Method of manufacturing a pipe liner for installation in an existing conduit

A method of manufacturing a thermoplastic liner in a collapsed and folded form for installation into an existing conduit comprising:

• extruding the thermoplastic liner material through a die to form a tubular shape of desired size;
• shaping the resulting hot tubular shape exiting the die to the desired collapsed and folded form;
• cooling the liner material in the collapsed and folded form so that the liner has a memory for the collapsed and folded form such that when reheated to render it pliable, it retains the collapsed and folded form;
• reheating the cooled collapsed and folded tubular liner to render it pliable;
• winding the liner in the collapsed and folded form for storage.

A method of manufacturing a thermoplastic liner in a collapsed and folded form for installation into an existing conduit comprising:

• extruding the thermoplastic liner material through a die to form a tubular shape of desired size;
• flattening the tubular material exiting the die and folding the liner to a flattened and folded form so that it has a short leg and a long leg and a rounded fold portion;
• cooling the thermoplastic liner material in the flattened and folded form after shaping so that the liner has a memory for the flattened and folded form such that when reheated to render it pliable, it retains the desired flattened and folded form;
• and
• storing the thermoplastic liner in the flattened and folded form by winding the liner on itself in a layered condition.