Case Study: Gob Loading in a Glass Moulding Machine

Abstract

In the industrial production of container glass, it is essential to maintain constant parameters in the forming process. Above all, the delivery of the 1150°C hot glass gob and its loading into the mould is a critical procedure. On machines used today with up to 12 forming sections the current delivery system is reaching its limit. The objective of this work is solving the contradiction – improving gob loading, i.e. temperature constancy, homogeneity, and speed without altering the machine setup – by using the TRIZ method. The result, a modified path of the movement with the trajectory of a clothoid, has been derived theoretically, put into practice, and tested experimentally. Assessment of the new trajectory has been performed by measuring the gob velocity and by recording the gob fall with a high speed camera. By means of the newly designed trajectory, wear of the delivery channel has been reduced. The variation in travelling speed of the gob on its way through the delivery system has also been able to be reduced. Furthermore, the gob loading into the mould has been improved as well. The gob remains standing vertically in the mould and will not tip off to one side. The result of this measure does not only increase the service life, but also improves the quality produced.