The product line of inorganic iron pigments Bayferrox C offers 5 basic color shades – yellow, orange, red, brown and black. A wide range of final colors can be mixed from these shades. These are compacted, compact pigments in which standard powder is pressed into irregularly shaped granules offering color consistency and high tinting power. Pigments do not have a negative effect on the properties of wet or dry concrete, including setting time and compressive strength. This modern form was specially designed for coloring cement and concrete materials.
Bayferrox C is a cost-effective, low-dust, free-flowing pigment that can be easily and accurately dosed in all applications where pigment powders are traditionally used, including dry mixes such as mortars and grouts. The chemical structure of the pigment makes it insoluble under normal conditions and resistant to chemical and weathering.
Care must be taken to ensure that the granules are processed in a sufficiently dry state. If the polymer melt has too high a moisture content, it can result in surface defects (silvering) and degraded properties of the molded parts (hydrolytic degradation). The permitted residual moisture content is 0.01%. The recommended drying conditions are as follows – drying temperature between 100 and 110 °C and drying time: 4 to 12 hours with a dryer using air circulation, 2 to 4 hours with a dryer with fresh air and 2 to 4 hours with a dryer using dry air.
The values given for mold and melt temperatures apply to all injection types (except special products). The melt temperature for products with a higher flowability is usually chosen at the lower end of the range, and the melt temperature for materials with a lower flowability then at the upper end of the range. Long residence times in the plasticizing cylinder, which are caused by long cycle times or insufficient batch volume utilization, require a reduction in melt temperature to prevent thermal degradation. The melt temperature during injection is in the range of 250 to 270 °C for PC+PBT mixtures and 260 to 280 °C for PC+PET mixtures. The recommended mold temperature is then 60 to 80 °C.
