10 Reasons Why FFKM Is Chosen For Harsh Environments
Posted by CDI Products on Sep 06, 2022
The utilization of elastomers is extremely common in our modern environment. Elastomers are used in a variety of applications, including sealing fluid applications, tires, chemical plants, semiconductor manufacturing equipment, dust and moisture seals on cell phones, and aircraft engine seals, among others. Elastomer applications can range from something as simple as a rainwater barrier to more complex applications like essential sealing applications on the International Space Station (ISS). Even though there are many different elastomers available on the market today, there was a time when material scientists needed to develop something new to meet increasingly demanding environments and applications.
By the 1960s, there was a growing demand for a polymer that was more chemically resistant and could withstand greater temperatures. Perfluoroelastomers compounds, abbreviated as FFKM, which combine the chemical resistance of PTFE with the flexibility and elasticity of traditional FKMs, provided an effective solution to the challenge.
The Demand for a Stronger Elastomer
FFKMs receive greater elasticity due to their fluorinated backbone (and higher fluorine content than fluoroelastomer or FKM compounds), which makes them an excellent choice in a variety of demanding applications. When first introduced, they were considered the next stage of elastomer technology and were almost entirely the domain of space programs and chemical operations. However, once their positive features were fully recognized by the material science world, it was quickly adopted by the larger industrial community. Nowadays, FFKM is a common sight in numerous industries.
Selection of the appropriate elastomer for a given application is critical for the successful and long-term operation of the equipment. FFKM is well-suited for usage in highly aggressive chemical processing, semiconductor wafer production, pharmaceutical processing, oil and gas recovery, and aerospace applications. Although the polymer structure has essentially remained unaltered since the debut of perfluoroelastomers, the polymerization method has been refined over the decades, and FFKM materials can now be manufactured as part of a safer, greener manufacturing process.
Why FFKM is better than FKM
FFKM and FKM, like all elastomers, are typically compounded with fillers, processing aids, and other additives. Examples of common fillers include carbon black, mineral fillers such as silica, talc, clay, and polymeric fillers. Mechanical characteristics, chemical resistance, plasma resistance, and thermal stability of the finished material are highly influenced not only by the polymer but also by the other elements in the compound formulation.
For applications requiring harsh chemicals at temperatures up to 620°F (325°C), FFKM elastomers fill a critical gap. They are the most chemically resistant elastomers on the market, with exceptional temperature and chemical resistance. It is resistant to over 1,800 chemical compounds, including hydrocarbons, lubricants, and fuels. They are also resistant to steam, ozone, and weathering, and have a low gas permeability. They also offer a high level of static and dynamic load dependability due to their low compression set.
Advantages of FFKM
- Wide temperature range (-55°C – 330°C).
- Universal chemical resistance (best in class, similar to PTFE).
- Excellent gas and liquid permeation resistance.
- Excellent weather ability and ozone resistance.
- Self-extinguishing and non-flammable in air.
- High Density.
- Good mechanical properties, improving sealing performance.
- Compatible to ultra-pure manufacturing.
- Resistant to explosive decompression.
- Resistant to compression set.
Manufacturing Methods Using FFKM
Manufacturing of high performance FFKM-based products begins with the use of specialized molding presses. The injection molding technique forces raw material into a mold, which molds it to the desired shape. On the other hand, when the compression method is used, molding is preceded by raw material preparation via an extrusion system. Once extruded, the elastomer is ready to be put into the press, where it is formed into the desired formation using high pressures and high temperatures. All gaskets eventually undergo a process that distinguishes them from the burr found on newly molded items. Some FFKM applications, like those used in semiconductor fabrication and pharmaceutical processing, require sealing products that are of a superior purity level (ultra-pure). The ultra-pure manufacturing process is carried out in a separate manufacturing cell, using equipment dedicated to the production of premium fluoroelastomers. This cutting-edge cell protects products from contamination caused by dust, mold sprays, foreign materials, handling, and other common causes. Each stage in the ultra-pure manufacturing process, from material formulation through final product packaging, is subject to measurement, assessment, and statistical process control. As a result, the product has unrivaled purity and consistency.
Why FFKM Is Preferred
Despite some limitations, FFKM’s can be a smart material selection because of the efficiency and operational gains. Long-term, proven performance of FFKM parts can mean fewer seal replacements, repairs, and inspections, resulting in increased process and equipment uptime and yield.
 Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. Polytetrafluoroethylene is a fluorocarbon solid (at room temperature), as it is a high-molecular-weight polymer consisting wholly of carbon and fluorine.
 Fluoroelastomers or Fluorocarbons (FKM) are highly fluorinated polymers that are suitable for continuous use at elevated temperatures. Various grades are available, including copolymer and terpolymers. Fluoroelastomers have excellent heat and flame resistance, and outstanding resistance to aging, ozone, oxidizers, oils and many chemicals.