A Microbiological Test Method to Determine the Cleanability of Filter Media in Solid‐Liquid‐Separation Applications

One of the major properties in the design and development of filter media for the food and drug industry is their cleanability. They should be designed according to hygienic criteria thereby decreasing residuals and reducing cleaning time and costs. A reproducible test method is necessary to determine or validate the degree of cleanability of filter media and to indicate areas of poor hygienic design. This work focused on the development of such a filter test and provides information about impurity, whether it occurs or not, and its local resolution. The growth of a microorganism, which is introduced as impurity, is used for the detection of residues which grow to the surface of the sample and offer a 2‐dimensional analysis. With this approach, different kinds of filter media can be compared with each other regarding their cleanability.