How to avoid Fogging in the car?

Dirk Tietz | 15. July 2019

What is fogging?

Generally speaking, fogging refers to the outgassing of individual material parts that condense in the surroundings of the component. Usually, the fogging effect is associated with heated living spaces. Here, black-dust settlements occur in flats during the heating period. Typical signs of fogging are planar black coating or black dust that sticks to the ceiling or the walls.

How does the fogging effect develop in the car?

The fogging effect, also called magic dust, is a coating on the inner side of the windscreen, which is the result of different emissions. Evaporations and substances in the plastic of the interior covering can lead to contamination of the windscreen in the area of the dashboard. This film is particularly noticeable on windows with poor insulation, like the ones in old buildings, window displays or cars.

The collective term VOC refers to the group of volatile organic compounds. VOC describes gaseous and vaporous substances of organic origin in the air. These are accompanying substances that are not always permanently embedded in the molecular structure of plastics and adhesives. The reason for the development of volatile organic compounds in the air are plastic surfaces of furnishings, which concentrate in the interior of more and more air-tight building covers and can add to the “fogging” phenomenon. Too high VOC exposure in the vehicle interior hence leads to an irritation of eyes, nose, throat and the skin or allergic reactions.

How can you prevent fogging in the car interior?

Almost all plastics used in the passenger space with which the vehicle occupants come into contact during the journey nowadays consist of low-emission materials, such as dashboard and steering wheel coatings, door panels, sun shades or gear knob. Lately, car manufacturers have been paying greater attention to smaller parts embedded in the interior of vehicles, such as plain bearings.

What requirements does my material have to fulfil for a low fogging effect?

What plastic can be used in the cabins of cars and lorries is regulated by specifications of the car manufacturers, which are usually based on legal requirements. igus® offers a wide range of high-performance polymers for moving applications, which adhere to the following requirements:

• Fogging (DIN 75201-B)
• Odour (VDA 270 variant B)
• Emission (VDA 277)
• Formaldehyde (VDA 275)
• Burning test (FMVSS 302)
  

Depending on customer-specific application parameters, the right iglidur® material for interior applications can be determined with the online tool”iglidur expert“. Technical consultants are also available at short notice on-site for support.

The following materials are being used as plain bearings a million times to reduce weight, noise and costs. At the same time, they are in line with the listed requirements: