Thermal stability is of major importance in polymer extrusion, where product quality is dependent upon the level of melt homogeneity achieved by the extruder screw. Extrusion is an energy intensive process and optimisation of process energy usage while maintaining melt stability is necessary in order to produce good quality product at low unit cost. Optimisation of process energy usage is timel...

Polymers for hot melt extrusion must exhibit thermoplastic characteristics in order to permit the melt extrusion process and they must be stable at extrusion temperatures. Other relevant characteristics are: suitable glass transition temperature (Tg) of 50–180 °C, low hygroscopicity and no toxicity since larger amounts of polymer are used [1]. Extrudability of a polymer is mainly determined by ...

A series of high temperature experiments was undertaken to study partitioning of several highly siderophile elements (HSE; Ru, Rh, Pd, Re, Os, Ir, Pt and Au) between Cr-rich spinel, olivine, pyroxene and silicate melt. Runs were carried out on a Hawaiian ankaramite, a synthetic eucrite basalt, and a DiAn eutectic melt, at one bar, 19 kbar, and 20 kbar, respectively, in the temperature range of ...

Abstract—The detection of the polymer melt state during manufacture process is regarded as an efficient way to control the molded part quality in advance. Online monitoring rheological property of polymer melt during processing procedure provides an approach to understand the melt state immediately. Rheological property reflects the polymer melt state at different processing parameters and is v...

[1] We derived the extent, onset date, end date, and duration of snowmelt in Antarctica from 1978 to 2004 using satellite passive microwave scanning multichannel microwave radiometer (SMMR) and Special Sensor Microwave Imager (SSM/I) data. A wavelettransform-based method was developed to determine and characterize melt occurrences. About 9–12% of the Antarctic surface experiences melt annually....

Alloy Al – 27% Cu – 6% Si has a composition close to an eutectic one [1, 2] and is widely used as a solder (A34) for soldering aluminum and its alloys [3]. The main problem in fabrication of cast solder A34 is the formation of a ternary ( + CuAl 2 + Si) eutectic and primary silicon crystals in its structure, which lowers substantially the process and operating properties of the alloys. It is kn...

Modeling turbulent convection in the melt is the most di cult part of the simulation of the transport processes in the growth of large-diameter silicon crystals by the Czochralski (CZ) process. We report the application of hybrid nite-element/ nitevolume methods for the integrated modeling of turbulence in the melt and heat transfer by conduction, convection and radiation throughout the CZ syst...

In this paper the relationship between molecular structure and behavior of the LDPE melt is discussed from a scaling perspective on the bases of results from GPC-MALLS analysis. Long chain branches introduce a characteristic length scale that marks a transition in rheology behavior of the melt with decreasing length scale of deformation i.e. with increasing process rate or decreasing temperatur...

An OPTOMEC Laser Engineered Net Shaping (LENS(™)) 750 system was retrofitted with a melt pool pyrometer and in-chamber infrared (IR) camera for nondestructive thermal inspection of the blown-powder, direct laser deposition (DLD) process. Data indicative of temperature and heat transfer within the melt pool and heat affected zone atop a thin-walled structure of Ti-6Al-4V during its additive manu...