Flow behavior of polymer melts under extremely high shear rates and flow analysis of injection molding (abstract)

1991 ◽  
Vol 35 (4) ◽  
pp. 712-712
Author(s):  
Hideroh Takahashi
Keyword(s):  
Injection Molding ◽  
Polymer Melts ◽  
Flow Behavior ◽  
Flow Analysis ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates

Molten Polymers in Strong Flows: A Nonclassical Proposal

MRS Bulletin ◽  
1991 ◽  
Vol 16 (1) ◽  
pp. 20-21 ◽  
Author(s):  
P.G. de Gennes
Keyword(s):  
Polymer Chain ◽  
Classical Theory ◽  
Polymer Melts ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates ◽  
Original Length ◽  
Molten Polymers

In spite of its importance for extrusion and molding, the rheology of polymer melts under high shear rates is not fully explained by the classical theory of Doi and Edwards. In this theory, each polymer chain is trapped in a confining “tube.” When the tube is suddenly stretched, the chain follows at first, but it soon shrinks back to its original length (“retraction process”). I propose a different view: Upon stretching, the tube becomes thinner so the chain is squeezed and tends to span a longer length of tube; there is no retraction.

scholarly journals Flow behavior of poly(phenylene oxide)-polystyrene blends under extremely high shear rates.

1990 ◽  
Vol 47 (7) ◽  
pp. 611-617 ◽  
Author(s):  
Hideroh TAKAHASHI ◽  
Yoshinori INOUE ◽  
Osami KAMIGAITO ◽  
Kunihiro OSAKI
Keyword(s):  
Flow Behavior ◽  
High Shear ◽  
Shear Rates ◽  
Phenylene Oxide ◽  
High Shear Rates

The Effect of Oil and Black on the Injection Molding of EPDM Compounds. I.

1969 ◽  
Vol 42 (5) ◽  
pp. 1321-1335
Author(s):  
William G. DePierri ◽  
J. R. Hopper
Keyword(s):  
Pressure Drop ◽  
Injection Molding ◽  
Flow Behavior ◽  
Injection Pressure ◽  
Flow Properties ◽  
Pressure Drops ◽  
Factors Affecting ◽  
Shear Rates ◽  
Divergent Flow ◽  
High Shear Rates

Abstract Factors affecting the flow properties of EPDM compounds have been studied and the findings of the study applied to the injection molding of these compounds. The level of oil and of black were found to change the flow properties of EPDM compounds. Higher levels of oil decreased the compound viscosity while higher levels of black increased the compound viscosity. The viscosity of the oil influenced compound viscosities. Compounds made with the more viscous (at 210° F) oil had slightly higher viscosities. However, changing from an aromatic to a naphthenic oil of similar viscosity had little effect on the compound viscosity. Compounds made from two different polymers of similar Mooney viscosity were found to have widely divergent flow behavior at high shear rates. Injection molding of EPDM compounds was studied with a molding assembly which had a capillary rheometer as barrel and plunger. Injection pressure data from the molding experiments was found to parallel closely the rheological data. An analysis of the pressure drops in passing through different parts of the mold assembly was made. The total calculated pressure drop agreed closely with the measured pressure drop. The viscous generation of heat was found to be proportional to pressure drop, and an equation is presented which relates the temperature increase to the pressure drop.

Relative Involvement of GPIb/IX-vWF Axis and GPIIb/IIIa in Thrombus Growth at High Shear Rates in the Guinea Pig

1997 ◽  
Vol 17 (5) ◽  
pp. 919-924 ◽  
Author(s):  
Patrick André ◽  
Patricia Hainaud ◽  
Claire Bal dit Sollier ◽  
Leonard I. Garfinkel ◽  
Jacques P. Caen ◽  
...  
Keyword(s):  
Guinea Pig ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates
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