Polyurethane foam is the major source of VOCs and odour in the automotive cockpit. Michael Holzwarth of design and development specialist imat-uve explains why it can be hard to change the smell of the foam
The global nature of the modern automotive industry makes cockpit odours a challenge. Those that are considered high status and pleasant smells in one part of the world can be perceived as unpleasant in another.
As car-makers try to produce one platform for each car worldwide, it is as important to deal with odours in the cab as it is to use uniform suspension or other physical components. This is why it is important to have a fundamental understanding of what smells are, and how humans perceive smell.
This has been an area of study for more than 100 years. But most of the knowledge generated by this branch of science is ignored by other sectors. We will use knowledge generated by that century of study to help explain the sense of smell and other sensory perceptions.
To evaluate the odour of a material, at least two questions must be answered. ‘What kind of odour is it?’ is the first, to establish odour quality. ‘What is the intensity of the odour?’ is the second, to determine odour quantity.
Strength and quantity
Before smell is tackled, it is perhaps simplest to approach the subject by building on more easily evaluated senses, starting with hearing. Sound waves are pressure fluctuations: volumes of air with higher and lower barometric…