Liquid paint systems are kept in ring lines in order to supply applicators of various types on the one hand constantly with paint and on the other hand to keep the paint material in motion.

The paint in the loop is mechanically stressed, for example by compression and relaxation or by promotion and dosage. The resulting shear can lead to a change in the complex composite paint system, which affects the technical and optical properties. This can mean that a complete loop has to be emptied - with a high economic damage for manufacturers and operators.