The State of U. S. State Legislative Research: A Comment

Kurtz, Karl T.; Newkirk, Marie; Pound, William T.; Tubbesing, Carl D.

doi:10.2307/439711

Cited by 2 publications

(1 citation statement)

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“…and distribute evenly low viscous PPA: elongated dies, circumferential grooves in the mandrel and housing near the die exit, as well as tapered ridges of the die and an elongated core. Kurtz in several patents [88][89][90] described various designs of the extrusion die to delay the onset of sharkskin instability that would also be beneficial for the use with our PPA. There is no explanation for the geometrical solution of the sharkskin problem in the patents of Kurtz.…”

Section: Mechanisms Of Lubricationmentioning

confidence: 99%

Low viscous hydrophilic processing additives for extrusion of polyethylene at reduced temperatures

Kulikov

Hornung

Wagner

2010

Polymer Engineering & Sci

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Industry is using fluorinated polymer processing additives (PPA) to delay the onset of sharkskin to higher rates of extrusion of PE resins. Yet it is necessary to keep elevated temperatures during extrusion to reduce apparent melt viscosity. We propose to use low viscous PPA made from reacting mixtures of polyethylene glycol with organic polyacids, phosphoric acid, and polyesters of oxiacids of Phosphorus. Surprisingly, extrusion pressures and apparent viscosity with the novel PPA at reduced temperatures are less, than at elevated temperatures. In total, extrusion pressures can be reduced 2-5 times for concentrations of PPA from 0.1 to 0.5 wt%, while sharkskin melt fracture can be eliminated for concentrations of PPA above 0.02 wt%. Extrusion with the novel PPA at reduced temperatures potentially increases productivity, reduces production cost, and allows processing of PE resins of higher MW and highly filled polymer composites.The use of novel PPA is a challenging opportunity to simplify processing of PO resins. The use of low viscous PEG in the composition of PPA with existing machinery has to be combined with changes in the die design for film blowing, blow molding, and pipe extrusion to extract

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Section: Mechanisms Of Lubricationmentioning

confidence: 99%