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Internal Lubricant (internal + lubricant)
Selected AbstractsEffect of Internal Lubricants on Defects in Compacts Made from Spray-Dried PowdersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2002Sreeram Balasubramanian The role of internal lubricants in the closure of large intergranular pores during dry-pressing was investigated. Alumina was spray-dried with and without an internal lubricant to yield granules with similar characteristics other than lubricant effects. Green and sintered microstructures were evaluated at different compaction pressures. The defects were quantified by evaluating the fracture surface of ,90% dense sintered compacts. The samples that contained an internal lubricant had higher green densities and fewer defects at comparable compaction pressures. The internal lubricant did not cause any significant reduction in green strength or increase in springback. [source] Gamma-irradiation effects on polypropylene-based composites with and without an internal lubricantPOLYMER ENGINEERING & SCIENCE, Issue 5 2009Witold Brostow Polypropylene (PP) based materials for nonreusable syringe applications have been investigated, some of them containing an internal liquid lubricant. Hardness, tensile properties, and friction measured by two distinct procedures have been determined. We report three series of results: for nonirradiated samples; for samples directly after stopping the irradiation; and also for samples after accelerated aging equivalent to 2 years of shelf life. We find that effects of irradiation and aging on Shore A and Shore D hardness are small. Tensile strength at break, elongation at yield, and elongation at break all decrease after irradiation and then decrease still more after aging; these results are quantified but expected. By contrast, results from pin-on-disk tribometry are quite varied. In some cases , irradiation and aging both increase friction, in other cases both decrease friction. We also have a case when irradiation increases friction while aging decreases it,as well as vice versa. Possible mechanisms of all these types of behavior are advanced. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source] Effect of Internal Lubricants on Defects in Compacts Made from Spray-Dried PowdersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2002Sreeram Balasubramanian The role of internal lubricants in the closure of large intergranular pores during dry-pressing was investigated. Alumina was spray-dried with and without an internal lubricant to yield granules with similar characteristics other than lubricant effects. Green and sintered microstructures were evaluated at different compaction pressures. The defects were quantified by evaluating the fracture surface of ,90% dense sintered compacts. The samples that contained an internal lubricant had higher green densities and fewer defects at comparable compaction pressures. The internal lubricant did not cause any significant reduction in green strength or increase in springback. [source] Influence of cylinder-on-plate or block-on-ring sliding configurations on friction and wear of pure and filled engineering polymersLUBRICATION SCIENCE, Issue 2 2007P. Samyn Abstract Polyamides, polyesters and polyacetals are often used in line contacts under reciprocating or continuous sliding. These contacts are simulated on cylinder-on-plate (COP) or block-on-ring (BOR) tribotests. Comparative tests for pure, oil-filled and solid lubricated polymers at 100N and 0.3m/s are presented for relative material classification. Differences are discussed according to the sliding geometries. Thermal effects dominate friction and wear behaviour: the polymer glass transition temperature is exceeded in COP tests while the temperature is lower in BOR tests. Thick and brittle films are observed for pure polymers in BOR tests, promoting higher friction. The test configuration is mainly important for evaluation of internal lubricants. The efficiency of oil-lubricated polymers is not demonstrated in COP tests, while solid lubricants are not efficient in BOR tests. Deformation restricts the diffusion of oil lubricants in COP tests while solid lubricants are deposited on the polymer surface rather than being incorporated in the transfer film in BOR tests. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||