Industry competition demands that manufacturers do more with less. One concern that remains is how to decrease production time while maintaining high quality. Equipment that can multi-task can replace several pieces. This combination can help eliminate steps in the production process.
Multi-shaft mixers can do just this. They function by using several separate agitators, dispersers and batch homogenizers and can easily change gears for creating several different products. This ability to handle various types of products can help respond to the demands of an ever changing market.
A mixer that has two or three shafts that remain stationary inside the vessel is considered a multi-shaft mixer. These agitators turn on their own axes. This type of movement helps make mixing very cost effective. Changes in design have made these mixers even more efficient and capable. There are three separate agitators and each one is controlled individually.
The three wing anchor agitator uses gentle mixing and promotes axial and radial flow. This low shear agitator uses a gentle mixing technique. Heat is dispersed by keeping the batch moving inside the vessel by using Teflon scrapers which prevent a layer from accumulating on the inside wall. The anchor is triangular shaped to help keep the flow pulled toward the interior of the batch. Large batches especially require such movement of the anchor agitator. It is in constant motion to help the batch flowing so that it is mixed consistently.
Moderate shear is applied by a high speed disperser mixer. It is flexible since several different blade styles can be configured. The high speed disperser helps achieve standard distribution of particle size and helps improve the quality of the final product. In the multi-shaft mixer this functions as a powder induction device, a premixer and a flow generator. It helps reduce larger particles so that they can be properly dispersed. Once they are smaller they can be disintegrated by the high shear homogenizer mixer. By creating a vortex both below and above the blade it helps to pull materials from both directions into the batch. This process sometimes also pulls in too much air and a vacuum phase later in the cycle is necessary.
The four blades of a high shear mixer applies intense hydraulic and mechanical shear. As they rotate they shear droplets and particles expelling matter at a high speed into the surrounding substance. This helps reduce particle size.
There are several things that must be considered when deciding on which type of mixer is best. What force is needed to keep an adequate flow in the vessel, the level of shear needed to mix properly and the material’s ability to tolerate heat and shear must all be considered.