Sterilized bag has been developed to prevent hospital infection. Normally the bag consists of plastic film and sterilized paper. Plastic film bag are made by heat seal method. When the seal strength is weak, the sterilant is lost. Instead, when the seal strength is too strong, the tearing fracture of the paper and the film occurs. Processing conditions such as heat sealing temperature and pressure so on greatly affect mechanical properties of heat sealed part. 　In this study, the mechanical properties of the heat sealed part of a sterilized bag were examined using peeling test and SEM. Optimum heat sealing temperature would be 190℃. Optimum heat sealing pressure would be 0.52MPa.

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An integrated approach to sustainability assessment for cushioning packaging based on Life Cycle Assessment (LCA) has been developed to meet challenges within the context of packaging. The approach measures the performance of the cushioning packaging with regard to social, economic and environmental aspects and produces quantitative results as a monetary unit, and integrates the results into a sustainability indicator (SI) for directly indicating the overall benefits of the cushioning packaging. Two types of cushioning packaging made from molded pulp and corrugated board respectively for packaging a gas appliance were assessed in this study as a case study demonstration. The results show that the main environmental impacts of the two cushioning packaging are global warming and acidification caused by the atmospheric emissions during production processes for the cushioning packaging materials and products. The molded pulp material with associated advanced component structure was found to be the scheme in the two cushioning packaging designs for achieving sustainability although it has somewhat higher physical costs than that of the corrugated board cushioning. The optimum for the two cases is indentified by calculating the newly developed SI.

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We proposed “Partial Seal Packaging” as a simple MAP (Modified Atmosphere Packaging) using conventional films and changing rolls of sealing machine. The bags, 600mm long and 85mm wide, were made of polypropylene (OPP) sealed partially with 0.4mm of fused part width and 0.6mm of non-fused part width. Heat sealing conditions such as temperature were decided by trial and error. In this study, we attempted to simulate temperature change in minute space inside films in the moment when a film touches a roller by Computational Fluid Dynamics (CFD). Heat sealing temperature was simulated to 125℃ by inputting initial conditions such as rotating speed, roller temperature and contact area of film and roller. This temperature was in suitable temperature range for heat sealing intensity. Temperature change simulation inside films by CFD can also be applied to evaluation of heat sealing temperature analysis of Partial Seal Packaging.

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