2.4 Glass2019-05-03T12:07:16+02:00

2.4 Glass

Properties of glass:

  • High light transmission
  • Resistant to a wide range of chemicals
  • Very low thermal expansion
  • Maximum temperature of use: 400 – 750°C
  • Sensitive to mechanical loads/stresses

Special feature of glass:

  • On contact with aqueous liquids, commonly used window glass forms a gel layer which is no longer firmly attached to the underlying glass, although this is not perceptible to the human eye and touch.
  • For effective bonded joints, the gel layer must be either stabilised or removed by suitable surface treatment.

Special note for glass: The gel layer is not firmly attached to the base material, namely it must either be stabilised or removed by suitable surface treatment.

Surface treatment of glass:

  • Degreasing with solvents
  • Cleaning with aqueous cleaning agents or distilled water
  • Warm drying after cleaning or degreasing to prevent formation of a layer of condensation and hence new formation of a gel layer
  • Risk of microcrack formation on mechanical pretreatment
  • Stabilisation of the gel layer by using primers