| Summary: | 碩士 === 國立臺灣科技大學 === 材料科學與工程系 === 103 === In this study, Ethylene vinyl alcohol、Low-density polyethylene and Polyamide6 is used as raw materials, using the Melt flow tester and the MCR rheometer to characterize the flow properties and rheological behavior and choose the proper materials to extrude EVOH/ Nylon6/LDPE multilayer film by three layer co-extruder .
The effects of drawing speed 、draw ration、drawing temperature and annealing process on the crystallinity and thermal property of the film were studied with Differential scanning calorimeter 、Dynamic mechanical analysis and Wide angle x-ray diffraction；and the barrier properties were measured by Water Vapor Transmission Tester and Oxygen permeation analyzer. The results showed that the tensile strength rised but the elongation droped with the increasing of drawing rate, and the crystallinity droped,too. The tensile test of heat drawing temperature shows the reverse trend with drawing rate and heat setting temperature should be controlled in the range of 55℃~75℃.The crystallinity increased with the drawing ratio .From the result of DSC and DMA ,the annealing temperature increased ,the crystallinity also ascending. The crystallization process nearly accomplished with the condition of 100℃ for 60 seconds. The tensile strength of machine direction is higher than transverse direction，and lower for elongation, and from the evidence of DSC the crystallinity of machine direction is larger than transverse direction. There is a positive relation between crystallinity and barrier property ,the barrier ability increased with the crystallinity.
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