Alignment of long reinforcing fibres in non=axial direction in tubular thermoplastic prods. - uses tubular tool with concentric rotor forming flow channel in which shear stresses between tubular tool and rotor effect radial alignment of fibres

摘要

A process for aligning glass or carbon reinforcing fibres in a non-axial direction in thermoplastic tubular products, esp. a hose, a pipe or a hollow shaft involves forcing the polymer matrix and fibres through a tool with an annular channel and rotating a rotor concentrically in the channel to effect both axial and rotational flow which tends to align the fibres in a radial rather than an axial direction. Equipment for prodn. of the tubular prod. comprises a tubular tool with a concentric rotor having no vanes and an external drive. Alternative claimed variations of the tool include: a) a similar externally powered tool having a rotor with axially aligned vanes; b) a similar arrangement to a), except that the rotor has vanes at an angle to the tool axis; c) a tubular tool with no external drive for the rotor, which is a low friction element powered by the shear stress of the flowing polymer and has vanes at an angle to the tool axis.