Unwinding apparatus, machine and method for wrapping a load with film

An unwinding apparatus associable with a wrapping machine to supply a film with which to wrap a load, comprising:

• a reel holder shaft rotatable about a first rotation axis and suitable to support a reel of film;
• at least one pair of pre-stretching rollers to unwind from said reel and stretch said film, said pre-stretching rollers being rotated about respective second and third rotation axes by a first motor system;
• a dancer roller mounted free to rotate about a fourth rotation axis on a supporting arm movable by said film during wrapping said load according to a first movement direction or according to an opposite second movement direction respectively to release or to recover the film so as to keep substantially constant a wrapping force of said film wrapped around the load;
• a drive unit connected to, and able to control, said first motor system;
• a second motor system associated with said reel holder shaft and connected to, and controlled by, said drive unit;
• wherein said first and second motor systems are suitable to be controlled by said drive unit in such a way as to rotate said pre-stretching rollers so as to unwind said film from said reel when said dancer roller is substantially stationary or is moved by said film along the first movement direction or in such a way as to rotate said pre-stretching rollers in opposite direction and additionally or alternatively rotate accordingly said reel holder shaft so as to rewind around said reel said film, when said dancer roller is moved by the film along the second movement direction.