Rotatable film wrapping apparatus and process for unitizing a load with a compressive overwrap

摘要

@ A rotatable film wrapping apparatus (30) for wrapping a load (24) having a film web pre-stretch mechanism (70) which dispenses film at a varying speed controlled independently of variations in film tension and speed between the pre-stretch mechanism (70) and the load (24), and a supply speed control mechanism (90) which varies the supply speed of web from the pre-stretch mechanism (70). The supply speed control mechanism (90) is configured as a predetermined model of the load (24) to minimize variation in film elongation and containment as successive load edges intercept film web during wrapping. A power pully or roller engages the supply speed control mechanism (90) to accelerate and decelerate the pre-stretch mechanism to overcome rotational inertia of the film roll (56) and pre-stretch mechanism (70). Tension reductions in the web (58) caused by holes at web imperfections do not slow or stop the pre-stretch mechanism (70).