MANUFACTURE OF THIN-WALLED CONTAINER

摘要

PROBLEM TO BE SOLVED: To manufacture a heat-resistant thin-walled container made of PET resin for which the softening temperature is increased without using a material which causes environmental hormone such as polycarbonate resin. SOLUTION: A molded PET sheet is manufactured through a process of reheating the molded sheet in the non-crystalline state to the temperature close to the melting temperature and softening the same, and then cooling gradually to immigrate the same into the polycrystalline state and quenching the sheet to discontinue the immigration into the crystalline state when the sheet is immigrated into the polycrystalline state to a certain extent (when lowered to approximately to 130 deg.C), and a process of heating and a softening the PET sheet varied into the state between the non-crystalline state and the polycrystalline state in the above process to form the sheet into a tray-shaped thin-walled container. Also, the container is manufactured through a process of stretching the PET sheet in the non-crystalline state to the stretch possibility limit or lower (approximately 2 times) and a process of heating and softening the PET sheet into the tray-shaped thin-walled container while pressing the periphery of the sheet stretched to the stretch possibility limit or less by the above process.