Method and device for producing a hard-foam film

A method for producing a rigid-foam film, the method comprising the steps of:

• providing a foam block (3) made of a thermoplastic, extruded PET-plastic rigid-foam material selected from a partially crystalline PET-plastic rigid-foam material, a closed-cell PET-plastic rigid-foam material or combinations thereof, wherein the PET-plastic rigid-foam material has a higher compressive strength along a thickness extension axis (Vs) than along a surface extension axis perpendicular to the thickness extension axis (Vs),
• cutting a film section (6) from the foam block (3) by cutting the foam block (3) by using a knife (2), which has a cutting edge (7), along a feed axis (Vb) extending perpendicular to the thickness extension axis (Vs), wherein the film section (6) is cut along the feed axis (Vb),
• lifting and separating the film section (6) from the knife (2) by elastic bending of the film section (6) to reduce friction forces acting on the knife (2) during the cutting process,
• wherein the PET-plastic rigid-foam material is at least partially heated by a heating means to a processing temperature above 40° C. and below the melting temperature of the PET-plastic rigid-foam material in such a manner that the PET-plastic rigid-foam material becomes se elastically bendable that the film section (6) can be elastic bent, lifted and separated from the cutting edge of the knife (2), and wherein the PET-plastic rigid-foam material of the film section returns to being rigid to form the rigid-foam film.