Abstract: A method for the production of multi-color striped pieces of soap by continuously extruding two strands of colored soap, passing said two strands of colored soap through a die orifice whereby a single strand of parallel stripes is formed having a varied colored aspect in cross-section, passing said single strand through a static mixer having a different configuration from said die orifice, cutting said strand and recovering multi-color striped pieces of soap, as well as the apparatus.

Abstract: A single extruder provided with a hopper at one end and a restricted nozzle at the opposite end and two press-screws arranged coaxially in one another within an outer jacket, each of said screws being provided with a male thread for feeding in the direction of said nozzle, said male threads extending into an outer annular space between said jacket and the outer press-screw and extending into an inner annular space between said two press-screws, said threads being oppositely oriented, means to rotate the outer of said press-screws and means maintaining the inner of said two press-screws stationary, said outer press-screw being provided with window-like openings communicating with said inner press-screw in the area of said hopper and separate feed means in said hopper to separately feed to said outer annular space and to said inner annular space through said window-like openings, the improvement consisting in that a rotating mixing element is positioned between said nozzle and said press-screws and attached to

Abstract: A method for the production of two-color striped pieces of soap by continuously extruding two strands of colored soap, one strand encompassed by the other strand, passing said two strands of colored soap through a die orifice whereby a single strand of parallel strips is formed having a varied colored aspect in cross-section, cutting said strand and recovering two-color striped pieces of soap; as well as the apparatus and the soap pieces so produced.

Abstract: This invention relates to an improvement in an extruder with two press screws arranged coaxially in one another in an outer jacket and each carrying a screw thread for feeding various plastic materials, for example, granulated soap, to the press nozzle, where the outer screw is driven while the inner screw is stationary, and where the inner screw is in communication with the charging material in the area of the charging hopper through window-type openings in the outer screw. The said improvement involves a mixing element between the end of the press screws and the extrusion nozzle whereby the two strands being extruded are mixed.