In times of continuously increasing standards of economic production, flexibility and hygiene in the production of cosmetics, pharmaceuticals and food, production and process technicians have a particular responsibility for the optimization of production processes.
The following report about manufacturing of cosmetics describes the possibilities production plants have today to comply with the aforesaid standards.
As example a producer of high-value cosmetic with products to be found wherever priority is given to the professional cosmetic advice, especially in cosmetic institutes, beauty farms, and spas. It goes without saying that these products, featuring proven properties and skin friendly pH-value, are as far as possible made of natural ingredients especially of herbal origin, and developed according to the latest scientific findings.
These high standards of product quality require identical standards for the production plants. In this respect it has to be considered that the variety of cosmetic products require frequent production changes with different batch sizes. So the machine has to guarantee a maximum of flexibility and short times of production and cleaning.
For the aforementioned reasons it was decided first of all to separate the preparation of the fat phase from the process of homogenization. On one hand it is true that this meant higher costs for the investment for a premix vessel. On the other hand, however, the times of production were considerably reduced.
Since the homogenizing mixer can be charged with other jobs while the premix vessel are already supplied with raw materials and the mixtures are prepared to have the process temperature indicated.
So-called circulation agitators were used instead of conventional propeller agitators for the mixing process in the premix vessels. These circulation agitators have the following advantages:
- Besides a thorough mixing, the prepared mixture can be transferred to the mixer by means of the circulation agitator. This is also possible when the vessel are evacuated which prevents air inclusion or foaming especially when washing active substances are processed or with hot-cold-procedures.
- The installation at the lowest point of the vessel bottom enables also the processing of smallest batches, and guarantees an easy cleaning, because no built-in components extend from the top into the vessel.
- Liquids or powder can be sucked into the circulating flow under vacuum.
- Short times of product heating are achieved by an even edge flow along the heated vessel wall.
- No further pumps for CIP cleaning (cleaning-inplace) of the vessel and all product pipes are needed because of the high pumping capacity of the circulation agitator.
In general, the merge of fat phase and cold water phase in the homogenizing mixer should be done under highest possible vacuum (just below the vaporization point of the product).
This requires a homogenizer which guarantees good homogenizing properties and a high throughput even such critical conditions of operation, in order to achieve a finest possible and even particle size and distribution with simultaneous absence of air inclusions.
In order to be prepared also for future products possibly requiring higher shear energies, and in order not to wear the material permanently to it is limits, effectiveness as well as capacity reserves should focused when the type of homogenizer was chosen.
Not the mere drive power is decisive in this respect, but the maximum rotor tip speed, transgression of which would cause cavitation in the homogenizer.
For the homogenizer a protective rotor available as an optional feature has proven to be particularly useful. It is function is to avoid the ingression of objects into the rotor stator toothing, which may get into the mixer unintentionally, mostly via bagged cargo, and destroy the homogenizer.
The design of the anchor agitator is crucial, for a good vertical mixture, especially during the cooling process, as well as to achieve and maintain a reliable homogeneity of the product by means of regular, clean scraping of the vessel wall during the heating and cooling process. This must be ensured for both senses of rotation of the agitator.
Besides the features mentioned above, the cleaning of the plant is of special importance, because it has to proceed as rapidly and reliably as possible.
Speed and reliability of the cleaning process can be provided if the following aspects are complied with:
• High pumping capacity (=pressurization) of the homogenizer.
• Accessibility of the product-contacted seals for the cleaning liquid.
• Round bending of all built-in components in the product area.
• If possible no screws, pins etc. in the product area.
By disconnection of the premix vessel from the mixer, the premix vessel can already be cleaned during the cooling cycle of the mixer. While the mixer is the last unit of the plant to undergo the CIP-cycle, a separation within the control program enables the start of a new batch in the water and oil premix vessels already under a new batch number. Thus, processing and documentation of several processes under different batch numbers is possible.
Daniel Gimpel
Sales Engineer
Netzsch Makine Sanayi ve
Tic. Ldt. Şti.
