Non-autoclave processing of advanced composite repairs

Historically, the repair of 180°C (350°F) curing carbon fiber reinforced plastic (CFRP) laminates has required the use of an autoclave during the cure process to produce acceptable void-free laminates. A common technique for repairing 180°C (350°F) CFRP laminates without an autoclave is to use a 121 °C (250°F) CFRP material or a wet lay-up. These repair laminates produce comparable RT/dry test results, although under the hot/wet condition there is a reduction in the laminate strength. Current high-pressure autoclave cure techniques work by pushing most of the entrapped air out of the laminate while compressing the remaining pockets of air into very small sizes. Using vacuum and ambient atmospheric pressure there is not enough pressure differential to squeeze out the entrapped air or compress the remaining pockets to small acceptable sizes. The double vacuum bagging technique produces a temporary degassing chamber over the repair laminate. A research program was established to develop a repair process that produces an autoclave quality laminate without the use of an autoclave. When combined with the C-staging of the repair laminate, the repair adaptation of the double vacuum bagging process is very promising. © 1999 Elsevier Science Ltd. All rights reserved.