Abstract: This invention is concerned with printing colored images on paper. More particularly, it is concerned with an improved method for preparing a set of engraved cylinders suitable for the reproduction of colored images on a web-fed gravure press.

Abstract: A washbox comprising a vessel divided into a stratification compartment and an adjacent reject compartment, a perforate grid plate extending across upper parts of the compartments. First pulsation means activates the water in the stratification compartment, and second pulsation means activates the water in the reject compartment separately and in isolation from the stratification compartment. A divider is mounted above the part of the grid plate which extends over the reject compartment, an upper surface of the divider defining a first outlet channel by which material of a lower density may pass from the washbox, whilst a lower surface of the divider, together with the said part of the grid plate which extends over the reject compartment, defines a second outlet channel along which material of higher density may pass from the washbox.

Abstract: A wash box for separating materials produced in, for example a mining operation, into fractions of different densities. The machine is divided vertically into compartments, including at least one stratification compartment and at least one reject compartment, the raw material being delivered onto the grid, the level of water in the compartments being higher than the grid. Vertical pulsations are applied to the water in the compartments, causing the water to travel through the perforations of the grid. The pulsations applied to the stratification compartment are effective to stratify the material on the grid, movement of the water through the wash-box tending to carry the lighter fraction from the wash-box while the pulsations applied to the reject compartment determine the rate at which the heavier fraction reject material falls from the grid plate into a reject extraction chamber adjacent to the reject compartment.

Abstract: A wash box for separating materials produced in, for example, a mining operation, into fractions of different densities. The machine is divided vertically into compartments, including at least one stratification compartment and at least one reject compartment, the raw material being delivered onto the grid, the level of water in the compartments being higher than the grid. Vertical pulsations are applied to the water in the compartments, causing the water to travel through the perforations of the grid, to stratify the material on the grid, while movement of the water through the wash box tends to carry the lighter fraction from the wash box.