DUAL ROTATING STRETCH WRAPPING APPARATUS AND PROCESS

摘要

A novel apparatus and process for high speed continuous film web wrapping of uniform loads, in which a first wrap is applied in a first direction transverse to the path of the moving load and a second wrap is applied in a second direction opposite the first direction. This dual wrap nullifies the disabling effects of helical wrap bias when a single wrap is applied at high speed to a moving load, and produces a longitudinal containment force after film web recovery over time on leading and trailing ends of the load. In the apparatus two wrapping stations are provided together with a wrapping conveyor assembly which carries the film web wrapped around the load and conveyor through the two stations. Each station includes a dispensing ring on which a film roll and an elongation mechanism are mounted, a drive motor to rotate the ring and means to drive the elongation mechanism to draw film web from the roll and stretch the same beyond its yield point at ambient temperature on its path from the roll to the load and conveyor. The regulation of elongation in the elongation mechanism and the regulation of film supply speed from the elongation mechanism are independent of film demand speed at the load.