Methods for recharging a machine which is used to pack groups of products with the aid of a plastic film wherein the film of a distributor reel is unwound, the film of a full reel is subsequently engaged into an injection device in such a way that said reel becomes a distributor reel in turn, then the empty distributor reel is replaced with a new full reel. While a reel is being distributed, the full reel is placed in the machine and the free end of the film connected to the full reel is maintained in a waiting position; when it is detected that the end of the film of the distributor reel has reached a predetermined position, the advance of the film of said reel is halted and the free end of the film connected to the full reel is driven in such a way that it becomes a distributor reel; while the full reel is being distributed, the empty distributor reel is replaced by a new full reel and the free end of the beginning of the film connected to said new reel is maintained, whereupon the previously mentioned cycle is resumed with a new reel when the final extremity of the film of the full reel which is being distributed reaches a predetermined position in the machine.