CarbonX Q&A: How to Break the Rules and Make Tires More Sustainable

As a Silver Sponsor for the Tire Technology Expo’s virtual event this year, CTO Daniela Sordi was able to share data and discuss why our latest success in tires is so exciting in her presentation, Back to Black: CarbonX® breaks the rules to combine performance and sustainability.

We have been thrilled by the positive reactions at the event and decided to re-publish Daniela’s response to six key questions posed at the event by experts in the tire industry:

1. How does CarbonX improve sustainability in tires?

Using sustainable/bio-based materials and incorporating resource efficiency, circularity, and carbon neutrality for sourcing, transport, production, and distribution are all excellent strategies for improving the overall sustainability in tires.

But 80% of a tire’s lifetime CO2 emissions occurs in the use phase, and this is where CarbonX can help tiremakers take sustainability one step further. CarbonX® can be used to make more durable, lightweight, and longer-lasting tires with better fuel efficiency and lower lifetime TRWP and CO2 emissions.

A full LCA conducted by a third party and will be available by Fall 2021, but we believe the ability to improve performance as well as sustainability for tires in the use phase makes our carbon material a unique and very relevant alternative for creating the next generation of tires.

2. Many tire manufacturers are moving away from carbon materials. Why would they choose CarbonX?

Tire manufacturers are moving away from carbon blacks because they cannot improve durability any further without compromising safety and fuel efficiency.

CarbonX® is technically a carbon black, so it improves durability like carbon blacks, but it also has the ability to improve grip and rolling resistance – which is what inspired us to see if CarbonX® could be used to replace silica as well.  

Our latest case is especially exciting because it shows that using CarbonX® to partially substitute silica as well as carbon black has the ability to overcome the limitations of these conventional fillers and improve fuel efficiency, durability, and safety at the same time.

3. How does CarbonX® work?

We believe the filaments in CarbonX®  provide reinforcement, keeping wear and mechanical properties intact. The stable pore structure allows the polymer to deform enough to improve grip and road adhesion while still preserving polymer-filament interaction, which reduces energy loss due to hysteresis and thus improves rolling resistance/fuel efficiency.

4. How was CarbonX® tested against carbon black and silica?

N375 was used as the carbon black reference in a high-silica formulation using Ultrasil 7000 (a high surface, high dispersibility silica) in an SSBR/BR matrix.

The first benchmark was carried out by doing a 1:1 substitution of N375 (with no substitution of silica), and all three parameters were at least somewhat improved. CarbonX® was then used to partially substitute silica as well as N375.

By increasing the CarbonX® loading and decreasing the amount of silica (so the total filler content was kept constant), we were able to simultaneously improve rolling resistance (13%), abrasion resistance (21%) and wet grip (7%).

We plan on taking these results one step further to see what happens when we substitute greater quantities of silica in different tire formulations.

5. Has CarbonX® been tested in tires?

CarbonX has undergone rigorous lab-scale testing, both in-house and together with accredited third parties. For our two commercial tires, CarbonX® has also undergone factory and road testing.

All tests have been carried out and reproduced multiple times following the relevant ISO/ASTM standards. Our methodology and results have also been validated by certified third parties.

The rolling resistance coefficient (RRC) was determined using tan delta at 60° in the lab and corroborated by tests on the road. The wet grip and abrasion resistance were measured in the lab using tan delta at 0° and DIN abrasion testing, respectively. Wear, handling, and grip were also measured on the road.

6. Is CarbonX® commercially available?

CarbonX® is produced on a commercial scale and supplied worldwide in powder and masterbatch form. You can find out more about our grades and working with CarbonX® on our Product & Services page.

In terms of commercially-available tires, CarbonX® is already being used to make winter tires and bicycle racing tires, both of which will be introduced into the market in Autumn 2021.

For the winter tires, CarbonX® was able to improve durability (13%) and grip (5%) while maintaining rolling resistance on par. In the bicycle racing tires, CarbonX® was able to improve rolling resistance significantly (44%) while maintaining abrasion resistance and grip on par. You can read more about these cases here.

If you are considering CarbonX® for your own applications or you would like more detailed information about the data in this presentation, please contact us using the form below.