GLASS CONDITIONING BY VISCOSITY CONTROL

During the forming profess of a glass melt the viscosity is the domina nt process parameter. Up to now in the industrial container glass prod uction only temperature-controlled systems have been used. With these control elements only thermally induced variations of the viscosity ar e visible. Variations in the composition, the redox state, the water a nd the SO3 content in the melting process cause a shift in the viscosi ty. Up to now these changes have not been detectable and therefore, it has not been possible to compensate them. A measuring device for the continuous determination of the viscosity in the glass was developed a nd tested for several months in a container glass plant. AU measured v ariations of the viscosity can now be corrected by the existing contro l elements for the thermally controlled glass conditioning. Dependent on the position of the viscosimeter in the feeder channel, a feedforwa rd or feedback controlling concept is practicable.