Friction drive stretch wrapping apparatus

Abstract From the Canadian patent

An apparatus for applying stretchable plastic film to loads for containment of the loads using two frictionally connected rollers which are held together and driven by the film web at different speeds to elongate the plastic film beyond its yield point. After the elongated film has been stretched, it is wrapped around a rotating load. The rollers are cammed apart during the beginning of the wrap so that relatively untensioned film is wrapped around the load at the beginning of the wrap. The cam force is then released and the rollers are pulled together in frictional engagement by the film web being pulled off of the film roll to stretch the film web.