Cleaning processes need to be adapted to the components PWIS cleanliness requirements to eliminate PWIS sources efficiently and economically. Every object needs to be examined for its properties, geometry and degree of contamination.

APO’s PWIS cleaning process is a combination of wet-chemical and low-pressure plasma processes. It provides optimal adjustment opportunities to pass subsequent lacquering compatibility tests.


Provided the components’ materials and condition allow for wet-chemical cleaning, the components’ surfaces are cleaned by means of appropriate processes.

Based on experience cleaning time and intensity as well as temperature and cleaning agents are adapted to each component and requirements. The wet-chemical cleaning processes serve as the basis for subsequent intensive low-pressure plasma cleaning.


The intensive cleaning of components with low-pressure plasma processes allows for the compliance with stringent PWIS requirements. Depending on the material, the low-pressure plasma cleans substances from the surface as well as from the inside of the components. It provides long-lasting cleaning effects without material damage, especially for elastomeric parts.

By means of modern low-pressure plasma technology, it is possible to minimize cleaning time and cost – without material strain or loss in cleanliness results.

It is worth the trouble to define PWIS compliances based on the actual application of the component when using adapted cleaning processes to reduce the costs to a minimum.


Depending on the different requirements, defined lacquering compatibility tests are carried out. Provided that the testing procedures are suitable for small mass produced parts, the tests generally can be undertaken at our facility. Such tests are described e.g. in PV 3.10.7 or VDMA 24364.