Injection Molding Process for Making Laboratory Test-Tubes and Mold to be Used in the Molding Process Thereof

摘要

A laboratory test tube is formed between male and female mold elements by injection of molten plastic material. The female element has a bottom element formed by first and second alternating complementarily shaped wedges. At least the second wedges are able to move under the pressure of the molten plastic from a rest position to an operative position in order to form slits which allow air, but not molten plastic, to exit from the mold.