Method and machine for making triple wall corrugated paper board

Claim 1

A METHOD OF MAKING MULTIPLE WALL CORRUGATED PAPER BOARD WHICH COMPRISES ADHESIVELY BONDING A CORRUGATED SHEET TO A LINER TO FORM A SINGLE FACE CORRUGATED PAPER BOARD SHEET CONTAINING MOISTURE, PLACING AT LEAST THREE OF SAID SINGLE FACE SHEETS IN SPACED RELATION AND PREHEATING THEM SEPARATELY TO CONDITION THE PAPER BY DRYING OUT SOME OF THE MOISTURE FOR THE RECEPTION OF ADHESIVE, APPLYING ADHESIVE TO THE RIDGES OF THE CORRUGATIONS ADHESIVELY TO SECURE THE RIDES OF SAID CORRUGATIONS TO THE LINER OF AN ADJACENT PLY AND TO A LINER SHEET TO FORM A COMPOSITE BOARD HAVING AT LEAST THREE CORRUGATED SHEETS AND AT LEAST FOUR LINER SHEETS, CONTINUOUSLY APPLYING PRESSURE TO THE COMPOSITE BOARD WHILE HEATING THE COMPOSITE BOARD FOR NOT LESS THAN 14 SECONDS AND NOT MORE THAN 24 SECONDS AT A TEMPERATURE OF NOT LESS THAN 300 DEGREES F. AND NOT MORE THAN 330 DEGREES F., ALL OF SAID OPERATIONS BEING CARRIED OUT WHILE THE MATERIAL IS CONTINUOUSLY MOVING THROUGH A PATH OF TRAVEL WITH THE CORRUGATIONS TRANSVERSE TO THE PATH OF TRAVEL.