As the market moves towards electric cars, polyurethane will be increasingly important.Simon Robinson finds out what Huntsman is doing in the area, and what is driving the changes
Polyurethane plays many critical roles in the modern car, from comfort to insulation – whether thermal or acoustic. Two MDI-based PU systems from Huntsman, Acoustflex and Rubiflex, are specifically designed for automotive applications. Acoustiflex systems are aimed at sound insulation applications in the car interior and in the engine compartment, while Rubiflex systems are designed to make foam-based comfort parts inside the car including seat cushions, backs, head rests, arm rests and for the driver, passenger, and rear seats. Both are fully formulated systems designed to meet OEM requirements for these applications.
As Irina Bolshakova, market manager for automotive and transportation at Huntsman EMAI, explained, in the past 18 months, sustainability has become the top topic for Huntsman’s development agenda. ‘There are three aspects,’ she said. ‘The first is around reducing emissions and the odour of our components, lower VOCs, and the ability to meet the most stringent requirements of OEMs for formaldehyde and acetaldehyde and reducing the odour of the final components. We can meet BMW’s requirements, which are the most stringent on the market in terms of emissions.’ This technology has been patented.
The second aspect is cutting the carbon footprint of its products in manufacturing and development. ‘This is driven by our own CO2 reduction targets, and reflects the automotive industry’s own commitments in these areas,’ she said. ‘All the manufacturing processes upstream are subject to this. A good example is at our facility in Rotterdam. Here, we have started to use only green-based energy, which will give us a significant reduction in carbon footprint, and we have reduced the carbon footprint of our transport in the EU by more than 50%. There are very aggressive targets globally.’
The third aspect is to add recycled and biobased content into the formulations. ‘We are already able to supply formulated systems with 15% bio-based raw materials,’ she said. ‘This is 15% in the final foam.’
The company is now working on delivering 30% biobased or recycled-based content in early 2022. The biobased content is for the polyol side of the formulation, and focuses on the use of natural-based oils and components. The recycled content is based on its Terol-based polyols, which are made from old PET bottles.
‘We have this technology in house and we are investing in this development,’ Bolshakova said. ‘Originally, this was a big part of the rigid and insulation foam portfolio. Now we are trying to find a way to get it into automotive applications.’
It represents quite a switch, going as it does from highly branched rigid polyols into more linear flexible polyols, and this is why it requires investment. ‘It will not be possible to do everything with this at first,’ she said. ‘Very soft flexible foam is a big challenge. But steering wheels, instrument panels, headliners are all good potential applications.’
The company has also started a project in Belgium, working with two partners to develop biobased polyol technology for Acoustiflex applications. The target is to put 45% biobased content in the final foam. The aim is to use raw materials derived from nature but, importantly, ones that have no impact on the food chain. The company hopes this will contribute significantly to the ‘green’ content of the materials, and also reduce carbon footprint.
Huntsman is working on a range of technological developments to meet current and future needs. For example, they are looking to develop acoustic systems that will withstand temperatures as high as 180°C, for insulating the motor and starter under the hood. ‘Hybrid technology is leading to higher under-bonnet temperatures, as smaller engines are squeezed into smaller spaces by the addition of more electronic components such as electric motors,’ she said.
As we move towards full-electric vehicles, there are going to be more requirements for motor encapsulation. ‘This reduces engine noise in the cockpit, it helps with thermal management, and provides flammability resistance, which is becoming more important with increasing levels of electronic components,’ she said. It’s a different story for the battery – these are not designed to get as hot, but may need insulation against low temperatures. Yet fire-rated performance is critical.
In the passenger compartment, the modern electric car does not have the ‘free’ source of heat from the inefficient combustion engine. When heating is required, it will come from the battery, and preventing its dispersion will be important for energy efficiency. Effective insulation will be key.
‘We expect that thermal insulation will be a much bigger topic than it is at the moment,’ Bolshakova said. ‘One of our assumptions is that there will be a significant improvement in battery technology itself, and the use of batteries in vehicles. There could be two or three batteries, with the tasks of heating and cooling separated from starting and driving the vehicle. I think that thermal insulation will become important as customers increasingly tell car makers what it is like to drive their vehicles.’
The company plans to launch highly bio-based engine insulation components in the Acoustiflex range later in the year. ‘These will be designated HT for high temperature, with the temperature resistance between 180° and 200°C and very high biobased content,’ she said. ‘We can reach up to 45% bio-content in the polyurethane part, depending on the customer’s requirements.’
This is a new application for the company, with the product aimed at all three current automotive power sources, conventional combustion, hybrid and electric. ‘This will increase the temperature range of PU components and exceed the green content which automotive companies demand,’ she said.
Huntsman developed the materials based on mapping the market, looking at where the technology is going and changes in the engine compartment and how they could be met. At the moment, she said, electric and hybrid are leading in terms of sales. This is being driven by government incentives, and the changing attitude of consumers. ‘The change is happening more quickly in Europe,’ she said. ‘In the US, the interest is there, but there is not yet the regulatory push.’