Glass pipettes for laboratory use - obtd by heating and drawing one tube which is then cut into two pipettes

摘要

In mfg. pipettes, a tube of brittle material is cut into sections of the same length, the ends of each section then being heated to round off the edge and the ends closed by wicks; the blanks thus obtd. are sterilised and the middle part heated to the softening pt. of the glass followed by drawing, and cutting the middle section by means which favour the sealing of the two ends. The cutting of the drawn, middle part, is pref. achieved by heat, i.e. sepn. into two parts by melting. Used for mfrg. of pipettes used in analytical laboratories or biological research, e.g. for insertion in cultures in test tubes. Reduces the number of mfg. operations, permitting mechanised prodn. at high rate and at low cost.