Abstract: A two-step method of laminating at least two plastic films of same or different nature, comprising contacting intimately said films at a temperature in the range from ambient up to the melting temperature of the film having the lowest melting point of said films in order to form a low peel strength composite, and subsequently subjecting the composite to a treatment at a temperature within the range from 60.degree. to 180.degree. C., the 60.degree. to 180.degree. C. temperature being below the melting or softening temperature of the constituents in the composite having the lowest melting or softening temperature, in order to form a high peel strength laminate, non-surface treated films being used and the composite of the first step being subjected to the treatment of the second step in a condition substantially free of tension and pressure.

Abstract: A method for improving the impact strength and other properties of monaxially oriented, thermoplastic polymeric film cross-laminates which comprises first forming the cross-laminate and then annealing it at an elevated temperature. The annealing may be carried out by passing the cross-laminate through an annealing oven or over a heated cylinder. Annealing temperatures can vary from 35.degree. C. to a temperature below the melting temperature of the lowest melting thermoplastic film, excluding any adhesive or extruded bonding layer. A particularly useful annealing temperature is within the range of 60.degree. to 180.degree. C.