| 摘要 |
PROBLEM TO BE SOLVED: To provide a light-weight plunger and prevent it from sticking to the inner wall of a storage container, by constituting the plunger to form a cylindrical shape with a flexible foam of closed cells, which has no adhesive property, and forming a little larger circumferential surface than the inside section of the storage container. SOLUTION: A plunger 7 is formed from a cylinder made of a flexible foam of closed cells which has no adhesive property. The plunger 7 has a little larger circumferential surface than the inside section of the storage container 2. And hence the plunger 7 can slide along the inner wall 8 of the storage container 2. Since the circumference of the plunger 7 is a little larger than the inside wall 8 in which the plunger is arranged, the plunger 7 has an outline fitting in the section of the storage container 2. Even when the section of the storage container varies at a bend part, the plunger can fit tightly in the bend because of elastic deformation of the flexible foam. |
