| 摘要 |
1,220,950. Process and apparatus for the production of speckled particulate material. UNILEVER Ltd. 19 July, 1968 [21 July, 1967], No. 34529/68. Heading C5D. A process for the production of a speckled particulate material comprising spraying at least one colourant solution over at least a proportion of the upper surface of a layer of particulate material, so that the colourant solution colours only the particles of the particulate material located at and near the upper surface of the layer leaving the other particles in the layer uncoloured, and mixing the particles so coloured with the uncoloured particles in the particulate material. A belt conveyer 20 is used to support a layer 23 of particles fed from a hopper 21 on to the conveyer through a gate 22 which is adjustable to control the width and depth of the particle layer 23 on the conveyer 20. Sprays 24 of colourant solutions are then directed on to the upper surface of the particle layer 23 as it proceeds along the conveyer. After having been sprayed, the particle layer 23 continues undisturbed along the conveyer while the coloured particles loose excess solvent until they are no longer tacky. At the end of the conveyer the particles are discharged into a continuous mechanical mixer 26. The coloured particles are dispersed thereby throughout the uncoloured particles so as to form a speckled particulate material. |
