| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for heat-treating polyester, which is used for obtaining heat-treated polyester chips, which contain small amounts of gel-state materials and cyclic compounds, from which a fiber, film or hollow molding of excellent quality is obtained and which is suitable for extrusion moldability. SOLUTION: The method for heat-treating polyester comprises the steps of: beforehand putting fines having 40-60% calculated crystallinity in a heat treatment apparatus by 10-80 mg/cm<SP>2</SP>-inner wall surface area of the heat treatment apparatus; throwing polyester chips into the heat treatment apparatus when the wall temperature is 60-170°C; and heat-treating the thrown polyester chips at the temperature equal to or higher than 190°C and lower than the melting point of the polyester chip. COPYRIGHT: (C)2009,JPO&INPIT
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