Further Production Lines

Further Production Lines

PE/PP-RECYCLING

The MRS devolatilization concept can not only remove water vapor from the melt efficiently; it is also an efficient system for the removal of harmful or unwanted volatiles from the polymer melt. Heavily contaminated materials can therefore be reprocessed with a drastic reduction in odor.
A manufacturer of film for packaging processes scrap printed LDPE blown film to carrier bags. As this film had been previously used for packing fish, it had assumed an unpleasant odor.
It was previously necessary to use a mixture of 6 % washed „fish“ film waste with 94 % virgin material to reduce the odor problem. Thanks to the MRS extruder it is possible to add 40% recycled material instead of the previous 6%.
The efficiency of the MRS technology was also proven in the manufacture of PP recycled compounds for the automotive industry. This work was carried out together with the Fraunhofer Institute in Pfinztal (Germany) which proved the results using themal desorption analysis. A large proportion of the volatiles are extracted from the polymer. The residual volatile level is 22 % at 50 mbar and only 10 % at 20 mbar.

Devolatilization of PA

In many polymerization processes, it is necessary to remove residual monomers after polymerization. In most cases, in a complex and cost intensive process, the residual monomer content of approximately 10 to 12 % is washed out with hot, distilled water and returned to the process (hot water extraction). This extraction process can be greatly simplified with the help of the MRS technology. The monomers can be extracted in the melt phase (before chip cutting) and are extracted in a form that permits them to be returned directly to the process.

Dispersion of Micro/Nano Particles in Polymers

Gneuss Compounding Cascade System

Today, the standard method for introducing additives into polymers is with the additives in powder form. These are fed into the plasticized polymers via a side feeder on the compounding extruder. Normally, the side feeder is a small single or twin screw extruder. The main extruder is typically a co-rotating twin screw extruder in order to achieve good inclusion and dispersion of the polymer.

With the Gneuss compounding system, the additives are not introduced to the polymer in powder form, but with the help of a suspension, which contains extremely fine, agglomerate-free particles. The suspension is introduced into the polymer melt by means of a special pump and a specially designed injection nozzle into a pressure and mixing chamber. The mixture of polymer and suspension can easily and immediately be thoroughly mixed, so that
no agglomeration of the additives takes place.
In order that the liquid carrier of the suspsension does not negatively affect properties of the polymer, it is completely extracted within 6 seconds. This takes place in the Gneuss MRS extruder, which is located immediately downstream of the suspension injection point. The extremely high devolatilisation performance of the MRS extruder ensures that the liquid is efficiently extracted as a volatile. Additionally, the additives are gently distributed in the polymer, and extremely homogeneous dispersion is ensured.

Further Applications for the MRS Technology

  • Extraction of residual water and monomer from polycarbonate (PC)
  • Monomer extraction and removal of monostyrene from acryl nitrile butadien copolymer (ABS) or styrene acryl nitrile copolymer (SAN)
  • Reduction of effluvia (VOC/fog) in final product, for example from vehicle interior components manufactured from polyacetal (POM), polypropylene (PP), acryl nitrile butadien copolymer (ABS)
  • The introduction of chemical or physical blowing agents and/or other components in gas form for the manufacture of foamed products from polystyrene (PS), polyethylene (PE), polyester (PET) or polypropylene (PP)