Abstract FIG-01 THE INVENTION RELATES TO A METHOD FOR OVERLAPPING SEALING FOAM PLASTIC FILMS OR FOAM PLASTIC SHEETS WITH A DENSITY BELOW 250 KG. PER M.3, WHICH ARE LAID ON TOP OF EACH OTHER WITHOUT A BONDING AGENT AND ARE COMPRESSED IN DIES AT A TEMPERATURE ABOVE TH SOFTENING POINT OF THE PLASTIC. THEREAFTER THE PRESSURE IS REDUCED, SO THAT THE COMPRESSED PRODUCT FOAMS RAPIDLY AGAIN TO FORM A NEW INTEGRAL SHEET OF A PREDETERMINED FOAM PLASTIC THICKNESS, AT WHICH TIME IT IS COOLED TO REFORM THE PRODUCT FOR EXAMPLE, A SINGLE BLANK FOLDED INTO A CONTAINER HAVING A BOTTOM CONSISTING OF FLAPS FOLDED INTO EACH OTHER, AND A SIDE SEAM CAN ALL BE SEALED AND REFORMED INTO AN INTEGRATED WHOLE. WITH A FINAL THICKNESS SUBSTANTIALLY EQUAL TO THE THICKNESS OF ONE SINGLE SHEET.