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. It is free of CMR substances. Process meets Qualanod requirements and can be applied on clear as well as coloured aluminium alloys.  Improves sealing quality and prevents sealing smut from formation on surfaces of parts.

Features & Benefits  

  • Overall improved product where systems utilize deionized water
  • Improved ADT results
  • Less water marks/finger printing
  • Eco-Friendly – free from Nickel, Cobalt and all other CMR substances
  • Acts as a buffer which reduces the number of pH adjustments required
  • Long solution bath life – can be further extended with continuous filtration
  • 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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