Powders dosing for dyeing

The powder colourants are stored in transparent tanks which base supports the variable speed dosing screw: the overall structure is tunnel shaped in modules, each one sporting 8 tanks on both sides while in centerlane the digital scale moves on its robotized carriage. Free access is then granted on both sides of the tunnel, either for independent vacuum powder refill through absolute filters, and for maintenance: slide mounted, each tank can be extracted without lifters, and any active part is at reach. Reproducible dispenses require constant humidity, therefore each tank has dry air fluidizing beds timedly activated; the airtight screw outlet is aimed upwards in order to pour the granules exactly in centerline of final tub. The workshop health is granted by individual air suction either from dispensing screws and from powder tanks probes, then a wet cell scrubber exhausts to atmosphere. An important complement is the automatic dilution station, with addition of water and auxiliaries: time and temperature of   mixing are variables embedded in the formula. The liquor is then pumped directly in the vessel of the demanding dyeing machine: special three-ways valves, pressurized to prevent contamination, select the final destination machine/vessel. At the end of transfer the piping is purged first in the vessel with water, then in the drain with water and bleaching agents.