J. Environ. Res. Develop. Journal of Environmental Research And Development Vol.10 No. 01, July-September 2015

Transcription

1 COMPARATIVE STUDY OF ADDITIVES TO IMPROVE FRICTION COEFFICIENT OF LUBRICATING OILS Shah Nimish Department of Chemical Engineering Institute of Technology, Nirma University, Ahmedabad (INDIA) Received March 2, 215 Accepted July 26, 215 ABSTRACT Lubricant separates two touching surfaces by providing a protective film, thus lessening the friction and wear between two moving surfaces. Non-liquid lubricants are like Teflon tape, grease, powders, etc. used in plumbing, air cushion and others. Additives are used along with lubricants. The basic role of additive is to improve oil quality, life and decrease the friction between moving parts. Various additives are used with different lubricating oils. In this study, we compared the performance of the most commonly used additives to help selection of additives with oil on the basis of reduction in friction coefficient. We also compared quantitatively, friction coefficient and cost of the additives. Key Words : Lubricating oil, Oil additive, retardant, Silicon oxide, Detergent INTRODUCTION Today the very heart and soul of all industries is its machinery and equipment. The main driving force of these machines and equipment is its proper lubrication and maintenance 1-2. The right lubricant will bring out the optimum performance of your machinery, which in turn it brings about maximum production capacity 3. Apart from friction, lubricating oils provide protection against tearing and grinding together to all the metal surfaces whilst transferring heat away from the combustion cycle 4. Lubricating oil must also be able to hold all the nasty by-products of combustion, such as silica (silicon oxide), acids, etc. 5 Lubricating oil keeps the moving parts coated and cleans the harmful build up, chemicals, etc. 6 It also reduces oxidation of surfaces at higher temperature by minimizing the exposure to oxygen. It performs under tremendous heat and pressure 5,7. Oil additives help lubricate oils to improve and maintain its performance in such situations. Additives are formulated to improve base oils properties like physical, chemical, anti-friction, etc. to enhance the performance of the lubricant. During 192s additives were used first time for lubricating oils and their use has since increased exponentially. They are organic or inorganic compounds dissolved or suspended as solids in oil. 8 According to application and requirement all lubricating oils are added one or more additives. Use of additives and their quantities are determined by the operating condition like temperature, pressure, contaminants, etc. and the characteristics of lubricant used. They are used in the range of - 3 percent of the oil volume, depending on the machine. 9 The basic role of additives is to act as demulsifying agents, anti-foam agents, corrosion inhibitors, antioxidants in the oil, in which it is mixed. It will enhance such properties of base oils. It also plays role to improve viscosity index (VI) and depress pour-point of the oils. Some additives acts as tackiness agents, metal deactivators, deter-gents, etc. 1 Friction modifiers Friction modifiers are the additives which help to reduce the fuel consumption by reducing the coefficient of friction 11. Crystal structure of most of friction modifiers consists of molecular platelets (layers), which may easily slide over each other. Commonly molybdenum compounds and derivatives of long chain fatty acids are used as friction modifiers Friction modifiers not only reducing friction, but also reduce wear, especially at low temperatures where the anti-wear agents are 79

2 inactive and they improve fuel efficiency The major solid lubricants are used as friction modifiers : Polytetra Fluoro Ethylene (PTFE), Tungsten disulfide (WS 2 ), Boron nitride (BN), molybdenum disulphide, graphite, etc AIMS AND OBJECTIVES To compare the solid friction modifiers on the basis of their capacity to reduce friction coefficient with their quantity and type of oils. MATERIAL AND METHODS Different oils like engine oil, knitting oil, sewing oil purchased from firms of repute. Additives like teflon emulsion, MoS 2 emulsion, graphite emulsion purchased from firms of repute. Diesel, methanol. During an experiment, we used standard instrument and followed standard test method for determining the static coefficient of friction ASTM D 247, ASTM C 128. RESULTS AND DISCUSSION Coefficient of Friction (µs) The ratio of maximum frictional force (F) developed to the normal reaction (N) developed between two bodies in contact, is termed as co-efficient of friction (Fig. 1). µs = F/N (1) Coefficient of friction of the instrument = 966. The followings are the results based on friction coefficient. (Fig. 2 to Fig. 7) Fig. 1 : Friction co-efficient instrument Fig. 2 : of engine oil Vs s 8

3 Fig. 3 : of knitting oil Vs s Fig. 4 : of sewing oil Vs s Fig. 5 : of engine oil Vs s 81

4 Fig. 6 : of knitting oil Vs s Fig. 7 : of sewing oil Vs s CONCLUSION After studying all the three friction retardants i.e. Teflon, MoS 2 and graphite in lubricating oils i.e. engine oil, sewing oil, knitting oils, it has been observed that, as we increase the ratio of friction retardants from to the friction co-efficient decreases. When, additives added with specific dosage to the engine oil, amongst all the three additives i.e. Teflon, MoS 2 and Graphite, Teflon reduce the maximum co-efficient of friction and cost wise also it becomes reasonable. With Knitting oil, MoS 2 and Graphite act as good retardants, but cost wise, graphite is more appropriate. In the case of Sewing Oil, MoS 2 reduces more coefficient of friction and reduces friction. 82 Its cost is comparatively less than Teflon and also varies with the dosage. Graphite and molybdenum disulphide though being cheaper, do not comparatively give well and maximum co-efficient of friction like that of Teflon. Thus, it would be more preferable and suggestive to use Teflon as a retardant for friction retardation. REFERENCES 1. Miyoshi K., Solid lubrication fundamentals and applications. CRC Press, (21). 2. Anderson A. E., ASM Handbook, Friction, Lubrication and Wear Technology, 18.

5 ASM International, Metals Park, , (1992). 3. Lansdown A. R., Lubrication and lubricant selection : A practical guide. ASME Press, (24). 4. Bhushan B., Modern Tribology Handbook, , CRC Press, (2). 5. Lansdown A. R., High-temperature lubrication, Proc. the Inst. of Mech. Eng., Part C: J. Mech. Engin. Sci., 24(5), , (199). 6. Harris, Tedric A. and Michael N. Kotzalas., Essential concepts of bearing technology. CRC press, , (26). 7. Khonsari Michael M. and E. Richard Booser, Applied Tribology : bearing design and lubrication. 12. John Wiley and Sons, 78-79, (28). 8. Donnet Christophe and Ali Erdemir, Tribology of diamond-like carbon films: fundamentals and applications. Springer Science and Business Media, 87-88, (27). 9. Hamrock Bernard J., Steven R. Schmid and Bo O. Jacobson, Fundamentals of fluid film lubrication. CRC press, , (24). 1. Rudnick Leslie R., Lubricant additives : Chemistry and applications. CRC Press, , (29). 11. Miyoshi Kazuhisa, Considerations in vacuum tribology (adhesion, friction, wear, and solid lubrication in vacuum), Tribol. Int., 32(11), , (1999). 12. Zhou Feng, Yongmin Liang and Weimin Liu, Ionic liquid lubricants : Designed chemistry for engineering applications." Chem. Soc. Rev., 38(9), , (29). 13. Voevodin A. A. and J. S. Zabinski, Super tough wear-resistant coatings with chameleon surface adaptation, Thin Sol. Fil., 37(1), , (2). 14. Tamilkolundu S. and Balasubrmanian K.G., Evaluation of engine performance and emission characteristics of zirconia coated piston surface in SI engine, J. Environ. Res. Develop., 7(1A) , (212). 15. P. Caumul, The role of surfactants and their intermediates in environmental chemistry,, 5(3), , (211). 16. Sriburi T. and Mathayam B., Grey oyster mushroom for food security versus CO 2 Emission,, 7(4), , (213). 17. Norelyza H. and Rashid M., Performance of MR-deDustar on particular emission control for a different area of axial entry, J. Environ. Res. Develop., 7(4), , (213). 18. CheHafizan and Noor Zainam Zainura, Biofuel : Advantages and disadvantage based on LCA perspective, J. Environ. Res. Develop., 7(4), , (213). 19. Vardhaman S. Y., Haridas Ajit and Manilal V.B., Closed retting : A green technology for controlling coir retting pollution of backwater,, 7(4A), , (213). 2. Qamar Izhar and S. Fahimuddin, Analysis global energy consumptions patterns, J. Environ. Res. Develop., 7(4A), , (213). 21. Yazdi S. and Shakouri Bahram, The economic model for CO 2 emission, energy consumption, economic growth foreign trade, financial development and urbanization of Iran,, 8(3A), , (214). 22. Patel A., Fluid-specific studies on percolation through different soil mass, J. Environ. Res. Develop., 8(3A), , (214). 23. Patel G. D., Dhaduk B.K. and Kapadiya D., Landscape gardening : A tool for environmental moderation, J. Environ. Res. Develop., 8(3A), , (214). 83