Patent ID: 7857932

Claim:
A method of preparation of a cured in place liner having an outer impermeable coating, comprising: providing a first tubular member of at least one layer of a resin impregnable material; providing a length of a material including at least a resin impermeable layer; feeding the first tubular member in a first direction about a tubular former; continuously forming the length of material including the resin impermeable layer into a second tubular member about the tubular former; simultaneously and continuously feeding the second tubular member along the tubular former in a direction towards the first tubular member and everting the second tubular member into the tubular former as the first tubular member is moving towards the second tubular member into the everting second tubular member; and continuing to feed the first tubular member into the lumen of the second tubular member as the second tubular member is everted into itself to envelop the first tubular member to form a cured in place liner with an outer impermeable layer encapsulating the first tubular member of resin impregnable material; and withdrawing the cured in place liner of first tubular member of resin impregnable material and outer second tubular member of resin impermeable material in the first direction.