The homogenizer is equipment used in various laboratories and industries and allows a sample or food to have the same characteristics throughout the substance. The process that makes this possible is called homogenization, it is used in different disciplines, such as agricultural sciences, molecular biology, food technology, among others. The system of homogenization is very important in the science and technology sector and in the food, beverage and cosmetics industries.
In homogenization, different insoluble phases are mixed to obtain a soluble suspension or emulsion. In some cases, inclusion of a substance that moistens solids is required. The homogenization can be done through three different methods, depending on the type of force used. Accordingly, the process is classified as follows:
- Mechanical homogenization
- Pressure homogenization
- Ultrasonic homogenization
The first two are widely used in the food industry, while ultrasonic homogenization is considered an emerging field. The type of homogenization used will depend on the materials to be homogenized and the purpose to be given to the final product.
In the food industry, homogenization is used extensively, with the aim of achieving a homogeneous texture in food, which is more attractive to consumers; in the pharmaceutical industry, it is used in the production of medicines and vaccines, while in the cosmetics industry, homogenization allows the reduction of particles to a size of less than one micron, which favors their absorption by the skin.
Types of homogenizers
There is a wide variety of homogenization equipment, depending on the type of processing they perform. We have the mechanical homogenizers, which can use mechanisms of different types, for particle size reduction. Among these are those based on blade mills, ball mills and rotor-stator.
There are also pressure homogenizers, whose main component is the disruption system. According to the mechanism of the interrupting system, these homogenizers can be of valves and holes. Finally, we find ultrasonic homogenizers, which use ultrasonic waves and generate a phenomenon known as acoustic cavitation.
Blade mill equipment has a mechanism for particle size reduction, consisting of cutting blades coupled to the engine. The effect on the material is produced by cutting, shearing or its combination. Speed is an aspect that must be taken care of and is influenced by the raw material and the characteristics that are desired in the processed product. Usually, blade mills are used for primary size reduction.
The ball mill devices are made up of a hollow cylinder containing spherical balls. For homogenization, the raw material is introduced into the cylinder and rotational motion is applied to the cylinder. This movement creates a centrifugal force in the balls, which impact the raw material, reducing the particle size. This type of homogenizer is used for the micronization of dried fruits and vegetables.
The rotor-stator type equipment is also known as colloidal mill or Willems homogenizer. This device has a rotating shaft (rotor), inside a fixed ring (stator). When the rotor moves, the sample is sucked into the space between the rotor and the stator. In this way, the sample is subjected to a high cutting force and allows obtaining a smaller particle size. It is usually used for emulsification.
Equipment consisting of two components, the first is a section with a positive displacement pump and the second is the homogenization section. The positive displacement pump is piston type, when the piston retreats, it opens the suction valve and enters the material into a compression area. Then, when the piston advances, it produces enough pressure to open the relief valve and the material passes into a high-pressure area, where it is forced through a small space. At this point turbulence and mixing are generated, which eventually homogenizes the material.
Pressure homogenizers are among the most commonly used, particularly by the food industry. This is due to the synergistic effect of homogenization and temperature increase, which promotes a long shelf life of the product, as well as improving its physicochemical properties.
Device operating by high power ultrasonic waves. These waves generate a large number of bubbles, which then collapse. This effect is known as cavitation. The bubble collapse forms large amounts of liquid jets, which promote shear forces. They break up particles and disorganize droplets and cells, with efficient mass transfer.
Cavitation produces sonomechanical and sonochemical effects that reduce the size of solid and liquid particles. In addition, it favors its mixing in a homogeneous formulation. These equipments are ideal for the elaboration of sludge (solid-liquid) and suspensions and solutions (liquid-liquid).
At Kalstein we offer stem and ultrasonic homogenizers, from the YR series. You can choose the one that best suits your needs. Kalstein ultrasonic devices have a touch screen, automatic sample temperature monitoring and an alarm system in case of risky temperature increases. These devices allow the configuration of the power from 1 to 100 %. In addition, they can communicate with a computer or print the data. For more information on Kalstein homogenizers, visit HERE