It is now two years since we examined the proportion of PP across the full range of automotive manufacture. To summarise briefly: PP is increasing, PA stagnating. The Asians are getting by with approximately one third less plastic. So nothing new there compared to 2011/12. But one thing is new: the proportion of PP in the automobile is now increasing more than the weight.
Every few years we take a fresh look at the proportion of plastics across a broad range of vehicles. As we know from studies of individual vehicles, a degree of caution is advised in interpreting absolute values. The only components that can be weighed are the ones that are marked correspondingly. The error is systematic, like a thread running through all the studies, and any changes from year to year are likely to be meaningful.
As always, we have omitted carpets and E+E parts. These are bound to pile on the grams or even the kilogrammes.
Overall, the database yielded 142 vehicles. Only the B-, C- and D-segments offer sufficient numbers for a survey, and we shall therefore be concentrating on these. For a more in-depth analysis, we shall be putting the strongest segment– the C-segment – with 61 disassembled vehicles, under the microscope.
In the C-segment the promises of the automotive industry are slowly starting to come true, cars are actually becoming lighter. The average weight has now been less than 1,400kg for the past two years and the downward trend continues.
Polyamide
In the C-segment the proportion of PA in Europe has been hovering at around 13kg/vehicle. The 2012 swing to 17kg is a one-off. Here, the Audi A3 with 21.5kg PA was included in the survey along with the others. However, it is the one vehicle in this segment that exhibits such a high proportion of PA (table 3).
As far as the Asians are concerned, there is not enough data to go on. All the vehicles examined during the last few years have come in at appreciably less than 10kg/vehicle. The average is around 8.5kg.
In a comparison between the European C-segment and the D-segment it is evident that, in the D-segment, something like 3kg to 4kg more PA is being used than is the case in the C-segment (table 4).
Polypropylene
Here, we see the kilogrammes piling on in Europe. We are approaching the 70kg/vehicle level. The figure for 2009 has been exceeded significantly by two Citroën vehicles and there is also a Citroën vehicle included in the figure for 2013 (table 5). Without this the average would be around 69.6kg. Compared to the D-segment the figures are similar.
The absolute weight of a vehicle is an interesting topic but even more so is whether the proportion of plastic in the motor vehicle is rising faster than the weight of the vehicle itself. Up to 2011 it was the weight of the car that tipped the scales rather than the increase in plastics. Only in 2012 was this overturned. Currently, the input of PP is increasing faster than the overall weight. PA, by contrast, remains proportionately stable.
Increased use of PP overall undoubtedly accounts for the considerable growth in the proportion of PP in vehicles. There is, however, another factor, namely that the automotive engineers have actually succeeded in making cars lighter. During the course of our deliberations we have smoothed out the peaks as described in tables 3, 4 and 5 (Citroën and Audi A3).
