| 摘要 |
Mfr. comprises surrounding a mandrel with an inner tube of vulcanisable elastomeric material, followed by at least one reinforcing layer, followed by an outer tube of vulcanisable elastomeric material, then hardening the elastomeric materials by applying heat. Before hardening, the outer tbe is surrounded by a tubular plastic sheath, pref. of thermoplastic material e.g. polysulphone or a thermosetting plastic, in which are formed zones which concentrate stress before or after hardening. The sheath is stressed in such a way that it breaks in these zones, and is then removed. Method avoids the difficult manipulation of Pb. |
