KTL (cataphoretic) systems are designed basically in two methods: sectioned and continuous operation. The difference between the two systems is in the moving of the work pieces. With the continuous system the work pieces arrive by a machine-driven conveyor and are in continuous movement also in the KTL painting tub. With the sectioned system the work pieces to be painted are forwarded along the technology by an elevator crane and places them always to the appropriate tubs. Following their placement, the work pieces do not move any longer. Selecting the appropriate method always depends on the characteristics of the work pieces to be treated (dimensions, weight and shape) as well as their volume to be treated. In case of rented painting operation it is the sectioned method which is recommended since altering dimensions and shapes of work pieces can be treated with it easily. Continuous operation method systems can be more advantageous and economical than the sectioned method mainly with the treatment of own products.
Applying the KTL technology, the work pieces to be painted can be provided with the appropriate paint layers in an electrochemical method. Painting is done in the way that the work pieces are dipped in water-based paint, on which direct current is switched. By the effect of that, the work piece attracts the paint to it and creates an even layer on its surface. A great advantage of the technology is that various shapes of work pieces can be painted with even coating layer on their surfaces. By an appropriate preparation process, the salt-spray resistance capacity of the coating created that way will be extraordinarily high also depending on the type of the paint applied. The work pieces treated with KTL painting will have high corrosion-proof feature.
The KTL system may be set up of the following phases:
- Pre-treatment
- KTL painting
- UF flushing
- Paint annealing
The basic metal to be coated will not be soluble while connected as cathode (there is no anodic electrochemical dilution), the ions of the base metal do not contaminate the paint coating and the tub, therefore the protective capacity of the coating as well as the life cycle of the tub will significantly increase.
The process is energy saving since for providing the same amount of protective capacity a smaller layer coating is necessary; generally 30% paint content can be saved.
The process is energy saving since for the separation 50% smaller amount of power is needed than in case of an anaphoretic process.
From the environmental protection aspect, it also means a lower emission load on the environment since the organic solvent content of the paint tub is 2.5 – 3%.
By applying ultra-filtration, 85% paint utilisation can be reached.
Material loss discharged to the environment appears in three points of the technology:
- Anolite-coagulation-waste water treatment
- Flushing zone, tub surface (evaporation)
- Air discharge (emission) from the stove varnish
The cataphoretic electro-dipping painting method therefore is environmentally friendly, material and energy saving.
A KTL system may consist of the following main and auxiliary units:
- KTL tub
- UF I-II tub
- Circulating pumps, backup pumps
- Filter system
- Cooling system
- Discharge system
- Paint agitator system
- Anolit circuit, with anode cells
- Rectifier network
- Ultra-filter system
- Measuring and control devices flow meters etc.
- Closing water system
- Exhaust system
- Pipelines, pipe assemblies
