Abstract: A method for manufacturing a liner, the method including forming a tubular body portion having a top circumferential edge, a bottom circumferential edge, and a weld seam or seams extending from the top circumferential edge to the bottom circumferential edge; stretching the tubular body near the top circumferential edge and welding a top liner sheet portion along the stretched top circumferential edge, the top liner sheet portion having a fitment welded thereto; and stretching the tubular body near the bottom circumferential edge and welding a bottom liner sheet portion along the stretched bottom circumferential edge. The weld between the tubular body portion and the top liner sheet portion may be effected with the inner wetted surfaces of each portion in contact. Similarly, the weld between the tubular body portion and the bottom liner sheet portion is effected with the inner wetted surfaces of each portion in contact.