of a new technology for seed encrusting and seed pelleting
the introduction in the early nineties of the rotary coater for film coating
of vegetable seeds, this technology has been rapidly
taking the place of conventional batch and even continuous seed
treaters. The fast growth has been triggered by an increasing demand
for more accurate pesticide application technology and the
availability of suitable film coating formulations.
world-wide there are several suppliers offering a broad range of
rotary coater types varying in size, level of automation and
sophistication but all based on the same characteristic principle of
the rotary technology. The very short process times and the
relatively high accuracy of the seed treatment in this simple and
effective batch coater, made it a coating system suitable for film coating
the total spectrum of species including the lower value
While recognizing the visible advantages, it makes
sense to make an evaluation of this conspicuous technology and take
a close look at the various aspects from a process technological
point of view.
From film coating on a rotary coater to coating with additional filler
material is not a tremendous step and over the past few years a
number of seed coating companies have been working on a pelleting
process on the rotary coater.
Meanwhile some companies have started
to offer equipment and/or coating materials to the seed industry to
do their own in-house pelleting.
When observing the rotary pelleting for the first
time, it is easy to become very enthusiastic about the apparent ease
and speed of the process which may take as little as 5-10minutes
only. Thìs obviously in contrast with the traditional drum
pelleting which by many is considered to be highly skill demanding
and, with process times ranging from 90 minutes to 4 hours, to be
highly time consuming.