The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Chris Stirling - One of the best experts on this subject based on the ideXlab platform.
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texture transport and mechanical properties of graphite nanoplatelet silicone composites produced by three Roll Mill
Composites Science and Technology, 2012Co-Authors: Mohsin Ali Raza, A. V K Westwood, A.p. Brown, Chris StirlingAbstract:Abstract Thermally conducting and highly compliant composites for thermal interface applications were developed by dispersing graphite nanoplatelets (GNPs) in silicone polymer using a three-Roll Mill process. X-ray diffraction and electron microscopy showed that the Roll Mill produces composites with better dispersion of GNPs than previously achieved by speed and mechanical mixing. The Roll Mill also allows production of a composite at 25 wt.% GNP loading. The thermal conductivities of the composites reached 1.03 and 3.15 W/m K at 8 and 25 wt.% of GNPs, respectively, compared to 0.17 W/m K for silicone. Compression testing showed that the composites’ moduli increase by 1.5 times up to 20 wt.% loading but the strength and strain to failure decrease. The Shore hardness was similar or slightly lower to that of silicone. The composites are thus promising alternatives to the commercial thermal interface materials currently available.
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Texture, transport and mechanical properties of graphite nanoplatelet/silicone composites produced by three Roll Mill
Composites Science and Technology, 2012Co-Authors: Mohsin Ali Raza, A. V K Westwood, A.p. Brown, Chris StirlingAbstract:Abstract Thermally conducting and highly compliant composites for thermal interface applications were developed by dispersing graphite nanoplatelets (GNPs) in silicone polymer using a three-Roll Mill process. X-ray diffraction and electron microscopy showed that the Roll Mill produces composites with better dispersion of GNPs than previously achieved by speed and mechanical mixing. The Roll Mill also allows production of a composite at 25 wt.% GNP loading. The thermal conductivities of the composites reached 1.03 and 3.15 W/m K at 8 and 25 wt.% of GNPs, respectively, compared to 0.17 W/m K for silicone. Compression testing showed that the composites’ moduli increase by 1.5 times up to 20 wt.% loading but the strength and strain to failure decrease. The Shore hardness was similar or slightly lower to that of silicone. The composites are thus promising alternatives to the commercial thermal interface materials currently available.
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Texture, transport and mechanical properties of graphite nanoplatelet/silicone composites produced by three Roll Mill
Composites Science and Technology, 2012Co-Authors: Muhammad Ahmad Raza, A. V K Westwood, A.p. Brown, Chris StirlingAbstract:Thermally conducting and highly compliant composites for thermal interface applications were developed by dispersing graphite nanoplatelets (GNPs) in silicone polymer using a three-Roll Mill process. X-ray diffraction and electron microscopy showed that the Roll Mill produces composites with better dispersion of GNPs than previously achieved by speed and mechanical mixing. The Roll Mill also allows production of a composite at 25. wt.% GNP loading. The thermal conductivities of the composites reached 1.03 and 3.15. W/m. K at 8 and 25. wt.% of GNPs, respectively, compared to 0.17. W/m. K for silicone. Compression testing showed that the composites' moduli increase by 1.5 times up to 20. wt.% loading but the strength and strain to failure decrease. The Shore hardness was similar or slightly lower to that of silicone. The composites are thus promising alternatives to the commercial thermal interface materials currently available. ?? 2011 Elsevier Ltd.
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Transport and mechanical properties of vapour grown carbon nanofibre/silicone composites
Composites Part A: Applied Science and Manufacturing, 2011Co-Authors: Muhammad Ahmad Raza, A. V K Westwood, Chris Stirling, Nicole HondowAbstract:Vapour grown carbon nanofibre (VGCNF)/silicone composites were produced at loadings of up to 12 and 15 wt.% by conventional mechanical stirring and 3-Roll Mill, respectively. The thermal conductivities of the composites produced by Roll Mill are 10-20% higher than the corresponding ones produced by mechanical stirring due to the presence of well dispersed and uniformly distributed fibres in the former, as observed by SEM analysis. The thermal conductivity of 12 wt.% VGCNF/silicone composite produced by Roll Mill is 0.7335 W/m K, compared to 0.1795 W/m K for neat silicone. An electrical conductivity of 1.47 S m -1 was attained at 15 wt.% loading of VGCNF in silicone. Compression testing results showed that VGCNF are effective fillers for increasing silicone compressive strength and strain to failure. ?? 2011 Elsevier Ltd. All rights reserved.
Rodney S. Ruoff - One of the best experts on this subject based on the ideXlab platform.
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Latex and two-Roll Mill processing of thermally-exfoliated graphite oxide/natural rubber nanocomposites
Composites Science and Technology, 2013Co-Authors: Jeffrey R. Potts, Om Shankar, Ling Du, Shanthi Murali, Rodney S. RuoffAbstract:Abstract Thermally-exfoliated graphite oxide (TEGO) is a graphene-based material that has been previously shown to disperse effectively into thermoplastic polymers by melt processing. In this work, dispersion of TEGO into natural rubber (NR) directly on a two-Roll Mill did not result in substantial property enhancement. However, by pre-mixing the TEGO with NR latex by an ultrasonically-assisted latex co-coagulation procedure followed by two-Roll Milling, the properties were improved substantially over the TEGO/NR nanocomposites mixed only on the Mill. Quantitative analysis of TEM micrographs suggested the difference in properties was primarily the result of improved dispersion, as fewer multi-layer tactoids and platelets of overall smaller dimensions were observed in the nanocomposites pre-mixed by latex co-coagulation. NR filled with carbon black showed comparable property enhancement to TEGO/NR mixed on the two-Roll Mill but much smaller property changes than the latex pre-mixed TEGO/NR nanocomposites.
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latex and two Roll Mill processing of thermally exfoliated graphite oxide natural rubber nanocomposites
Composites Science and Technology, 2013Co-Authors: Jeffrey R. Potts, Om Shankar, Ling Du, Shanthi Murali, Rodney S. RuoffAbstract:Abstract Thermally-exfoliated graphite oxide (TEGO) is a graphene-based material that has been previously shown to disperse effectively into thermoplastic polymers by melt processing. In this work, dispersion of TEGO into natural rubber (NR) directly on a two-Roll Mill did not result in substantial property enhancement. However, by pre-mixing the TEGO with NR latex by an ultrasonically-assisted latex co-coagulation procedure followed by two-Roll Milling, the properties were improved substantially over the TEGO/NR nanocomposites mixed only on the Mill. Quantitative analysis of TEM micrographs suggested the difference in properties was primarily the result of improved dispersion, as fewer multi-layer tactoids and platelets of overall smaller dimensions were observed in the nanocomposites pre-mixed by latex co-coagulation. NR filled with carbon black showed comparable property enhancement to TEGO/NR mixed on the two-Roll Mill but much smaller property changes than the latex pre-mixed TEGO/NR nanocomposites.
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Latex and two-Roll Mill processing of thermally-exfoliated graphite oxide/natural rubber nanocomposites
Composites Science and Technology, 2013Co-Authors: Jeffrey R. Potts, Om Shankar, Ling Du, Swetha Murali, Rodney S. RuoffAbstract:Thermally-exfoliated graphite oxide (TEGO) is a graphene-based material that has been previously shown to disperse effectively into thermoplastic polymers by melt processing. In this work, dispersion of TEGO into natural rubber (NR) directly on a two-Roll Mill did not result in substantial property enhancement. However, by pre-mixing the TEGO with NR latex by an ultrasonically-assisted latex co-coagulation procedure followed by two-Roll Milling, the properties were improved substantially over the TEGO/NR nanocomposites mixed only on the Mill. Quantitative analysis of TEM micrographs suggested the difference in properties was primarily the result of improved dispersion, as fewer multi-layer tactoids and platelets of overall smaller dimensions were observed in the nanocomposites pre-mixed by latex co-coagulation. NR filled with carbon black showed comparable property enhancement to TEGO/NR mixed on the two-Roll Mill but much smaller property changes than the latex pre-mixed TEGO/NR nanocomposites. © 2012 Elsevier Ltd.
A. V K Westwood - One of the best experts on this subject based on the ideXlab platform.
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texture transport and mechanical properties of graphite nanoplatelet silicone composites produced by three Roll Mill
Composites Science and Technology, 2012Co-Authors: Mohsin Ali Raza, A. V K Westwood, A.p. Brown, Chris StirlingAbstract:Abstract Thermally conducting and highly compliant composites for thermal interface applications were developed by dispersing graphite nanoplatelets (GNPs) in silicone polymer using a three-Roll Mill process. X-ray diffraction and electron microscopy showed that the Roll Mill produces composites with better dispersion of GNPs than previously achieved by speed and mechanical mixing. The Roll Mill also allows production of a composite at 25 wt.% GNP loading. The thermal conductivities of the composites reached 1.03 and 3.15 W/m K at 8 and 25 wt.% of GNPs, respectively, compared to 0.17 W/m K for silicone. Compression testing showed that the composites’ moduli increase by 1.5 times up to 20 wt.% loading but the strength and strain to failure decrease. The Shore hardness was similar or slightly lower to that of silicone. The composites are thus promising alternatives to the commercial thermal interface materials currently available.
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Texture, transport and mechanical properties of graphite nanoplatelet/silicone composites produced by three Roll Mill
Composites Science and Technology, 2012Co-Authors: Mohsin Ali Raza, A. V K Westwood, A.p. Brown, Chris StirlingAbstract:Abstract Thermally conducting and highly compliant composites for thermal interface applications were developed by dispersing graphite nanoplatelets (GNPs) in silicone polymer using a three-Roll Mill process. X-ray diffraction and electron microscopy showed that the Roll Mill produces composites with better dispersion of GNPs than previously achieved by speed and mechanical mixing. The Roll Mill also allows production of a composite at 25 wt.% GNP loading. The thermal conductivities of the composites reached 1.03 and 3.15 W/m K at 8 and 25 wt.% of GNPs, respectively, compared to 0.17 W/m K for silicone. Compression testing showed that the composites’ moduli increase by 1.5 times up to 20 wt.% loading but the strength and strain to failure decrease. The Shore hardness was similar or slightly lower to that of silicone. The composites are thus promising alternatives to the commercial thermal interface materials currently available.
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Texture, transport and mechanical properties of graphite nanoplatelet/silicone composites produced by three Roll Mill
Composites Science and Technology, 2012Co-Authors: Muhammad Ahmad Raza, A. V K Westwood, A.p. Brown, Chris StirlingAbstract:Thermally conducting and highly compliant composites for thermal interface applications were developed by dispersing graphite nanoplatelets (GNPs) in silicone polymer using a three-Roll Mill process. X-ray diffraction and electron microscopy showed that the Roll Mill produces composites with better dispersion of GNPs than previously achieved by speed and mechanical mixing. The Roll Mill also allows production of a composite at 25. wt.% GNP loading. The thermal conductivities of the composites reached 1.03 and 3.15. W/m. K at 8 and 25. wt.% of GNPs, respectively, compared to 0.17. W/m. K for silicone. Compression testing showed that the composites' moduli increase by 1.5 times up to 20. wt.% loading but the strength and strain to failure decrease. The Shore hardness was similar or slightly lower to that of silicone. The composites are thus promising alternatives to the commercial thermal interface materials currently available. ?? 2011 Elsevier Ltd.
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Transport and mechanical properties of vapour grown carbon nanofibre/silicone composites
Composites Part A: Applied Science and Manufacturing, 2011Co-Authors: Muhammad Ahmad Raza, A. V K Westwood, Chris Stirling, Nicole HondowAbstract:Vapour grown carbon nanofibre (VGCNF)/silicone composites were produced at loadings of up to 12 and 15 wt.% by conventional mechanical stirring and 3-Roll Mill, respectively. The thermal conductivities of the composites produced by Roll Mill are 10-20% higher than the corresponding ones produced by mechanical stirring due to the presence of well dispersed and uniformly distributed fibres in the former, as observed by SEM analysis. The thermal conductivity of 12 wt.% VGCNF/silicone composite produced by Roll Mill is 0.7335 W/m K, compared to 0.1795 W/m K for neat silicone. An electrical conductivity of 1.47 S m -1 was attained at 15 wt.% loading of VGCNF in silicone. Compression testing results showed that VGCNF are effective fillers for increasing silicone compressive strength and strain to failure. ?? 2011 Elsevier Ltd. All rights reserved.
Muhammad Ahmad Raza - One of the best experts on this subject based on the ideXlab platform.
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Texture, transport and mechanical properties of graphite nanoplatelet/silicone composites produced by three Roll Mill
Composites Science and Technology, 2012Co-Authors: Muhammad Ahmad Raza, A. V K Westwood, A.p. Brown, Chris StirlingAbstract:Thermally conducting and highly compliant composites for thermal interface applications were developed by dispersing graphite nanoplatelets (GNPs) in silicone polymer using a three-Roll Mill process. X-ray diffraction and electron microscopy showed that the Roll Mill produces composites with better dispersion of GNPs than previously achieved by speed and mechanical mixing. The Roll Mill also allows production of a composite at 25. wt.% GNP loading. The thermal conductivities of the composites reached 1.03 and 3.15. W/m. K at 8 and 25. wt.% of GNPs, respectively, compared to 0.17. W/m. K for silicone. Compression testing showed that the composites' moduli increase by 1.5 times up to 20. wt.% loading but the strength and strain to failure decrease. The Shore hardness was similar or slightly lower to that of silicone. The composites are thus promising alternatives to the commercial thermal interface materials currently available. ?? 2011 Elsevier Ltd.
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Transport and mechanical properties of vapour grown carbon nanofibre/silicone composites
Composites Part A: Applied Science and Manufacturing, 2011Co-Authors: Muhammad Ahmad Raza, A. V K Westwood, Chris Stirling, Nicole HondowAbstract:Vapour grown carbon nanofibre (VGCNF)/silicone composites were produced at loadings of up to 12 and 15 wt.% by conventional mechanical stirring and 3-Roll Mill, respectively. The thermal conductivities of the composites produced by Roll Mill are 10-20% higher than the corresponding ones produced by mechanical stirring due to the presence of well dispersed and uniformly distributed fibres in the former, as observed by SEM analysis. The thermal conductivity of 12 wt.% VGCNF/silicone composite produced by Roll Mill is 0.7335 W/m K, compared to 0.1795 W/m K for neat silicone. An electrical conductivity of 1.47 S m -1 was attained at 15 wt.% loading of VGCNF in silicone. Compression testing results showed that VGCNF are effective fillers for increasing silicone compressive strength and strain to failure. ?? 2011 Elsevier Ltd. All rights reserved.
D W Fuerstenau - One of the best experts on this subject based on the ideXlab platform.
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role of feed moisture in high pressure Roll Mill comminution
International Journal of Mineral Processing, 2007Co-Authors: D W Fuerstenau, Abdelzaher M AbouzeidAbstract:Abstract The application of high-pressure Roll Mills (HPRM) for industrial comminution has been growing, particularly because of its energy efficiency. Many aspects of HPRM comminution have not been fully characterized because the performance of the machine is affected by numerous parameters that still need to be investigated and optimized. The present paper is concerned with the effect of feed moisture on HPRM performance. The comminution of minus 8-mesh dolomite feed at several different moisture levels was conducted with a laboratory HPRM to delineate the effect of feed moisture on product characteristics, specific energy consumption, and such Mill operating parameters as applied load, Roll gap and Roll speed. The results showed definite effects of moisture on these parameters and the product size distribution, most likely because of lubrication of the particles in the compacting bed as they pass through the Roll gap.
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influence of particle size and shape on the comminution of single particles in a rigidly mounted Roll Mill
Powder Technology, 2004Co-Authors: O. Gutsche, D W FuerstenauAbstract:Abstract In single-particle Roll Mill comminution, the degree of size reduction is contRolled by the ratio of the nip size of the particle and the Roll gap. However, the nip size or effective particle size of irregularly shaped particles is generally unknown. An experimental procedure is presented to assess nip size of irregularly shaped particles and to evaluate energy consumption and energy utilization in their comminution. A series of experiments in which the Roll gap was successively reduced reveals that the height of a particle, that is, the particle's dimension normal to the plane in which it resides in its most stable position, is a satisfactory approximation of the nip size which can be conveniently measured with a slot classifier. The nip size or particle height is distributed in √2 and √4 sieve–size fraction according to a Gaussian normal distribution, the median size being roughly 80% of the geometric sieve size. The energy investment for comminuting single particles in a rigidly mounted Roll Mill varies with the nip size in the manner of a power function. Estimated Weibull coefficients of uniformity for dolomite, galena, and quartz are 7.5, 1.9, and 7.9. Product size distributions of comminuted nip-size fractions are self-preserving in a dimensionless size X/X50 and thus, the median size is a measure of product fineness. Grindabilities calculated from the linear reduction ratio energy relationships are 7.8, 14.0, and 4.5 t/kWh for dolomite, galena, and quartz, respectively. Single-particle grindabilities of these three minerals are power functions of the nip size. Dolomite and quartz data follow closely Rittinger's Law of Comminution.
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the effect of ball size on the energy efficiency of hybrid high pressure Roll Mill ball Mill grinding
Powder Technology, 1999Co-Authors: D W Fuerstenau, J J Lutch, A DeAbstract:Abstract To find ways to reduce energy consumption in comminution, dolomite was ground in a hybrid grinding system, involving the operation of a laboratory-scale high-pressure Roll Mill and ball Mill in series. The work presented here has demonstrated the energy efficiency of the hybrid system can be increased by reducing ball size, provided the Roll Mill product contains sufficient internal damage to allow for the use of the smaller balls. There is an optimum range of energy partitioning between the high-pressure Roll Mill and the ball Mill in the hybrid system. The increased efficiency of hybrid grinding is related to the particle damage imparted by the Roll Mill, as evidenced by the increased breakage rates of high-pressure Roll Mill product relative to particles that had not been Roll Milled.
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On assessing and enhancing the energy efficiency of comminution processes
Mining Metallurgy & Exploration, 1997Co-Authors: D W Fuerstenau, Javier Vazquez FavelaAbstract:This paper shows how the efficiencies of size-reduction processes depend on the mode of particle constraint and energy transfer within the comminution device: namely, whether the process consists of single-particle loading, confined-particle-bed comminution or loose- (unconstrained-) particle grinding. The relative efficiency of single-particle comminution, ball Mill grinding and particle-bed comminution in the recently invented high-pressure Roll Mill is evaluated by making use of the self-preserving nature of the size distributions of comminuted products. The highest energy efficiency can be achieved by utilizing a hybrid two-stage system in which the material is first ground in the high-pressure Roll Mill and then the ball Mill.
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Rheology of coal-water slurries prepared by the high-pressure Roll Mill grinding of coal. Final report
1996Co-Authors: D W Fuerstenau, A DeAbstract:The preparation of coal water slurries to replace fuel oil for direct combustion has become an important field in modem coal technology. The U.S. Department of Energy has planned or has underway several demonstration projects to burn coal-water slurries to replace fuel oil is attractive not only because there is an assured domestic supply of coal, but also on various technoeconomic grounds. Coal-water slurries combine the handling flexibility of fuel oil in power plants and various other industrial applications. This report discusses the rheology of coal-water slurries and the correlation to the coal preparation by grinding with a choke-fed high pressure Roll Mill. Performance of the Roll Mills and energy consumption are described.
