|  A carbon-containing additive is, as a rule, added to the bentonite-bonded moulding sand in order to minimise sand adhesion to the casting, to improve the casting surface, to combat the occurrence of casting defects and to optimise the properties of the moulding material. In the field of lustrous carbon formers, we can offer proven, sophisticated products that have been continuously improved and further developed on the basis of many years of experience and a programme of careful, multi-faceted research work that has been in place virtually since the company was founded in 1964. These additives produce brilliant results and have long delighted our customers around the world. Lustrous carbon formers are essentially organic in nature. They contain H - C compounds that volatilise under the effect of the casting temperature. The gas atmosphere thus produced is supersaturated with carbon and exerts a reducing effect. C supersaturation ultimately becomes so extensive that pyrolitic carbon in the form of lustrous carbon precipitates onto the mould surface. The degree of supersaturation in the mould atmosphere depends on the composition [Z] of the lustrous carbon former (C-H-O ratio), the carbon concentration [K] and the temperature [T] (LC =f[Z,K,T]). The precipitation of lustrous carbon onto the hot mould wall reduces the degree to which the wall can be wetted by the molten metal. The gases produced also influence the impact of the liquid metal against the mould material. They have a so-called “cushioning effect”. The presence of LC also improves moulding sand/casting release and the disintegration of the moulding material. The lustrous carbon former itself becomes plastic under the influence of the heat and numerous classic casting defects can thus be prevented by the presence of such carbon carriers, e.g.:
 Burnt-on sand
 Erosion
 Graphite degeneration
 Penetration
 Surface roughness
 Chemical reactions
Good reasons for using our LC formers include:
 Reduction in the wettability of the mould surface
 Absorption of compressive stresses within the mould during casting
 Reduced environmental burden through minimised emissions of organic crack products
 Maximum recyclability through improved sand release and separability and sand disintegration after casting
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