Additive for hot water sealing of anodised aluminium

This liquid concentrate is a weakly acidic solution for use in hot (high temperature >100°C) sealing of anodized including anodized and coloured aluminium. The process is free of any heavy metals. Improves sealing quality and prevents sealing smut from forming on surfaces.
All International Standards (admittance, weight loss, dye-spot test, etc.) for sealing are achieved using the process

Features & Benefits

  • Eco-Friendly, free from Nickel, Cobalt and all other CMR substances
  • Works good if water quality is less than deionized – compatible with hard water.
  • Less water marks/finger printing
  • Buffers hot sealing baths at a pH of 5.8 ± 0.2 to obtain best sealing results and reduces number of pH adjustments required.
  • Can be used for a long time and lifetime can be further extended with continuous filtration
  • Good ADT results are achieved.
  • Optimum quality values according to International standards ISO 2143 (dye-spot test), ISO 3210 (weight loss), ISO 2931 (admittance)

This process belongs toALUMAL SEAL SERIES

Because of the porous structure obtained in commercial sulfuric acid anodizing, the pores require sealing to optimize performance of the layer, including corrosion resistance and dye colour intensity, colour stability and fade resistance. Sealing of anodized layers is simply filling up the pores with some type of larger molecule, and converting the inside of the pore to a hydrated aluminium oxide which closes/plugs the pore.

There are different types of seals that all offer various levels of corrosion performance and dye absorption/stability. ALUMAL Cold Seal technology provides the maximum protection qualities and corrosion resistance for sulfuric anodized coatings. The oxide layer benefits from the sealing process after formation or after colouring. This specific type of hydration of the oxide pores helps with stain and corrosion resistance. Due to higher energy costs of higher temperature sealing, 75-85 OC for mid temperature and 100 OC for traditional hot seals, the cold sealing at room temperature is favoured and allows all the proper chemical reactions to take place for improving anodize layer performance. Sealing at room temperature also helps better stability of colouring or dye processing and offers improved colour fade resistance over conventional high temperature or mid temperature sealing processes.

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