the present invention forms screw - like projection at the entrance of ceramic bottle and enables air - tightening with plastic cork , formed with screw - like projection in its body . it guarantees air tightening of ceramic bottle , and does not use imported cork , which decreases the need to import . moreover , increases productivity by automating the air - tightening process of plastic cork . the present invention can reduce cost of production , at the same time , increasing productivity , and it can be re - used multiple times after the air - tightening .