The,Significance,of,Proper,Pour,Point,Depressant,Selection,when,Formulating,Engine,Oils,to,Meet,the The time when

　　1 Engine Oil Pumpability 　　 　　As stated above, pour point depressants are poly- meric molecules that are added to mineral oil - based lu- bricants to improve the cold flow properties of the lubri- cants. Without the addition of a PPD, many lubricants at cold temperatures would be too viscous to flow easily and the result would be little or no lubricant moving through the system. Paraffinic stocks make excellent lu- bricants because they are chemically stable, resistant to oxidation, and have good viscosity index values. How- ever, paraffinic stocks, by their nature, contain waxy materials, which, if unhindered, can form crystal net- works and ultimately cause pumpability failures at low temperatures. In addition, other sources of waxy mate- rial, some viscosity index improvers (VII) and compo- nents of the detergent - inhibitor (DI) package, can participate in the crystallization process and exacerbate any pumpability issues. 本文为全文原貌 未安装PDF浏览器用户请先下载安装 原版全文