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Swell Ratio (swell + ratio)
Selected AbstractsInvestigation of the derived fuel rod formation from auto shredder residue using an extrusion apparatusENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2006Hua-Shan Tai Abstract The objective of this study was to form auto shredder residue,derived fuel (ASRDF) by using an extrusion apparatus, to solve the disposal problems of auto shredder residue (ASR) and to recover the heat value in its combustible content. ASR is the waste material produced by shredding vehicles. In general, these materials contain 20,30% of each vehicle by weight. ASR should be preprocessed into extruded rods before being used for fuel to remove about 20,30% inorganic, incombustible materials and to accommodate easy transportation and storage. The analytical results of ASR indicated the moisture content to be <2%, ash was <20%, and combustibles were nearly 80% by weight. Concentrations of N and S in the ASR were very low, although the chlorine content of ASR was in the range of 1.32,2.79%, which is the main burden of the ASR utilization. The heat content of ASR was about 5000,6000 kcal kg,1 (9000,10,800 BTU lb,1). Particle size had no significant effect on the analytical chemical composition. All the data indicated that ASR had a significant potential use as RDF. Through observations of the appearance and density of the ASRDF rod, we found that better appearance and higher densities could be achieved at higher extrusion temperature and pressure. The heat content of ASRDF was much lower than that of ASR, and it decreased with increasing extrusion temperature and pressure. The reasons for the better appearance, higher densities, and heat loss on the conditions of higher extrusion temperature and pressure may be explained by the proposed die swell ratio and skin,core effect. © 2006 American Institute of Chemical Engineers Environ Prog, 2006 [source] Rheological behavior of polymer melts in monodimensional flow through low-angle convergence and spiralling diesADVANCES IN POLYMER TECHNOLOGY, Issue 2 2001L. Mascia An experimental study was carried out to examine the rheological behavior of polymer melts in laminar flows through channels with small-angle convergences (2,3°) and spiralling walls (6°/mm along the flow direction), using an extrusion grade of low-density polyethylene. The results show that convergence is the main factor responsible for the observed deviations from steady state laminar shear flow, particularly with respect to additional pressure requirements to maintain a constant mass output. The swell ratio, calculated from the dimensions of the channel at the exit, was found to be considerably higher for flow-through converging channels. Only a small increase in swell ratio could be attributed, on the other hand, to the rotational elements of the die configuration. It is inferred that even for small angles of convergence the increased level of swelling is associated with elongational stress components, which were grouped together and denoted as the "additional stress." This was obtained from the difference between the calculated average shear stress at the wall, using the recorded pressure at the die entry, and the value of the average shear stress at the wall calculated from the shear viscosity data for the melt. © 2001 John Wiley & Sons, Inc. Adv Polym Techn 20: 99,107, 2001 [source] Effects of diatomite on extrudate swell behavior of polypropylene composite meltsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2010J. Z. Liang Abstract Extrudate swell (i.e., die swell) is an important parameter for characterization of melt elasticity during extrusion of polymeric melts, and die swell ratio (B) is usually used to describe quantitatively the melt swell degree. The B of the polypropylene (PP) composites filled with diatomite particles was measured by means of a melt flow rate instrument to investigate the effects of the filler content and size on the die swell behavior of the composite system melts under the experimental conditions with temperature from 210 to 230°C and load varying from 1.2 to 7.5 kg. The particle diameters were 5, 7, and 13 ,m, and the filler volume fractions were 5, 10, and 15%, respectively. The results showed that the B of the composites decreased nonlinearly with an increase of the filler volume fraction, whereas it increased as a quadratic function with an increase of the particle diameter when the load and temperature were fixed. It might be attributed to the interaction between the inclusions and the matrix, leading to blocking the recovery of the elastic deformation as the composite melts left from the die exit. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] A parallel coextrusion technique for simultaneous measurements of radial die swell and velocity profiles of a polymer melt in a capillary rheometerPOLYMER ENGINEERING & SCIENCE, Issue 10 2004N.-T. Intawong This article proposes a new experimental technique to simultaneously measure radial die swell and velocity profiles of polystyrene melt flowing in the capillary die of a constant shear rate rheometer. The proposed technique was based on parallel coextrusion of colored melt-layers into uncolored melt-stream from the barrel into and out of the capillary die. The size (thickness) ratio of the generated melt layers flowing in and out of the die was monitored to produce the extrudate swell ratio for any given radial position across the die diameter. The radial velocity profiles of the melt were measured by introducing relatively light and small particles into the melt layers, and the times taken for the particles to travel for a given distance were measured. The proposed experimental technique was found to be both very simple and useful for the simultaneous and accurate measurement of radial die swell and velocity profiles of highly viscous fluids in an extrusion process. The variations in radial die swell profiles were explained in terms of changes in melt velocity, shear rate, and residence time at radial positions across the die. The radial die swell and velocity profiles for PS melt determined experimentally in this work were accurate to 92.2% and 90.8%, respectively. The overall die swell ratio of the melt ranged from 1.25 to 1.38. The overall die swell ratio was found to increase with increasing piston speed (shear rate). The radial extrudate swell profiles could not be reasoned by the shear rate change, but were closely linked with the development of the velocity profiles of the melt in the die. The die swell ratio was high at the center (,1.9) and low (,0.9) near the die wall. The die swell ratio at the center of the die reduced slightly as the piston speed was increased. Polym. Eng. Sci. 44:1960,1969, 2004. © 2004 Society of Plastics Engineers. [source] COMPARISON OF INSTRUMENTAL METHODS FOR MEASURING SEED HARDNESS OF FOOD-GRADE SOYBEANJOURNAL OF TEXTURE STUDIES, Issue 1 2008BO ZHANG ABSTRACT Breeding specialty soybeans for the soyfood market requires proper methodology in evaluation of seed quality attributes. In this study, efficient methods that could be potentially used for testing soybean seed hardness were developed by examining different instruments and seed parameters. Five food-grade soybean genotypes with different seed sizes were used to determine seed water-absorption capacity and hardness. Water absorption capacity was expressed by swell ratios for seed weight, seed dimension, and volume of water changes before and after soaking. Seed hardness test was conducted by a one-bite method using a food texture analyzer equipped with five different probes. The results showed that hardness testing by a 75 mm cylinder with 10 steamed seeds, single blade with five steamed seeds, and shear cell with 30 g steamed seeds produced dependable and consistent results with low coefficient of variance. However, shear cell may not be practical for early plant selection in a breeding program due to a relatively large sample requirement. Seed size can be used as indirect selection indicators for seed hardness. PRACTICAL APPLICATIONS Seed hardness is an important factor in determining soybean suitability for natto production. This study used two texture analyzers equipped with five different probes to test hardness of five soybean genotypes with different seed size. The methodologies for testing the seed texture of soybean have been established, which can help regulate the seed hardness testing for commercial production and provide consistent hardness references for natto breeding programs and the seed industry. [source] | |||||||||||||