Die characteristics curves

Figure 3.6 Screw and die characteristic curves for a 45 mm diameter extruder with an PE-LD.

Dubinin, M.M. and Radushkevich, L.V., Equation of die characteristic curve of activated charcoal. Proc. Akad. Set. USSR 55 (1947) 331. 

In contrast to extruder output, die output increases with head pressure (Fig. 5.27). Die output is also enhanced by low-viscosity melts and larger die gaps. The match between extruder and die output shifts with operating conditions. The simple die characteristic curve in Fig. 5.27 shows the optimized processing conditions. However, this curve does not consider extrudate quality. Other lines would be required to locate the onset of surface defects, such as melt fracture, and for incomplete melting. 

The pumping capability and characteristic of an extruder can be represented with sets of die and screw characteristic curves. Figure 3.6 presents such curves for a conventional (smooth barrel) single screw extruder. 

Fig. 18. Transfer characteristics ofthe inverter shown in Fig. 17 FDD was fixed at 40 V with Fgo = —70 V, — 60 V, and — 50 V. The dashed lines are Die theoretical curves, the solid lines from experiment. [From Nara and Matsumura (1982).]...

Fig. 3.17. J-V characteristics of the ITO/PEDOT PSS/MEH-PPV/Au diode at 240 K. The thickness of the active layer is 120 nm. The symbols represent die experimental data. The dash-dot line represents the ohmic region due to thermally generated and background carriers. The dashed line represents die calculated values using the conventional equation (3.42) with a zero Schottky barrier, while die dotted curve represents the calculated values using Eq. (3.46) with a Schottky barrier = 0.1 eV. At lower voltages below die point D, the plot of Eqs. (3.46) and (3.42) are practically identical. The values of die parameters used in this representation are N0 = 1019 cm-3, Tc = 400 K, e = 3, e0 = 8.85x 1(T14 F/cm, fi = 7x 1(T5 cm2/Vs, iVv = 2x 1019 cm-3 and Hh = 4.5 x 1018 cm-3 [44],...

The characteristic curve of extrudate flow including adherence to the walls, and hence representative of shghtly to moderately entangled polymer flow in sudden two-dimensional or axisymmetrical contractions [7, 32], is represented in Fig 2. It shows a slope discontinuity above a certain pressm-e level, which depends on the pol3uner-die pair considered. With low flow rates, the flow is stable. Indeed, for these regimes, allowing for entrance effects, the flow curve is in fact representative of the shear rheometry of the polymer imder consideration, at low shear rates [34]. The slope discontinuity of the head loss curve indicates a modification in the structure of flow. It will be seen that this corresponds to the triggering of a hydrodynamic instability upstream of the contraction. 

Equation (5.25) for the metering section and Eq. (5.26) for the die, can be solved graphically. The solution, lying at the intersection of the two curves (Fig. 5.11), is known as the extruder operating point. The performance of a real extruder at different screw speeds (varying V) and with different dies (varying the pressure flow component) can be used to construct the screw and the die characteristics, and confirm the analysis. 

Single-component adsorption equilibria on activated carbon of the n-alkanes Q-C4 and of the odorant tert-buty I mercaptan were measured at the operating conditions expected in a large-scale facility for adsorbed natural gas (ANG) storage. The experimental data were correlated successfully with the Adsorption Potential theory and collapsed into a single temperature-independent characteristic curve. The obtained isotherm model should prove to be very useful for predicting die adsorption capacity of an ANG storage tank and to size and optimize the operation of a carbon-based filter for ANG applications. 

Figure I displays the experimental characteristic curve obtained and die values employed to generate it. The existence of very little scatter in the data demonstrates that the isotherms of the various adsorbates were successfully correlated as a single temperature-independent characteristic curve. This fact corroborates the applicability of the Potential theory to the carbon under study.

It is now possible to obtain the characteristic curve of the transfer function as long as the alternating field is smaller flian the widfli of the absorption line at halfmaximum, which is usually the case in an EPR experiment die small value of die spin-spin relaxation time, T2, causes the width of the lines to become greater than about 10 Gauss. 

Fig. 19.23. Characteristic screw and die operating curves. Courtesy Monsanto.)...

Figure 8.23 shows emission spectra characteristic of the energy transfer systems studied in Ref. 2. In each case the principal excitation in the ultraviolet is of the donor, Cl. The lowest curve (a) is for a neat Cl solution in glycerol at 3x 10 M. The second curve (b) is the spectrum of a bulk sample containing the donor and an acceptor (R6G at a concentration of 3 x 10 s M). The upper curve (c) shows the spectrum of a 10-/mi-diameter spherical particle of die same material used to obtain curve b. The emission intensity, normalized to the donor peak, is considerably enhanced at the acceptor peak, indicative of extra transfer in the particle compared to the corresponding bulk sample. 

As a result of the non-Newtonian behaviour both expressions for the pressure flows bxpirj and cxplrj) are no longer valid. The curve for the die is now curled upward since the apparent viscosity decreases with increasing shear stress. Also the shape of the screw characteristic changes. 

The response is indicative of die electrothermal behavior of die bridgewire-explosive interface. Bridgewir.es which deviate from the characteristic heating curve have been dissected and examined to determine the cause of die abnormality. Deliberate faults have been fabricated into squibs. The relationship of the specific abnormality and the fault associated with.it have been demon strated (Ref 1, abstracted in Ref 3)... 

Typical curves schematically showing the current-voltage characteristics of a redox system are shown in Fig. 2. Curves A and C are the polarization curves for the anodic and cathodic reaction, respectively. Eeq is die reversible potential for the various concentrations of the cathodic reactant - tne metal ion in the case of a metal - and Cp C2 and the polarization curves for decreasing concentration. 

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