Abstract In order to be suitable for food processing application, besides having the usual characteristics as high adhesion, high cohesion, high compactness and maximum hardness and wear resistance, the thermal spray coating should not release foreign substances, as prescribed by the international standards. This paper defines a very strict procedure according to valid EC and FDA standards in order to test the compatibility of the coating with the food. It discusses the applicability of this test method, in which a contact is created between a food-simulating solvent and the thermally sprayed coating to be analyzed. The inert nature of the drawn migration cell, the adopted time-temperature conditions and the characterization of the coating before and after the migration test are discussed. Paper includes a German-language abstract.

Abstract Zirconia and Hydroxyapatite obtained by means of Plasma Spray deposition process are candidate coating materials for use in advanced industrial applications as in wear resistance and thermal barrier coatings and biomedical applications respectively. This paper deals with the test methodology for the analysis or evaluation of some physical and mechanical properties of zirconium oxide and hydroxyapatite coatings that have been applied by vacuum plasma spraying. Results of quantitative tests are presented based on the measurement of thickness, coating/substrate interface condition, porosity, coating microstructure, surface topography and microhardness. The main phases of the experiments, the choice of instruments and their application domain, the test methodology and procedure, specimen preparation and test conditions are discussed as applied to test cases. Paper includes a German-language abstract.

Abstract The paper discusses the testing methodology and identifies the analytical protocols, with proper validation, in order to evaluate the compatibility of thermal spray coatings in the food production technology, according to EU and FDA applicable standards. A brief state-of-the-art analysis of the international standards on food additives and human health is given, namely on indirect food additives (as defined in 21 CFR 170.3(e)), that can migrate into the food during the process. An outline of the test protocols, based on contact between coating and food simulating solvents in a set time/temperature conditions, are presented, and the main phases for the proposed testing methodology, as the choice of the simulating solvent, the migration cell design and the time/temperature conditions, are discussed. Finally the proposed methodology and protocols are validated through a thermal spray coating for food process application test case.