Manufacture of marbled detergent bars

Abstract From the Canadian patent

A liquid component can be introduced into a detergent bar by injecting liquid within or immediately downstream of a multi-apertured plate positioned before the compression cone of an extruder. The method can be used to produce marbled bars with the aid of a coloured liquid and is described in UK 1387567. When a double extruder is used together with a common compression cone the injected liquid becomes unevenly distributed within the detergent. Even distribution of the liquid as striations is achieved by use of a partition in the cone to ensure each detergent stream is subjected to separate compression during movement down the cone.