Apparatus for producing multicolor patterns and sheet material produced thereby

Claim 1

An extrusion assembly for fabricating synthetic plastic sheet material having differentially colored bands therein extending along the length thereof and comprising: a. an extrusion die block having a chamber therein generally of streamlined non-circular cross section, an elongated extrusion orifice in one surface thereof and a discharge passage between the said chamber and said orifice, said chamber having an enlarged intermediate portion of generally curvilinear configuration extending beyond both sides of the discharge passage and streamlined surfaces tapering from said enlarged portion to said discharge passage; b. a first feed conduit to said chamber at a point spaced to the opposite side thereof from said discharge passage for supplying a matrix of fluid synthetic thermoplastic resin; c. at least one additional feed conduit to said chamber having a portion within said die member extending generally parallel to said extrusion orifice for supplying a differentially colored fluid synthetic thermoplastic resin; d. a pair of sleeve members in said chamber extending generally parallel to said extrusion orifice, said sleeve members having streamlined non-circular outer surfaces extending in spaced relationship to the surfaces of said enlarged intermediate portion and being spaced apart to provide a passage therebetween, said sleeve members each having a feed bore therein communicating with said additional feed conduit and a main bore spaced therefrom towards said discharge passage, each sleeve having a flow passage between said feed bore and main bore and a multiplicity of discharge openings extending from said main bore to the outer surface thereof adjacent said discharge passage, said sleeves having pressure compensating means therein to provide substantially uniform flow of resin over the length of said feed and main bores; e. distributor elements seated in said main bores of said sleeves providing intermittent flow of differently colored fluid synthetic thermoplastic resin through said multiplicity of discharge openings; f. means for driving said distributor elements to provide intermittent flow; and g. a flow diverter member in said chamber adjacent said discharge passage and having trailing surfaces extending in spaced relationship to the surfaces of said sleeves adjacent said discharge openings of said sleeves with projecting portions at said discharge openings to direct flow of matrix resin towards said discharge openings and leading surfaces converging towards said discharge passage and spaced from said streamlined surfaces of said chamber to provide passages therebetween, whereby matrix fluid synthetic plastic resin entering through said first conduit into the upstream end of said die chamber is caused to flow about and between said sleeve members as a differentially colored fluid synthetic plastic resin being fed through said additional conduit to at least one of said feed bores is intermittently discharged through said discharge openings of said sleeve member and wiped therefrom by the matrix resin to produce encapsulation of the discharged synthetic plastic resin from said sleeve members in the matrix resin flowing thereabout.