Fibre reinforced polymer matrix composite pipes

Abstract

A method of manufacturing a fluid impermeable rigid composite pipe () or hollow tube comprising the steps of:—a. providing a supporting mandrel () that is shaped to define a bore of the pipe (); b. laying onto the outer circumferential surface of the mandrel () one or more first tapes () made of a thermoplastic material thereby to create a first region () that is predominantly thermoplastic material adjacent the bore of the pipe (); c. providing a plurality of tows () that comprise co-mingled reinforcing fibers and thermoplastic filaments; d. weaving a plurality of the tows () to form one or more circular braids () and laying down the one or more of the circular braids () on to the first layer (): to form a second region (); e. applying to the outer surface of the second region () a heat-shrinkable layer (); f. heating the product of steps (b) to (e) on the mandrel () to a first temperature at which the thermoplastic materials of the one or more tapesand the towsmelt and the heat-shrinkable layershrinks radially inwards to consolidate the melted thermoplastic material to form a thermoplastic matrix in which the reinforcing fibers are embedded and a fluid impermeable thermoplastic rich region () is formed at the bore of the pipe (); and, g. allowing the pipe () to cool to form a self supporting pipe ().