Wall thickness distribution in drug press through blisters

Thin wall areas at Blister packaging (press through blister) reduce the stability of medicines. Following a preceding publication showing some first strategies to avoid those problems, latest research results from the IKV (Institute for plastic processing) at the Rhine-Westfalian Technical Highschool of Aachen (Germany) are displayed in this articel. A homogenous wall thickness over the entire capsule chamber enables the manufacturer in the end to use thinner starting foils without a lack of quality. This leads to the saving of raw material and other expenditures. For the examinations in this project foils with different thicknesses are used for transforming a complicated capsule chamber geometry. To gain a homogeneous wall thickness distribution is just one aim of the research project. An other is the reduction of blister warpage after punching. By using PP-foils with aluminium seal foils a strong warpage hinders the packaging of blisters into the cartboard boxes. Reject loss in the packaging machine is very expensive because there blisters are filled already with medical products. A model theory gives an insight into the problem of mechanical warpage in plastic products and how to reduce it.