Multi-layer laminates and method of manufacturing hollow articles therefrom

Claim 1

IN MAKING HOLLOWED PRODUCTS BY SELECTIVE EXPANSION OF AREAS OF A MULTI-LAYER LAMINATE, THE PROCESS WHICH COMPRISES SUPPORTING IN A DIE A MULTI-LAYER LAMINATE CHARACTERIZED BY HAVING ADJACENT LAYERS PEELABLY BONDED TOGETHER AT THE INTERFACE THEREBETWEEN INCLUDING AT LEAST A SUBSTANTIAL PART OF SAID INTERFACE IN THE AREAS THEREOF TO BE EXPANDED, INTRODUCING FLUID UNDER PRESSURE BETWEEN SAID ADJACENT LAYERS WHERE THE BOND IS, BREAKING SAID BOND IN AN INCREMENT OF THE AREA TO BE EXPANDED, PROGRESSIVELY WORKING AND EXPANDNG THE THUS SEPARATED PORTION OF AT LEAST ONE OF SAID LAYERS INTO SAID DIE BY THE PRESSURE OF SAID FLUID WHILE SAID LAYERS IN AN ADJACENT INCREMENT OF SAID AREA TO BE EXPANDED ARE RESTRAINED FROM PEELING BY SAID BOND, CONTINUING TO PROGRESSIVELY BREAK SAID BOND IN SUCCESSSIVE INCREMENTS OF THE AREA TO BE EXPANDED, ALONG THE DIRECTON IN WHICH THE FLUID FLOWS, AND TO WORK AND EXPAND THE THUS SEPARATED SUCCESSIVE PORTIONS OF AT LEAST ONE OF SAID LAYERS, WHEREBT THERE IS ACCOMPLISHED SAID SELECTIVE EXPANSION WITHOUT EXPOSING THE SEPARATED PORTIONS OF SAID LAMINATE, ALONG THE BOUNDARIES OF SAID AREA TO BE EXPANDED, TO THE FULL LOAD OF EXPANSION PRESSURE.