US Patent 7842209 Vacuum debulk and radiation cure method

To fabricate a composite item from a layup of composite material, the layup is degassed, debulked, and cured. To degas the layup, an envelope pressure within an envelope that includes the layup is reduced, a chamber pressure within a chamber that includes the envelope is reduced, and the layup is heated. To debulk the layup, the chamber pressure is increased relative to the envelope pressure so that the envelope exerts a compressive force upon the layup in response to the relatively higher chamber pressure as compared to the envelope pressure. To cure the layup, the layup is exposed to radiation.