Extrusion Aids

Extrusion Aids

Borregaard LignoTech’s lignin-based products are frequently used as processing aids in the production of solid materials such as granules and pellets.

A typical example is the use of our products in the wet granulation of agricultural chemicals.  In this process, low pressure extrusion is used for the conversion of powders into granules. The final granule represents a more user friendly formulation than the original powder since:

  • Flow properties are improved
  • Segregation of components are prevented
  • Dust during handling is reduced

Our lignin-based products offer possibilities to control and optimise extrusion process conditions. This is possible since the addition of our products can strongly influence the consistency of the premix, i.e., the properties of the moistened powder or paste being fed to the extruder.  The premix consistency (or its rheology) determines the efficiency of the extrusion process.

The mechanism of action of our products is multifunctional and is best described as a combination of binder, rheological modifier and dispersant. The best way to descibe the performance at the microscopic level, is to say that they offer controlled flocculation or agglomeration of particles (see also the Dispersant functionality page). This means that both the agglomeration of particles (needed for the compaction of the powder) and the dispersing of the same (needed for eventual disintegration of the granules) is made possible by the fact that Borregard LignoTech’s products are adsorbed at the particle interface.