We are living in an age when we rely heavily on artificially manufactured chemicals. Most creams, lotions, other cosmetic items such as wax and mascara, gels and ointments for medical and pharmaceutical usage, food products such as mayonnaise, jam, butter and margarine, chemicals for everyday use such as shoe polish, polyester, synthetic fibres, etc. are manufactured on a large scale industrially by means of machines known as homogenizers or emulsifiers. These machines work on a principle known as emulsification, in which particles of mutually insoluble materials (solids or liquids or both) are agitated at very high speeds under very high values of shear force, such that they get blended together to achieve a final product which contains a homogenized mix of the individual ingredients in a suspended or colloidal state.
In order to obtain large quantities of these emulsions, the batch homogenizer is used. This system consists of a few basic components that enable the homogenization process, including a rotor, a stator, a motor and a transmission component. The rotor creates the required centrifugal force by rotating at speeds that hover around about 3000 rounds per minute. This force coerces the ingredients to enter the narrow gaps between the stator and the rotor blades, and in turn get further dispersed or broken down into smaller particles. The rotor also creates a linear movement at a tangential velocity of about 30 meters per second, further homogenizing the cream, and pouring it out through the openings of the stator.
Homogenizers are termed and categorized differently on the basis of the method that is used to feed the ingredients into them. As a result, top entry, side entry and bottom entry homogenizers are marketed and promoted separately, each type having its own advantages and disadvantages. In the case of the bottom entry batch homogenizer, the whole setup is mounted on top of a tank into which the synthesized cream is released. The entire process is then reiterated over and over again till the required degree of emulsification or the desired fineness of particles is achieved. Bottom entry batch homogenizers are preferred when the desired end result to be manufactured is a liquid with a high viscosity. The usage is not restricted to such liquids alone however, and the same setup can be used to generate low viscosity liquids as well, but only when these are then used to wet out a powder as a second step of the process.