Methods of making ground containment liners
View Patent ↗The present invention provides methods of making containment liners to protect the environment from spills and leaks at oil and/or gas production sites and other sites. The containment liners comprise a first felt geotextile layer and a polymeric barrier layer embedded partially into the felt geotextile layer.
1. A method of making a containment liner comprising:
providing first and second felt geotextile layers comprising polypropylene fibers, polyester fibers, or a combination thereof; and
extruding a first molten polymeric barrier layer material adjacent to the first felt geotextile layer and applying pressure between the first molten polymeric barrier layer material and the first felt geotextile layer to thereby embed at least a portion of the first polymeric barrier layer material into the first felt geotextile layer, wherein the first polymeric barrier layer extends into the first felt geotextile layer at least 5 percent of a thickness of the first felt geotextile layer and a distance of from 3 to 30 mil, and wherein a second polymeric barrier layer is embedded in the second felt geotextile layer, and an intermediate layer comprising a continuous, liquid impermeable polymeric layer is placed between the first and second polymeric barrier layers.
2. The method of claim 1 , wherein the polymeric barrier layer material is extruded at a temperature of from 175 to 300° C.
3. The method of claim 1 , wherein the pressure is applied by pressing the at least one felt geotextile layer and polymeric barrier layer material together after the extrusion step.
4. The method of claim 3 , wherein the pressing step is performed by nip rollers.
5. The method of claim 3 , wherein the pressing step is performed at a temperature of from 4 to 300° C.
6. The method of claim 1 , wherein the first polymeric barrier layer extends into the first felt geotextile layer from 10 to 80 percent of a thickness of the first felt geotextile layer.
7. The method of claim 1 , wherein the first polymeric barrier layer extends into the first felt geotextile layer from 15 to 50 percent of a thickness of the first felt geotextile layer.
8. The method of claim 1 , wherein the first and second geotextile layers further comprise fibers selected from wool, hemp, coconut, jute, nylon, rayon, polytetrafluoroethylene, aromatic polyamide aramid, poly para-phenyleneterephthalamide or a combination thereof.
9. The method of claim 1 , wherein the first and second felt geotextile layers comprise needlepunched polypropylene or woven reinforced needlepunched polypropylene.
10. The method of claim 1 , wherein the first and second felt geotextile layers have thicknesses of from 25 to 500 mil.
11. The method of claim 1 , wherein the intermediate layer comprises polypropylene thermoplastic olefin, linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyvinyl chloride (PVC), nylon, polystyrene, polyurethane, ethylene vinyl acetate, styrene block copolymers or a combination thereof.
12. The method of claim 1 , wherein the intermediate layer comprises multiple polymeric layers.
13. The method of claim 1 , wherein the intermediate layer comprises reinforcements selected from the group consisting of fibers, strings, scrim cloth and combinations thereof.
14. The method of claim 1 , wherein the intermediate layer is coextensive with at least one of the first and second felt geotextile layers.
15. The method of claim 1 , wherein the first polymeric barrier layer comprises polypropylene, thermoplastic olefin, linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyvinyl chloride (PVC), nylon, polystyrene, polyurethane, ethylene vinyl acetate, styrene block copolymers or a combination thereof.
16. The method of claim 1 , wherein a non-embedded portion of the first polymeric barrier layer has a thickness of from 2 to 60 mils.
17. The method of claim 1 , wherein the containment liner has an average tear resistance of at least 42.5 lbs.
18. The method of claim 1 , wherein the containment liner has an average break tensile strength of at least 85.5 ppi.
19. The method of claim 1 , wherein the containment liner has an average puncture resistance of at least 182 lbs.