Wednesday, January 8, 2014

Krytox® PFPE in Vacuum Applications

Krytox® performance lubricants are the products of choice for applications where complete nonflammability, oxygen compatibility, and resistance to aggressive chemicals are requirements. These synthetic lubricants provide superior performance and extended life as lubricants and sealants.

xtronix caters to a variety of vacuum and non-vacuum applications with different grades of Krytox® oils and greases. We have addressed aerospace related markets, high voltage industrial applications, paper mills, tribology applications in clean room environments, and many others.

An important area of use for Krytox® relates to vacuum-based applications:
• Vacuum pumps, where safety is critical
• Hostile environments, where semiconductor process chemicals can attack most other lubricants
• Vacuum system valves, seals, bearings and connectors, where low vapor pressure, outgassing, and contamination are intolerable
Krytox® performance lubricants for vacuum systems are reliable, cost-effective, and safe in all environments. Even in the most chemically severe environments, Krytox® oils and greases are:
• Superior lubricants offering thermal stability over a wide range of temperatures
• Chemically inert; non-reactive to all elastomers, metals, plastics, and process chemicals
• Nonflammable
• Insoluble
• Resistant to aggressive chemicals
• Recyclable (oils only - customers with large annual consumptions contact xtronix)
• Long-lasting, improving performance and extending the life of components
• Low vapor pressure to reduce or eliminate outgassing and contamination
• Available in a diverse portfolio of products to perform dependably, regardless of your system's operating conditions

Selection of the best lubricant involves analyzing your operating conditions and choosing from the many synthetic and petroleum based products. Most petroleum products begin to degrade before 99°C (210°F) and cease turning at temperatures just below -18°C (0°F). Krytox® synthetic lubricants have operating ranges from <-70 to >316°C (<-94 to 600°F) (see tables below).

Krytox® Oils and Greases offer a unique combination of properties that provide exceptional, yet cost-effective solutions to your most difficult lubrication problems. Compared to other lubricants, only Krytox® Oils and Greases combine high-temperature performance, non-flammability, and chemical inertness under a variety of conditions. Krytox® Oils and Greases increase the service life of critical components, allowing equipment manufactures to extend warranties, and manufacturing plants to reduce costly maintenance due to component failure. Krytox® Oils and Greases are exceptional lubricants that provide superior protection and load-carrying ability under the most severe conditions. They are especially suited for use in 100% liquid or gaseous oxygen services.

Vacuum Pump Fluids
Krytox® Vacuum Pump Fluids (VPF) are used in applications where conventional vacuum pump oils cause safety, waste disposal and maintenance problems. They are nonflammable and eliminate the chance of fire in pumps. They are non-reactive and safe to use in oxygen systems. They can replace any competitive PFPE fluid as well as any other type of vacuum fluid. Krytox® fluids do not contain acetal groups, which are susceptible to attack by Lewis acids (see PDF datasheet). This gives Krytox® superior stability as a vacuum pump fluid. Krytox® VPF fluids are precisely distilled to provide low vapor pressures and give superior performance (see PDF datasheet). In addition, Krytox® fluids are recyclable.
High Vacuum Greases
A special low-vapour-pressure Krytox® oil is used to formulate a grease for high-vacuum applications. Krytox® greases are an excellent choice for lubricants or sealants used in all vacuum environments, especially when access for repair or replacement is difficult or impossible.

Low vapor pressure greases offer:
• Less than 1x10-13 torr. vapor pressure at 20°C (68°F)
• Less than 1x10-5 torr. vapor pressure at 200°C (392°F)
Krytox® is a PerFluoroPolyEther (PFPE)--also called PerFluoroAlkylEther (PFAE) or PerFluoroPolyAlkylEther (PFPAE). Krytox® fluorinated oils are a series of low molecular weight, fluorine end-capped, homopolymers of hexafluoropropylene epoxide.

Krytox® oils' unique properties are derived from its fluorinated structure. This structure, polyhexafluoropropylene oxide, is an extraordinary fluorinated ether and yields a highly lubricious liquid with extremely low volatility. This polymer is represented in the graphic below. It consists of a carbon (gray) and oxygen (red) ether backbone. This provides a flexible platform onto which the fluorines (green) are attached. The fluorine is responsible for providing the thermal and chemical stability ideal for use in severe environments. Krytox® oil is insoluble in water, acids, bases, and all common organic solvents and is nontoxic.

The polymer chain is completely saturated and contains only the elements carbon, oxygen, and fluorine; hydrogen is not present. On a weight basis, a typical Krytox® oil contains 21.6% carbon, 9.4% oxygen, and 69.0% fluorine.

The Chemical Abstracts Index name for Krytox® fluorinated oils is oxirane, trifluoro (trifluoromethyl), homopolymer and the CAS Registry Number is 60164-51-4.

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