For a good basis
The proper and professional pretreatment of the workpieces is the basis for superior coating quality. During pre-treatment, the workpieces are first degreased and cleaned. Subsequently, a corrosion protection layer or conversion layer is applied, if necessary. Depending on the component and the required pre-treatment process, the components pass through subsequent rinsing zones and, if necessary, are passivated, phosphated and neutralized.
Our product portfolio includes not only classic pretreatment methods such as continuous spraying systems, chamber spraying systems and immersion cleaning systems, but also ionization systems, systems for flame treatment, CO2 cleaning systems and systems for snow blasting
Continuous spraying systems are typically used in wet chemical processes for medium and high throughputs. During the wet chemical pretreatment, metal surfaces are cleaned under the influence of chemicals and heat. Water serves as a carrier material. Pretreatment and cleaning are carried out regularly in several synchronized process steps. Between these process steps are rinsing processes.
The process structure itself depends on the workpiece shape and size, part throughput and the material to be processed. As part of the plant project planning, AFOTEK develops in cooperation with the chemical supplier a pretreatment concept for parts cleaning which is tailored to the needs of the end customer
Parts can be transported by conventional conveyor systems as well as the AFOTEK Shuttle Conveyor System (ASF).
Continuous spraying systems are environmentally friendly, energy-efficient and investment-friendly.
Chamber spraying systems are mostly used within the metal industry. Adjustable nozzles spray a liquid cleaning medium onto the workpieces, which are supposed to be cleaned. Contaminations are thus dissolved and flushed from the workpiece by the energy of the spray nozzles.
In chamber spraying systems, several treatment steps are carried out in one chamber. The workpieces move into one or more chambers, depending on the required throughput and the required treatment steps.
As part of the project planning, AFOTEK equips the spraying system to ensure that the workpieces are optimally flooded from all sides. This includes an offset nozzle system. The workpieces pass through the chamber spraying system hanging on a conveyor, occasionally also laying loosely on a conveyor belt.
Compared to immersion pretreatment systems, significantly shorter treatment times at lower bath temperatures can be achieved due to the additional mechanical effect of the spraying process. In addition, the space requirement is smaller compared to immersion pretreatment plants and the process control is simpler.
Workpieces, which have surfaces that are difficult to access, are advantageously treated in immersion cleaning systems. They ensure that not only the external surfaces are treated but also all cavities. This type of pretreatment is particularly recommended for complex geometries where a spray system cannot reach the entire surface.
AFOTEK plans and projects the entire system based on customer-specific products and requirements and develops the optimum concept in cooperation with chemical suppliers concerning the number and length of the process steps.
The various immersion basins are usually arranged in rows or in a horseshoe-shape. The size of the immersion pretreatment depends both on the size of the workpieces and on the required treatment steps. An integrated conveyor system completes the automated process of the AFOTEK immersion pretreatment.
Compared to conventional spray pretreatment systems, immersion pretreatment is characterized by lower energy consumption as well as high-quality corrosion protection of steel and aluminum components.
Many plastics used today attract particles floating in the air due to electrostatic surface charges. These particles affect the painting quality, o.k. rate, rework rate and reject and should therefore be professionally removed before coating.
Since the removal of these particles can hardly be achieved with conventional methods, AFOTEK uses ionization devices for cleaning - if it is reasonable and necessary. The ionizing units neutralize the surface and thus improve the quality of the coated end product. In this process, the workpieces are usually wetted from above and/or from the side.
AFOTEK has developed a circulating air process for the ionization zone that does not require expensive compressed air, so that enormous savings potentials can be achieved concerning process costs.
Flame treatment belongs to the physical surface treatment procedures,particularly of plastics. During flame treatment, the surface is briefly heated with a gas-flame with excess oxygen without beginning to melt the plastic.
Activating the surface
Specifically in the plastic coating field, but also in that of adhesive application, prior treatment of the surface with a flame is often required. We choose the optimal solution for you depending on the materials to be treated and the existing surface tension.
During CO2 cleaning, carbon dioxide and compressed air are used as blasting media. It is a dry, healthy and environmentally friendly cleaning process that is operated without the use of chemicals and/or solvents. The advantage is that the workpieces must not be dried after the CO2 cleaning, which means that the production process can be shortened and the cycle time optimized.
CO2 cleaning is mainly used for the pretreatment of finely structured and sensitive workpieces.
AFOTEK designs CO2 cleaning to meet the specific needs of our customers. It can be used both in continuous and cyclic operation.