Process investigation of a liquid PA-12/carbon fibre moulding system

A new RTM-type process has been developed to process complex geometry compo nents utilising a thermoplastic matrix. The matrix is an anionically polyme rised liquid PA-12 (APLC-12) system which may be injected into a fibre pref orm, with polymerisation occurring in-situ. The initially low melt viscosit y can be utilised to good effect for the impregnation of all types of compo site fabrics, yielding fibre volume fractions as high as 60%. Large, comple x-shaped components can be manufactured using low injection pressures. A me lt processing system was established and a test mould was constructed. Diff erent geometries were used to investigate the processing characteristics an d residual stress build-up effects of the unreinforced PA-12, composite pla tes and composite sandwiches. An industrial-scale dosing/mixing unit was al so designed and developed, and used to produce carbon-fibre/PA-12 laminates for measurement of mechanical properties. Mechanical properties were teste d and the results obtained were found to be comparable to those obtained fr om commingled carbon-fibre/PA-12 laminates. (C) 2001 Elsevier Science Ltd. All rights reserved.