PIPETTE JET

摘要

A method of manufacture is disclosed suitable for the production of a multiple of pipettes, each such pipette having a jet of consistent shape, volume and aperture size. A glass tube (8) accommodates a removable mandrel (9) which is a close fit within the bore of the glass tube (8) but is tapered at one end in the required shape of the intended profile for the resultant jet. A metallic heat sink ring (11) is positioned around the exterior of the tube (8) where the mandrel (9) is accommodated. An upper gas jet (12) and a lower gas jet (13) independently heat the glass tube (8) simultaneously at different points in the region of the tapered portion of the mandrel (9) deforming the glass tube (8) downwards to become substantially contiguous with the outer surface of the tapered portion of the mandrel (9). After cooling, the mandrel (9) is removed and the end of the now tapered portion of the glass tube (8) is smoothed, if necessary, and/or ground to an aperture diameter required for the jet.