A study on improving the mechanical properties of composites prepared from flax polypropylene needlepunched nonwovens

Abstract

Fibre reinforced composites are currently used in various applications such as aircraft automobiles pipelines lightweight structures and sporting goods Meanwhile nonwoven fabrics made with natural and thermoplastic fibres have been extensively used in the composite industry due to their intrinsic low processing costs and acceptable mechanical properties A strong interface between the fibre and matrix produces high strength and stiffness but such structures are brittle in nature and also have easy crack propagation Poor interfacial bonding results in structures which are prone to delamination The performance of fibre reinforced composites depends on the interfacial strength between the fibre and matrix Many attempts were made to improve the mechanical properties of thermoplastic composites by modification in weaving knitting and braiding structures using commingled fibre or yarn Powder impregnated materials where impregnation occurs during final forming is also gaining significant interest At the same time the final composite properties are highly dependent on the processing conditions such as moulding temperature cooling rate holding time temperature and the annealing conditions newline