TPT September 2015

Article

VOSS Fluid GmbH

lower than for other zinc-nickel coatings. Depending on the connecting component, a lubricant and partial inner coating are used, for example union nuts. Experienced application technicians support assembly-reliable production processes at the customer facility. These technicians accompany fitters and maintenance personnel, from selection of the system- compatible hydraulic coupling and training covering all aspects of leakage-free couplings through to regular assembly audits. In-house electroplating The company-internal electroplating forms the basis for the high-quality coating of tube connections. This plant corresponds to a high technological standard as well as the current environmental provisions for mixed residential areas. It is also one of the most modern plants in Europe and is ideally designed for the internal process steps during coating – this high degree of specialisation would not be attainable via outsourcing. In contrast to normal coatings, the process is optimised in respect to component damage prevention, layer distribution, visual appearance and friction coefficients – qualitative reproducibility of the 6,600 different articles from which the larger product spectrum is derived is always guaranteed. Weight, size, geometry – these are only some of the on average twelve program parameters saved for each article in the production system. They are an important prerequisite for optimally coating the different connecting parts on a recurrent basis. Current strength during electroplating, retention time in the basin, and handling are clearly defined specific to the article. The frames and baskets used for transporting the connecting parts in the plant are in-house developments. Larger connecting parts with up to 2.5kg weight and sensitive outer threads are placed manually on frames by personnel, thereby preventing potential damage to the thread during the coating process. During pretreatment, the articles are cleaned via ultrasound in order to remove any dirt in the bores. Smaller components are fed to the process via drums. The filling cycle utilises a conveyor belt in order to minimise falling heights and prevent process-related damage. A significantly reduced coating time also conserves the material. For resource-efficient production, the entire electroplating process is controlled and monitored via online analysis and sensor systems. Automatic dosing pumps ensure that the correct amount of chemicals is always supplied specific to the product. The baths thus remain stable within the specified process limits. The chemicals are continuously kept in motion to ensure they are distributed evenly. After the electroplating process, the layer thickness and nickel content are monitored for each production batch. This means the articles receive a verifiable even coating with VOSS coat, which permanently protects them against corrosion. A pilot electroplating has been operated since 2013. This enables the entire electroplating process to be mapped in miniature form, while simulating production parameters modified to save resources. Besides the refinement of VOSS coat, optimisation of the internal processes in relation to efficiency and sustainability are also integrated here. Users therefore benefit from a future-orientated surface coating and customised system solutions.

Smaller components with inner threads are fed to the process via drums

Regulation 1907/2006 for determination of the nickel release of products coming into direct and prolonged contact with the skin. When comparing the VOSS coat surface directly with a €2 coin, this fell below the limit value by 2,230 times. The surface is not only environmentally compatible due to the hard nickel content, but also more wear resistant against the mechanical loads to which hydraulic couplings are exposed during transport and assembly through to practical application. VOSS coat consists of a zinc-nickel base coat, which is then passivated and finally sealed. These three layers prevent corrosion of the base material and enhance the connecting components in a sustainable way. According to VDMA Standards Sheet 24576, the zinc-nickel surface attains the highest corrosion resistance class K5. This denotes the protective capacity of the surface, which exhibits resistance a minimum of 720 hours against red rust and at least 360 hours against white rust. Under laboratory conditions with non-assembled parts, corrosion resistance of more than 2,000 hours was attained in the salt spray test according to DIN EN ISO 9227. In the practical test with random goods from current production, they did not reveal any base metal corrosion even after 1,000 hours of handling and assembly. For optimum assembly torques, the friction coefficients are continually improved in development and production for cutting ring couplings. That means they are significantly

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S eptember 2015