Resin-infusion process for composites manufacturing

A resin-infusion system for manufacture of a composite part, the system comprising:

• an inflatable rigid bladder defining at least one infusion-flow pathway on an outer surface thereof;
• a preform lay-up formed on the bladder such that the infusion-flow pathway defines space between the bladder and preform lay-up;
• a mold into which the bladder and preform lay-up are placed such that the preform lay-up is constrained against the mold;
• and
• a resin injection system configured to feed resin into and to flow along the infusion-flow pathway and be infused into the preform lay-up;
• wherein the bladder is configured to expand during an expansion process against the infused preform lay-up during consolidation and curing such that the infusion-flow pathway is flattened against the preform layup due to the expansion of the bladder resulting in a smooth surface of the finished part and the pathway is reformed when pressure is evacuated from the bladder after inflation.