Method for producing a single- or multi-layered film, single- or multi-layered, extruded, simultaneously biaxially stretched and thermofixed film and corresponding uses

A method for producing a single- or multi-layered film, the method comprising at least the following steps:

• a step of extruding one layer or co-extruding a plurality of layers, thereby obtaining an extruded film;
• a step of simultaneous biaxial stretching of the extruded film;
• and
• a step of thermofixing the stretched film;
• wherein the film comprises a first polypropylene;
• wherein the first polypropylene has a heat deflection temperature of greater than 75° C. measured according to ASTM D648-18;
• wherein the film contains the first polypropylene in a mass fraction of greater than 30%, relative to a total mass of the film;
• wherein the film does not contain any of the following polymers selected from the group consisting of polyethylene terephthalate, polyvinylidene chloride, and polyamide;
• wherein a stretch factor in a machine direction is greater than a stretch factor in a transverse direction;
• wherein the film has a second temperature of greater than 120° C. and less than 180° C. during stretching;
• and
• wherein the film has a third temperature of greater than 60° C. and less than 200° C. during thermofixing.