Abstract: A wrapping machine (1) for wrapping a load (100) with a film (50) comprises a main frame (2) that slidably supports a supporting carriage (3), a moving ring (4) rotatable and supporting an unwinding unit (5) provided with a reel (51) of film, pre-stretching rollers (52, 53) and at least one electric motor (37, 38) to rotate said pre-stretching rollers (52, 53), sliding electric contact means (10) for supplying electric current to, and/or exchanging electric signals with, the unwinding unit (5) and comprising brush means (11) fixed to the moving ring (4) and arranged to slidably abut conductive bar means (12) fixed to a supporting ring (6) of the supporting carriage (3), drive and control means (40) fixed to the brush means (11) and to the unwinding unit (5) to drive and control the electric motor (37, 38) and comprising a detector device (46) connected to the brush means (11) and configured to detect and record possible supply interruptions of electric current during operation.

Abstract: A method for wrapping a load with a film by a wrapping machine including an unwinding apparatus provided with a reel of the film includes moving the wrapping apparatus and the load in relation to one another and unwinding from the reel an established effective length of film per revolution of the wrapping apparatus or of the load. The established effective length of film is calculated with the formula: where: Sf. initial length of film is determined on the basis of dimension and/or shape of the load; ?: rotation speed around a wrapping axis of the unwinding apparatus or of the load; Vt: movement speed of the unwinding apparatus parallel to the rotation axis; ?max: maximum rotation speed around the wrapping axis of the unwinding apparatus or of the load; ?corr: corrective parameter.

Abstract: A method for wrapping a load with a film by a wrapping machine including an unwinding apparatus provided with a reel of the film includes moving the wrapping apparatus and the load in relation to one another and unwinding from the reel an established effective length of film per revolution of the wrapping apparatus or of the load. The established effective length of film is calculated with the formula: where: Sf. initial length of film is determined on the basis of dimension and/or shape of the load; w: rotation speed around a wrapping axis of the unwinding apparatus or of the load; Vt: movement speed of the unwinding apparatus parallel to the rotation axis; ?max: maximum rotation speed around the wrapping axis of the unwinding apparatus or of the load; ?corr: corrective parameter.