EREMA'S Counter Current Principle Improves Productivity


EREMA'S Counter Current Principle Improves Productivity

EREMA'S Counter Current Principle Improves Productivity

Recycling: Cutting, homogenising, heating, drying, degassing, compacting, buffering and dosing - all in a single step: the patented cutter/compactor is an all-round talent and rightly called the "centrepiece" of an EREMA facility. It stands out in particular through its flexibility in processing a multitude of feed materials - irrespective of which polymer type, density, shape and moisture content - and prepares it in the best possible way for the robust single-screw extruder. This is a crucial factor, because the better the plastic material is prepared already at the beginning of the recycling process, the higher the quality and throughput at the end of the process - in the finished recycled pellets.

With the INTAREMA® recycling system, Erema GmbH, Ansfelden, Austria, presents a system concept with a new core technology and further innovations. The name "INTAREMA®" comes from INverse + TAngential + eREMA® and is based on the newly developed and globally patented Counter Current technology from EREMA. The result of this innovation: INTAREMA® brings together in an unparalleled way top productivity, flexibility and extremely easy operation with considerably lower energy consumption.

The central core technology of the new INTAREMA® is the patented Counter Current system which shows its impact in the border area of the cutter/compactor and tangentially connected extruder. Inside the cutter/compactor the rotation of the rotor disc which is equipped with tools forms a rotating spout so that the material is circulating the whole time. In the Counter Current system this material spout - unlike the previous technical standard - moves against the direction of the extruder. As a result, the relative speed of the material in the intake zone, i.e. when passing from the cutter/compactor to the extruder, increases to such an extent that the extruder screw acts in the same way as a sharp cutting edge which now cuts the plastic. Thanks to this inverse tangential configuration of the new INTAREMA® plants, the extruder handles more material in a shorter time and is much more independent in terms of the pre-compacting level of the material. To date the worldwide technical standard has been a system in which the material in the cutter/compactor moved in the direction of the extruder. The centrifugal forces arising in the process were used for the feeding of the extruder and the treated, warm material was thus "packed" into the extruder screw. The inverse tangential configuration of the Counter Current system, on the other hand, now ensures that the extruder screw is filled virtually pressure-free with the preheated material. The screw takes what it needs; the extruder always has the ideal filling level and is never overfilled, which makes it much better to regulate.

Feeeding is automatic: loose material such as film shreds or regrind material is fed in via a feed conveyor belt and film enters direct on rollers using a roller intake system. The cutter/compactor cuts and mixes the feed material with rotating tools, At the same time the feedstock is dried and compacted ready for intake in the extruder.
Michael Heitzinger, CTO at EREMA, describes the positive impact which the new system has on productivity and the quality of the recyclate as follows: "The screw basically "takes what it needs", the extruder always has the ideal filling level and is never overfilled, which makes it much better to regulate." With the system used previously the packing and pressure had the risk of sticking, especially in the case of very light materials with low energy content (such as fibres or thin packaging films) or materials with a very low softening point (such as PLA) which could mean reduced material intake. With Counter Current technology, thanks to the improved material intake, capacity is not only increased, it also stays at a constantly high level over a much broader temperature range. This is of particular advantage when processing very temperature-sensitive materials.

 

 

Constant output despite input fluctuations

INTAREMA® technology also represents a quantum leap in the field of post-consumer recycling. The new system likewise gives you the highest possible flexibility when processing materials with particularly high input moisture and contamination levels, such as e.g. washed agricultural films, washed post-consumer film flakes (PE-LD, PE-LLD, PE-HD), films with solid content such as paper, wood or metals and also thick-walled regrind materials from waste automobile and electronic goods, PS cups and PE lids. The recycling of car batteries, for example, is an interesting example of an application. The INTAREMA® T recycling system with single screw extruder (without extruder degassing) and cutter/compactor tools optimised especially for this application offers the perfect technology for the processing of polypropylene (PP) from car batteries which are recovered, washed and broken up into chips. As these are very thick-walled, moist particles (Fig. 4), high residence times in the cutter/compactor are very important so the material is dried efficiently and above all has sufficient time to be warmed thoroughly and homogeneously. With this application-oriented INTAREMA® plant the particles are optimally dried, completely and thoroughly warmed, forwarded to the extruder and the material is then melted carefully in the short extruder screw with minimum shearing strain.Furthermore, the melting process with minimum shear stress increases the cleaning efficiency of the melt filter as the size of organic or minearl solid matter is not reduced. This in turn improves the qualilty of the recylced pellets. This means that new end products with a considerably higher share of recycled pellets can be produces, such as new battery packs made up to 100% recycled pellets. 

The INTAREMA systems are designed for capacities ranging from 50 to 3000 kg/h. There is a chouice of configuration depending on the application in question.