Die geometry

For other die geometries it is necessary to use the appropriate form of equation (4.12). The equations for a capillaiy and a slit die are derived in Chapter 5. For other geometries it is possible to use the empirical equation which was developed by Boussinesq. This has the form... 

Complete potential energy surfaces have been developed for a few very simple systems. However, they will remain scarce in the future for two primary reasons. First, die geometry of an N-atom molecule is described by 3N-6 internal coordinates. If the energy of 10 different values along each of these internal coordinates is sufficient to describe the surface, then 103N 6 energy points still must be computed. [101] For benzene, where N = 12, this is 1030 energy points Even with the capability... 

Chicago, II., 29th Aug-2nd Sept.l993,p.403-6. 6A MULTILAYER EXTRUSION DIE GEOMETRY FOR THERMOFORMED POLYPROPYLENE FOAM SHEETS AND BIAXIALLY ORIENTED FOAM FILMS Raukola J Savolainen A Tampere,University of Technology (TAPPI)... 

For example, reaction of ( , )-2,4-hexadiene with methyl crotonate gives a single product in which the relative stereochemistry of four contiguous stereogenic centers is explicitly defined by die geometry of the starting materials and the endo transition. 

Note that the flow rate increases with the pressure drop and decreases with increasing wire speed at constant die geometry. 

Fig. 3.14 Experimental and matching numerical simulation data for the smooth convergent die geometry of HDPE, Stamylan HD862 at T = 190°C. [Reprinted by permission from J. F. Agassant et al., Intern. Polym. Proc., 17, 3 (2002).]...

Fig. 14.25 Schematic parison die designs (a) convergent (b) divergent, and (c) straight. [Reprinted by permission from A. Gracia-Rejon, R. W. DiRaddo, and M. E. Ryan, Effect of Die Geometry and Flow Characteristics on Viscoelastic Annular Die Swell, J. Non-Newt. Fluid Mech., 60, 107-128 (1995).]...

N. Orbey and J. M. Dealy, Isothermal Swell of Extrudate from Annular Dies Effects of Die Geometry, Flow Rate, and Resin Characteristics, Polym. Eng. Sci., 24, 511-518 (1984). 

The thickness of the calendered tape depends mainly on the calender nip setting. The tape width depends on several factors, such as lubricant type and content, reduction ratio and die geometry during the extrusion, and the speed and temperature of the calender rolls.9... 

Figure 1-2. Correlation plot between calculated and experimental N nuclear shieldings of diazines obtained in three different environments, namely cyclohexane, acetone, DMSO and water. Calculated shieldings have been obtained at B3LYP/GIAO/6-311+G(d,p) while die geometries were optimized at...

The output rate of the extruder is a function of screw speed, screw geometry, and melt viscosity. The pressure developed in the extruder system is largely a function of die resistance and dependent on die geometry and melt viscosity. Extrusion pressures are lower than those encountered in injection molding. They are typically 500 to 5000 psi (3.5 to 35 MPa). In extreme cases, extrusion pressures may rise as high as 10,000 psi (69 MPa). Variants on the single screw include the barrier or melt extraction screw and the vented screw (Chapter 3). 

For the other die geometry, that of a annular space between two cylinders shown in Figure 13.24, we have the foDowing momentum balance ... 

Y.Y. Su and B. Khomami, Interfacial stability of multilayer viscoelastic fluids in slit and converging channel die geometries, J. Rheol., 36 (1992) 357-387. 

Figure 19. Change in birefringence patterns with the die geometry (Lotrene FC 1010,145 °C, ja = 36 S l).

For long die geometries (which imphes the existence of a Poiseuille flow downstream of the contraction), fully developed velocity and stress profiles are imposed at the entry section only the velocity profile is imposed at the final section. 

For short die geometries, the same boundary conditions are considered in the entry section but free surface equations are written in the downstream flow region (see paragraph 5.2.4). 

We present here numerical results obtained in a planar short die geometry with both constitutive equations for the two differential models ((30B and mPTT). 

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