Patent ID: 7238251

Claim:
A method of preparation of a cured in place liner having an inner impermeable layer, comprising: forming a first tubular member of at least one layer of a resin impregnable material having an inner resin impermeable layer by: providing a length of a resin impregnable material having an impermeable layer bonded to one surface; feeding the length of resin impregnable material in a first direction and forming the length of material into tubular form having the impermeable layer on the outside; joining the longitudinal edges of the length of resin impregnable material together to form a tubular member; sealing the joined longitudinal edges of the tubular member; everting the tubular member into itself in a second opposite direction so that the outer layer is the resin impregnable material; and continuously removing the tubular member with the integral impermeable layer on the inside; feeding the first tubular member into a resin impregnation tower of suitable height filled with resin to provide sufficient pressure and path to impregnate the resin impregnable material with resin; withdrawing the impregnated tubular member from the tower; and placing a resin impermeable coating about the impregnated tubular member.