Cleveland, Ohio – For many, the intersection between the polyurethanes and automotive industries suggests only the type of foam used to deaden sound in a vehicle. However, polyurethanes play a much more expansive role in automotive manufacturing. Moreover, the polyurethanes industry is taking the lead on establishing new quality specifications for vehicle interior air quality (VIAQ) standards that will benefit both industries.
Automotive advancements with polyurethanes
Incredible advances in polyurethane chemistry help make automobiles safer and more comfortable in many ways. Different types of polyurethanes can be used to make engine covers, structural parts, chassis components, filters, cables, springs, and support bearings; interior components like consoles and steering wheels; and exterior components like bumpers, spoilers, and roof modules.
Polyurethane foams can be used to create seats and trims and add padding behind other components for safety and vibration resistance. Polyurethane coatings on the exterior of vehicles provide a high-gloss, scratch-resistant layer over the car’s paintwork. Coatings can also be used on the interior of windshields to add strength, reduce glare, and increase fog resistance. Use of polyurethane for these components adds to the overall comfort of cars and contributes to lightweighting.
In recent years, the polyurethanes industry recognized yet another important area of vehicle manufacturing where polyurethanes could play a significant role: improving the vehicle interior air quality (VIAQ). Most commonly, discussions about VIAQ focus on obvious factors, such as emissions from paint, rubber, and molded plastic.
Components just beneath the surface of the car’s interior, like polyurethane foams and coatings, are not typically at the top of the list of materials to evaluate when experts explore ways to improve VIAQ. However, they play an important role. In fact, every year, the industry unveils new research on additives, polyols and foams that informs improvement in VIAQ.
Moreover, the polyurethanes industry leads the development of harmonized standards for measuring and controlling VIAQ.
Global volatile organic compound specifications
Many factors affect VIAQ, including the air above a road, exhaust gases from the vehicle, exhaust from other vehicles, air supplied by the air conditioning and ventilation system, and the evaporation of substances from materials used on the car’s interior. The scientific term for these evaporations is volatile organic compounds (VOCs) – man-made or naturally occurring chemical compounds that have a vapor pressures near room temperature.
Most smells or scents are made up of VOCs. In fact, the famous new car smell is the concentration of chemicals that are a function of material properties, temperature, soak time, ventilation, and aging of the materials used in the vehicle’s interior. Changes in temperature can impact how much evaporation these materials produce.
Because an automobile is a closed environment frequently subjected to significant changes in temperature, manufacturers carefully monitor for VOCs to identify and control any potentially harmful chemicals. VOC testing provides detailed information on which materials are in the car’s interior environment. In turn, this information allows original equipment manufacturers (OEMs) and materials suppliers to work together and improve the performance of the materials.
Auto manufacturers, component suppliers and materials suppliers apply strict guidelines when it comes to VOCs to help ensure vehicles perform for the occupants. In fact, OEMs around the world maintain performance-based VOC methods and standards to develop and build vehicles that exceed VIAQ regulations and improve quality. However, a unified set of specifications does not currently exist.
Each OEM maintains its own method of testing and measuring VOCs in a vehicle. This presents issues for any company doing research and development on new materials for use in a vehicle. Say a component manufacturer wanted to use a new, lighter polyurethane foam for seating. The manufacturer must decide which OEM’s method to use when testing the material for VOCs. Many OEMs will not accept the results if the tests are not conducted according to their own specifications. So, in order to get a new product on the market, the manufacturer must run these tests multiple times over or run the risk of limiting the use of their product on the market.
Finding a Solution
Efforts are underway to harmonize performance-based standards at all levels to enhance safety, benefit the OEM and customer, and facilitate compliance. The annual Polyurethanes Technical Conference, run by the American Chemistry Council’s Center for the Polyurethanes Industry, serves as a host for inter-industry discussions on VIAQ, VOCs, and progress towards global specifications.
For the past three years, meetings and technical presentations at this event have enabled chemical suppliers to meet with members of the automotive industry and talk about what they are doing collectively to standardize VOC specifications. At this year’s event, planned for October in New Orleans, panelists of internationally active experts from OEMs, academia and the polyurethanes industry will share the latest progress toward harmonized standards for VOC compliance. They will also discuss some new legislative changes around this important topic.
Many of these participants – representatives from Addivant, BASF, ChemTrend, Dow Corning, Euromolder, Evonik, Ford Motor Co., Huntsman, Lanzess, Milliken, Momentive, TOSOH Corp., Toyota, and Woodbridge Foam Corp. – are active members of an important inter-industry group taking the lead on VOC harmonization discussions: the Industry Panel for Flexible Molded Foam.
This group, established in 2005, seeks to build bridges among industry players. It is composed of OEMs and companies that either manufacture cars, assemble seats, mold foam or manufacture the chemicals for making foam. After successfully establishing a set of U.S. standards related to the foams used in seating cushions, this group has turned its attention to establishing global VOC specifications. They are prioritizing and coordinating their efforts with similar activities in standards, such as ASTM International and the Society of Automotive Engineers.
Looking to the future While progress on this scale takes time, discussion opportunities at events like the Polyurethanes Technical Conference and initiatives like the Industry Panel for Flexible Molded Foam help the development of global VOC specifications forward.
In addition to the discussions within the polyurethanes and automotive industries, working groups at the United Nations, ISO, and the Society of Automotive Engineers are among those discussing harmonized, global specifications for VOC compliance. Some potential guidelines exist, but they have not been widely adopted for use by the OEMs, including ISO 12219-3 “Interior air of road vehicles, Part 3: Screening method for the determination of the emissions of volatile organic compounds from vehicle interior” and ASTM D7706 “Standard Practice for Rapid Screening of VOC Emissions from Products Using Micro-Scale Chambers.”
As OEMs and suppliers work together to create harmonized standards, the science for VIAQ test technologies also improves. With the help of sampling and analytical suppliers, new ways of measuring and controlling VOCs are being developed. Beyond material contributions, these systems will also measure other air pollutants in the vehicle interior from various external sources. As a result, the vehicles of tomorrow can possibly have innovative air systems with advanced low-VOC materials, high capacity air filters, new sensors and intelligent software to improve and maintain interior air quality. Together, these efforts will make tomorrow’s cars even safer and more comfortable for consumers.
About the authors: Hamdy Khalil is the senior global director for Advanced Technologies and Innovation at Woodbridge Foam Corp. His pioneering work in the selection, development and commercialization of renewable polyurethane materials for use in automotive interior parts is now the benchmark for the global automotive industry. Khalil also serves as an adjunct professor at the University of Guelph; is a member of the board of directors of the Center for Research in the Bio Economy and the Ontario BioAutocouncil; a member of the National Research Council’s steering committee for bio-product development; and a member of the scientific advisory panel for ArboraNano. Khalil holds a Bachelor of Science in chemistry and physics from the University of Alexandria and a Master of Science in nutritional biochemistry from the University of Cairo.
Mark Polster is an emissions test technology expert for Ford Motor Co., responsible for Radio Frequency, Electromagnetic Compatibility, Pass-By-Noise, and Vehicle Interior Air Quality Homologation and Compliance. For the past 16 years, Mark focused his career on the development and implementation of fuel economy, tailpipe emissions and ambient air measurement systems. His research and published results shaped many international standards and governmental air quality requirements. Polster is chair of the Society of Automotive Engineers’ Volatile Organic Compounds Committee and the U.S. representative on the United Nations/ISO Working Party on Pollution and Energy committee for vehicle interior air quality.