Patent Number: 8,713,993

Title: Method and apparatus for inspecting pinhole in synthetic resin bottle

Abstract: Provided is a pinhole inspecting method for suitably inspecting a pinhole in a bottle compared with conventional pinhole inspection. A reference inner pressure (P.sub.1) is a bottle inner pressure obtained directly after closing a supply valve (3) after opening the supply valve (3) for only a predetermined time. Whether the reference inner pressure (P.sub.1) is over a previously specified first threshold value (P.sub.th1) or not is checked, and when it exceeds the first threshold value (P.sub.th1), airtight status of the bottle is held for a predetermined time, and then a pressure reduction quantity (.DELTA.P) of the bottle inner pressure from the reference inner pressure is measured after a fixed time. The bottle is judged to have no pinholes only when the value of .DELTA.P is not exceeding the previously specified second threshold value (.DELTA.P.sub.th2).

Inventors: Matsushita; Yousuke (Yokohama, JP), Sawane; Noboru (Yokohama, JP), Oobuchi; Yasushi (Yokohama, JP)

Assignee: Toyo Seikan Kaisha, Ltd.

International Classification: G01M 3/34 (20060101)

Expiration Date: 5/06/12018