The aim of this section is to grant the feeding of a constant and uniform quantity of pellet to the following phase: normally the frying in an oil bath, but could also be the expansion by a hot air oven, or the expansion by a “puffing-press” machine for micropellets. We desire to point out that consistent feeding means consistent processing of the pellets themselves.

A good DOSING UNIT should grant:

• feeding of constant and uniform quantity according to process capacity;
• reproducible processing parameters;
• 'gentle' handling of the pellet in order to avoid breakage;
• reliability.

The pellet feeding can be performed by means of several TECHNOLOGIES.
The main are the following:

• vibrating doser: it is the most economical system, but does not allow to have precise feeding and information concerning production capacity and quantity processed;
• volumetric doser: it is a reliable way in terms of constant dosing but, similarly to vibrating doser, it does not give indications concerning the quantity processed;
• weighing doser: it is the most reliable system, and it allows knowing how many kgs of pellet are processed every hour. As a consequence, it is the most expensive one.