Pre-perforated material for packages and method of making same

Claim 1

A FILLED AND SEALED PACKAGE COMPRISING A TUBE OF FLEXIBLE PACKAGING MATERIAL HAVING TRANSVERSE SEALS AT ITS ENDS, SAID MATERIAL BEING A MULTILAYER MATERIAL COMPRISING A BACKING AND A LINER OF HEAT-SEALABLE PLASTIC BONDED TO ONE SIDE OF THE BACKING AND COVERING THE ENTIRE AREA THEREOF, SAID LINER CONSTITUTING THE INSIDE FACE OF THE MATERIAL IN THE TUBE AND BEING IMPERVIOUS TO ESCAPE OF THE CONTENTS OF THE PACKAGE, SAID END SEALS BEING INSIDE-FACETO-INSIDE-FACE HEAT SEALS, THE ENDS OF SAID SEALS DEFINING CORNERS OF THE PACKAGE, AT LEAST ONE OF TWO OPPOSITE WALLS OF THE PACKAGE WHICH ARE SEALED TOGETHER BY THE INSIDEFACE-TO-INSIDE-FACE END SEAL AT ONE END OF THE TUBE HAVING A LINE OF PERFORATIONS IN THE BACKING THEREOF ONLY, SAID LINE EXTENDING INWARD FROM AN EDGE OF SAID ONE WALL ADJACENT A CORNER OF THE PACKAGE AND TRAVERSING AN UNSEALED PORTION OF THE TUBE, SAID LINER BEING IMPERFORATE THROUGHOUT ITS AREA BETWEEN THE END SEALS AND THEREBY PREVENTING ESCAPE OF THE CONTENTS OF THE PACKAGE THROUGH THE PERFORATIONS WHERE THEY TRAVERSE SAID UNSEALED PORTION OF THE TUBE, SAID PACKAGE BEING ADAPTED TO BE OPENED BY GRASPING IT AT THE CORNER ADJACENT SAID LINE OF PERFORATIONS AND PULLING ON SAID CORNER TO TEAR SAID OPPOSITE WALLS THROUGH BOTH THE BACKING AND LINER ALONG SAID LINES OF PERFORATIONS IN THE BACKING.