The Complete Dow Solids Conveying Data Set

The stress at the sliding interface was measured using a Screw Simulator as outlined in Section 4.3.1 for the LDPE resin and is shown in Fig. A5.17 at a pressure of 0.7 MPa and shown in Fig. A5.18 at a pressure of 3.4 MPa. At temperatures of less than about 110 °C, the stress at the interface is due to a frictional force mechanism. At temperatures higher than 110°C, the forces are from a viscous mechanism. The coefficients of friction were reported as stresses so that the data from both mechanisms can be reported on the same figure. The coefficient of friction is related to the stress at the interface r as follows  

and Spalding, M.A., A New Model for Solids Conveying In Single-Screw Plastlcatlng Extruders, SPEANTEC Tech. Papers, 43, 211 (1997) 

Spalding, M. A., and Hinton, C. E., Theoretical and Experimental Analysis of Solids Conveying In Single-Screw Extruders, SPE ANTEC Tech. Papers, 42, 199 (1996) 

Yamamuro, J.A., Penumadu, D., and Campbell, G.A., Modeling Solids Conveying In Polymer Extruders, Int. Polym. Process., 13, 3 (1998) 

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