Abstract: Bags custom-sized to the volume of articles packed and to be packed therein are manufactured on-site and on-demand at the location at which the articles are packed in the bags. The bags are formed from a continuous sheet of flexible film material which is shaped into a tubular wrapper along the interior of a generally quadrangular former. The bags are sealed along their tops so as to prevent inadvertent spillage of articles therefrom and may incorporate unitary handles formed during manufacture of the bags and a readily removable protective envelope at least partly defining the top closure thereof.

Abstract: The present invention relates to a device for continuous hot-sealing of thermoplastic films.This device comprises a sealing head, the sealing head being provided with two rip cord electric resistances that are heated by causing an electric current to flow therethrough and being made of a material the electric resistance of which is proportional to the temperature, the sealing head being caused to rapidly vibrate against a counter-plate so as to cause the thermoplastic film to be sealed to be rapidly pounded as it glides between the head and the counter-plate. The sealing of the thermoplastic films is brought about by the synergistic action of the heat of the resistances and of the pressure due to the pounding.