Liquid Colors - Slurry
The term (liquid colour) slurry initially refers to a suspension of pigment in water. A simple suspension becomes a stable dispersion by adding special additives such as wetting and dispersing agents, rheological agents as well as preservative agents.
Most of the inorganic pigments such as iron oxide, chrome oxide green, cobalt blue can be used for a slurry and thus can be converted into the form of a liquid colour. They are incorporated with the aid of appropriate dispersion equipment, as a dissolver for example. In the slurry, the mostly dry powder pigments in an agglomerate form are reduced to the primary particle size.
The formulation in combination with the additives used enables a high pigment content of usually 50 - 60 % obtaining stable coloristic and physical properties as well as sedimentation and storage stability. It is possible to mix a slurry of various inorganic pigments allowing any mixed shades to be provided ready for use.
The advantages of ready-made slurries as against powder pigments are a reduced dust emission and their good dosability.
Respective specifications are defined for every individual product in order to ensure a constantly good quality from consignment to consignment and thus in the application too. These specifications include colorimetric properties such as dE* and relative colour strength as well as physical properties such as viscosity, pH value, solid content and density.
The specification conformance of every single batch of the liquid colour manufactured is ensured by an internal quality control (certified according to DIN EN ISO 9001). Upon request, a batch-related certificate of conformity is issued based on these test results.
Main fields of application
The main field of application of the slurries is the colouring of cementitious systems such as concrete paving blocks, concrete planters, concrete roof tiles, etc. Inorganic pigments are exclusively used for these liquid colours ensuring a high resistance to alkali as well as light and weather fastness.
Packaging is available in plastic drums of various filling capacities, returnable containers (so-called UFO, MTC) and one-way containers (IBC). Delivery in road tankers is also possible.