Overmolding PEEK onto PAEK laminate.

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Victrex, W. Conshohocken, Pa., announced new materials and process technology for hybrid thermoplastic composite molding of aerospace components. Victrex produces high-performance PEEK resin. It found that injection overmolding of a preconsolidated, PEEK laminate with more PEEK resin doesn’t work because the energy available from the melt is not sufficient to melt the laminate surface and ensure a good bond. The solution was Victrex’s development of a new PAEK resin to serve as the matrix for a continuous-fiber laminate that can be overmolded successfully with PEEK. Victrex PAEK has a lower processing temperature than PEEK and crystallizes quickly. Equally important, it has mechanical properties similar to PEEK.

Other elements of the hybrid composite process optimized by Victrex include preforming the consolidated laminate to the net shape, mounting the net shape in a mold, and injecting PEEK onto the surface. Benefits over previous methods include minimizing heat cycles for the laminate resin, ensuring that the laminate fiber structure does not change during overmolding, and eliminating post-mold trimming.

To demonstrate this new polymer and technique, Victrex worked with custom TP-composites molder Tri-Mack Plastics Manufacturing Corp., Bristol, R.I.,  to develop an aerospace bracket. It can be produced in minutes rather than the hours that would be required for a metal or thermoset equivalent, while saving up to 60% in weight.