Radial piston motors for producing rubber

Radial piston motors for producing rubber
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March 2016

 

When it comes to optimally kneading and rolling various rubber mixtures, powerful drives are called for. KRAIBURG, a specialist in individual rubber mixtures, uses Hägglunds drives from Rexroth for this very reason.

Whether it’s windshield wiper blades or cooling hoses, you first need the right rubber. This is where a kneading machine with rotors comes in, which produces the rubber mixtures. The compound is then fed into a mixing mill where it is repeatedly passed through the rollers and finely homogenized. The right formula for the mixture plays a vital role in how the material will perform later on and how long it will last in practice. KRAIBURG has quite a number of these formulas in its database.

A wide range of mixtures in Europe

Günther Beisser, who is part of the systems planning team at KRAIBURG, tells us: “Around 4,000 different mixtures are actually ordered by our customers as real formulas.” When it comes to the range, being able to run as many different products as possible on one system is particularly important to KRAIBURG.

The machines have to be designed in such a way that both soft and hard mixtures can be produced. For KRAIBURG, it is therefore essential that the drives deliver torque all through the speed range. Hägglunds drives meet this requirement.

Quick stop

During a job, the production staff at KRAIBURG are constantly present at the mixing mill, cut out the mixture and lift it onto the so-called stock blender. For this reason, operator safety is an especially important issue at the company, located in Upper Bavaria. “The standard for the rollers stipulates that they must have stopped after 57.3 degrees at the latest in case of emergency shut-down,” explains Beisser. With Hägglunds drives, the roller stops after an angle as small as 10 degrees. “These were the best values we could find on the market.” The quick stop is enhanced by a Rexroth roll back function fitted at each mill. This allows the rollers to run backwards after the opening of the gap at an emergency stop.

Since energy efficiency is playing an increasingly important role alongside function and safety, the company is currently working together with Bosch Rexroth to make controlling the hydraulic units even more effective and economical.