| 摘要 |
PURPOSE:To judge the property of dried synthetic resin powder and the existence of trouble occurring in a drier body during its operation by detecting the vacuum keeping property of the inside of the drier body at the state where the synthetic resin powder is being included in the drier, after the drying has been finished. CONSTITUTION:Synthetic resin powder is supplied into a drier body capable of vacuum heating. While evacuating the inside of said body, the heat drying under vacuum of the synthetic resin powder is begun by hasting said resin from the outside of the body. After the heat treatment under vacuum has been finished, the operation of a heat source is stopped and the resin powder is cooled by heat radiation at the state where the synthetic resin powder is being kept in the body. Next, a vacuum source is operated, and when said powder in the body is cooled to a specified temperature, the vacuum source is stopped, and the connecting path between the vacuum source and the body is closed, thereby causing the drier body to be perfectly sealed, while vacuum is being kept. While leaving the sealed condition for a specified time, the property of drier synthetic resin powder and the propriety of said body-reuse are judged, detecting the change of the vacuum degree during said time. |
