| abstract |
An unstretched first plastic foil is laminated with a longitudinally stretched second plastic foil by the application of heat and pressure. The second foil is preheated, thereupon stretched and thereafter tempered prior to being laminated with the first foil which is heated prior to lamination. The laminating step can coincide with the tempering step and immediately follows the stretching step so that the laminating step can be carried out by utilizing heat which is required for stretching of the second foil. The material of the first foil is or can be identical with the material of the second foil; in any event, the two materials are sufficiently compatible to permit bonding of the unstretched foil to the stretched foil by the application of heat and pressure alone, i.e., without resorting to an adhesive. |