The PFAS phase out: a catalyst for innovation in the wire & cable industry

Thanks to their strong carbon-fluorine bond, fluoropolymers are outstanding electrical insulators with exceptionally high resistance to heat and other chemicals. But there’s a reason they’re known as ‘forever chemicals’. They build up in the environment, pose a risk to human health, and don’t break down for hundreds, or even thousands, of years.

The regulation of PFAS, to the point of outright bans for certain uses, is ramping up. The U.S. and E.U. are leading the way with stringent measures, while other regions are also moving towards tighter control. The clock is ticking and the race for safer alternatives is on.

Let’s take a look at the challenges, potential alternatives and key considerations for selecting the right materials for your product development needs.

PFAS are ideal for enhancing performance, durability and reliability of the final product thanks to properties like thermal stability, chemical resistance, biocompatibility and low friction.

For the later reason, PFAS are used as process additives in compounds.

Take die drool formation in halogen-free flame retardant (HFFR) compounds, for example. Buildup of material around the extrusion die is a significant issue in wire and cable manufacturing. It’s caused by thermal or oxidative degradation of the polymer forced by high shear stress at the die exit, which can make small fragments build up around the die lips. If these break off and embed in the extruded product, it can lead to surface imperfections that cause short circuits.

PFAS have been particularly effective in minimising die drool, thanks to low surface energy and lubricating properties. Developing alternative materials with the same performance presents a complex challenge.

A few potential replacements for PFAS in wire and cable compounds have emerged in recent years, aimed at reducing drool and improving processability.

-Silicone-based additives can significantly reduce die drool, but don’t always exactly match the effectiveness of PFAS, so higher dosing levels are sometimes required. In particular, PDMS/silica composites present a ready-to-use solution as a processing aid for many wire and cable applications. They are sure to play an increasingly important role in manufacturing.

PDMS/silica combines the beneficial properties of both materials. PDMS has low surface energy, which helps minimise adhesion to the die surface. Silica can remove microdeposits and lead to cleaner extrusion processes and higher-quality products. Welcome side effects at higher dosing levels are a reduced coefficient of friction (for better abrasion resistance), improved flame-retardant properties, and reduced smoke density in case of fire. PDMS/silica-based materials are also highly versatile and customisable for diverse applications.

-PEG derivatives are particularly promising in reducing die drool but, with lower thermal stability, they require careful management of temperature conditions.

The other use of PFAS in wire and cable is for insulation. Common insulating materials in the industry contain PFAS. These include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxy (PFA), and ethylene tetrafluoroethylene (ETFE).

What’s important to understand is that the PFAS they contain are not all the same. In fact, only a few are classed as controlled substances under the Stockholm Convention — namely PFOS, PFOA, and PFHxS. These belong to a class of PFAS made up of long carbon chains, which accumulate in organisms along the food chain.

Most fluoropolymers on the market today are already PFOA free, and most producers never used PFOS or PFHxS to begin with. The next generation of fluoropolymers will be produced by a new process without fluorosurfactants (fluorinated emulsifiers), which should substantially reduce PFAS contamination in the environment.

In the search for more sustainable alternatives, the challenge is to balance performance with environmental stewardship. For the time being, PFAS are irreplaceable for critical applications where safety, performance, and operational continuity are paramount.

For example, aerospace and defence communication networks rely on fluoropolymers to reduce signal interference and prevent loss of high-frequency signals over long distances. Viable PFAS-free alternatives continue to be sought.

Likewise, in the healthcare sector. Pacemakers rely on the durability of fluoropolymers. Catheters and guide wires depend on their low-friction surface to smoothly navigate through blood vessels. Finding sustainable alternatives will hinge on mechanical properties, flexibility, sterilization methods, and biocompatibility.

-Thermoplastic polyurethane (TPU) is one viable substitute for some medical cable applications. They offer flexibility, durability, biocompatibility, and processing ease, but may not completely match fluoropolymers in chemical resistance or friction properties.

-Silicone offers unmatched flexibility and biocompatibility but isn’t as chemically resistant as fluoropolymers.

The search for PFAS alternatives for wires and cables continues. There is no single replacement across the board, especially for specific high-performance applications like medical, defence and communication cable.  

The good news is that the landscape is rapidly evolving. Every principal partner we work with is actively developing PFAS replacement technologies. The availability of alternatives will improve over time. 

With wire and cable producers driven to develop products that are safer for people and planet, one thing is clear: It’s time to rethink your formulations. At IMCD, we’re here to explore the possibilities together.