The different models of paddles mainly result from the intended mode of action in the materials to be mixed. Depending on the mineral and chemical components of the materials to be mixed and the resulting viscosity of these, it is necessary to use the appropriate paddle geometry.
One of the most common mixing action is from the bottom up (type WK and MK). This is ideal for materials with heavy components, such as mortar, plaster, screed or concrete. With their clockwise action, the paddle work themselves into the mixing material like a screw and convey the heavy constituents upwards. This mixing action thus also reduces the amount of force required for mixing.
When mixing downwards, the mixing blades press the material downwards from above. This mixing action is preferred for very soft or low-viscosity materials such as self-leveling compounds, paints, coatings, gypsum plaster, etc., to avoid splashing of the medium. When mixing materials with a higher density, with these paddles, a higher amount of force must be taken into account.
This mixing effect describes a lateral material movement, as the design of the paddle has no parts pointing upwards or downwards. Thus, the inconspicuous geometry of the KR paddle counteracts the formation of lumps frontally due to its very high shear forces and ensures rapid homogenization. This makes it the ideal candidate for mixing tile adhesives.
Two counter-rotating paddles create a so-called forced mixing action. The material is forced to pass through the mixing zone of the two paddles. This results in rapid and intensive mixing of the material. This mixing principle is particularly suitable for materials that are difficult to mix (e.g. concrete screed, synthetic resin-based materials, etc.). At the same time, the torques of the two paddles cancel each other out in relation to the machine, which makes mixing much easier for the operator.