Apparatus and method for coinjection of a multilayer molded article with a segmented internal layer

A method of coinjection molding a multilayer article having a multi-segment internal layer, comprising:

• injecting a surface layer material into a mold cavity from at least one of an inner outlet and an outer outlet of a multi-channel nozzle;
• and
• intermittently injecting an internal layer material into the mold cavity from an intermediate outlet of the multi-channel nozzle such that the internal layer material is entirely encapsulated by the surface layer material, the intermediate outlet being between the inner and outer outlets of the multi-channel nozzle,
• wherein the injecting of the surface layer material into the mold cavity comprises:
• before the intermittent injecting of the internal layer material, injecting the surface layer material into the mold cavity from both of the inner outlet and the outer outlet of the multi-channel nozzle with the intermediate outlet in an open state;
• and
• throughout the intermittent injecting of the internal layer material, injecting the surface layer material into the mold cavity from only the outer outlet of the multi-channel nozzle with the inner outlet in a closed state, and
• wherein the intermittent injecting of the internal layer material is controlled, at least in part, by intermittent opening and closing of the intermediate outlet, and
• wherein the intermittent injecting of the internal layer material comprises:
• closing the intermediate outlet;
• pre-compressing the internal layer material in the multi-channel nozzle by activating an injection unit upstream of the intermediate outlet while the intermediate outlet is closed;
• and then
• forming each of a plurality of internal layer segments of the multilayer article by:
• opening the intermediate outlet of the multi-channel nozzle to release a stream of internal layer material with injection by activating the injection unit upstream of the intermediate outlet when the intermediate outlet opens for injection;
• and then
• closing the intermediate outlet of the multi-channel nozzle to terminate the stream of the internal layer material with suspending injection by the injection unit upstream of the intermediate outlet when the intermediate outlet has closed.