Granulator

A granulator is a machine tool that is used to produce particles in the millimeter range from strands or larger pieces by dividing them. These granules are easy to handle, e.g. B. sag, shovel and flow.

Strand granulator

The strand granulator is used to shred thermoplastic strands . It has two guide rollers and a cutting roller with helical cutting teeth. The guide rollers bring the strands and the cutting roller cuts them off at the cutting edge. The plastic strands are formed in the extruder from the plastic mass obtained during production and cut into granules 2 to 6 mm in size by the strand granulator that follows immediately. This plastic granulate is easy to handle and is filled into sacks. It can be used for the final shaping of the thermoplastic material, e.g. B. in the extruder, can be easily reheated because the heat transfer to the granulate is good.

Underwater granulator

In addition to strand pelletizing, there is also the option of cutting pellets under water. This is done with rotating cutter heads running on hard metal disks . There are holes in the discs that determine the basic size. The fine adjustment of the shape, the weight and other parameters can be controlled externally by the speed, material throughput and temperatures on this system.

The range in which granules are produced using this process is 0.2 mm (mini or micro granules) up to 12 mm.

Advantages compared to strand pelletizing are the compactness of the machine park in relation to the production output, the noise reduction due to the closed structure and the reduced dust exposure due to the underwater process.

The procedure is also called UWG.