Thermoshrinking tunnel oven for making thermoshrinking plastic material film package and the packaging method performed thereby

A thermoshrinking tunnel oven for making packages of thermoshrinking material film, characterized in that said thermoshrinking tunnel oven comprises a thermoshrinking chamber and control means for controlling a temperature of said chamber for in turn controlling a thermoshrinking temperature of said film in packages housed in said chamber, said control means comprising a bottom plate arranged under said packages, said plate including a plurality of variable cross-section holes for directing hot air supplied by hot air supplying fans in a direction of said packages, said oven further comprising at least a bottom slider element associated with said bottom plate and including a plurality of perforations which can be displaced between a position coinciding with said holes, thereby leaving said holes fully open, and a position inward or outward offset of said_holes, thereby fully closing said holes, said at least a bottom slider element comprising a shaft and lever driving device, controlled by a corresponding knob, and designed to provide said displacement with respect to said plate, a plurality of mutually adjoining bottom slider elements thereby covering all said bottom plate, said thermoshrinking chamber comprising a covering element and a bottom base, said covering element having walls defining a thermoshrinking air passage gap, for conveying thermoshrinking air under said bottom plate, in said gap a plurality of heating resistances for heating air supplied by said hot air supplying fans, said oven additionally comprising a perforated top plate associated with at least a top perforated slider element which is slidably mounted with respect to said perforated top plate for opening and closing holes of said perforated plate.