Abstract: Measuring pipettes including integral or encapsulated filters, as well as methods and apparatuses for forming the same, are provided. A filter material (e.g., a discrete element in solid form) or a filter material precursor (e.g., a foamable thermoplastic composition and a blowing agent) to be introduced into a hollow interior of a softened thermoplastic material present within a mold during pipette fabrication. A pipette includes a filter element comprising foamed polymeric material within a mouthpiece region, wherein an outer portion of the filter element is bound to or encapsulated in an inner wall of the mouthpiece region. A filter material precursor may be supplied coaxially with a tubular flow of thermoplastic material into the mold, may be supplied laterally through a mold wall, or may be injected into a molten thermoplastic pipette forming material upstream of an extruder outlet.

Abstract: A serological pipette has an elongated hollow tubular body having an optical transmission of 40 to 70% over a range of 390 to 700 nm. The pipette body is formed from a polymer composition that includes 5 to 30 wt. % poly(styrene-butadiene-styrene) and 70 to 95 wt. % polystyrene. The tubular body is formed by extrusion at a barrel temperature ranging from 400 to 500 F.

Abstract: Measuring pipettes including integral or encapsulated filters, as well as methods and apparatuses for forming the same, are provided. A filter material (e.g., a discrete element in solid form) or a filter material precursor (e.g., a foamable thermoplastic composition and a blowing agent) to be introduced into a hollow interior of a softened thermoplastic material present within a mold during pipette fabrication. A pipette includes a filter element comprising foamed polymeric material within a mouthpiece region, wherein an outer portion of the filter element is bound to or encapsulated in an inner wall of the mouthpiece region. A filter material precursor may be supplied coaxially with a tubular flow of thermoplastic material into the mold, may be supplied laterally through a mold wall, or may be injected into a molten thermoplastic pipette forming material upstream of an extruder outlet.

Abstract: A serological pipette has an elongated hollow tubular body having an optical transmission of 40 to 70% over a range of 390 to 700 nm. The pipette body is formed from a polymer composition that includes 5 to 30 wt. % poly(styrene-butadiene-styrene) and 70 to 95 wt. % polystyrene. The tubular body is formed by extrusion at a barrel temperature ranging from 400 to 500F.