| 摘要 |
<p>A flexible perforated moulding, esp. a tubular rubber membrane closed at one end, is made around a core in a mould. Part of the mould void is transversed by pins, mounted in one wall and penetrating without contact into a corresp. recess in the opposite wall. After vulcanising, the mould is opened, air is introduced inside the moulding through a valve in the core to separate moulding and core and, finally the thin rubber regions left at the tips of the pins are pierced.</p> |
