The manufacture of products of pharmaceutical and cosmetic use worldwide is based on the mixing of two or more mutually insoluble liquids under agitation and high values of shear force or pressure. These products, may it be creams, gels, shampoos, toothpaste, externally applied ointments and even some vaccines, are chemically known as emulsions, meaning, a physical combination involving the simultaneous existence of the parent liquids with their constituent particles in a suspended state. To be successfully marketed these emulsions need to be perfectly homogeneous, implying that the dispersed droplets in the emulsion should be of the same size. The second desirable for a good emulsion is that the particles should have the finest possible droplet size, usually ranging from 2 to 5 microns, and sometimes as low as 0.5 microns.
These industrial emulsions are produced in bulk in machines that are known as homogenizers or emulsifiers. When the constituent materials involve solids rather than liquids alone, the resultant suspension is known as a colloid. A powder liquid mixer is used to produce colloids industrially. Some of us might recall the ice cream machines of yore. The principle of the mixer is similar. It is often more difficult to successfully blend powders with liquids to create a consistent mix. The selection of an ideal mixer is made by considering parameters such as the volume of powder required to be suspended in the liquid, the size of a single batch of this production and also the end viscosity of the final mix.
The powder liquid mixer adopts a high shear mixer system that agitates the ingredient solids and liquids at a very high speed, either continuously or at intervals, as per the specific requirement. The production rate is almost as high as 30000 pounds per hour. The mixer is capable of handling liquids of varying viscosities, and its programmable features ensure that manual labour is kept at a bare minimum. For the amount of manual labour that cannot be avoided, the machine comes with a protective insulating aluminium silicate coating on the outer surfaces of the tanks and the agitators, so that any rise in temperature, quite a common occurrence in the emulsifying process, does not harm the operators in any way. The mixer also includes accessory units that help to keep it clean by removing powder residue from the inner walls of the tanks and thus reduces the need for manual maintenance.