| 摘要 |
PURPOSE:To improve a flatness appearance of a refrigerator door and to enable its manufacturing to be easily carried out by a method wherein an outer frame made of synthetic resin filled with thermal insulating agent in it and another outer frame made of synthetic resin covering a front surface of the former outer frame and forming a door surface are made substantially in flush with each other and both of them are thermally adhered to each other by an ultrasonic melting process. CONSTITUTION:A stepped part 6a is formed at an outer circumference of an outer frame 6, and a depth of the step part 6a is made substantially equal to a plate thickness of an outer frame 5. The outer frame 6 filled with foam thermal insulating agent 8 and an outer frame 5 of a door surface member of synthetic resin layered plate are melted and adhered to each other by ultrasonic waves. Since the outer frame 5 of synthetic resin and the outer frame 6 of synthetic resin are integrally assembled by an ultrasonic melting process, there is no peeling at a melted interface part caused by a thermal shrinkage and further there is no projection toward the door and so a door rich in flatness feeling can be obtained. |
