プラスチックフィルムの粘弾性特性を考慮した巻取りロール内部の熱応力解析(第1報，ポリプロピレンフィルムにおけるクリープコンプライアンスの応力・温度依存性)

抄録

Plastic film, formed as wound roll, is often stored and transported. Then the in-roll stress may vary over time due to viscoelastic property of the film. As a result, it could lead to wound roll defect such as slippage or blocking. One of the causes is that the film creeps in radial direction and circumferential direction depending on the stress and the temperature of the wound roll at a given time. It is important to consider the viscoelastic property on theoretical estimation of the in-roll stress in order to prevent the defect efficiently. In this study, a polypropylene film is applied as a plastic film and the creep compliances are measured by compression/tensile creep tests under various conditions. From the experimental results, it is shown that the film has anisotropic creep behavior, which depends on stress and temperature. Additionally, it is shown that stress and temperature significantly affect the radial creep compliance and the circumferential creep compliance, respectively. Furthermore, to estimate the creep compliance values on arbitrary stress/temperature condition, a prediction model expressed by the creep function is obtained based on the measurement values, which is able to apply on winding model.