a method and apparatus are disclosed for production of containers for packaging liquids . plastic - coated supporting material is drawn as a web from a supply roll in a first direction along a web path . at a first position , the web is cut into sheets . the sheets are conveyed along a transport path in a second direction transverse to the web path . at a second position , each sheet is partially shaped into a tube , and an edge of the sheet is folded over and sealed . at a third position , shaping is completed to cause the side edges of the sheet to join , and the tube side is sealed . a plastic lid is molded onto the top of each tube , and the bottom end is folded and sealed into a quadrilangular bottom .