“Silicone Is What Makes It Possible”

Automakers all over the world are taking electric drive trains to the next level. And the high temperatures generated by powerful electric motors make silicone products indispensable, as they protect sensitive electronics, support thermal management and more.

Demands on silicones are constantly changing – both in terms of new drive technologies as well as in other industries and applications – which is why development of these high-performance materials is always ongoing. In this interview, Christian Gimber of WACKER SILICONES describes the outlook for the most important development trends.

Christian Gimber

Christian Gimber is the vice president of the Silicone Engineering business unit at Wacker Chemie AG.

The Silicone Engineering business unit oversees the global business in customized solutions for silicone elastomers in high-end applications.

Mr. Gimber, what progress has been made in the development of silicone materials over the past ten years?

One of the most important advances has been in the development of self-adhesive liquid silicone rubber – an efficient option for producing hard/soft combinations without the use of bonding agents. That holds a number of advantages, especially in terms of sealing technology: because silicone seals are bonded to the component, they make assembly easier and possess superior sealing power. Mechanical properties such as tear resistance, compression set and resistance to media have improved enormously over the past few years as well. We now offer a liquid silicone rubber with a Shore A hardness of 90, which is quite close to that of a thermoplastic. Progress has also been made in terms of devolatilization. Non-postcure grades are so hard after curing that there’s no need for postcuring, which eliminates a costly, time-consuming step.

What are the most important jobs that this class of materials will have to perform in the future, and where does the greatest potential lie for development?

Silicone elastomers are characterized by excellent mechanical properties, high elasticity and extreme resistance to heat. All of that’s going to become more important going forward. Demands on sealing materials will be especially high, and not just in the automotive sector. Their resistance to media and excellent elastic recovery make silicone elastomers extremely robust and well-suited for sealing applications. As encapsulants, silicones protect sensitive electronic components from dust and vibrations – specialty silicones are now used for encapsulating LEDs as well. Given its dielectric properties, silicone is also used for power supply applications and cable fittings. In airports and public buildings, fireproof cables are frequently insulated with ceramifying silicones that prevent short circuits in the event of a fire. The use of silicones in medical technology is likewise growing in applications such as catheters, respirator masks, OR supplies, orthopedics and prosthetics. Now there are even wound dressings coated with gentle adhesive silicone gels. The market still holds a great deal of potential.

“Vehicle electrification and the tremendous success of driver assistance systems – up to and including self-driving vehicles – represent a huge opportunity for silicones.”

Christian Gimber, vice president of the Silicone Engineering business unit at Wacker Chemie AG

How does silicone fit in with sustainability and products that conserve resources? What can the material bring to the table?

Silicones can withstand higher temperatures and have better mechanical properties than other kinds of rubber, allowing automakers to design more efficient, energy-saving engines. Downsizing has been the key: thanks to modern engine management and more compact designs, motors in today’s vehicles are much more efficient and use far less energy than they used to. The disadvantage, however, is that they produce more and more heat. Unlike many other synthetic materials, silicones have the thermal stability to meet these growing demands. They can also be processed efficiently: liquid silicone rubber is pretty much a perfect fit for injection molding, which is a highly efficient method of mass-producing components. Our UV-activated silicone gels conserve resources as well: they crosslink quickly with no need for oven curing, which saves time, energy and heating costs.

What are your thoughts on elastomers in e-mobility and lightweight construction applications?

Silicones have a lot of uses here, such as insulating hybrid cables, dissipating heat, and encapsulating sensors and on-board electronics. The importance of thermal management in particular has grown due to increasing vehicle performance and ranges – the heat generated in the battery, motor and electronic systems has to be dissipated, after all. That can be accomplished through the use of gap fillers and specialized silicone adhesives that connect electronic equipment to the heat sink. Silicones are also in demand for lightweight construction applications: lightweight laminates coated with flame-retardant silicones, for example, are used as spacers between vehicle elements, such as the battery and passenger compartment. Foams and other silicone-based materials are also playing a more significant role in recent safety concepts in battery design. Here they unite two core characteristics: heat resistance across a wide range of temperatures and excellent functional reliability throughout the life of the vehicle. For the aviation industry, WACKER has also developed foamable silicone elastomers that make seats and pillows extremely lightweight and very safe, since silicones are fire resistant.

Where are WACKER silicones headed in automotive engineering?

The automotive industry is currently undergoing a major transformation. The race for the dominant drive technology has only just begun. Every day we’re confronted with new technical demands, which our competence centers in Germany, China and South Korea turn into solutions. These innovative solutions will give WACKER a decisive role in helping alternative drive technologies achieve a breakthrough.

Want to learn more about WACKER silicones?

WACKER silicones are indispensable in an array of applications, including electromobility and lightweight construction. For more information about our silicones, visit the WACKER product portal.

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