| 摘要 |
A method of manufacturing level vials involving:
a. Moulding a core (1) having the required barrel-like shape of an opaque thermoplastic material around a pin, in a conventional double-injection moulding machine.
b. Transferring said core (1) into a suitable mould in the same machine and moulding the vial body (8) of transparent thermoplastic material around it,
c. After cooling, removing said body (8) and withdrawing first said pin from the core (1) and then said core (1) from the body;
the softening temperature of said transparent plastics being lower than that of the opaque plastics. |
