Q&A: Michelin Resicare on road to RF-free future

Clermont-Ferrand, France – Michelin’s Resicare unit is ramping up its efforts to increase demand for its tire cord adhesive, developed as a bio-based and non-toxic alternative to conventionally used RF (resorcinol-formaldehyde) products.

Having reached a milestone with over 100 million tires produced using the resin this year, Clermont-Ferrand-based Resicare is now actively promoting the technology to other major tire manufacturers.

Here, ERJ asks Emeline Chamoux, business development – Resicare, Michelin Engineered Polymers, about the current status of the product and future prospects for its industry-wide adoption:

ERJ: Please describe the programme behind the development of Resicare

EC: In 2006, Michelin's laboratories embarked on a journey to develop a non-toxic, high performance resin solution. This ambition gave birth to Resicare, a dedicated subsidiary to take this innovation accessible to the entire industry, including Michelin's competitors.  The results speak for themselves: over 100 million tires have been manufactured using ResiCare resin: marking a major milestone in sustainable tire production.

ERJ: What have been the main technical challenges in developing Resicare for use in tires?

EC: Several years of R&D were needed to find a non-toxic, high-performance, and bio-sourced solution. It was necessary to prove the technical robustness in terms of product performance, industrialisation and economic viability – for use in premium tires today and in the future.

ERJ: Is Resicare a drop-in replacement for RF resins or are modifications needed for the tire cord and/or converting processes?

EC: It's a plug & play technology, meaning that you will reach the same performances in terms of adhesion, peel strength etc, without any changes on the dipping line: we just change the RF part in the traditional RFL (resorcinol formaldehyde latex) solution. This approach ensures a smooth transition to safer chemistry, with minimal disruption to production.

ERJ: How does the cost of Resicare compare with that of conventional RF resin adhesives?

EC: As a premium and disruptive technology, the price is higher in absolute terms. But relatively over cost is acceptable (4 cents per tire) and the scale-up effect will optimise the cost in the coming years. While some may be tempted to compare costs per kilogram, this misses the broader value proposition. ResiCare is a premium solution but not just in price, in what it delivers. Traditional RF resins come with hidden costs: regulatory compliance, worker safety measures, and environmental liabilities. European directives like 2004/37 are already pushing manufacturers to reduce formaldehyde exposure. ResiCare anticipates this shift, offering a future-proof alternative that reduces risk and simplifies operations.

ERJ: How does the performance of Resicare compare with conventional RF resin adhesives?

EC: Compared to RF resin, our solution removes all the toxicity generated by formaldehyde and resorcinol (carcinogenic and endocrine perturbator), however since it's a Novalac phenolic resin (an araminolic) it behaves like the ‘old’ generation in terms of performance – sometimes even slightly better. ResiCare's solution, free from SVHC (substances of very high concern) criteria, offers a safer alternative than: formaldehyde, classified as a carcinogen 1B since 2016, and resorcinol, recognised as a category 1 endocrine disruptor by EU and REACH regulations. 

ERJ: How does Resicare compare with other non-RF tire cord adhesives being introduced into the tire market?

There are a lot of non-RF free solutions appearing on the tire market: showing that the world is moving toward RF-free solution. Some tire leaders do have their own solution; some others are using external technologies.  All RF-free solutions have their advantages and benefits  - industrialisation, performance, chemical [safety] etc. Our solution has proven it's robustness by being used in mass production by the [tire industry] leader, and does not contain any monomers, such as isocyanates, that fit the criteria to be classified as SVHC in the near future.

ERJ: At which location(s) is Resicare being manufactured?

EC: We are based in Europe and Asia, our customers are served worldwide. ResiCare is already fully deployed at industrial-scale across Europe and Asia and has been validated by five major converters: allowing an international network with production at eight industrial sites. It has been tested and deployed globally, with strong support from Michelin’s teams to overcome industrialisation and scale-up challenges. Today, ResiCare is not just a viable alternative, it’s the fastest-deployed RF-free system on the market.

ERJ: Resicare is also now introducing Resi4TEX. Where does this product fit into the portfolio?

EC: Resi4TEX is an aromatic aldehyde-, water-based phenolic Novolac resin that does not contain measurable SVHC components, such as formaldehyde, resorcinol, phenol and isocyanates and is projected to transition to a bio-based model by 2027. The ‘araminolic’ chemistry not only matches but often exceeds the performance characteristics required for tire reinforcement, with temperature and fatigue resistance enhanced by forming a 3D network. Also, the latex component contributes flexibility and reactivity with rubbers. This combination enables the bonding of textile reinforcements, , such as PET, polyamides 6 and 66, aramid and rayon, to various types of rubber and textiles.  

ERJ: How would you describe the tire industry’s progress to date in transitioning to more sustainable tire cord adhesives?

EC: The tire industry is clearly moving towards RF-free solutions, with many leading manufacturers developing their own alternatives. ResiCare stands out by offering a proven, robust solution already in industrial production by Michelin. This milestone of 100 million tires manufactured using ResiCare resin is not just symbolic, it represents a significant environmental achievement.  By avoiding the use of approximately 30 tons of formaldehyde, Michelin ResiCare is paving the way for a safer, more sustainable future in tire manufacturing. 

ERJ: Thank you.