| 摘要 |
The vulcanized elastomer extrusion (3, 5) has the visible portions of its outer surface covered with a thin layer (9) of a thermoplastic material which has a greater resistance to aging than the elastomer coextruded with it. The surface layer is less than 0.6 mm thick and has a hardness above 40 Shore D, while the elastomer's hardness is no more than 70 Shore A. |
