The surface of the glass is slightly rough at the initial stage of moldy. Although the mold is not
visible to the naked eye, the glass is more difficult to clean and easy to stain. Then there will be
small spots, flakes, filaments and misty spots will appear gradually.
Moreover the rainbows will appear and the hand feel is rough, the smoothness and transparency
of the glass are significantly reduced.
Glass surface weathering process:
Weathering of the glass surface first manifests itself as the glass surface reacts with moisture
in the atmosphere.
The result of the reaction makes the glass surface alkaline and produces tiny spots/spots on
the glass surface, also known as alkali evolution.
Research has shown that: when the PH value of the glass surface is greater than 9, the alkali
starts to attack and dissolve the basic silicate network.
The reaction formula is as follows SiO ₂ + 4 N a O H = N a ₄ S i O ₄ + 2 H ₂ O
The process of this reaction caused the glass network structure to be eroded and damaged,
causing the glass to produce roughness, rainbows, and a drop in transmittance.
