Advantages and characteristics of underwater granulation in industrial production

I. Excellent Quality of Product Pellets
After the molten polymer is cut at the die surface during underwater pelletizing, it is rapidly cooled by water, and the surface tension of the particles is uniform, forming a spherical or quasi-spherical shape, with a rounded appearance and no burrs, which reduces the adhesion problem in subsequent processing. Underwater pelletizing has high particle density and good fluidity, which is suitable for precision injection molding and functional masterbatch production. Rapid cooling reduces molecular chain entanglement, reduces internal stress, and the mechanical properties of the particles are better.

II. Improve product production efficiency
Underwater pelletizing adopts a fully enclosed automated process, without frequent shutdown and material replacement. The production capacity of large equipment can reach 25 tons/hour, which is far higher than the efficiency of strand pelletizing and water ring pelletizing. In the face of low-viscosity or sticky materials, other methods are prone to agglomeration, while underwater cutting water flow can avoid adhesion.

III. Environmental protection and energy saving
The water used in the underwater pelletizing process is filtered and recycled to reduce wastewater discharge and meet food-grade production standards. Underwater cutting can also suppress the generation of dust, with a noise level of only 65-75 decibels, which is lower than the 90 decibels of dry pelletizing. Compared with the multiple heating/cooling processes of strand pelletizing, the underwater process integrates melting and shaping steps, reducing the overall energy consumption by 20%-30%.