Recyclability Must Improve to Boost Circularity in Plastics

New data shows CarbonX® could provide performance-enhanced plastics with the recyclability that manufacturers need to achieve real circularity.

 

Using recycled plastic can save up to 80% CO2 emissions and requires up to 88% less energy than producing virgin plastic from scratch. It could also save on cost, particularly in light of the substantial rise in cost of virgin plastics since 2020.

A circular economy could cut global GHG emissions by nearly 40% – more than 28 GtCO2 per year; circular plastics alone would cut 25%. With that in mind, binding targets for recycled content in new products in the EU are designed to align with the Climate Target Plan 2030. The EU Directive on plastic packaging, for example, will require at least 30% recycled plastics by 2030.

But recycled plastics replaced only 8% of virgin polymer demand in 2020. So why aren’t more recycled plastics being used to make new products?

Not all plastics can survive recycling

Thermoplastics used in countless products typically contain fillers designed to enhance performance, processability, safety, and durability. This makes them stronger, lighter, and longer-lasting.

But it also means that they cannot undergo mechanical recycling without losing most of their properties – their value. Without additional treatment, manufacturers are limited in how much recycled material they can use and still meet high performance requirements. And recovering these properties often costs more than using virgin materials.

So most thermoplastics are downcycled instead of being used to make new products with high performance requirements – a linear trajectory, rather than a circular one.

Stop downcycling and close the loop

Closed-loop recycling can help reduce the need for petroleum-based virgin materials, cut down on emissions, and reduce waste – but it’s not very cost-effective if the recycled materials cannot be re-introduced into the production line. Applications with high performance requirements must find alternative solutions.

“Higher-quality recycled compounds would mean that more recycled material could be used to make new product,” says Daniela Sordi, the CTO at CarbonX, “allowing manufacturers to achieve real circularity and truly leverage the benefits of a closed-loop recycling system.”

Filling in where conventional fillers fail

Carbon black and glass fibres are both commonly used to add conductivity and reinforcement to thermoplastics. But they also compromise impact resistance and break easily, limiting processability as well as recyclability. These limitations must be overcome in order to make a closed-loop system work.

CarbonX produces a novel carbon material that can meet high performance requirements – and still retain its properties even after being recycled multiple times. The material, CarbonX®, was recently tested to see how well it could retain its initial properties after being recycled.

Polypropylene is one of the most commonly used materials for heavy-duty applications because of the durability it already offers even before more fillers are added to meet other performance requirements. We used a 45% CarbonX®-polypropylene compound, then re-processed it 10 times and measured the mechanical and electrical properties after each cycle.

Conductivity and impact resistance retained after recycling

Figure 1A shows that volume resistivity is largely preserved in the CarbonX® compound, and the stability of the E-modulus and yield stress indicate that strength is also retained, even after 10 cycles.

Figure 1A. Volume resistivity, E-modulus, yield stress

Impact resistance, however, is typically the property that is most affected by the recycling process. Figure 2A shows how much the process damages the polymer itself, losing 80% of its impact resistance after 10 cycles. But the CarbonX® compound was able to retain its impact resistance significantly better.

Figure 2A. Impact resistance

The results show that CarbonX® can outperform conventional fillers because combination of higher impact resistance and strength translates into greater durability, which contributes to the sustainability of the product.

It also brings significant advantages in terms of recyclability. By retaining more of the original properties, CarbonX® allows manufacturers to introduce much larger quantities of recycled compounds back into the production process – making it more cost-effective to invest in a closed-loop recycling system and vastly improve the sustainability of their products.

 Tipping the balance

Binding targets for recycled plastic content, along with more stringent regulations on plastic waste, will soon extend to all industries. The recommendations for post-consumer plastics in new cars, for example, is 25% by 2025, 30% by 2030, and 35% by 2035. 

For applications with high performance requirements such as automotive plastics or plastic pallets, the most cost-effective way to meet these targets will be implement a closed-loop recycling system and maximize how much they can use for making new products.

CarbonX® could offer the performance and the recyclability they need to support circularity, meet their sustainability goals, and meet the EU’s mandate for recycled content.

 

Want to know more about how CarbonX® improves performance and recyclability at the same time? Watch our video from Compounding World Expo 2021. Got a specific application in mind? Find out whether CarbonX® is the right fit by contacting our sales team directly at sales@carbonx.nl.