The importance of greases

Read the text and write out the words which characterize the properties greases are to possess for a) metallurgy; b) printing machinery; c) food and beverage industries; d) vehicles.

Almost 300 different greases are manufactured at present. Greases are, of course, the oldest products within the framework of today's comprehensive range of lubricants. Greases as well as adhesive lubricants, e.g. for large, exposed transmissions, are of the highest technical and eco­nomic importance.

Greases are manufactured from base oils, a rule with the help of additives and thickeners. The formula and the manufacturing process determine their performance. Greases are considered today to be construction elements above all, when they are used in "lubricated for life" applications. Their functions are varied. Therefore their formula depends on their respective requirements. These requirements include reducing pressure and friction, thermal stability and life-span.

The largest users of greases are the mining, steel, vehicle and engineering industries where lubrication of roller-bearings and ball-bearings has a predominant role. But also in the cement industry, in certain high-temperature areas and other sectors where moisture, acids or alkalies affect workpieces, greases are needed. In printing machinery greases must be resistant to solvents and cleaners and in the food and beverage industries greases must meet the high safety standards required for food. As the new calcium-complex grease has an excellent compatibility with water, weak acids and alkaline solutions, it is also suitable for the use under wet conditions.

For many applications, thicker greases are preferable to the liquid oils. In such cases, chemical engineers solve lubricating problems in all technological sectors with special greases. The tasks of reducing friction and wear, of corrosion protection, of sealing, cooling and cleaning, can all be mastered with special greases.

Notes on the Text:

life-span – продолжительность жизни

meet the standards – соответствовать стандартам

11. Answer the questions to the text:

1. What are greases? 2. What factors determine their performance? 3. What does the greases formula depend on? 4. What are the largest users of greases? 5. Why are thicker greases preferable to the liquid oils in many applications? 6. What standards required for food industry must greases meet? 7. What standards required for printing machinery must greases meet? 8. What are the functions of greases?

Дата добавления: 2014-10-31