Selection of the best lubricant involves analyzing operating conditions and choosing from the many synthetic and petroleum based products available today. While most petroleum products begin to degrade before 210°F (99°C) and cease turning at temperatures just below 0°F (–18°C), Krytox™ fluorinated synthetic lubricants have operating ranges that are significantly broader (–94 to 600°F [–70 to 316°C]). These lubricants are more effective at even higher temperatures, regardless of operating duration. Using base oils, thickeners, and additives with chemistry designed to create high and low viscosity, these products are targeted for use solely in the very high-temperature range.
Available in several grades that offer anticorrosion, extra bonding, and non-melting properties, these lubricants have applications in a variety of industries, including chemical, textile, tire, aviation, conveyor, glass, plastic film, nonwoven manufacturing, and mining and metal processing.
XHT greases are available with useful temperature ranges up to 680°F (360°C) for continuous use, with spikes to 752°F (400°C), when used in proper metallurgy with periodic re-lubrication.
STABILITY
Nonflammable
Krytox™ lubricants contain only carbon, oxygen, and fluorine. Because hydrogen is not present, these products are nonflammable. They will not burn or support combustion, even in 100% liquid or gaseous oxygen.
Chemically Inert
Krytox™ performance lubricants are not only resistant to oxygen, but are inert to virtually all chemicals used in a variety of industries. They are insoluble in most solvents but are soluble in highly fluorinated fluids and in some supercritical fluids such as CO2.
Thermal and Oxidative Stability
The temperature at which thermal decomposition of Krytox™ oils takes place depends on the test method used and how the point of incipient deterioration is measured. By differential thermal analysis, deterioration occurs at about 878°F (470°C) in the absence of air. The isoteniscope technique shows an initial decomposition point of 671°F (355°C) as measured by excess pressure increase. At 355°C (671°F), the decomposition rate is approximately 0.03 wt% per day. At 750°F (399°C), the decomposition rate increases to 1.3 wt% per day. When tested under nitrogen for six hours at 700°F (371°C), Krytox™ showed no increase in neutralization number and no significant change in viscosity. The presence of air does not substantially lower the decomposition point of this oils. During depolymerization, gaseous decomposition products are given off, and the remaining fluid is less viscous, but no sludge or gummy deposits are formed.
Standard Grades
XHT-S and XHT-SX
482-608°F (250-320°C)
For small or large bearings with relatively high speeds. Higher viscosity, lower evaporation of oil extends life.
Anticorrosion Grades
XHT-AC and XHT-ACX
482-608°F (250-320°C)
For machines that run for shorter duration with frequent starts and stops. Frequently cooled machines require anticorrosion additives.
Typical applications for XHT-S Series and XHT-AC Series include:
- Paint plant conveyor bearings
- Corrugator and paper machine bearings
- Aluminum can manufacturing bearings
- Welding machines
- High temperature fans
- Textile equipment
- Tenter frames
- High temperature ovens
- Conveyor systems in glass and aluminum plants
- Textile calender roll bearing.
- Brick kiln car bearings
- Valve lubrication
- Ventilation fan bearing grease
- Rod mills
Extra Bonding Grades
XHT-BD, XHT-BDX, and XHT-BDZ
572-752°F (300-400°C)
For use when machine movement is not purely rotational. This grease is non-melting for high temperature use and offers better adhesion to substrate. For use in low speed bearings or in pillow housings.
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