Plastics and automotive - From yesterday to today

At first glance, the discovery of plastics seems to coincide with the beginnings of the automobile. But this impression is misleading. The development and industrialization of most of the plastics likely to be used in automobile construction came much later.

In fact, the automotive industry already had decades of experience with steel and cast iron when high-performance plastics became available. As a result, we witnessed an inter-material struggle that continues to this day.

For a long time, tire rubbers were the only significant contribution of polymer-based materials to the automotive industry. The mass of other polymer materials has gradually increased from a few grams to 150 kg per vehicle. All areas of the vehicle have been invested to a greater or lesser extent, particularly the interior. However, the forecasts made in the 1980s for the massive development of plastic bodies have not materialized. On the one hand, the problems of mastering the behavior and industrialization of composites have not all been resolved, and on the other, steel and aluminum manufacturers have been able to improve the products available on the market.

When properties are compared, plastics often rank favorably. But good properties are not enough. The design of parts and their industrialization must be compatible with the specific needs of the automotive industry and actual consumer demand.

Here are a few significant examples of how plastics have gradually made their mark in this highly demanding sector. The example of sheet molding compound (SMC) provides a good illustration of the difficulties encountered.

Manufacturers have conducted experiments with varying degrees of success. Often, they concerned small and medium-sized production vehicles.

However, the major chemical and plastics industries, for which the automotive sector is important, have, thanks to sustained efforts, been able to develop adapted products.

In the second part , we look at the current challenges faced by players in the automotive sector and how polymer materials can be developed in this context.