Shear controlled orientation technology for the management of reinforcing fibres in moulded and extruded composite materials

doi:10.1016/0924-0136(96)85104-1

Journal of Materials Processing Technology

Volume 56, Issues 1–4, January 1996, Pages 272-281

https://doi.org/10.1016/0924-0136(96)85104-1 Get rights and content

Abstract

The controlled application of macroscopic shears to solidifying melts containing alignable constituents provides for the management of fibres in, and the production of components to close tolerances. Shear controlled orientation technology (SCORTEC) may be applied to the thermoplastic and thermoset matrix composites, and to ceramic and metal matrix composites processed with the aid of sacrificial polymer binders. The principles of SCORTEC as applied to moulding and extrusion processes will be described, together with examples of typical property enhancement possible, and potential fields of application.

References (8)

P.S. Allan et al.
Development and application of multiple live-feed moulding for the management of fibres in moulded parts
Composites Manufacturing
(1990)
J.R. Gibson
The multiple live-feed moulding of DMC s
Composites Manufacturing
(1990)
P.S. Allan and M.J.Bevis, “Oriented Mouldings” Br.Pat....
P.S. Allan et al.
Multiple live-feed injection moulding

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Shear controlled orientation technology for the management of reinforcing fibres in moulded and extruded composite materials

Abstract

Composites Manufacturing

Composites Manufacturing

Multiple live-feed injection moulding