Bottom forming process

A process for the preparation of a glass container from a glass tube, comprising the steps of:

• providing a glass tube with a first portion, a second portion, and a longitudinal axis (Ltube) that passes through a centre of the glass tube;
• holding the first portion in a first clamping chuck and the second portion in a second clamping chuck;
• rotating the glass tube around the longitudinal axis (Ltube) while the glass tube is held in the first and second clamping chucks;
• heating the glass tube, via at least one heater, between the first and second portions to a temperature above a glass transition temperature while the glass tube is rotating around the longitudinal axis (Ltube);
• separating the first and second portions from one another by pulling apart in a direction along the longitudinal axis (Ltube) while the heated glass tube is still rotating around the longitudinal axis (Ltube) by moving the first and second clamping chucks away from each other;
• and
• moving the at least one heater, while moving the first and second clamping chucks, along the longitudinal axis (Ltube) so that the at least one heater follows a mass remaining on a circular end region of the first and/or second portion while the glass tube is still rotating around the longitudinal axis (Ltube).