Patent ID: 7354496
Filing Date: 2008-04-08
Classification: F42D,Y10T

Abstract:
1. A method of making a double-walled liner, comprising: supplying an outer liner web and an inner liner web, wherein the outer liner web includes sheeting material having two substantially longitudinal edges and a longitudinal centerline, and the inner liner web includes tubing material; longitudinally lining the inner liner web substantially to one side of the outer liner web centerline, said inner liner web having a circumference less than the outer liner web width; folding the outer liner web along its centerline such that said edges are placed adjacent to each other to envelop the inner liner web; seaming the edges together; and transversely seaming the inner liner web and the outer liner web at one end thereof to form a closed terminal; wherein the outer liner web is fed continuously from an outer liner web feedstock; wherein the inner liner web is fed continuously from an inner liner web feedstock; wherein at least one of the inner liner web feedstock and the outer liner web feedstock is a substantially liquid impermeable material; wherein the inner liner web is fed in a form that is one of a hollow sheeting tube and a folded over longitudinally seamed sheeting web; wherein said folding includes passing said outer liner web over a break, said break having a first break edge and a second break edge, a first portion of said outer liner being passed over said first break edge, a second portion of said outer web liner being passed over said second break edge; wherein said folding includes passing all of said inner liner web over said first break edge in company with said first portion of said outer liner web; and, calendaring the folded over outer liner web and the inner liner web enveloped therewithin; and, wherein said break is a folder having a generally V-shape, one arm of the V defining said first break edge and the other arm of the V defining the second break edge, the arms of the V converging at an apex, and said folding includes passing the outer web from the broad end of the V toward the apex, and bending the outer web over the arms of the V.