GB1437323A - Milled detergent bars striped in a controlled pattern - Google Patents

Abstract

1437323 Extruding striped soap PROCTER & GAMBLE Ltd 10 Aug 1973 [11 Aug 1972] 37561/72 Heading B5A A soap or synthetic detergent bar is extruded with a stripe, or stripes, of a distinctive colour or colours, by injection of an aqueous solution or dispersion of the colourant into the soap at a location or locations in a tapering chamber 7, upstream of the outlet from which the soap is extruded. The colourant is injected from one or more injection nozzles 13 which are connected, by a pipe 12 through which the colourant is delivered, to a stainless steel plate 6 at the inlet to the chamber 7 and which comprises either a plurality of openings 16 through which the soap is delivered Figs. 3 and 4 (not shown), or a plurality of radially extending webs, Fig. 5 (not shown). The supply pipe 12 is aligned along the flow lines of the soap, and the upstream end of the nozzle 13 is at a distance "D" from the plate 6 of at least twice the width of imperforate regions of the plate 6, to be out of the region of eddy currents in the soap flowing from the plate 6. The cross-sectional diameter of the nozzle 13 is at least twice that of its supply pipe 12 to generate a high static pressure in the soap passing across the nozzle 13 and thereby prevent upstream flow of the colourant. A spring loaded run-return valve is included in the nozzle 13, which also has a perforated, sintered metal, or mesh outlet 14. The chamber 7 includes a perforated plate or mesh 15 functioning to mix the colourant into the soap. The colourant is delivered to the nozzle by a metering pump, the output of which is automatically related to the extrusion rate and pressure of the soap. The soap with which the colourant is injected may be transparent, white, or a pale non-white colour, and the example relates to a titanium dioxide soap composition into which is injected eight green stripes. By using vanes within the tapering chamber 7, spiralling stripes can be produced. The outer layer of the extruded bar may be removed by skimming. The soap is extruded by a worm 5a, to which it is delivered from a further extruder, via a perforated outlet, at which it is cut by a rotating knife to fall through a vacuum chamber on to the worm 5a. The bar extruding from outlet 8 is cut transversely by a knife.