VISION-LITE® / VISION-LITE II®
PROCESSING GUIDELINES
MAY 2022
15
3.6. TEMPERING / HEAT-STRENGTHENING
•
Drying:
• Use an air-blowing installation equipped with filters
• Clean and regularly maintained filters;
•
Water should be sprayed directly onto the glass, not onto the brushes (as per below drawing;
•
The glass sheet does not stop inside the washing machine. The washed panes should not remain in
the washing unit for any length of time, especially not while the brushes are rotating;
•
No water must remain on the coated surface after the drying process;
It is strongly recommended that the washing machine is regularly cleaned, especially for the brushes
and in areas where demineralised water is used. Clean the filters every day, and the tanks every week.
For the brushes, steam cleaning gives good results, but do not spray the bristles with high temperature
and high pressure water.
•
In case dirt / stains are still present on the coating after the washer, cleaning may be performed
using a soft cloth and isopropanol (IPA) or ethanol followed by rapid drying, provided this is done
carefully and immediately after contamination has occurred.
•
For interim stacking of washed panes, use cork pads near the edge of the sheets.
•
In case, in a further step, for VISION-LITE® or VISION-LITE® II, it is of the highest importance that no
residues or marks are left on the coating surface after the exit of the pre-processing washing machine.
For instance, pollutions left on the coating may induce at tempering hot corrosion (giving the aspect of
pinholes) of the coating. Such marks may not be washable. Also, even in case of annealed version, there
is a risk that residues will be not eliminated during final washing.
VISION-LITE® II (and only the ‘to be tempered’ version) can be heat-treated to get a tempered / heat-
strengthened coated glass.
The cleanliness of VISION-LITE® II coating before entering the tempering furnace is important.
From
the exit of the washer to the entrance of the tempering furnace, only the use of perfectly clean gloves
should be permitted. The coating may be gently cleaned with isopropanol (IPA) on the furnace entry
bed to remove dirt or marks (from gloves, separators, fingerprints…).
Special care and attention must be taken at every stage of processing, in particular before and during
the toughening process. Please consult your local TSM if necessary. Washed panes should be toughened
maximum 2 days after washing.
Generally speaking, VISION-LITE® II can be toughened using oven settings that are suitablefor standard
clear glass. The exact settings being of course furnace dependent cannot be given in these guidelines.
However, it is recommended that the sheets should be handled as “cold” as possible to achieve a flawless
coating after toughening and obtain the desired level of stress (breaking pattern). This means that the
temperatures and heating times are set so as just to avoid breakage in the blower box and to meet the
requirements for single-sheet safety glass.
3.6.1. General
3.6.2. Prerequisites for tempering / heat-strengthening
3.6.3. Toughening instructions
