Biaxially oriented thermoplastic pipette, and method and apparatus for forming same

Abstract

Unitary measuring pipettes include a tubular body of biaxially oriented thermoplastic material, together with size reduction, elimination, and/or reorientation of longitudinally spaced, raised circumferential witness features, to mitigate or avoid interference between such witness features and graduated volumetric markings on an outside surface of the tubular body. Methods and apparatus for vacuum forming of unitary measuring pipettes are also provided. Gas permeable apertures or pores having a maximum width of no greater than 150 microns, in ranges of 10-100 microns, 10-50 microns, or subranges thereof, may be defined in face plates or inserts received by mold blanks, or defined in molding surface of cooperating mold bodies, and may be used to produce a tubular pipette body having reduced height witness features. Cooperating mold bodies may each be produced from multiple mold body sections with gas passages defined therein and/or therebetween.