| 摘要 |
PURPOSE: Thermo-shrinkable polyester film is provided to prevent a label, printing and physical property from being damaged by shrinking the film at a low temperature. CONSTITUTION: The contraction start temperature of thermo-shrinkable polyester film in a main contraction direction is 72-88°C. The maximum contraction temperature of the main contraction direction is 85-100°C. The maximum contraction tension of the main contraction direction is 0.65-1.30kg/mm^2. The dynamic glass transition temperature of the main contraction direction measured by a dynamic thermal mechanical analysis method is 90-100°C and viscosity is 0.60-0.70dl / g. A manufacturing method of thermo-shrinkable polyester film comprises the following steps. Polyester is pressured at 200-350°C. Artificially, the polyester film is extended with 0.1-5% more compared to the ratio which happen to be extended naturally. The pressurized polyester is pre-heated at 80-100°C. The polyester is extended in a width way at 70-95°C. [Reference numerals] (AA) Maximum contraction stress (Smax); (BB) Initial load (Ls); (CC) Shrinkage initiating temperature (Ts); (DD) Maximum contraction expression temperature (Tsmax) |
