Abstract: A method for forming a layered composite (62) uses extrusion apparatus including a coextrusion structure (226) and a partition member (228). The relative orientation of first and second flow streams are reoriented within the extrusion apparatus and melt laminated to form the layered composite (62). The reorientation occurs via a flow sequencer (250). The coextrusion structure (226) may also include one or more removably disposed, flow-shaping inserts (206, 207, 208, 209), and the partition member (228) may be a removably disposed partition plate.

Abstract: A method and apparatus for the extrusion of multilayered composite products, is provided. In accordance with the inventive method, the relative orientation of a first shaped flow stream and a second shaped flow stream to one another is changed, and the reoriented shaped streams are melt-laminated to produce a layered composite formed independent of division of a layered precursor stream. Beneficially, layered flow streams that differ from one another may be used. Differences in volumetric or mass flow rates may also be used to advantage. The inventive apparatus includes a coextrusion structure and a partition member. The coextrusion structure may advantageously include one or more removably disposed, flow-shaping inserts, and the partition member may be a removably disposed, partition plate. The inventive apparatus beneficially further includes a removably disposed flow sequencer for changing the relative orientation of the flow streams.

Abstract: An extrusion apparatus including a die and a combining adaptor is provided. The combining adaptor is inserted in a cavity in the die. The extrusion apparatus includes flow channels, which converge in the proximity of a locus at which a layered melt stream formed by the convergence, is caused to diverge and flow transversely. The locus of divergence is within a manifold. As a result, the apparatus makes a laminate having layers of substantially uniform thickness without profiling of the layered melt stream. Also provided is a process for making the laminate without profiling. The invention lessens the curtaining effect in the layers of the laminate formed.

Abstract: A multimanifold extrusion die that minimizes or eliminates the curtaining effect is provided. This die furthermore also provides for convergence of molten thermoplastic streams at substantially equal flow velocities without external adjustment of the die. More specifically, this die has a self-balancing feature that is responsive to a flow rate differential. Also provided by this invention is a process for minimizing or eliminating the curtaining effect in the melt-lamination of thermoplastic materials.

Abstract: An extrusion method for the formation of multi-layer laminates of thermoplastic materials comprising introducing melts of thermoplastic materials into separate feed channels and then into back pressure cavities of greater cross-section than the feed channels where transverse flow occurs under conditions of heat and pressure so as to stress-relief the molten thermoplastic materials, release strain therein and provide equal pressure distribution, passing the resulting thermoplastic materials into elongated flow restriction channels of smaller cross section then the back pressure cavities with the material exerting equal pressures along the length of the elongated flow restriction channel and converging the materials into a melt laminate at the exit end of the flow restriction channels. Also provided is an apparatus for conducting the method.

Abstract: An extrusion method for the formation of multi-layer laminates of thermoplastic materials comprising introducing melts of thermoplastic materials into separate feed channels and then into back pressure cavities of greater cross-section than the feed channels where transverse flow occurs under conditions of heat and pressure so as to stress-relief the molten thermoplastic materials, release strain therein and provide equal pressure distribution, passing the resulting thermoplastic materials into elongated flow restriction channels of smaller cross section than the back pressure cavities with the material exerting equal pressures along the length of the elongated flow restriction channel and converging the materials into a melt laminate at the exit end of the flow restriction channels. Also provided is an apparatus for conducting the method.