Limper: Complexity driving change in rubber mixing

Manchester, UK – Makers and end-users of rubber-mixing equipment must look to automation to deal wth increasing complexity in both the materials they process and the markets they serve, believes Prof, Dr Andreas Limper, member of board of management of HF Mixing Group

The German machinery expert was speaking at a HF Mixing event in Manchester, 25-26 Oct, marking 100 years of the Banbury mixer – the internal mixer invented by Fernley Banbury in 1916, which is still widely regarded as one of the most significant ever developments in rubber processing.

“We do not speak about the mixer alone anymore: we have to look at the system," said Limper, reviewing advances in the productivity of the internal mixer, through improvements in heating and cooling, as well as downstream weighing and handling.

End-user markets are also driving change, Limper noting, for example, how the number of car models offered in the German market had almost doubled over the last 20 years and was continuing to grow.

“And as every car can have different tires, and some models have different tire alternatives, the number of tires has increased very much,” he said. “I think this trend will go further with new challenges like full electric cars requiring low rolling resistance designs and so on. So you will see a higher variety of compounds [used] in the tire industry.”

Meanwhile, the introduction of silica tire compounds has led to the mixer now being used as a reactor, Limper continued. He added that today’s trends towards the use of modified and functionalised polymers was making control of temperature and other parameters more critical within the mixer.

“Unfortunately, these polymers are also very reactive: with some of them mixing becomes more complicated and we have to prevent some scorching effects happening in the mixer,” the HF executive commented.

This increasing complexity, concluded Limper, will create “a lot of challenges for the producers of mixers and operators of mixers, which will have to become even more versatile than today to deal with more complicated recipes and mixing procedures.

“Automation will, therefore, gain in importance, because you cannot do complex chemical reactions with manual control.”