45D-19 |
Modification of surface properties for food packaging polymers using RF plasma surface treatment |
C. L. HSU, Dept. of Food Science, Yuanpei Univ. of Science & Technology, 306 Yuanpei St., Hsinchu, 300, Taiwan, M. C. Kao, Deaprtment of chemical engineering, Chung Yuan Christian University, Chung-Li, Taiwan, C. M. Huang, Department of Environmental Engineering, Kun Shan University of Technology, Tainan, Taiwan, and W. H. Tao, Department of Chemical Engineering, Chinese Culture University, Taipei, Taiwan. JUSTIFICATION: Most polymeric surfaces are inert and water resistant, and have low surface energy. There are not considered to be the properties needed for food packaging applications. Consequently, surface treatments are needed to modify the surface layer of a polymer by inserting some functional groups onto the surface, improving its wettability, sealability, printability, dye uptake, or adhesion to other polymers or metals, while maintaining desirable bulk properties of the polymer. OBJECTIVES: The objectives of this study are to improve the wettability, printability and barrier properties of the food packaging polymers, such as Polyethylene terephthalate (PET) and polypropylene (PP), using the plasma surface modification technology. METHODS: The hydrophilic functional group was grafted on the surface of food packaging polymers using plasma surface treatment technology. The operation parameters include power generator (RF), power output, operation pressure, percentage of gas or monomer mixtures were controlled to investigate the optimum conditions. The contact angle meter and FT-IR were used to measure the surface properties of the treated packaging polymers. The barrier properties and aging test were also investigated to verify the effectiveness of the treatments. RESULTS: Results indicated that the wettability and the printability of PET surface could be significantly improved using oxygen plasma. The contact angle of the treated PET surface increased as increasing of the aging time until a certain level. The spectroscopic diagram of the FT-IR indicated that the bulk properties of the polymer did not be changed after surface treatment. SIGNIFICANCE: These results suggest that the surface properties of the food packaging polymers could be improved by utilizing the plasma surface treatment technology. These results can be used as a basis for optimizing plasma operation parameters so as to widen the applications of the packaging polymers and to increase the commercial value of the polymer products.
Session 45D, Food Packaging: General
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