Selecting a mixer used to be a rather easy task, just choose the one that’s been working the best. However, over the last few years it has become more complicated because of all the changes and improvements that have occurred. It takes careful planning to find the one that will do the job. One must consider efficiency, conservation of time and space. And of course what is at the forefront of any lab manager’s mind is the initial cost as well as any other overhead associated with production.
Mixing efficiency must be considered when expanding the process industry. Mixers are not a generic tool used for production but rather a decisive tool for the business. Labs must remain competitive with other businesses and also remain profitable. They simply must be cost effective as well as efficient. This means that every type of mixer must be considered when looking at increasing productivity.
There are three main types of mixer designs to consider, a double planetary mixer, a planetary/disperser and a dual shaft mixer. The main difference with these three types is the mixing approach. The dual shaft mixer as well as the planetary/disperser starts with a liquid and builds thickness as solids are added. This order is reversed in the double planetary mixer. The increased viscosity develops the high level of shear that is needed to disperse without using a high speed disperser. Then a small amount of liquid can be added to get the right thickness.
Generally the selection of a mixer becomes very complex due to the needed versatility. However, systematic lab tests can help fine tune the process to find the right mixer that is needed for the job. Testing also allows lab techs the chance to fine tune their technique of mixing. This is a chance to try various combinations, vacuum applications, how powders are added as well as shear rates and agitator speeds. This will also enhance production and improve performance.
Mixer tests should be arranged and conducted using the same materials that will be used in production lines. The entire process must be replicated to see what changes may be beneficial. Also remember to use your own materials when testing mixers. This helps when considering the design of the mixer. Carefully consider test results so that the final product will be improved profits and increased productivity. Testing in the lab can be time consuming but well worth it as the process is fine tuned to yield the greatest profit.