Fiber reinforced composite liner for lining an existing conduit and method of manufacture
View Patent ↗A reinforced liner for cured in place pipe rehabilitation of an existing pipeline having a plurality of high-strength low-elongation fiber bundles disposed circumferentially around the tubular liner at both inner and outer surfaces of a resin absorbent layer of the liner is provided. The bundles of reinforcing fibers are continuous lengths of high modulus fibers laid circumferentially with the ability to stretch to accommodate variations in host pipe diameter. The fibers on the inner surface are secured to a porous scrim to form an inner tubular reinforcing layer. A resin absorbent layer is formed into a tube about the inner layer. An outer layer of bundles of reinforcing fiber are formed into a tube about the absorbent layer. An outer impermeable tubular layer is wrapped around the inner layers. The reinforcing layer may include longitudinal reinforcing fiber in either or both reinforcing layers to increase the longitudinal strength of the liner.
1. A composite tubular liner suitable for the trenchless rehabilitation of existing conduits, comprising:
at least one layer of a resin absorbent material joined at its edges in tubular form;
at least one layer of a plurality of bundles of high modulus fibers disposed circumferentially on both the inner and outer surfaces of the at least one layer of resin absorbent material;
an impermeable layer disposed about the outer layer of high modulus fibers; and
the bundles of high modulus fibers aligned circumferentially on both sides of the resin absorbent layer with the ends of the bundles overlapping so that upon installation and expansion of the tubular composite, the ends of the high modulus fibers slide past each other to allow for expansion to the wall of the existing conduit before the resin is cured.
2. The composite tubular liner of claim 1 , wherein the resin absorbent material is a needled felt.
3. The composite tubular liner of claim 2 , wherein the needled felt is polyester.
4. The composite tubular liner of claim 1 , wherein the resin absorbent material is joined by one of a butt seam, flame bonding and adhesive.
5. The composite liner of claim 1 , wherein the inner layer of high modulus fibers are disposed on and secured to a porous substrate.
6. The composite liner of claim 5 , wherein the porous substrate is a polyester netting.
7. The composite liner of claim 5 , wherein the porous substrate is a resin absorbent material.
8. The composite liner of claim 5 , wherein the high modulus fibers on the inner surface of the resin absorbent material are joined to the substrate by longitudinal stitching substantially perpendicular to the bundles of fibers.
9. The composite liner of claim 1 , wherein the outer layer of high modulus fibers are disposed on and secured to a porous substrate.
10. The composite liner of claim 9 , wherein the high modulus fibers are joined to the porous substrate by longitudinal stitching substantially perpendicular to the bundles of fibers.
11. The composite tubular liner of claim 1 , wherein the high modulus fiber is selected from the group consisting of glass, polyester, polypropylene, nylon, carbon, Aramid (aromatic polyamide), steel and mixtures thereof.
12. The composite tubular liner of claim 1 , wherein the high modulus fiber is carbon fiber.
13. The composite tubular liner of claim 12 , wherein the carbon fibers are disposed in tows containing between about 30,000 to 100,000 individual fibers of between about 200 to 750 feet per pound.
14. The composite tubular liner of claim 1 , wherein the high modulus fiber is glass fiber.
15. The composite tubular liner of claim 14 , wherein the glass is a type E glass in bundles with strands having a continuous length of about 100 to 1,000 feet per pound.
16. The composite tubular liner of claim 1 , wherein the at least one outer layer of high modulus fibers are joined by stitching substantially perpendicular to the substantially parallel bundles of fibers.
17. The composite tubular liner of claim 1 , wherein the high modulus fibers in at least one of the layers of high modulus fibers are joined joined at their edges with the joined edges folded back over the fibers to allow for expansion before the resin is cured.
18. The composite tubular liner of claim 1 , wherein the high modulus fibers are disposed circumferentially around the resin absorbent layer with the ends of the bundles overlapping to allow for expansion before cure and provide for overlap of the bundles.
19. The composite tubular liner of claim 1 , wherein the impermeable layer disposed on the outer layer of high modulus fibers includes resin absorbent material on the inner surface forming a bond with resin in the resin absorbent layer after cure.
20. The composite tubular liner of claim 1 , wherein at least one of the layers of reinforcing fibers includes a high tensile strength fiber in the axial direction.