METHOD AND APPARATUS FOR INSPECTING SEALED STATE OF CONTAINER MOUTH, SEALING STRUCTURE OF CONTAINER MOUTH, SYNTHETIC RESIN CONTAINER, SCREW CAP AND PREFORM OF THE SYNTHETIC RESIN CONTAINER SUITABLE FOR THE INSPECTING METHOD AND APPARATUS

摘要

PROBLEM TO BE SOLVED: To allow a container to be evaluated in its sealability without unplugging the container by placing markers having a certain positional relation with a screw end of each threaded part of the container and a screw cap and determining whether or more screwing is appropriate from the positional relation of a pair of markers after the screw cap is mounted. ;SOLUTION: A container is equipped with a male screw 11 to be screwed with a screw cap 20 on an outer periphery of a mouth 10, and a cap locking ring 12 and a support ring 13 are formed below it. In this case, markers M1, M2 provided along an outer periphery of the support ring 13 and an outer periphery of the screw cap 20 are provided to be in a line at a predetermined distance in an axial X-direction of the mouth 10 when the screw cap 20 is screwed into the male screw 11 by a predetermined amount to have the mouth 10 sealed. When a screwed amount of the screw cap 20 is inappropriate, since the marker M2 is shifted in a peripheral direction with respect to the marker M1, it is determined that the screw cap has been appropriately mounted by a size of this shift.;COPYRIGHT: (C)1998,JPO