Cured In Place Pipe Liner
AssigneeLubrizol Advanced Materials, Inc.
InventorRobert J. Wiessner
Life of this patent
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Abstract
A liner for repairing damaged pipes, such as underground sewer or gas pipes is disclosed. The liner comprises a TPU coating on a fibrous mat of non-woven fabric. The TPU coating is a high heat resistance polyester TPU which allows an epoxy resin/amine to be saturated in the non-woven fabric and the cure initiated by the use of steam or hot water. The cured epoxy resin converts the liner from a flexible state to a rigid state as the liner is cured in place inside the pipe. The TPU containing liner may also be used with thermoset resins other than epoxy resins, such as polyester resins and vinyl ester resins.
Claims32
A cured in place liner for a passageway or pipe comprising:
- (a) a resin absorbent material layer;
- (b) a thermoset resin absorbed into said resin absorbent material layer;
- and
- (c) a polyester thermoplastic polyurethane coating layer on at least one side of said resin absorbent material layer;
- wherein said thermoplastic polyurethane coating layer has a DSC 2nd heat endotherm peak temperature of greater than about 140° C.
A method for lining a cavity of a passageway or pipe comprising introducing a liner into said cavity;
- said liner comprising:
- (a) a resin absorbent material layer;
- (b) a thermoset resin saturated into said resin absorbent material layer;
- (c) a polyester thermoplastic polyurethane coating layer;
- wherein said thermoplastic polyurethane coating layer has a DSC 2nd heat melt endotherm peak temperature of greater than about 140° C.;
- introducing steam or water into the inner opening of said liner to force the said liner against the inner surface of said passageway or said pipe and to activate the cure of said thermoset resin.
Dependencies are inferred from the claim text.