Automotive and transportation industry leaders need to meet increasingly stringent carbon emission regulations imposed by governments, as well as rising consumer demand for affordable zero-emission vehicles. Many car, bus, van and truck manufacturers are responding to this pressure by investing in battery-powered electric vehicle (EV) technology. To address performance challenges posed by EVs, including limited driving ranges and long recharging times, automakers are leveraging hydrogen-powered fuel cells. This technology represents a fast-growing segment of the global passenger and commercial transportation market – which is expected to see a CAGR of 66.9% from 2019 to 2026.
A long-standing barrier to increasing the adoption of hydrogen vehicles is the weight and cost of their pressurized fuel tanks – which are typically made of steel or aluminium and limit a vehicle’s range and load capacity. As a result, manufacturers are looking to replace metal hydrogen tank materials with engineering thermoplastics that enable them to simplify designs, reduce part weight and lower production costs.
Yet, the materials selected for producing these parts need to withstand mechanical stress from rapid hydrogen filling and depressurization, as well as extreme temperature changes between -40°C and 85°C. Thermoplastics used to manufacture tank liners, which prevent chemical contamination, corrosion and leakage must comply with regulations that ensure hydrogen is safely stored in a high-pressure environment.
High-density polyethylene (HDPE) is used for numerous tank manufacturing applications, but is susceptible to blistering and requires higher wall thickness compared to polyamides (PA) to meet permeation standards. Standard PA6 materials are cost-effective and demonstrate high thermal resistance, but often become brittle at sub-zero temperatures. To get ahead of competing suppliers, manufacturers need to select a thermoplastic solution that effectively balances their design, performance and cost considerations.
DSM launched Akulon® Fuel Lock 10 years ago to respond to rapidly increasing demand for sustainable materials for vehicles and outdoor equipment. The advanced PA6 is ideal for producing type IV pressure vessels that are 70% lighter than steel alternatives, and offer excellent mechanical strength, dimensional stability, and impact resistance throughout part lifetimes. Akulon Fuel Lock tank liners enhance vehicle safety and fuel efficiency by providing an excellent barrier that reduces permeation leakage of hydrogen from the pressure vessel.
Due to its unique chemical structure, Akulon Fuel Lock provides superior properties compared to HDPE and PA11. The material achieves a higher safety margin than HDPE when heated to 85°C and exceeds widely-used thermal stability safety standards. Fast fill testing conducted in a -40°C environment verifies that Akulon Fuel Lock performs well in low temperature conditions.
Akulon Fuel Lock’s outstanding processing capabilities enable manufacturers to produce light, thin-walled designs and reduce curing time during production of the composite layer, saving significant operational costs. The highly versatile polyamide is compatible with injection molding, roto-molding, blow molding and tube extrusion processes, which allows parts suppliers to easily apply the material to existing production setups. DSM also offers hands-on computer-aided engineering (CAE) support, including permeation behavior prediction.
DSM is committed to helping automotive and transportation industry leaders meet goals to protect the environment. As we bring more sustainable engineering thermoplastics to market, we leverage close relationships with customers to understand how our material solutions can solve complex design, performance and cost challenges. Together with our partners, we build on one another’s expertise to deliver innovative, eco-friendly products that exceed the expectations of automakers and OEMs to reshape the future of clean-energy transportation.
13 December 2021
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Application Development Engineer
Bert Keestra studied chemical engineering at the Technical University Eindhoven (TU/e) in the Netherlands. After he completed a PhD in polymer technology at the same university, he started working at DSM in the corporate research department of materials science. In 2010 he transferred to the business unit Engineering Materials as product development specialist and later as application development engineer, focusing on composite pressure vessels.
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