18
MIXING
TOGETHER
| MIXING future
Among all the issues that were examined at the ‘Science
meets Tires’ conference, the tyre material occupied a
central role. Not for nothing are the tyre manufacturers’
compositions kept just as secret as the original recipe
of Coca-Cola. With Prof. Ulrich Glese from the German
Institute of Rubber Technology in Hanover, an eminent
authority in the rubber industry took the audience on a
fascinating journey to the world of molecular chains.
His speech especially looked at the highly complex
chemical interactions between elastomers, fillers, sili‑
cates, polymers and other components found in rubber
tyre compositions.
Above all, the focus of scientists is currently on the
silica compounds and newly developed S-SBR poly-
mers, which play a major role in shaping the material
properties in terms of reducing rolling resistance. These
components in particular place high demands on the
process of rubber mixing. The parameters of the mixing
process must be precisely observed in order to guaran-
tee the consistently high quality of the desired rubber
properties. When it comes to the silica compositions
touched upon by Prof. Glese, for instance, controlling
the temperature during the mixing process is of crucial
importance.
Put simply, the further development of the tyre goes hand
in hand with the further development of the tyre material.
Some of the approaches relating to the use of new or al-
ternative materials were presented at the conference.
For the manufacturers of the production technology in
the tyre industry – particularly those who produce mix-
ing and mixing room systems – there are some huge
challenges in store for the future. The mixing methods
must be capable of coping with the ever increasing
complexity associated with producing the compound
using new materials, while also being able to manage
properties essential to the quality, such as dispersion
and distribution, in the mixing process. Ultimately, the
question still arises of how the results of research can
be transferred to industrial series production in an eco-
nomically effective manner.
A system which not only perfectly illustrates these de-
mands from a process technology perspective, but
also provides a highly efficient solution in economic
terms is the tandem process, which was patented in
1989 by Dr Julius Peter, then chief technical officer at
Continental AG. One mechanical engineer which has
perfected this process is the HF MIXING GROUP. Busi-
ness unit director Dr Harald Keuter presented the key
advantages of the principle to the professional audi-
ence. Essentially, this involves separating the two basic
actions in the rubber mixing process: dispersion and
distribution. Dispersion describes the breaking down of
materials and in particular solid materials. Distribution,
on the other hand, is concerned with achieving the
most even mix of the different chemical contents within a
compound.
By separating both of these tasks into two cascading
mixing stages in ‘tandem’, both stages can be optimised
Not all rubber is the same. Manufacturers and researchers are on the hunt for the perfect composition.
