PROCEDIMENTO PER LA REALIZZAZIONE DI CORPI SAGOMATI CAVI DI VETRO,RIVESTITI INTERNAMENTE, E TUBO DI VETRO COME SEMILAVORATO PER LA

摘要

Numerous applications for hollow glass bodies made from low melting glass material require an increase in the chemical resistance of the interior surface of the glass body. In order to avoid a disadvantageous de-alkalizing process the hollow glass body must be provided with an interior coating in a comparatively expensive prior art process. In an improved process according to the invention a glass tube acting as a semifinished product from which the hollow glass body is made is provided with an interior coating of oxide material, preferably SiO2, Al2O3, TiO2 or mixtures thereof, having a predetermined coating thickness according to the required chemical resistance or working conditions for forming the glass body and then the hollow glass body is made from the glass tube. The coating is advantageously provided by means of a PICVD process.