Dual constituent container and fabrication process

A process for forming a container with a compartment and an inwardly projecting recess isolated from the compartment, including:

• providing a plurality of mold sections including a selected mold section with an elongate recess shaping feature;
• assembling the mold sections into a mold in which the recess shaping feature projects longitudinally into a mold cavity of the mold, wherein the recess shaping feature has an outer surface and includes at least one channel along the outer surface, the channel having a predetermined channel width and being recessed inwardly from the outer surface to an inner surface of the channel by at least a predetermined channel depth;
• forming an annular gap between the selected mold section and at least one remaining mold section forming the mold, and the at least one channel having an end region in fluid communication with the annular gap;
• mounting a thermoplastic preform to the mold such that an expandable part of the preform projects into the mold cavity;
• with the preform so mounted and with the expandable part heated to a processing temperature above a glass transition temperature of the preform, introducing a fluid under pressure into the preform to cause the expandable part of the preform to undergo a plastic expansion into surface contact with a cavity wall of the mold cavity and with the outer surface of the recess shaping feature to form an expanded container structure;
• cooling the container structure to a temperature below the glass transition temperature to solidify the container structure;
• after cooling the container structure, supplying a fluid under pressure via the at least one channel to an interface between the container and the shaping feature while simultaneously moving the selected mold section longitudinally relative to the container structure to separate the shaping feature from the container structure;
• and
• removing the container structure from the mold cavity.