Roll with it

Buhler has developed a roller mill for grains, bean, seeds and cocoa which allows such commodities to be ground into an ultrafine consistency - crucial for effective processing.

The micromilling of commodities such as cocoa pose serious challenges to millers. The products of Nature are usually tough and sticky. Even specialty milling equipment such as high-speed pin mills or jet mills have great trouble grinding these materials to the required fineness. Normally, this calls for costly processes involving, say, pin mills in combination with air classifiers or grinding under nitrogen. Moreover, throughputs are normally low in these processes.

To allow such materials to be ground to an ultrafine degree, Buhler has developed a special roller mill: the Micromill. Operation of the mill is based on the mortar principle: The machine grinds the material by means of three smooth roll pairs, with one roll in each pair rotating faster than the other. In the narrow roll gaps, the tough kernels are sheared apart by high forces. This ruptures the plant cells, releasing their contents. Superficially viewed, the micro-flakes have a thickness between 10 and 50 microns. They still consist of coherent cell material which will readily dissolve when subsequently used in foods. One micrometer is one thousandth of a millimetre.

Buhler​ is a global Technology Group and System Partner for plant and equipment and for process expertise in the fields of Food Processing, Chemical Engineering, and Die Casting, with a worldwide payroll of about 6,000.