Extrusion

With the long lasting experience in the field of extrusion we can design screws and dies with analytical and numerical 3D-FEM calculations. Furthermore, we are able to to solve different tasks via experiments on the available extrusion equipment. This enables us to verify the simulated and calculated results with practical experiments and to improve the methodologies.

Projects

The SUSMAGPRO project aims to achieve the sustainable recovery, recycling and reuse of rare earth magnets in a circular economy. © MIMplus Technologies GmbH & Co. KG
The research activities focus on applications such as automotive rotors, water pumps, loudspeakers and wind turbines.
© MIMplus Technologies GmbH & Co. KG

Sustainable recovery, recycling and reuse of rare earth magnets

The aim of the SUSMAGPRO project is to identify, separate, process and reuse permanent magnets based on rare earths such as neodymium-iron-boron (NdFeB) on a pilot scale across Europe.

As part of the project, a circular business model is being developed in the context of the circular economy: Instead of disposing of critical resources in landfills or exporting NdFeB-containing waste to other parts of the world, SUSMAGPRO will use the latest technologies to extract the elements from the magnetic scrap and re-integrate the metals into new products for the European market over a shortened cycle. The focus is on applications in automotive rotors, water pumps, loudspeakers and wind turbines.

The institute of polymer processing is responsible for the development, optimization and characterisation of polymer-NdFeB compounds for extrusion and injection mounding to be used in the production of sintered and bonded magnets.

Test your knowledge about rare earth magnets --> SUSMAGPRO QUIZ

 

 

     

 


SUSMAGPRO is a follow-up project to:
REMANENCE project: https://cordis.europa.eu/project/rcn/106545/en
REProMag project: https://cordis.europa.eu/project/rcn/193433/factsheet/en 

SUSMAGPRO is funded under the EU's "Horizon 2020" Research and Innovation Program (Grant Agreement No. 821114). Project duration: 06/2019 - 05/2023 Participating countries: Denmark, Germany, Italy, Netherlands, Austria, Sweden, Slovenia, Spain, United Kingdom

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Microgranulation - development of an underwater pelletizing system of microgranules used for rotational molding

The goal of the FFG Coin project microgranulation was the development of an underwater pelletizing system of microgranules used for the rotational molding.

At the chair of polymer processing a great number of simulations had to be done on the pelletizing head, as the thin holes with a diameter of 0,5 mm tend to freeze. In cooperation with other companies and universities the die plate and the flow concept was revised.

Co-rotating conical twin screw extruder

This  FFG funded project dealt with the procedural description of a co-rotating conical twin screw extruder from the company M-A-S (Maschinen und Anlagenbau Schulz GmbH). At the chair an analytical program for the calculation of the pressure at the die was developed and the results could be verified with measurements at the laboratory extruder at M-A-S.

With the conical geometry of the screws a very big free volume at the intake can handle bulk goods with a very low density. So materials like flakes from the recycling with a bulk density of about 300 kg/m³ can be processed. The pressure built up, increased by the conical concept enables a direct extrusion without the need of a melt pump.

Material characterization of bulk material

In the feed zone of extruders the bulk material properties of the granules are very important. The density, the pressure anisotropy but also the friction between the material itself and to the surrounding machinery plays a vital role in conveying. As an example the density of PET flakes at different pressures was researched.

The pressure anisotropy, the relation of the radial to axial pressure can vary between zero and one and is dependent of the pressure and temperature.

The friction coefficient can be measured with the friction extruder. The pressure along the screw, the torque and the screw speed are measured and the friction coefficient between the bulk material and the cylinder can be calculated.

Measurement of the residence time using a dielecrically tracer

The FFG Bridge project was funded for the development of a method to measure the residence time measurement using a dielectrically tracer.

A tracer (lead zirconate titanate) is given in a pulse and the change of the capacity over the time is measured and leads to the residence time distribution. Different dies were constructed in which the capacitor plates are integrated. The frequency of the charging is directly proportional to the concentration of the tracer in the melt flow. In the figure three residence time distributions are shown. With an increase of the screw speed the residence time diminishes, while an increase of the tracer amount only shows the influence on the frequency (concentration).

Screw and die design with 3D FEM simulation and analytical methods

In addition to analytical calculations screws, dies and tools are also designed with 3D fluid and structural simulation.

Both methodes use the equation of state. For flow problems the programm Ansys Polyflow is used. At the chair of polymer processing programs for single and twin-screw extruders but also for reciprocating screws were developed.

For the calculation of dies the viscoelastic properties of the polymer are a major challenge.

Equipment

Film line Collin

Film line Collin

  • Extruder “Teachline” E30P
  • Extruders “Teachline E20T-H SCD 15”
  • 5 layer feedblock
  • Coathanger die 250 mm
  • Chill roll with haul off unit CR 136/-350 mm
  • Corona treatment

Single screw extruder for foaming and casting

Single screw extruder ROEX 30.24 F

Single screw extruder for foaming and casting

  • Rosendahl Ø = 45 mm
  • Different screws 24-36 D
  • Cast film unit SML, width 600 mm
  • Metering station for regrind
  • Gas dosing unit for foams

    Single screw extruder ROEX 30.24 F

  • Screw diameter of 30 mm
  • L / D ratio of 24/1
  • Cylinder made of fluorine-resistant bimetal
  • Snail of Inconel

Pipe extrusion line

Pipe extrusion line

  • Extruder battenfeld-cincinnati Proton 45-28 G
  • Vacuum cooling bath Kuag ATL-C 63
  • Caterpillar haul-off unit Kuag RAE 63/1
  • Cutter Graewe TE 63 H

Further equipment

Further equpiment

  • High-temperature corotating twin screw extruder Leistritz ZSE 18MP-48D
  • Conical counterrotating twin screw extruder battenfeld-cincinnati Konos 38 RP
  • Filtertest extruder Collin FT-E20T-MP-IS
  • Friction measurement extruder
  • Blow moulding machine Kautex KEB 1
  • Thermoforming machine Illig UA 60EDH OST G