Some melts remain liquid even when cooled below their melting point and are known as subcooling melts. The reason they refuse to crystallize and solidify is the lack of the crystal nuclei.

With the Rotoform 4G SC system, we have developed an innovative supercooling process to overcome this problem by introducing a homogeneous suspension of crystal nuclei into the melt. This is done with the scraped-surface heat exchanger, called precrystallizer, using a cold cylindrical surface and a heated rotor.

This process enables the slurry (a mix of nuclei and liquid product) to crystallize on the water-cooled steel belt of the Rotoform unit in a very short time and can be used to produce the desired product form – such as pastilles, micropastilles or flakes.

We have designed, supplied and installed more than 100 supercooling plants, each a turnkey system incorporating everything from the precrystallizer heating/cooling equipment to the Rotoform, steel belt cooler and measurement and control equipment.

Typical applications

Antioxidants for rubber chemicals as an example for a typical subcooling product solidified on a Sandvik pastillation system

Typical applications for our supercooling process include:

  • Agrochemicals
  • Photochemicals
  • Plastic additives
  • Rubber chemicals
  • Stabilizers
  • Pesticides and herbicides
  • Flame retardant

Environmentally-friendly production of uniform pastilles

Free-flowing, uniform pastilles are produced which are easy to handle, bag and transport. Because little dust is created in the production process, or subsequently by the pastilles, the entire production is environmentally friendly.