The possible uses for a homogeniser or mixer are manifold. They range from reducing materials to a size and consistency that renders them more suitable for laboratory testing and examination, to creating the fine emulsions that are often required in the manufacture of products such as sauces, cosmetics and the topical creams and ointments used for medical treatments. Basic mixing in order to create an even and homogenous suspension can generally be achieved at relatively low speeds, but in the instances mentioned above, where fine droplets with a particle size in the micron range are the norm, higher speeds and additional options, such as high pressure, depending upon the composition, may also be necessary.

In essence, a homogeniser is a specialised type of mixer. However, unlike stirring your tea which simply ensures that the milk and infused contents are evenly mixed and that any added sugar is dissolved, homogenization may be used where the components are all insoluble. Effectively applied, the process is designed to produce stable emulsions that are able to maintain the component particles in their fine and evenly mixed state of suspension.

A variety of processes have been applied to achieve this effect including ultrasonic agitation and the use of a series of narrow valves under pressure that create flow restrictions. The resulting jets give rise to intense turbulence that, in turn, enables this type of homogeniser, mixer combination to force the various dispersed particles into closer proximity with one another, which then results in the required, even mix.

A typical everyday application for this technology is to be found within the dairy industry. Here it is used in the processing of milk. Prior to processing, milk from several sources are normally combined to produce a more consistent raw product. Left alone, this natural emulsion will tend to separate into water and cream with the latter forming a layer on the surface.

To prevent this separation, the raw milk mixture is first blended with a mechanical mixer and then fed to a homogeniser in which it is forced through small holes at high pressure. This treatment breaks down the comparatively large fat globules present naturally into particles that are then simply too small to separate out under the effect of gravity. The result is a product that displays the consistent taste, the appearance and the other properties that the modern consumer has grown to expect. By removing some or all of the cream beforehand, low fat and fat free products can be created. A similar process is used in the preparation of popular soft drinks where pressures as high as 35,000 psi are commonly used to arrive at the required degree of homogeneity.

Homogenisers and mixers, then, come in a variety of types and making a suitable choice will most often be influenced by the application in which the end-user may be proposing to employ them. It is an area in which a quality product will invariably be needed and it is also one in which some informed professional advice could prove to be of value. In South Africa, you will be unlikely to find a supplier with more experience of world-class equipment such as homogenisers and mixers and their use within the food processing and testing industries than IEPSA.

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