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Aqueous cleaners replace hazardous chlorinated hydrocarbon cleaners (trichloroethylene and many other allied solvents) which are increasingly regulated and their use controlled by Legislation, e.g. REACH (Registration, Evaluation, Authorisation & restriction of Chemicals). In conjunction with aqueous surface preparation solutions, aqueous cleaners provide an eco-friendly solution for many substrates, including mild steels, zinc coated steels, aluminum and, plastics.
Traditional techniques to pretreat metals and plastics include:
- Shotblasting
- Detergent Washing
- Solvent Cleaning
- Aqueous Cleaning
- Aqueous Surface Preparation
- Etching
A typical application for the conversion coating preparation of ferrous and non-ferrous metal substrates is preparing them in readiness for painting. Where, zinc, iron, manganese, and zirconium phosphates provide protection and a key for both wet-sprayed and powder coated paints.
Modern nanotechnology phosphates, e.g. zirconium, have both the benefits of lower temperature operation (reducing energy costs and improving carbon footprint) and, unlike their heavy metal alternatives, they can normally be discharged directly to drains. Avoiding increasingly expensive proscribed waste procedures. They additionally deposit less sludge into the tanks of dip and spray application tanks and, sustain cleaner pipe work and spray jets.
Salt spray testing is the standardised test method to check corrosion resistance of coated materials, and an effective conversion coating is essential to achieve best results. Whilst nanotechnology phosphates produce good results, it is generally recognised that heavy metal chromates achieve better results for architectural and exterior finishes.
The process requires substrates to pass through a number of treatment stages. The number of which varies upon application but, the minimum requirement is a combined degreasing and phosphate solution followed by a single water rinse. However, two rinse stages are more typical and, can be provided with back flow facilities to reduce water consumption.
By comparison, to achieve the industry recognised Qualicoat standard, for the powder coating of architectural aluminium components, a plant would provide up to ten stages, e.g. clean, rinse, etch, rinse, desmut, rinse, chromate or chromate free conversion, rinse demineralised water rinse, dry.
Airflow work closely with all major pre-treatment chemical providers and, recently supplied plants operate using Henkel, Chematell and, Houghton treatments.
Please browse our website for more information about our rapid specification, quotation, manufacturing, installation & after sales Pre Treatment Plant Equipment service then contact us on 01142 327788 to speak to one of our team or e-mail us on sales@airflow-group.com.
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