MACHINE DRILLED POLYETHYLENE FILM FOR MODIFIED ATMOSPHERE PACKING

Federico Hahn; Francisco Marin; Salvador Valle

Volume : IV, Issue : X, October - 2015

MACHINE DRILLED POLYETHYLENE FILM FOR MODIFIED ATMOSPHERE PACKING

Federico Hahn, Francisco Marin, Salvador Valle

Abstract :

Modified atmosphere packing (MAP) is used to increase the shelf life of fruits and vegetables. Plastic films for MAP require perforations with diameters ranging between 50 and 200 �m. This drilling process requires an automatic machine for plastic film punching. A transmission-based cam was used so that hot needles perforated the film while it was stationary. The transmission disk allows the cam to rotate when the plastic film is moved horizontally. When the cam stops, film movement ceases and the plate with needles attached moves down punching holes in the film. In order to produce well-formed circular perforations it was found that optimum needle temperature was 90�C and that the plastic film tension should be maintained at 80 N. When the machine is required to process several bag sizes, the cam transmission is replaced by an electronic controlled clutch system. Two clutches are used in order to synchronize the roller movement and the plate punching. Only one clutch operates at a time and the clutches are activated by an encoder signal.