Extrusion energy requirements

Third, the pronounced difference in stability between the naphtho[2,3-sulfur extrusion processes. In contrast to the substantial instability of 116, the increased stability of 114 may be due to the energy required to convert two aromatic rings into the o-quinoid form in 114a. 

A theoretical analysis based on shear energy was carried out with the aim of illustrating the mechanism of shear nucleation through a slit channel die in continuous microcellular foam extrusion. The shear energies for different positions and for different experimental conditions were calculated to demonstrate the various contributions to the surface free energy required for bubble nucleation. 14 refs. 

Processibility is dependent on the viscosity or plastic flow of the rubber compound,i.e., resistance to flow. Plasticity or viscosity determines the energy requirement of the rubber during milling, calendering or extrusion while the time to the onset of curing, i.e., scorch time, indicates the amount of heat history which can be tolerated before the rubber is converted from the plastic to the elastic state at which time processing becomes virtually impossible. 

The OPS extrusion process is distinguished from conventional cast extrusion (unoriented) processes by the additional energy requirements of the MDO and TDO units. Cast extrusion processes generally require 0.2-0.7kWh per kilogram of extruded product. The OPS process requires 0.7-0.9 kW h per kilogram of extruded product, which increases conversion cost. 

The energy required for both compression and extrusion is decreased by a factor of about two as temperature increases from room temperature to 225 C. 

In addition to the photochemical activity of titanium dioxide, grades have been developed for many other reasons discussed below. Millennium developed its Tiona RCL-188 grade for high performance extrusion. A surface treatment based on phosphate and an undisclosed organic material lowers the energy required for the process, improves the dispersion of pigment even at very high concentrations and without the addition of process aids. When stearates are used in formulation... 

Energy Requirements. As mentioned earlier, the energy requirements for extrusion processing are furnished by a drive motor whose energy input is converted into heat. An energy balance of the extruder is shown in Equation 2 (9) ... 

Apart from the heat of reaction occurring in exceptional cases, all energy required for the extrusion process is introduced into the system through the surfaces of the machinery elements involved (barrel, srew, kneading ele-... 

However, due to their uptake of Ca " that would otherwise act as a feed-back inhibitor of influx pathways, functioning mitochondria may, under certain circumstances, increase the total amount of Ca " influx following an excitotoxic stimulation (Budd and Nicholes 1996). Mitochondrial Ca extrusion is an energy requiring process (33 kj/ mol) linked to exchange. The net effect is the import of two in exchange of one Ca " exported. 

The extrusion process is generally designed such that the majority of the total energy requirement is supplied by the extruder drive. The rotation of the screw... 

If T, is taken as ambient temperature and T2 as the process temperature, the specific enthalpy indicates how much energy is required to accomplish this temperature rise. This can be considered to be the theoretical minimum specific energy requirement in the extrusion process. 

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