摘要 |
PURPOSE:To achieve good air tightness and water proof of a packing by providing the packing with a longitudinally extending central hollow portion, coating the inner peripheral surface of the hollow portion and a longitudinally extending outer peripheral surface with smooth skin layers, and making a body between the two surfaces of a foamed rubber material. CONSTITUTION:As a seal packing is made of a rubber material, a skin layer formed on the surface during foaming is a smooth surface with no minute pores, so that its water proof can be improved. As the seal packing 10 is provided with a longitudinally extending central hollow portion 11, it has an improved resilience and rapid recovery after deformation in comparison with a prior art seal packing 10. During handling of a unit with such a seal packing 10 attached thereto, the seal packing 10 will not be readily separated, permitting improvement of handling operativity. |