Linings for sewers
AssigneeChanneline Sewer Systems Limited
InventorGeoffrey Lewis Florence
Life of this patent
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Abstract
During manufacture of a sewer or tunnel lining section, sand-resin material is deposited over a mould, to define a central part of the section. Sand-resin material is removed using a wire arranged to lie a predetermined radial distance from the surface of the mould. The wire is 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 a preset minimum thickness. The use of a wire to remove excess sand-resin material has been found to be particularly effective, and surprisingly the excess material does not re-adhere to the underlying surface after the wire has passed. This is despite the required tackiness of the sand-resin mixture.
Claims7
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.
A method as claimed in 1 wherein each roller arrangement comprises a single roller, the wire extending between the two rollers along the axis of rotation of the two rollers.
Dependencies are inferred from the claim text.