Plansifters Optimal Sizing of Pellets
Sifting machines guarantee high quality of pharmaceutical productions as they size pills. But pharmaceutical manufacturers require for the sizing process not only high throughput. Sifters need to fulfill hygienic and explosion protection requirements.
Hygiene and repeatable quality are of utmost importance particularly in the production of medical products. Beginning with the sifting of adjuvants and pharmaceutical active substances through to the securing of the constant pill size and quality during the whole production process, hygienic facilities are used to ensure products of maximum quality. Before deciding to invest in a pellets sizing solution Losan Pharma went through an evaluation and testing program of various sifters, from which the Siftomat plansifters manufactured by Fuchs Maschinen emerged as the most suitable machine for the intended use. The aim of these tests was to determine the efficiency of the plansifters related to the product to be processed and the extremely high quality requirements of the company regarding variations in quality of coated pellet batches. During this sizing process undesired fractions have to be removed in order to obtain an impeccable and consistent quality of the product. More concretely, over- and undersized particles are sized and removed from the “good” particles of the product. When it comes to process 400 kg/h during 360 hours per year no compromise can be allowed. Another key argument in favor of the plansifter is its absolute proven reliability as since its commissioning no breakdown has occurred.
And this is how it works
For applications in the pharmaceutical industry the plansifter version in stainless steel and closed housing is required. All product wetted parts are mainly of stainless steel (1.4301), all others in glass pearl blasted stainless steel (1.4301), the motor being completely integrated in the raised machine base. Sealing between the machine base and the driving cylinder is carried out by a highly resistant tightening sleeve with zipper.
The Siftomat plansifter can be fitted to carry out sizing into up to four fractions. In the present case only three fractions are required: oversized and “good” particles, dust or undersized particles with meshes between 0,16 and 2,5 mm. With its low installation height integration of the machine in existing production lines is very easy and coping with the required performance entails no problem.
The machine is based on a straightforward working principle. An eccentric drive makes the sieves swing in a plane eccentric movement. The coarse product to be sifted passes over the sieve mesh while the fine product falls through the mesh. The plansifter offers the advantage of very gently processing. Furthermore, the pure plan sifting movement shows a very positive effect on the sifting quality.
Setting the machine for optimum sifting is extremely simple just by adjusting the slope of the sieves. For higher throughputs with good flowing products, just increase the sieve slope. On small and middle-sized sifters just loosen two screws, and on bigger machines eight screws. The optimum sieve slope is factory set and need normally no further adjustment. This also applies to the machine speed. In special cases and with more demanding products, where bulk products must be sorted according to their length, the use of a frequency converter is required.
In the pharmaceutical industry where hygiene is an absolute priority, machines must be easy to clean. The plansifter is made in its closed version entirely of stainless steel and can be very easily dismounted and cleaned without having to use tools. This guaranties minimal downtimes and the best possible hygiene. Furthermore, it is also very simple to remove the sieves and the spacer frames to clean the sieve case and place them back again.