Perfluoroelastomer (FFKM)

Perfluoroelastomer (FFKM) is a high-performance class of synthetic rubbers known for their exceptional chemical and thermal resistance. Structurally, FFKM is closely related to PTFE (polytetrafluoroethylene, or Teflon) but with added elastomeric properties that allow it to stretch, compress, and return to its original shape, making it ideal for sealing applications. FFKM materials are specifically engineered to perform in extreme environments where standard rubber compounds would quickly degrade.

Unlike standard elastomers such as Nitrile (NBR), EPDM, or even high-grade FKM (like Viton®), FFKM contains a fully fluorinated backbone. This molecular structure gives FFKM its near-universal resistance to chemicals, including acids, alkalis, solvents, and aggressive gases. It also enables continuous operation at elevated temperatures, typically up to 260°C (500°F), with some formulations tolerating spikes as high as 327°C (620°F).

As one of the most chemically and thermally resistant rubber materials available, FFKM is widely used in demanding industries such as semiconductor manufacturing, aerospace, pharmaceutical production, oil & gas, and chemical processing. Common products include O-rings, rubber gaskets, and custom-moulded FFKM seals for critical environments.

No, while FFKM (Perfluoroelastomer) and FKM (Fluoroelastomer) are both high-performance rubber materials, they differ significantly in chemical structure, resistance capabilities, and cost. Both are part of the fluorinated elastomer family and offer resistance to heat and chemicals. FFKM is a fully fluorinated material, whereas FKM still contains hydrogen atoms in its polymer chain. This difference makes FFKM significantly more resistant to aggressive chemicals, solvents, and high temperatures.

While FKM resists oils, fuels, and many common chemicals, it can fail in the presence of strong acids, ketones, steam, or amines. FFKM, by contrast, offers near-universal chemical resistance, withstanding some of the harshest industrial substances, including nitric acid, ozone, and plasma.

Temperature performance is another key difference. FKM typically handles up to 200–230°C, whereas FFKM can operate continuously up to 260°C, with some grades tolerating peaks of 327°C. This broader temperature range makes FFKM ideal for extreme heat applications and for environments where thermal cycling is a concern.

However, FFKM is significantly more expensive than FKM due to its complex formulation and processing. It is used where sealing reliability is critical. FFKM’s higher cost means it’s reserved for applications where standard elastomers like FKM would not suffice.

Yes, FFKM can be moulded like other rubber compounds, but the process is more complex and requires specialised equipment and expertise. While the fundamental moulding techniques, such as compression, transfer, and injection moulding, are the same, FFKM’s unique properties demand tighter process control and higher processing temperatures.

This makes perfluoroelastomer rubber moulding a specialist task. FFKM compounds typically require moulding at elevated temperatures, often between 170°C and 230°C, followed by a carefully controlled post-curing process to complete the crosslinking and remove any residual by-products. This post-curing stage is essential to achieving the high thermal and chemical resistance that FFKM is known for, especially in applications where purity and performance are critical.

Due to the cost of the material and its sensitivity during processing, mould tools must be precision-engineered to manage shrinkage, maintain dimensional accuracy, and ensure consistent results across production runs. Cycle times may also be longer compared to standard elastomers due to the thermal stability and curing characteristics of FFKM.

At Kea-Flex, we have extensive experience in moulding advanced elastomers like FFKM. Our in-house tooling capabilities, precision process control, and deep understanding of high-performance compounds enable us to deliver consistently reliable results for even the most demanding applications. Whether you need small-batch prototypes or high-spec production runs, we’re equipped to meet your performance and quality requirements.

Yes, FFKM (Perfluoroelastomer) does require post-curing after the initial moulding process. Post-curing is a critical step that completes the crosslinking of the polymer chains and removes residual by-products from the compound. This process is essential for achieving the material’s full chemical and thermal resistance properties.

During moulding, FFKM is exposed to high temperatures to initiate curing, but this alone is not enough to stabilise the compound for high-performance use. The post-curing stage typically involves placing the moulded components in a controlled oven for an extended period, often at elevated temperatures specific to the compound formulation. This ensures that the parts reach their final chemical structure and mechanical strength.

Post-curing is especially important for applications in chemical processing, pharmaceuticals, and semiconductors, where purity, performance, and long-term sealing reliability are non-negotiable. Without proper post-curing, FFKM components may off-gas, degrade prematurely, or fail under extreme service conditions.

At Kea-Flex, we follow strict post-curing protocols tailored to each FFKM grade to ensure our moulded parts consistently meet the highest standards of performance and reliability.

FFKM (Perfluoroelastomer) is used in demanding environments where extreme chemical resistance, high thermal stability, and long-term sealing performance are essential.

One of its most common uses is in the semiconductor industry, where it’s found in vacuum systems, plasma chambers, and chemical delivery equipment. These environments require materials that can handle aggressive gases, high temperatures, and ultra-clean conditions. FFKM performs exceptionally well due to its low outgassing, minimal particle generation, and excellent purity.

In the pharmaceutical and food sectors, FFKM is used for seals, gaskets, and diaphragms in contact with products or cleaning agents. Many grades meet FDA and USP Class VI standards, making them ideal for sterile, hygienic applications. Its ability to withstand steam, CIP (clean-in-place) processes, and harsh sanitisers makes it a reliable long-term solution.

FFKM is also widely used in the chemical and petroleum industries, where seals must resist highly corrosive fluids, acids, and solvents. Its chemical resistance helps prevent leaks, lower maintenance, and improve safety in aggressive environments.

In the aerospace and defence sectors, FFKM components are used in fuel systems, hydraulic lines, and engine assemblies, where they withstand extreme heat, pressure changes, and chemical exposure. Similarly, in the oil and gas industry, it’s found in downhole tools, valves, and pumps exposed to sour gas, high pressures, and elevated temperatures.

FFKM (Perfluoroelastomer) is more expensive than standard rubber materials because of its complex chemistry, specialist manufacturing, and high-performance capabilities. Unlike common elastomers, such as nitrile rubber, EDPM, and natural rubber, FFKM is fully fluorinated. This gives it exceptional resistance to chemicals and heat, but also makes it more difficult and costly to produce.

Its manufacturing requires high-purity ingredients, precise processing, and high-temperature moulding, followed by a controlled post-curing stage to ensure full performance. These added steps increase production time and cost.

FFKM is used in critical industries like chemical processing, semiconductors, aerospace, and pharmaceuticals, where reliability is essential. While the upfront cost is high, its durability and long service life help prevent failures, reduce downtime, and justify the investment in demanding environments.