| Abstract [eng] |
Multilayer polymer films are widely used in manufacturing food packaging. Before putting food products inside them, packages usually undergo sterilization process in high temperatures. In this work research was done on film systems composing of polyethylene terephthalate (PET), polyethylene (PE), cast polypropylene (CPP), aluminum foil (AL) : PET/AL, PET/PET/CPP, PET/AL/CPP, PET/AL/PE. Polyurethane glue was used for film lamination. Thermostability and mechanical characteristics were evaluated while stretching samples. It was determined that thermostability of film depends on it ‘s origin and casting orientation. It was found that most thermostable films are PET and CPP. While PE showed 35% reduction of its size. While researching multilayer PET/AL, PET/PET/CPP, PET/AL/CPP films laminated with Adcote 811 A EA/F glue and PET/AL/PE film laminated with Adcote L 785/CR765 glue, it was concluded that PET/AL film shows highest thermostability. Its dimensions after testing showed practically no change. PET/PET/CPP films dimensions after thermal exposure to 120°C temperature reduced 2 times in size laterally and 3 times longitudinally. PET/AL/CPP film dimensions laterally and longitudinally decreased twofold. PET/AL/PE film after exposure to 120°C temperature shrunk 5 times laterally and 6 times longitudinally. PET, PE, CPP polymer films mechanical characteristics dependence on film orientation during casting was researched. It was found that PET film had highest tensile strength. PE and CPP film casting orientation had no impact for its tensile strength. It was determined that after exposure to thermal effect, film deformation properties get worse, and tensile strength depends on film origin and film orientation during molding process. |
