Thermoplastic composite access cover manufactured by co-consolidation after thermoforming stiffers

This paper reported an integrated manufacturing process of one thennoplastic composite airplane access cover with L-shaped stiffers of poly( ether ether ketone )(PEEK) matrix carbon fiber reinforced composites. The used flexible prepreg fabric was cowoven with carbon fiber and PEEK fiber. It was found that the stiffer margins were not well consolidated by directly press forming after laying up the designed number of fabric in mold though the cross round part was smoothly consolidated. However, a matched-die press thennofonning from the prefonned blank solved the problem while the cross round part was easily delaminated. The L-shaped stiffers were then fixed in upper molds with their lower surface close to the multiple fabric for cover flat part and finally bonded to such post-fonned part during consolidation. In fact, the stiffers were melted again but their shape was remained because there was less enough flow under small pressure in them. Therefore, the process referred to co-consolidation. This way overcame the common problems by direct welding. The bad stickability of the dry prepreg for curved part was not met in thennofonning. The fabrication cost could drop dramatically in large volume production. In all, thennofonning and co-consolidation were perspective in fabricating aerospace composites 3-D structural parts.