In recent years, in the face of the increasingly stringent environmental protection and emission reduction challenges, it is imperative for traditional vehicles to promote lightweight design. For electric vehicles, the lighter body design is expected to alleviate one of the biggest bottlenecks hindering its development, namely the contradiction between the cruising range and the weight of the vehicle; its importance is also unmatched.
As the world's leading specialty chemical company, Evonik has long been committed to the lightweight development of the automotive industry, and took the lead in finding another breakthrough in the curing agent used in epoxy system sheet molding compound (SMC). This is Evonik's leading amine-based curing system VESTALITE® S.
Make automotive molding compounds have better mechanical properties and lower emissions
Evonik and Vestaro worked together to jointly develop VESTALITE® S, an amine-based curing system suitable for epoxy SMC technology. At present, automobile components including tailgates and luggage hatches have been manufactured by SMC technology. The technology is robust and fast, with wide geometric design freedom and functional integration.
Li Shuanghu, technical engineer of Evonik's cross-linking agent business line, said: "VESTALITE® S is an ideal solution for epoxy SMC. The advantages are mainly three points: First, the mixed viscosity of the system is low, and the wettability with the reinforcing fiber is good. The SMC material has high storage stability. The production efficiency is high, and it can be cured within 3 minutes at high temperature. The second is that the cured product has excellent mechanical properties and heat resistance. Finally, its volatile organic compounds ( VOC) Very low emissions, in line with increasingly strict environmental protection policies."
Significant weight loss of parts and components, unleashing the potential for lightweight vehicles
In the "Lightweight Open Innovation Challenge" held by the European Automotive Lightweight Feasibility Alliance in 2018, scientists from the Institute of Automotive Engineering (IKA) at the Technical University of Aachen, Germany, demonstrated the carbon fiber-SMC components of the VESTALITE® S system in Potential in prototype auto parts.
The reference part of the experiment is a steel tail gate, and the inner panel of the tail gate is replaced by VESTALITE® S carbon fiber-SMC elements. The simulation results show that the stiffness values of VESTALITE® S carbon fiber-SMC components under various load conditions are almost the same as the steel reference values. More importantly, the weight of the internal structure of the preliminary designed tailgate has been reduced from 3.96kg made of steel to 2.01kg, and the weight of the components has been reduced by nearly 50%.
On the other hand, the life cycle assessment results of VESTALITE® S carbon fiber-SMC components show that due to the reduction in weight, the CO2 equivalent emissions during the entire life of the component are reduced by more than 15% compared with steel. The solid hammer demonstration of scientific research has made the VESTALITE® S system SMC stand out from 22 applications from 9 countries and become one of the four winners of the final award.
This makes us wonder: if more epoxy SMC is used on appropriate components in the future to realize the integration of functions and components, the weight of the product can be further reduced. This will not only improve the cost effectiveness of auto manufacturers, but also contribute to the overall ecological balance of automobiles and promote the sustainable development of the industry.
At present, Evonik is working with partners in the automotive industry to verify other potential applications to further unlock the potential of automotive lightweighting.