| 摘要 |
A method of coextruding a sheet or ribbon formed flow of extrudable material A with a sheet or ribbon formed flow of extrudable material B in a zone of joining in a coextrusion die (which term includes an adaptor upstream of the final product forming die) in which B is extruded on A through a port, and the two materials proceed together through a passageway towards an exit of the die, wherein the separation wall between said flows, immediately before it ends in a port, is formed as a flap closure adapted to act as non-return valve for the flow B onto A, wherein the extrusion of B through the port takes place in pulses. |
