| 摘要 |
PROBLEM TO BE SOLVED: To provide a cap of a PET bottle or the like which can be easily opened even by a person with weak in opening the cap such as an elderly person. SOLUTION: The cap such as the PET bottle is grooved so that the cap is fitted to the PET bottle or the like by setting the diameter of a practical part of the cap touched by a hand when opening/closing the cap to be larger by 30% than the diameter of a tip of the PET bottle or the like. |
