EFFECT OF STORAGE-TEMPERATURE ON THE HEAT SEALABILITY OF POLYPROPYLENE FILM

Storage temperature effects on the sealing properties of corona-treate d polypropylene film were investigated. Samples of film stored at room temperature, 50-degrees-C, 75-degrees-C, 100-degrees-C, and 125-degre es-C for a period of 48 hours showed dramatic changes in both sealing temperature and sealing range, with sealability rapidly declining with increases in storage temperature. Differential scanning calorimetry w as used to assess changes in crystallinity of the samples. Total cryst allinity was found to increase with storage temperature. This in turn affected the film's sealability.