Methods and systems for forming composite parts

A method for forming composite parts, the method comprising the steps of:

• loading an uncured composite material into a middle cavity of a chamber between an upper membrane and a lower membrane, wherein a lower cavity is defined below the lower membrane, and wherein an upper cavity is defined above the upper membrane, wherein a forming tool is disposed within the upper cavity;
• applying a vacuum to the upper cavity, the middle cavity, and the lower cavity to remove at least a portion of gas entrapped within the uncured composite material;
• releasing the vacuum from the upper cavity and the lower cavity while maintaining the vacuum in the middle cavity;
• heating the chamber to a forming temperature of the uncured composite material to yield a heated composite material;
• after releasing the vacuum from the upper cavity and the lower cavity, controlling pressure in the upper cavity and the lower cavity to form the heated composite material, wherein a greater pressure is applied to the lower cavity than to the upper cavity such that a pressure differential between the lower cavity and the upper cavity causes the heated composite material to form around the forming tool;
• and
• heating the chamber to a curing temperature to cure the heated composite material, thereby yielding a cured composite material.