Metal effect pigments

Metal effect pigments are luster pigments consisting of platelet-like metallic particles, mostly of aluminum (so-called silver bronzes), copper, copper/zinc (so-called gold bronzes), and zinc flakes. After parallel orientation in their application medium, they show a metal-like luster by reflection of light at the surface of the flat metal particles in one direction. Thus, the pigment particles act similar to small mirrors and lead when orientated parallel in the application system to a reflecting metal luster (metallic effect). Metal effect pigments are used in all relevant application systems such as coatings, paints, plastics, artist paints, cosmetics, printing inks, leather, construction materials, paper, glass, and ceramics. Specific composition, particle size distribution and surface quality determine the coloristic and application technical properties of the individual pigments. Many pigments are coated with a specific surface treatment to improve the quality concerning the stability and the compatibility with the application system. Metal effect pigments are offered in form of powders, pastes, pellets, suspensions or color concentrates. They are manufactured starting from a metal granulate (grit), which is ground under formation of flakes.

Metal Effect on Reliability of Balise Transmission System Antennas

In railway networks, metal objects near the balise transmission system can affect the performance of antennas in the system operating at 27.095 MHz and 4.23 MHz. In this paper, the performance of the antennas in the proximity of steel rails and metal plates are simulated and tested in terms of resonant frequency, magnetic field distribution. The results show that the metal effect is dependent on the distance between the metal and the antenna. They shift the resonant frequency and change the magnetic field distribution. In order to solve the problem, we find that the antennas should keep specified distance with the steel rails. Also, a metal plate is fixed on the back of on-board antenna unit to reduce the sensitivity to metal. These methods increase the robustness and reliability of balise transmission system antennas in railway signalling.