Incomplete melting

Knob mixers work well to eliminate fine striations in color uniformity and thermal gradients. Since knob mixers are primarily distributive mixers, they are not suited for mitigating solid polymer fragments from an incomplete melting process. 

Figure 11 Oxygen isotopic compositions of whole-rock primitive achondrites. Data for a given class are much more scattered than data for differentiated achondrites shown in Figure 10, as a result of incomplete melting and homogenization. Several genetic associations are implied by the data (i) aubrites and enstatite chondrites (ii) acapulcoites and lodranites (iii) lAB irons and winonaites and (iv) ureilites and dark inclusions in carbonaceous chondrites. This and Figure 10 are drawn to the same scale for comparison (source Clayton and Mayeda, 1996).

Figure 5.20 Characteristic surface features of a typical APS hydroxyapatite coating with well developed overlapping particle splats and some loosely adhering incompletely melted spherical particles (Heimann, 2007, 2008).

Fig. 3. Unlinking and melting of covalently closed DNA by topoisomerase V. (A) Electrophoresis of control relaxed plasmid DNA (1), negatively supercoiled (2), and the same DNA as in (1) but after incubation at 95°C with topo V (3). —SC and U indicate negatively supercoiled and unlinked DNA, respectively. (B) Unlinked DNA strands of pBR322 DNA by electron microscopy. The molecule shown here is magnified approximately 120,000. ssDNA circles are linked onee. (C) An illustration of incomplete melting of circular DNA at high temperature and its complete melting and unlinking by topoisomerase V. Duplex regions and melted strands are shown by thick and thin lines.

Relic-grain bearing 12 Rehc ohvine, metal/sulfide grains, incompletely melted... 

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. 

Flaws produced in glass fabrication are usually a result of incomplete melting of the batch constituents or of attachment of contaminant particles to the surface of the glass during forming. Rapid quenching at contact with a mold can produce chill marks that result in high stress concentrations. 

Partial Melting Incomplete melting of a rock mass. The magma commonly separates fl om the site of melting. 

Figure 10.9 Typical plasma-sprayed hydroxyapatite coating for biomedical implants, showing well-developed stacked splats and loosely adhering incompletely melted oversized particles with a spherical shape.

Figure 9 shows the effect of polymer composition on the physical properties of a series of PET copolymers containing p-hydroxybenzoic acid and hydroquinone. The tensile strength, flexural modulus, and Izod impact strength all have maximum values for polymers containing about 50 mol % PET and 50 mol % PHB/THQ combined. The increase in physical properties is believed to reflect the increase in liquid crystallinity of the polymer melts as the combined PHB/THQ components approach 50 mol %. The lower physical properties values obtained at the 70 to 80 mol % PHB/THQ levels may result from incomplete melting of the polymers at the 280°C melt temperature. 

With a demand over the intervening years for higher output rates, the possibility of incomplete melting due to solids bed break-up needed attention. This lead to the development of melting devices and barrier screws. 

Completion of melting of the solids bed moves towards and beyond the end of the compression/melting zone as screw speed is increased. It may even result in incomplete melting at the screw tip and lumpy extrusions. 

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