge and storage tanks.
Degreasing booths are designed for surface pretreatment of sizeable components or for plants of a lower production capacity where automatic degreasing machine is not economically beneficial. Grease removal, or a combination of degreasing and phosphating, is carried out by manual spraying. A strong cleaning effect is attained by the pressure and temperature of the cleaning bath. The washing fluid is constantly cleaned and recycled, which significantly reduces the production waste water and as well as the consumption of chemical agents.
Cleaning machines for inter-operation cleaning and cleaning of extremely soiled components before their rework are delivered as special equipment. Tests of cleaning are always carried our as part of the technological preparation of these cleaning machines, which facilitates designing the optimum system. Together with the component cleaning itself, it is necessary to find a solution for treatment of the used cleaning fluid from mechanic impurities and floating grease. In the heavy-duty operations, such as railway vehicle repairs, the machines are equipped with a special mechanical rake which skims the grease floating on the surface of the degreasing or cleaning bath over the rim of the storage tank and into a separated tank from which it is periodically pumped off into a transport container.