Untersuchungen zum Flammspritzen von Polyethylen fuer den Korrosionsschutz

The aim of this dissertation consisted in the investigation of the flame-sprayed layers and their suitability to protect pipe joints under building site conditions against corrosion. Furthermore, a technical equipment had to set up to ensure a reproducible coating process. Therefore, a device has been assembled that allows programmed coating sequences of sheets and pipe parts. An external powder feeder was constructed to transport the polymer powder to the spray gun for a stable and adjustable feeding process as well. In coordination with the feeding rate, the coating velocity and the number of single coating steps, the layer thickness can be varied. The mechanical investigation of sprayed layers revealed that lower tension strengths will be obtained compared to the non-sprayed material. Besides, a general impairment of the properties was measured, such as the decrease of the elongation after break and the raise of the young's modulus. Voids and interfaces between embedded particles within the layer as well as a higher surface roughness have been seen as the cause of these effects. Yet, comparisons between sprayed and non-sprayed sintered layers have shown that for equal void contents still different mechanical properties were measured. (orig.)Available from: http://www.deposit.ddb.de/cgi-bin/dokserv / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman