Vehicle Insulation: Why should the vehicles of the future be insulated?
Interview of Prof. Dr. Stefan Bratzel
On one hand, overheating can damage vehicle components and evaporate essential fluids. On the other, vibrations and noise create an unpleasant environment while undermining noise emission limits. Let’s find out more about the role played by vehicle sound and heat insulation with Prof. Dr. Bratzel from the Center of Automotive Management (CAM).
Prof. Dr. Bratzel, how important do you think acoustics will be when constructing tomorrow’s vehicles?
"Requirements for driver and passenger acoustics have steadily increased in recent years, especially with the growing importance of infotainment. In terms of exterior sound, pass-by noise tests are now clearly defined procedures in the vehicle development process and limits for noise emissions are being further tightened by EU regulations.
For us to reduce noise levels across the entire vehicle, we need to improve the sound absorption of numerous components, in particular, the engine compartment, powertrain, wheelhouse and underbody. To meet this challenge, the choice of vehicle insulation is essential. One of the materials at the forefront of reducing noise directly at the sound source is thermoformable glass wool. "
Focus: why use thermoformable glass wool?
To meet the vehicle sound and heat insulation needs of customers, ISOVER has developed a special grade of glass wool blankets. Ideal for insulating engines and driver compartments, the automotive green mat combines excellent thermal insulation, sound absorption and mechanical resistance.
What acoustic challenges do OEMs face when developing electric vehicles?
"The rolling noise of electric vehicle tyres isn’t all that differs from a vehicle with an internal combustion engine. By eliminating background noise inside vehicles, the noise of ventilation from the heating and air conditioning is more noticeable. The solution? Optimising the vehicle sound insulation for components in the heating system, air conditioning and fans, as well as the interior of the passenger compartment. Soundproofing will, without doubt, remain an important topic."
In your opinion, will thermal insulation continue to play a major role in vehicles?
"Effective vehicle heat insulation plays an important role in optimal thermal management. In electric vehicles, all the energy must be covered by the battery, unlike the combustion engine where eliminating engine heat produces heat energy. Good thermal insulation saves energy and, of course, this also has a positive effect on passenger comfort and the driving range of an e-vehicle."
What challenges are presented by the lack of fire regulations?
"Fire protection in vehicle construction should be a priority and standard, as it has been in the building industry for many years now. It is no secret that fires in e-vehicles due to their large batteries are extremely problematic for fire departments. For me, it is clear that non-combustible sound and heat insulation should be installed as standard in vehicles. For example, installing non-combustible glass wool insulation, rather than PU foam or other plastics, would significantly reduce the fire load. Given the growing focus on e-vehicles and the associated dangers of battery fires, it seems the ideal time for legislators to set uniform specifications and fire safety standards for vehicle insulation."
Does substituting PU foams with non-combustible materials make sense?
"PU foams have numerous advantages that justify their use in vehicle construction. However, to improve the vehicle insulation and fire protection, we also need to reduce the fire load. Wherever it is technically and conceptually feasible, plastics should be exchanged by non-combustible materials for fire safety reasons. There are now enough alternatives, for example, thermoformable glass wool, which can be used for a wide range of applications without sacrificing acoustic performance, stability and durability. For possible fire sources - engine compartment, batteries, electrical components and wiring - it would be advisable to install non-combustible insulation materials."
What role do the materials used in vehicle construction play in terms of emissions, sustainability and health?
"These are three very different yet interconnected impacts, which all need to be taken into account when designing and manufacturing vehicles. Protecting the environment is a complex yet essential issue that influences almost all areas of society, particularly mobility. For example, it is important to choose sustainable raw materials and develop low-emission production processes, as well as focusing on end-of-life recyclability. Made from natural raw materials, glass wool has a huge advantage over chemically produced products. It has been also shown that glass wool products don’t present any health problems during their use and have been defined as harmless by the WHO (World Health Organization)."
Prof. Dr. Stefan Bratzel
Center of Automotive Management (CAM)
Focus : just how environmentally friendly is ISOVER glass wool?
Manufactured from locally sourced natural raw materials like sand, ISOVER glass wool products have Zero Ozone Depleting Potential (ODP) with no CFCs or HCFCs produced during the manufacturing process. Since 1990, up to 80% of the glass used to make glass wool is recycled.