Process of making containers made of thin pliable synthetic material

Claim 1

A process for the continuous manufacture of identical containers with handles in a thin and pliable composite synthetic material heat-weldable on one face only, which process consists in: advancing horizontally in a stepwise manner a strip of composite material folded longitudinally to the shape of a letter W, each feed step being a little greater than the width of each container to be produced or than a multiple of its width, and, to produce at least one container between each two successive feed steps, simultaneously welding the bottoms of the two V-shaped folds in said strip; making a first and second weld, extending transversely of said strip and separated by a distance corresponding to the required width of each container to be manufactured, and interconnecting the inner faces of said folded strip and of its two V-shaped folds; making a third weld, delimiting, together with the first weld, a main cavity in the container to be produced and, together with said second weld, delimiting a closed handle forming pocket in said container, said cavity and pocket then remaining open at the brought-together upper edges of said strip at least at said main cavity; separating said upper edges and introducing a liquid into said main cavity; injecting a gas under pressure into said pocket to provide rigidity to said container; pressing the upper edges of said folded strip against each other during injection of gas under pressure; then, after injection of said gas has been completed, welding together the upper edges of said folded strip so as to close said main cavity and said pocket, said pocket thereby forming a permanently sealed handle.