To prevent a panel surface from being damaged as a result of the rigid surface of a hinge member colliding with the surface of other panel when partition panels are overlapped with each other by mounting a buffering material on a part of the outer surface of the hinge member of a door.

When panel parts 5 are contained in an overlapped state from a state that partitioning panels 1 are developed into a linear state, since the hinge member 1 is protruded from the surface of a panel 2, the hinge member collides with a subsequent panel 2. Thereby, there is a fear of the rigid outer surface of the hinge member 1 damaging the surface of the subsequent panel 2, and collision noise is generated. Thereby, the whole periphery of the cylindrical outer surface of the hinge member 1 is covered with a cylindrical buffering material 6. The buffering material 6 is a cylindrical body in a C-shape in cross section and formed of a material, such as rubber, porous resin, and foamed urethane, having proper elasticity. This constitution prevents the generation of noise and the occurrence of damage even when the hinge member 1 collides with the surface of other panel 2 with the partition panels 1 overlapped with each other.