Thermoplastic Starch

Before we tried grinding the sample finest possible, we used a coarse sieve shell set with 1,0 mm trapezoidal perforations to check the grindability of the sample.

Enough of sample material was provided and we prepared a batch of 22 grams for our first test. The sample was slowly transferred into the grinding chamber. The sound of grinding was very smooth and vanished directly, after the last lentil of sample was transferred into the mill.

The residues inside the grinding chamber were minimal. There was no significant smearing or clogging of sample material on the grinding parts. Surely even higher amounts of sample could be ground this way, too.

About 19 grams of sample could be packed from the cyclones collecting glass. The rest of sample remained as fine ground dust, stuck by electrostatic charge inside the mill or cyclone. The cleaning was performed rapidly by vacuuming with a soft brush.

Compressed air is recommended for an intensive cleaning of the sieve shell holder.

Also a direct grinding of the starch sample is possible with 0,5 mm sieve shell set. We fed and ground 22 grams without a precutting step.

The sound of grinding was very smooth and vanished after we fed the last lentil (after 90 seconds of feeding). Only a bit of sample dust remained inside the grinding chamber (electrostatic charged). There was no clogging or smearing of sample. Most likely even the fine 0,2 mm perforated sieve shell set can be used directly.

Cleaning was performed rapidly by vacuuming with a soft brush.

Finally, the Amitroplast starch was ground directly to < 0,2 mm.

22 grams were fed even faster into the mill. Still, the grinding sound was smooth. After only 60 seconds, all sample lentils were fed and ground without any obstacles. The majority of the ground sample remained inside the collecting vessel with outlet. The sample was very fine and electrostatically charged. We used a brush to push the fine ground, electrostatic charged sample from the collecting vessel into the cyclone while the sample exhauster was still running.

Even with sieve shells of 0,2 mm trapezoidal perforations, no significant cogging of perforations was observed. Surely even higher amounts of the starch sample could be ground this way, too.

A loss of 5 grams of sample could not be packed because of electrostatic charge.

For intensive cleaning, the sieve shell holder was disassembled and all grinding parts were washed with hot water. It would also be possible to place the grinding equipment into a ultrasonic cleaner, too.