JPS6447928A - Leakage detector for sealed container - Google Patents

Abstract

PURPOSE:To achieve a higher detection accuracy and speed of a fine leakage in a sealed container made of soft material, by pressing the sealed container at a fixed pressure at a measuring section after the pressing thereof at a compressing section to detect a displacement thereof. CONSTITUTION:As a sealed container reaches a compressing section 19 conveyed with a conveyor 40, the body of the container is pressed passing between a pair of press rolls 22. When the sealing of the container is poor, air and a content liquid at an upper space leaks at a defective part and the container is depressed at a point depressed with a reduction in pressure. After a specified time, as the container reaches a measuring section 31 with the depression left, an air cylinder 26 is operated at a fixed pressure to press the side of the container at a fixed pressure with press rolls 24 and 25 again. At this point as the depression developed by a pressing section 22 is not restored, a displacement of the cylinder rod 27 increases. The displacement of the rod 27 is detected with a displacement meter 30 to be compared with a set value by a CPU. When the displacement is not within an allowable range, a rejection signal is emitted and a discharge device is operated to discharge the defective sealed container outside a line from the conveyor 40.