Methods for making composite parts from stacked partially cured sublaminate units

• Main Author: Butler, Geoffrey A
• Format: Patent
• Language: English
• Published: 14.07.2020
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

A method of forming a composite article. One step involves applying adhesive on surfaces of a plurality of sublaminate units, each ply of each sublaminate unit comprising fibers impregnated with resin which has been initially cured to 30% to 50% of full cure. The initially cured sublaminate units are then arranged in a stack, which stack is pressed against a surface of a forming tool. While pressure is being applied, the stack is heated to an intermediate temperature above a glass transition temperature of the resin for a time interval sufficient to intermediately cure the resin to 50% to 70% of full cure to form a composite laminate having a contour defined by the surface of the forming tool. Then the resin is finally cured at a final temperature higher than the intermediate temperature.