Abstract: Die plates for polymer extrusion may include a die plate having an entrance face for accepting a polymer flow and an exit face for extruding one or more polymer strands, wherein the exit face including at least one element constructed from polycrystalline diamond. Systems for extruding polymer may include: an extruder, a die plate attached to an outlet of the extruder and having (i) an entrance face for accepting a polymer flow and (ii) an exit face for extruding one or more polymer strands; an array of blades configured to rotate so as to contact and slide along the surface of the die exit face, thereby cutting the one or more polymer strands extruded therethrough; wherein (a) the exit face, (b) the blade array, or (c) each of the exit face and the blade array comprises at least one element constructed from polycrystalline diamond.

Abstract: Provided is a stirred tank polymerization reactor system having a reactor tank, a stirring assembly including a rotatable shaft that extends through a wall of the tank, and a triple barrier mechanical seal. The mechanical seal includes an outer cylinder mounted in the wall of the tank, an inner cylinder that is rotatable relative to the outer cylinder and connected to the shaft, and first, second, and third fluid barrier seals mounted between the outer and inner cylinders at different positions along the axis of rotation of the inner cylinder. First and second sources of pressurized barrier fluid are connected between the first and second pressure fluid barrier seals and the second and third barrier seals, respectively. The three barrier seals advantageously “step down” the differential pressure experienced by the uppermost barrier seals, substantially reducing mechanical stresses experienced by the annular sealing rings and seats.

Abstract: Disclosed in one aspect is a valve comprising (a) a valve body having a poppet valve chamber with an axis running there through; (b) a seat having a seat sealing surface, and a outer-seat surface, the seat located axially within the poppet valve chamber; and (c) a poppet having a poppet sealing surface, the poppet being located axially within the poppet valve chamber; wherein a poppet-seat interface is created between at least a portion of the seat sealing surface and at least a portion of the poppet sealing surface, the poppet-seat interface being at an angle ? of from 20 to 90° to the axis. In one embodiment the seat is removable, allowing the geometry of at least the poppet head surface and/or the seat inside surface, which defines a fluid flow-path cross-section, to be tailored.

Abstract: Provided is a stirred tank polymerization reactor system having a reactor tank, a stirring assembly including a rotatable shaft that extends through a wall of the tank, and a triple barrier mechanical seal. The mechanical seal includes an outer cylinder mounted in the wall of the tank, an inner cylinder that is rotatable relative to the outer cylinder and connected to the shaft, and first, second, and third fluid barrier seals mounted between the outer and inner cylinders at different positions along the axis of rotation of the inner cylinder. First and second sources of pressurized barrier fluid are connected between the first and second pressure fluid barrier seals and the second and third barrier seals, respectively. The three barrier seals advantageously “step down” the differential pressure experienced by the uppermost barrier seals, substantially reducing mechanical stresses experienced by the annular sealing rings and seats.