A method for renovating the interior of a hollow structure such as a sewerage pit (1) is described. The method provides an access opening (16) to the hollow structure (1); provides a plurality of material sheets (3) comprising reinforcing fibers and a curable resin composition through the access opening (16) and against a wall (11a, 11b) of the hollow structure (1); and provides an inflatable pressure means (4a, 4b) within the hollow structure (1). The pressure means (4a, 4b) are inflated against the wall (11a, 11b). A curing means (6) is then provided within the hollow structure (1) for curing the resin composition; and the resin composition is cured to harden the material sheets and provide a renovated interior of the hollow structure (1).

A method for renovating the interior of a hollow structure such as a sewerage pit (1) is described. The method provides an access opening (16) to the hollow structure (1); provides a plurality of material sheets (3) comprising reinforcing fibers and a curable resin composition through the access opening (16) and against a wall (11a, 11b) of the hollow structure (1); and provides an inflatable pressure means (4a, 4b) within the hollow structure (1). The pressure means (4a, 4b) are inflated against the wall (11a, 11b). A curing means (6) is then provided within the hollow structure (1) for curing the resin composition; and the resin composition is cured to harden the material sheets and provide a renovated interior of the hollow structure (1).

A pipe liner comprising a nonwoven felt, and process for making said nonwoven felt, the nonwoven felt consisting essentially of 0 to 85 weight percent polyester staple fibers and 15 to 100 weight percent para-aramid staple fibers, the nonwoven felt having a basis weight of 250 to 600 grams per square meter and a thickness of 2.0 to 5.0 mm; wherein: 20 to 100 weight percent of the total amount of para-aramid staple fibers are re-purposed para-aramid staple fibers, 0 to 80 weight percent of the total amount of para-aramid staple fibers are crimped virgin para-aramid staple fibers having a uniform cut length, and at least 50 weight percent of the total amount of the combined polyester and para-aramid staple fibers are crimped staple fibers.

A pipe liner comprising a nonwoven felt, and process for making said nonwoven felt, the nonwoven felt consisting essentially of 0 to 85 weight percent polyester staple fibers and 15 to 100 weight percent para-aramid staple fibers, the nonwoven felt having a basis weight of 250 to 600 grams per square meter and a thickness of 2.0 to 5.0 mm; wherein: 20 to 100 weight percent of the total amount of para-aramid staple fibers are re-purposed para-aramid staple fibers, 0 to 80 weight percent of the total amount of para-aramid staple fibers are crimped virgin para-aramid staple fibers having a uniform cut length, and at least 50 weight percent of the total amount of the combined polyester and para-aramid staple fibers are crimped staple fibers.

A composite fuel tank includes a tank-shell and a tank-liner, located within the tank-shell. The tank-shell is formed from a composite layup that is placed, consolidated, and cured on a bladder. The bladder forms the tank-liner after formation of the tank-shell.

A composite fuel tank includes a tank-shell and a tank-liner, located within the tank-shell. The tank-shell is formed from a composite layup that is placed, consolidated, and cured on a bladder. The bladder forms the tank-liner after formation of the tank-shell.

A resin composition and method for installing a pipe liner that allows the liner to be fully wet out with a resin and activator and stored for a period of up to six months prior to installation and curing. A method of lining a pipe with a delayed curing resin composition is also provided that includes fully wetting out a liner with a blended two part epoxy composition such that the liner can be transported in a wet out fashion, placed in a pipe to be lined and repositioned as needed without concern for the resin composition to begin curing.

A resin composition and method for installing a pipe liner that allows the liner to be fully wet out with a resin and activator and stored for a period of up to six months prior to installation and curing. A method of lining a pipe with a delayed curing resin composition is also provided that includes fully wetting out a liner with a blended two part epoxy composition such that the liner can be transported in a wet out fashion, placed in a pipe to be lined and repositioned as needed without concern for the resin composition to begin curing.

A device for applying a film to a three-dimensional article includes an inflatable shape having at least one opening connected or connectable to a source of heated gas. The inflatable shape is configurable in a deflated configuration and in an inflated configuration when the heated gas is introduced into the inflatable shape through the opening. The inflatable shape is configured and sized to allow an article to be placed thereon, at least when the inflatable shape is in the deflated configuration. In the inflated configuration, the inflatable shape is configured for pressing against the article and for adhering, to the article, a film interposed between the inflatable shape and the article. The inflatable shape is impermeable to the heated gas and has a thermal transmittance greater than 600 W/m.sup.2K.

A device for applying a film to a three-dimensional article includes an inflatable shape having at least one opening connected or connectable to a source of heated gas. The inflatable shape is configurable in a deflated configuration and in an inflated configuration when the heated gas is introduced into the inflatable shape through the opening. The inflatable shape is configured and sized to allow an article to be placed thereon, at least when the inflatable shape is in the deflated configuration. In the inflated configuration, the inflatable shape is configured for pressing against the article and for adhering, to the article, a film interposed between the inflatable shape and the article. The inflatable shape is impermeable to the heated gas and has a thermal transmittance greater than 600 W/m.sup.2K.