Anilox rolls are ink-metering rolls used in the printing industry to transfer an exact amount of ink to the printing cylinder. The importance of high quality anilox rolls has increased with the demand for higher quality printing. Improvements of the characteristics of anilox rolls have been achieved mainly by using laser-engraved, ceramic-coated rolls rather than the common chrome-plated and mechanically engraved rolls. The best results concerning the ceramic coating of anilox rolls were achieved by Cr 2 O 3 coatings. These coatings require a bond coat for good corrosion resistance. By far the most-used technology to produce this bond coat is high velocity oxygen fuel (HVOF) spraying using NiCr material. In order to lower the cost of the anilox roll coating it has been investigated if NiCr can be replaced by the chromium steel 316L as bondcoat material. 316L was applied to the surface by HVOF. The characteristics of 316L / Cr 2 O 3 layers were compared with respect to the required quality of the coating. The results were 316L / Cr 2 O 3 coatings with good mechanical characteristics compared to NiCr / Cr 2 O 3 layers. In particular, the metallographic sections showed compact coatings having a tensile adhesive strength slightly higher than and a corrosion resistance similar to the coatings with a NiCr bond coat.

This article gives an overview of thermal spraying of polymers with respect to the different spraying processes, the polymer materials in use for thermal spraying and new trends of using polymers as separate spraying material and in combination with plastic and non-plastic materials. Flame spraying is by far the most common process used for thermal spraying of plastic materials. In addition in the past years two other processes have been used to produce thermal sprayed plastic coatings: plasma spraying and high-velocity oxy fuel spraying (HVOF). The areas where the different processes are used as well as the modifications to conventional plasma and HVOF devices and the advantages and disadvantages using these two processes to produce plastic coatings will be described. In addition to the common materials used for flame spraying (e.g., PA 11, PA 12 or EVAL), other materials giving new opportunities of application of thermal sprayed coatings have been used like PEEK and LCPs. The areas where these materials are used are described as well as the special features of these materials. Furthermore there are new trends in using plastic materials for thermal spraying. Thermal sprayed polymer materials are for example combined with plastic as well as non-plastic materials or pigments giving special effects to the coatings, e.g, reflective or anti-skidding coatings. It is described how coatings with the mentioned effects can be produced.

The improvement of the tribologic characteristics of surfaces is an important application of thermal sprayed coatings. Also various ranges of application demand good antiadhesive characteristics. The tribologic and antiadhesive characteristics of fluorine containing polymers are very good. Since furthermore those polymers have the highest thermal resistance of all plastics it has been investigated if those polymers can be integrated in thermal sprayed oxide and carbide coatings. The aim was to improve the tribologic and antiadhesive characteristics. The processes Plasma- and HVOF-spraying have been used to apply the coatings. The polymers in the coatings were detected by examinations with the light-optical and the scanning electron microscope. To heighten the contrast for the light microscopy examinations the metallographic sections of the specimens were physically contrasted. To clearly identify the different phases with the scanning electron microscope EDX-analyses have been carried out. Samples have been tested to investigate the mechanical characteristics of the coatings. Paper text in German.