| 摘要 |
The invention is a moulding method for the manufacture of elastic tubular elements (S) with helical profile, comprising the following operations: positioning of a mould (1) into an injection moulding press, said mould (1) comprising a die (4) and a punch (2) in the shape of a truncated cone, whose side surfaces have helical profile; injection of plastic material (M) in the mould (1) to obtain a hollow elastic moulded element (C) in the shape of a truncated cone and with the side surface shaped according to the helical profile of the punch (2) and of the die (4) and with closed small base (Ca); extraction of the punch (2) from the moulded element (C) through rotation on its longitudinal axis (3); opening of the die (4); extraction of the moulded element (C) from the mould (1); cutting of a through hole in the small base (Ca). The extraction of the punch (2) from the moulded element (C) starts when the die (4) is closed and continues when the die is open, and is facilitated by blowing a pressurized aeriform substance between the punch (2) and the moulded element (C). |
