Erema increases efficiency in post-consumer recycling

Large plastics recycling plants need more than simply upscaling the individual components. The larger the size of the extruder screw, the greater the technological challenges. The start-up last summer of the largest Intarema system to date, with a throughput of over four tonnes per hour, confirms that EREMA offers reliable solutions for high throughputs. The next smaller size 2021 has now been further developed. At the K show, Erema will launch the Intarema 2021 TVEplus with a diameter of 2 metres for the preconditioning unit (PCU) and 212 millimetres for the extruder screw, which for the first time features a single end-to-end extrusion unit. With a throughput of up to 3.5 tonnes per hour and a footprint of just 15.1 x 3 metres, this recycling system is over two metres shorter than the previous cascade design, in which two extruders were connected by a melt pipe. The new design also reduces the melt temperature, lowers energy consumption and minimises maintenance requirements.

Based on TVEplus and Erema PCU technology, the new 2021 produces even higher quality recycled pellets. Counter Current technology makes a significant contribution to this because it continuously feeds the extruder with preheated material that is 5 to 15 degrees Celsius warmer than with conventional cutter compactor systems. This is a technological advantage, especially for an extruder screw with a large diameter with correspondingly deep screw flights. The melt is processed more gently with less shearing and without additional particle size reduction. This makes it easier for impurities to be extracted by the melt filter, which is a key element of the new development.

Consistently high recycled pellet quality is essential for food and cosmetic grade applications. Recyclates for food packaging must meet the requirements of the European and American food safety authorities. Erema has initiated numerous approval projects and, together with customers, has already received positive Non Objection Letters (NOL) from a US authority for HDPE, PP and LD/LLDPE. Further approval proceedings are ongoing, especially in Europe.

There are two decisive prerequisites needed for food-grade: an input stream consisting of at least 99 per cent food packaging, and technology that is able to clean and decontaminate the input material. A key technology here is the combination of Intarema TVEplus RegrindPro and the ReFresher, which reliably removes substances with low volatility, and as a result also removes odours.

A joint venture with Lindner has established a close partnership between Erema and Lindner Washtech. While Lindner Washtech provides high-quality preparation of the input material with sorting, cold and hot washing, EREMA ensures effective cleaning and decontamination with its extrusion and filtration technology. Because the processes are well-coordinated, consistent recyclate quality is produced with optimised energy consumption. One specific application example is a project at Polymer Matters in Ireland, who have applied to the European Commission for food-grade approval. In this application, HDPE milk bottles from household recycling schemes are processed into rHDPE and used for the production of new milk bottles.