The stretch blow moulding process is used to produce PET bottles. In this process so called preforms are produced by injection moulding, which are then stretched axially and radially. This is possible because of the biaxially orientation of the macromolecules within the plastic. The characteristic of the stretch blown bottles is the gate mark of the perform shown at the bottle bottom whereas extruded bottles show pinch- off welds.
Within the stretch blow moulding process we differ in single-stage blow moulding and two-stage blow moulding. In the single-stage process the perform is blown within the same machine. Therefore is it possible to realize complex geometries and high surface quality.
The two-step process is typically uses in mass production (e.g. drink bottles). The perform is produced with special injection moulding machines and then reheated and blown in the blow moulding machine in an additional step. Here it is possible to achieve short cycle times and therefore higher output rates.
We have chosen the two-step process and work with small, flexible linear machines. Therfore we can combine short cycle times and high output rates with small quantities and customer oriented production.