Volkswagen Evaluates Sustainable Composites

Sustainability has become a core part of Volkswagen AG’s corporate strategy, and it’s shaking up the company’s supply chain, processes and material selection. This presents an excellent opportunity for composite suppliers. “We are seeing large corporations going against very small startups – and sometimes the startups have the more interesting materials for automotive applications,” says Timo Achtelik, a material engineer at Volkswagen AG. Suppliers looking to get their foot in the door with Volkswagen will find their products must first pass through a four-step stage-gate process Volkswagen implemented in 2021. The steps include idea collection, a feasibility assessment, material testing and validation, and testing and validation of the material within a specific component. Step 1: Idea collection – Suppliers, as well as Volkswagen team members from vehicle designers to construction engineers and material development engineers, are encouraged to suggest new materials. “We try to implement a process where every department works together and can push forward ideas,” Achtelik says. Currently, Volkswagen has approximately 250 sustainable materials in its database to assess for potential use across all vehicle components, from seats and steering wheels to body panels and batteries. Companies not already serving as suppliers can submit suggestions to the Procurement Department’s Innovation Offices via innovation@volkswagen.de. Step 2: Feasibility assessment – Next, material engineers assess the technical characteristics of the suggested materials in their database. This includes screening sustainability data and creating first-cost estimations. “Since sustainability is a fuzzy concept, we've tried to make it measurable,” Achtelik says. Suppliers are asked to provide details on product composition that help classify the material within Volkswagen-set norms for post-consumer recycled materials, post-industrial recycled materials, renewable materials and virgin material. Material engineers also evaluate these characteristics in accordance with their internal sustainability goals. “We always have to focus on the recyclability of the material, as well as our decarbonization and circular targets,” Achtelik explains. “A carbon fiber-reinforced plastic might lead to huge decarbonization measures, but at the end of the day we cannot recycle this material. We try to get composites that fulfill all targets into our cars.” While Achtelik notes that the strength and light weight of CFRP will likely prove crucial for meeting overall sustainability targets, Volkswagen is also searching for renewable fibers used in conjunction with recyclable thermoplastic polymers. The company is also interested in biodegradable materials that can be recycled and even compostable on an industrial scale. One solution that Volkswagen is developing is a leatherette for vehicle interiors that uses coffee bean waste as a principal component – in this case to replace petrochemical-based plastics. Another area of interest is around chemical recycling, where polymers are broken down to get material with virgin qualities again. “Currently, the chemical recycling industry faces challenges when it comes to its life cycle analysis (LCA) and energy demand in general, so it's not reasonable or useful for the automotive industry to use it for now. But we will see about the future,” Achtelik says. Step 3: Material testing and validation – This pre-development step includes testing of product characteristics, such as tensile strength and aging, as well as sustainability characteristics, such as emissions generated during production. At this stage, testing is still performed without the aim of incorporating the material into a specific vehicle project but to ensure that it meets Volkswagen’s stringent requirements. Achtelik notes that one of the biggest challenges suppliers face at this step is ensuring a consistent level of quality at the high supply levels demanded by automotive applications. “We have a lot of new suppliers entering the market right now that have little or no experience with the automotive industry,” Achtelik says. “When we talk about automotive applications, we’re talking about tons of material per year, not kilograms per week. Sometimes we have to remind manufacturers of this.” Step 4: Testing and validation of the material in a part – During the last stage, design and construction engineers collaborate with suppliers to validate the material in a part that will ultimately move into production for a specific vehicle. This is an area where composite materials may find progress stalls. “The biggest challenge with implementing sustainable materials in automotive applications is actually the limited knowledge of how to handle this whole new way of sourcing and working with sustainable materials,” says Achtelik. “With sustainable materials it may be the same polymer, but it's a different process.” For example, he explains, the availability of recycled material and potentially higher upfront costs change the procurement processes. There may be differences in how engineers need to manage critical emissions and odors generated by recycled material. Sourcing decisions may need to balance LCA values against inconsistent material supply and quality. All of the changes require new processes. “This is all new for us, and we all have to learn – at Volkswagen and in the OEM world, as well as in the supply chain,” says Achtelik. That said, the company is finding ways to incorporate recycled materials in unique ways. The ID.Life concept car is proof of that. This electric mini-SUV does not feature any conventionally manufactured plastic. However, the hood and roof are made using an air chamber textile composed entirely of recycled PET bottles, and recycled PET is featured in other components as well. The vehicle is slated for production around 2025. Volkswagen is also still evaluating how to strike the best balance between incorporating new materials without sacrificing component quality. While the OEM aims to use the highest possible percentage of recyclable materials possible, each material switch comes at a cost. “We have to think about the real customer requirements and needs in balance with where we can put in reduced material or materials,” Achtelik says. Megan Headley is a freelance writer in Fredericksburg, Va. She can be reached at megan@clearstorypublications.com.