Process for laminating a polymeric film to a metal strip substrate and a metal strip substrate produced thereby

A process for laminating a polyester film onto a major surface of a metal strip in a coating line comprising the subsequent steps of:

• providing a metal strip substrate;
• providing a Machine Direction Oriented polyester film having a room-temperature yield stress YS for laminating onto the major surface of the metal strip substrate;
• providing an adhesion layer for promoting the adhesion between the metal strip substrate and the polyester film, and/or
• heating the metal strip substrate to a temperature T1 above Tg and below Tm of the polyester facing the major surface of the metal strip substrate;
• forming a laminate by pressing the polyester film onto the metal strip substrate by means of laminating rolls, wherein a laminating pressure is exerted on the laminate in a nip between the laminating rolls, and wherein tension is exerted on the polyester film in the longitudinal direction of the film prior to entering the nip;
• wherein the line speed of the coating line is v (in m/min) and wherein the tension as a percentage of the yield stress (YS) of the polyester film (Xtens) is at least
• Xtens(%)=50·v−0.46 (eq. 1)
• and the tension (Ftens) on the polyester film in MPa is
• Ftens=YS*Xtens(%);
• (eq. 2)
• heating the laminate to a temperature above Tm of the polyester film to melt the polyester film;
• quenching the heated laminate with the molten polyester film to a temperature below Tg of the polyester film.