Specialty chemicals company LANXESS increasingly uses recycled raw materials in the production of its thermoplastic compounds and composite materials. Dr. Guenter Margraf, a global product manager at LANXESS and the company’s high-performance materials (HPM) business unit, explained: "We want to help transform from a discarded society to a circular economy. Our goal is to enable more and more plastic products to have Sustainability, thereby reducing our dependence on the consumption of limited resources, improving our carbon footprint and protecting the environment."
Durethan ECOBKV30H2.0, ECOBKV35H2.0 and ECOBKV60XF are the latest product examples produced under this strategy. Recycled fibers made of waste glass account for 30%, 35% and 60% (by weight) of these three new polyamide 6 compounds, respectively. The independent quality inspection company Ecocycle has checked the amount of recyclable materials in each compound and the long-term use of the glass waste stream through a mass balance method, and issued an ecoloop certificate according to ISO 14021:2016. The glass comes from the waste remaining in the production of glass fibers (post-industrial recycling).
Mass balance method brings benefits to the processor
The mass balance method originates from an initiative launched by the nonprofit Ellen MacArthur Foundation and is used by companies around the world, including many plastics manufacturers, for chemical recycling of post-industrial and post-consumer waste. Through this process, the recovered raw materials are blended into the production together with the originally commonly used petrochemical or mineral raw materials, and then distributed to the final product through an algorithm. The basic principle is similar to the way of feeding environmentally friendly electricity or natural gas into a power grid or natural gas network. The amount of energy that can be generated sustainably in the grid increases with demand, although these energy sources are not differentiated at the level of a single household. The advantage of the mass balance method is that the characteristics of the finished product (such as a polyamide compound reinforced with recycled waste glass fiber) are the same as the characteristics of the original material. In other words, using this method does not mean sacrificing any product characteristics. Margraf said “This means that injection molders can use existing equipment to process mixtures like traditional products, while enjoying the sustainability advantages of certified products.”
Focus on automotive applications
The main objective of the three new compounds in the high-performance materials sector is the automotive industry. As Margraf explained: “For example, Durethan ECOBKV60XF has excellent strength and rigidity, making it suitable for manufacturing structural components such as front ends, pedal bearing brackets and A, B and C pillars, and for electric vehicles.”
Currently developing polyamide 6 to reduce carbon footprint
The High Performance Materials Division will gradually increase the number of ECO product types certified according to the mass balance method. For example, it plans to launch a new polyamide 6, which has a glass fiber content of 30% and a reduced carbon footprint. The caprolactam required to produce this more environmentally friendly polyamide 6 is a variety of petrochemical feedstocks that support this problem.
Waste glass fiber – precious commodity
The High-Performance Materials Division currently does not use waste glass fibers (called post-consumer recycling) in end-of-life components, but it does consider it a particularly sustainable raw material for manufacturing new glass fibers. After all, they do provide similar benefits to domestic collection and recycling of glass containers, which has been successfully implemented for some time. The melting temperature of the waste glass is lower than the temperature of the raw materials used to make glass fibers, so it can save energy and reduce CO2 emissions. "Using waste glass can also reduce the use of resources, because it can save glass raw materials," Margraf said, "This also means that there is no need to deal with waste glass."