Melting flux

Figure Al. a) Porosity distribution for a ID melt column (solid curve) assuming constant melt flux (see Spiegelman and Elliott 1993). Average porosity is shown as the dashed line, b) Emichment factors (a) calculated from the analytical solution (solid curves) and approximate analytical solution (dotted curves) for °Th and Ra. c) Emichment factors (a) calculated from the numerical solution of Spiegelman and Elliott (1993) for °Th and Ra. In these plots, depth (z) is non-dimensionalized. See text for explanation.

KEYWORDS Ulsan carbonate rocks, Kyongsang Basin, magnetite deposit, melting/fluxing of crustal carbonate melt, Alkaline A-type granitic rocks... 

Other separation methods mentioned by Fisk and Remeika (1989) include centrifuging off low-melting fluxes, evaporation of a high-vapour pressure metal, cutting crystals from the melt, etc. In the conclusion of their review, Fisk and Remeika... 

In this chapter the physical properties of resins related to processing will be described. The chapter and Appendix A4 include physical properties for many resins. These properties include bulk density and compaction, lateral stress ratio, stress at a sliding interface, melting flux, heat capacity, thermal conductivity, and melt density. Some of these properties are easy to measure by many laboratories while others such as the melting flux and stress at a sliding interface can be measured in only a few places using highly specialized equipment. 

Figure 4.13 Melting flux for a PC/ABS blend with an MFR of 1.7 dg/min (260 °C, 3.8 kg). The data were measured using a pressure of 0.7 MPa...

As discussed in Chapter 5, the solids-conveying rate for a specific screw is directly proportional to screw speed. That is, if the screw speed is increased by a factor of two the solids-conveying rate will nearly double. The melting flux of the screw as measured in kg/(h-m2) at the barrel wall, however, will not increase at the same rate. Typically, the melting flux will increase by 40% for a doubling of the screw speed [1]. In order to complete the melting process, additional area at the... 

The melting process for a resin is complex and depends on many parameters, including screw speed, screw geometry, barrel temperatures, and channel pressures. Moreover, the compression ratio and compression rate also affect the pressure in the channel. The melting flux is known to increase with increasing pressure in the channel [1,12]. A series of Maddock solidification experiments were performed at... 

Altinkaynak, A., Gupta, M., Spalding, M.A., and Crabtree, S.L, Shear Stress and Melting Flux for Polycarbonate Resins, SPEANTEC Tech. Papers, 54, 1405 (2008) Maillefer, C., Swiss Patent 363,149 (1962)... 

The Screw Simulator was also used to measure the melting flux of TPU resins at conditions similar to those expected in the melting section of the screw. At these conditions, the melting flux was measured at 0.2 kg/(m s). This melting flux is relatively low. For example, the melting fluxes [11] for linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE) resins are 0.3 and 0.4 kg/(m2- s), respectively. The relatively low melting flux for TPU resins is a contributor to the solid polymer fragments in the extrudate. 

Appendix A4 Shear Stress at a Sliding Interface and Melting Fluxes for Select Resins... 

Table A4.2 Melting Flux Data for Select Resins in this Book...

Melting fluxes for select resins are shown in Figs. A4.9 through A4.16. Like the resins in Section A4.1, these resins were commercially available when tested, and they contained only low levels of standard additives. 

Figure A4.15 Melting flux for an LDPE resin with an Ml of 2.0 dg/min (190 °C, 2.16 kg) as a function of temperature and sliding velocity at a pressure of 0.7 MPa. This resin was identical to that used in the solids conveying study in Section A5.6...

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