02 | 2008

Natural Fibres
Go, Trabi Go!
„Back to the future?“
Article contributed by
Rosemarie Karner
It started about 50 years ago
The Zwickau motor factory (AWZ) produced its first
pilot series of small cars in 1957. In total 50 of the
so-called P50‘s were built. Because the spirit of the
times was still one of optimism and a bright future,
a simple name like the P50 for such a ‘modern example
of ingenious socialist engineering’ was hardly
in keeping with the mood. It was therefore fortuitous
that in October 1957 the Soviet Union launched the
first „Sputnik“ earth satellite. This led to the adoption
of the name „Trabant“, which, like „Sputnik“, means
„travelling companion“. In 1964 the 601 model was
introduced, with one of the main features being new
bodywork. The car no longer looked quite so rotund,
and there were small changes to the rear „fins“ that
were popular at the time, especially in the USA. After
1964 nothing on the Trabant really changed. Between
1957 and 1991 a total of 3,051,385 Trabants
were built (source: www.sueddeutsche.de)
An old Trabant is also shown on this issue’s cover
photo and you can see the original 601 commercial at
http://www.teamburg.de/bioplastics/misc/trabi.php
The Trabant - it still to be seen on German roads (and
not only German roads). A mass-produced car from
the former DDR (German Democratic Republic).
Fans of the Trabant call it the ‘Trabi’, others call it ‘Rennpappe’
(‘cardboard racer’). But as well as being a nostalgic
icon the Trabant has some interesting features, particularly
with regard to the material used for the bodywork.
Let’s go back to the 1950‘s, where we can take a closer
look.
History
At that time the automotive engineers at the VEB Sachsenring
car factory in Zwickau were faced with a serious
problem. The situation regarding automobile mass production
was far from good. There was a serious lack of
machines and materials. During the Cold War there was
an embargo on sheet steel, and a regular supply from the
USSR was also subject to limitations.
Something had to be done. A solution had to be found,
and the East Germans started experimenting with different
kinds of materials. After initial trials with a fibre mixture
based on PVC with wood chip and cotton fibres the
search was on to find a better solution. The need to find
a material that could withstand substantial temperature
variations, both heat and cold, with better mechanical
properties, and that would be reasonably easy to process
led researchers down various routes until they finally developed
a thermosetting material whose properties they
were able to improve as time went by and the manufacturing
process was perfected.
Cotton fibres and phenolic resin
In the early trials a carding machine was used to produce
a fibrous mat from cotton, which was then wound onto a
drum. As it was wound onto the drum the cotton mat was
impregnated, by a sprinkler device, with a synthetic resin
powder until the resin content reached 52%. The impregnated
mat was then compressed by passing it between
calendar rollers. The next step was to produce two more
resin-impregnated mats with modified resin levels.
The aim of the three layer process was to achieve a particularly
weatherproof outer surface with a high level of
Photo: Th. Kraft / Wikipedia
16 bioplastics MAGAZINE [02/08] Vol. 3