5. Conclusion

Immersing a glass part in a satin-finishing solution based on hydrofluoric acid and bifluorinated alkali salts leads to the formation of a semi-passivating layer on the glass surface. The reaction products of the hydrofluoric acid attack on the glass precipitate with the alkaline cations present in solution to form this layer. Its main components are potassium or ammonium hexafluorosilicates, depending on the nature of the bifluorinated salt introduced. The layer's passivating nature and the way it is formed, first appearing at isolated points and then extending to the entire surface, enable microscopic pyramids to be obtained, responsible for the satin appearance. Depending on the nature of the products making up the passivation layer, the size and geometry of the pyramids are different, enabling original satin finishes to be obtained. Particular satin finishes can also be obtained by adding...