A method for producing packages holding a food product, said method comprising providing a web of packaging material comprising at least an outer protective layer, a cellulose-based mid-layer and an inner protective layer, providing a protective strip, heating a first longitudinal edge section of an inside surface of the web by applying a first flow of heated air via a first nozzle, heating a first longitudinal edge section of an inside surface of the protective strip by applying a second flow of heated air via a second nozzle, attaching the outside surface of the first longitudinal edge section of the protective strip onto the inside surface of the first longitudinal edge section of the web, forming a tube of the web of packaging material by directing the first longitudinal edge section of the web inside a second longitudinal edge section of the web, attaching an outside surface of the first longitudinal edge section onto an inside surface of the second longitudinal edge section, attaching an inside surface of a second longitudinal section of the protective strip onto an outside surface of a mid-section of the web, wherein the mid-section is placed between the first and second edge sections (208, 306), thereby providing for that the food product is hindered from coming into contact with the cellulose-based mid-layer of the packaging material, filling the food product into the tube, sealing the tube transversally in transversal sealing sections in a lower end of the tube, and cutting the tube in the transversal sealing sections such that the packages are formed characterized in that the first flow of heated air has a first temperature, and the second flow of heated air has a second temperature, wherein the first temperature is adjusted in accordance with properties of the packaging material, and the second temperature is adjusted in accordance with properties of the protective strip. providing a web of packaging material comprising at least an outer protective layer, a cellulose-based mid-layer and an inner protective layer, providing a protective strip, heating a first longitudinal edge section of an inside surface of the web by applying a first flow of heated air via a first nozzle, heating a first longitudinal edge section of an inside surface of the protective strip by applying a second flow of heated air via a second nozzle, attaching the outside surface of the first longitudinal edge section of the protective strip onto the inside surface of the first longitudinal edge section of the web, forming a tube of the web of packaging material by directing the first longitudinal edge section of the web inside a second longitudinal edge section of the web, attaching an outside surface of the first longitudinal edge section onto an inside surface of the second longitudinal edge section, attaching an inside surface of a second longitudinal section of the protective strip onto an outside surface of a mid-section of the web, wherein the mid-section is placed between the first and second edge sections (208, 306), thereby providing for that the food product is hindered from coming into contact with the cellulose-based mid-layer of the packaging material, filling the food product into the tube, sealing the tube transversally in transversal sealing sections in a lower end of the tube, and cutting the tube in the transversal sealing sections such that the packages are formed characterized in that the first flow of heated air has a first temperature, and the second flow of heated air has a second temperature, wherein the first temperature is adjusted in accordance with properties of the packaging material, and the second temperature is adjusted in accordance with properties of the protective strip.