- The rotation process for the anodizing of aluminum, patented by SCHMID, meets the strict requirements of the automotive industry at XingLi without the normally required post-processing. This makes CYKLOS an absolute competitive advantage for the Chinese anodizer.
Colorful carabiners, highly precise injection nozzles, noble aluminum packages – the possible applications of chemical surface finishing are manifold. In the conventional processes of chemical surface treatment the parts are treated by immersion in a bath. The layer thickness may vary and scooping parts with partially enclosed cavities may show poor coating results due to gas bubbles that arise during immersion. The situation is different with CYKLOS from SCHMID: the patented rotation process ensures better convection (flow movement) in the process baths, so that the gas bubbles are released from the cavities and the surface treatment is optimized.
For one year now the company KunShanshi XingLi Automotive Parts Co. Ltd, specialized in chemical aluminum processing, has been anodizing hydraulic valve blocks made of aluminum on the CYKLOS machine. The valve block controls the switching operations of an automatic transmission. The tribological requirements are correspondingly high. In order to prevent hysteresis the uniformity of the oxide layer, the fitting accuracy and the surface roughness must be exactly met.
XingLi’s customer, one of the world’s most renowned automotive suppliers, regularly carries out hydraulic tests on a test stand specially developed for this component. In order for the components to pass the test, anodizing may change the surface roughness by max. Ra 0.3 µm. In the conventional static immersion process,the Delta Ra is about twice as high so that the parts have to be mechanically reworked. Since then XingLi, employing 30 people at its site in Kunshan (China), has been using CYKLOS for anodizing aluminum cast blocks, the reworking step for surface smoothing can be omitted. An absolute competitive advantage.
Patented rotation process
Thanks to the rotation process CYKLOS achieves excellent surface qualities. Unlike with the immersion process the 360° rotation separates all gas bubbles from the workpiece and especially from the cavities. Thus, the process can take place uniformly everywhere. The process technology is similar to that of photochemical milling and circuit-board processing – areas in which SCHMID has been the technology leader for decades.
Like all SCHMID wet processing systems, also CYKLOS has a modular design and a high degree of automation. Thanks to its modularity, CYKLOS is precisely adapted to the needs of the user. In general, CYKLOS can be designed either for the anodizing of aluminum or titanium or for the chemical deburring of steel parts.
For an optimum contacting the workpieces are clamped on product-specific workpiece tray before processing. The format of the workpiece tray is 450 x 330 mm each, the max. height is about 200 mm. The subsequent process is fully automatic. A transport arm linearly pushes the workpiece tray into the subsequent tank. There, a rotor system accommodates up to four workpiece carriers, immerses them and leads them through the process bath by rotation. The automation follows the “First In – First Out” principle. It ensures that all workpieces pass through the identical process. Depending on the geometry and size a throughput of 0.5 million to 50 million workpieces per year is possible.
Better working environment
During anodic oxidation, the aluminum part serves as an anode (positive pole) in an electrolyte of diluted sulfuric acid. Supported by electrical load the generation of oxygen grows the aluminum oxide on the workpiece surface. CYKLOS is completely enclosed and consequently does not emit any harmful substances into the work environment. Since the system operates fully automatic – which minimizes operator intervention – CYKLOS offers the best possible protection to the employees.
Furthermore, CYKLOS disposes of an HMI-controlled process monitoring. A data logging system is integrated therein for the monitoring and recording of all necessary process parameters. The suitability for industry 4.0 allows traceability and ensures consistent quality and reproducibility. With the precise control and regulation it is possible to directly influence the quality of the oxide layer to be produced. Above all the roughness as well as the uniformity of the layer can be controlled here. Moreover, the controlled dosing lowers the chemistry consumption. The processing time depends on the desired layer thickness and the alloy and is about 10 to 60 µm per hour. Without anodizing, aluminum has a hardness of about 100 HV. Depending on the anodizing recipe, hard-anodized surfaces reach up to 450 HV, i.e. high resistance to wear.
Technology Center for processing experiments
SCHMID has installed a CYKLOS system for chemical surface treatment at its Technology Center in Freudenstadt (Germany). With this system the company founded in 1864 carries out processing experiments and processing of samples. A unique feature which XingLi has used in the run-up to procurement as well. During the processing of samples the qualitative expectations were even exceeded.
High customer satisfaction
XingLi is extremely satisfied with the CYKLOS and produces high quality products. As a result of increasing order numbers the company plans to expand the production line. The typical modular design of SCHMID allows the capacity of the system to be increased by about 50% through an upgrade. In the medium term XingLi wants to continue growing. During expansion of the modern production hall space was already provided for a second CYKLOS.
CYKLOS is completely enclosed and works fully automatic. As a result, the work environment for the employees is no longer harmful to health offers the best possible protection to the employees