Patent ID: 6554536
Filing Date: 2003-04-29
Classification: B29C,B29K,B29L,F16L

Abstract:
A method of manufacturing a sewer or tunnel lining section over a mould having a central section and side regions which provide guide surfaces, comprising:forming a fiberglass-resin layer over the central section of the mould; applying a sand-resin mixture over the fiberglass-resin layer to a thickness which results in the combined structure having a thickness greater than a preset minimum thickness; removing sand-resin material from the surface of the sand-resin layer using a wire arranged to extend between a pair of roller arrangements, the wire being mounted so as to lie a predetermined distance above the guide surfaces when the roller arrangements are passed over the guide surfaces, the wire thereby being arranged to lie a predetermined radial distance from the surface of the mould, the wire being passed around the surface of the sand-resin layer whilst maintaining the predetermined radial distance, the predetermined radial distance comprising, or being slightly greater than, the preset minimum thickness; and forming a second fiberglass-resin layer over the sand-resin layer.