LensFree Radical Polymerization

The LIST Kneader Reactor Solution for Bulk Polymerization

In an effort to increase cost efficiency while streamlining the manufacturing process, many companies involved in polymer processing are turning to bulk polymerization. As a result, they are discovering the unique value of LIST kneader reactor solutions.

The innovative design of LIST kneader reactors translates into key competitive advantages when compared to traditional reactors:

  • More effective mixing
  • Lower shear
  • Higher conversion rates
  • Fewer dead spots
  • Longer residence times

The difference is an advanced shaft geometry that provides gentle kneading for minimal shear and maximum heat transfer. It also enables operators to process high-viscosity and other hard-to-handle materials. The results are improved product quality, lower operating cost, increased safety, and more efficient overall processing. 

At the same time, LIST kneader reactors enable many producers to combine the separate steps of solution, emulsion, and suspension polymerization into a single bulk polymerization process; thus simplifying the manufacturing process, cutting raw materials costs, and saving energy.

Solvent-Free Bulk Polymerization

During bulk polymerization, conventional stirred-tank reactors require solvents to transfer heat and facilitate mixing of the viscous mass. The solvents must later be removed which decreases the final conversion rate to as low as 10% while increasing recovery and purification costs. It also adds to the operator’s safety and environmental risks.

LIST kneader reactors, however, are able to operate solvent-free or solvent-lean – even with highly concentrated masses. Therefore, end polymer conversion rates range from 90% - 99%.  The polymer mass can also be directly devolatilized, to 500–1000 ppm or lower. The technology is suitable for solvent-free living and free-radical polymerization.

Large heat exchange surfaces and excellent evaporative cooling make LIST kneader reactors especially effective in exothermic bulk (co)-polymerization applications. The unique design provides constant surface renewal that improves heat transfer and minimizes the diffusion and mass transfer limitations.

The new generation of KneaderReactors for bulk (co-)polymerization offer precise temperature control through evaporative cooling, plus maximum yield in minimum volume.