Post- Consumer Recycling With Pre

Post- Consumer Recycling With Pre - Consumer Quality

10-Nov-25

Post-consumer films are largely obtained from household collections such as the dual system and are often heavily contaminated. Thanks to innovative technologies from recycling specialist EREMA, regranulates from these waste streams can be produced economically, even for sensitive end applications.

Films from post-consumer material streams place high demands on the recycling process due to their composition and previous use. The input material often contains organic residues such as fats and oils, labels (and therefore paper and adhesives), foreign materials such as sand, metal, or wood, as well as foreign polymers. Furthermore, film waste from household garbage is often printed and predominantly has a strong odor. High, stable regranulate quality is crucial for use in high-quality end products and supports multiple recycling. Regranulate quality depends on the effective removal of contaminants and, additionally, on gentle melt handling. The DuaFil® Compact design developed by EREMA for the INTAREMA® recycling system, in combination with TVEplus® technology, enables the efficient processing of post-consumer waste. This technological innovation results in excellent melt quality with high throughput and low energy consumption.

Filtration and degassing optimize polymer melt
Effective filtration is one of the key strengths of the newly developed dual filtration solution. Thanks to the gentle preparation of the material in the Preconditioning Unit (PCU) using counter-current technology, the input material is homogenized, compacted, dried, and preheated. Due to the special pretreatment and gentle melting during plasticization, dirt particles, contaminants, and foreign polymers, such as PET or PA, are barely broken down and thus remain large enough to be removed from the melt early on by the laser filter. The early removal of unwanted substances prevents the formation of disruptive degradation products and the resulting unpleasant odors – a crucial quality characteristic for the melt and the subsequent end product. The "Plus Zone," which can be precisely tailored to the specific needs of different material streams, homogenizes the melt after the first filtration unit and before degassing, bringing it to the optimal melt temperature for the respective application. Degassing in EREMA systems always takes place in three stages: The first degassing occurs directly in the PCU, followed by reverse degassing in the extruder thanks to the sophisticated screw design. The final double-venting degassing zone is particularly efficient and effectively removes any remaining volatile components from the melt. The DuaFil® Compact design ensures exceptionally high melt degassing efficiency, which is crucial for organic contaminants and heavily printed films. Overall, the machine is characterized by a significantly larger free screw volume during degassing and, consequently, a higher degassing performance of up to 33%*.

Lower mass temperature reduces energy consumption
A crucial factor in improving regranulate quality is decoupling pressure and temperature build-up. With conventional double filtration solutions, the highest temperature in the extrusion process occurs before the second filtration unit and after degassing. With INTAREMA® TVEplus® DuaFil® Compact , the polymer melt reaches its highest temperature before extruder degassing. This significantly reduces the risk of degradation products and volatile components forming, which can lead to odors, discoloration, or gassing of the regranulate. This is a decisive advantage, especially with organic materials such as food contaminants or cellulose impurities like paper or wood.

Decoupling pressure and temperature build-up using a newly developed control concept for the interaction between the extruder and melt pump allows for a shorter extruder (minus 10 L/D*), a reduction in melt temperature by an average of 20°C*, and a 10%* decrease in the overall system's energy consumption. Simultaneously, it was possible to increase the system's throughput by 10%*. This resulted in reductions not only in operating expenses (OpEx) (energy costs) but also in capital expenditure (CapEx) (investment per kg of system throughput). In addition to these technical advantages, this leads to an economically attractive overall package.

The unique positioning of the primary filtration system upstream of the melt pump in INTAREMA® TVEplus® DuaFil® Compact systems offers a further advantage. This ensures that only purified and degassed melt flows through the pump, reducing wear and significantly extending service life in post-consumer applications.

Optimized process conditions for the highest demands in the end application
Originally, the main applications for regranulates from household waste were in construction films and garbage bags with a film thickness greater than 40 µm. The newly developed DuaFil® Compact design now serves a broader, more demanding market segment. Thanks to efficient pressure build-up, filtration down to 30 µm on the second filtration stage can, for the first time, be economically achieved – i.e., without throughput limitations – depending on the polymer. This allows for the use of up to 50% washed LD/LLDPE film flakes (DSD 310) in high-quality PCR shrink films and up to 30% of rPE post-consumer supermarket film (e.g., 98/2) in 8 µm stretch films and up to 50% in shrink films >20 µm. The first customer installations have confirmed the trials conducted at the EREMA technical center and have resulted in significant improvements.

Odor-optimized and food-safe
Another milestone is effective odor removal. This is also one reason why regranulates from post-consumer collections are now being used more frequently for higher-value applications. The key here is the neutralization of unwanted odors, for which the advantages of the INTAREMA® TVEplus® DuaFil® Compact , with its optimized degassing performance and gentle material processing , combined with the ReFresher anti-odor technology, offer the best prerequisites. Even heavily odor-contaminated input materials can thus be processed into high-quality regranulates. Volatile components are continuously removed from the granules using solid-phase diffusion. The process is particularly energy-efficient thanks to the utilization of residual heat and the use of heat exchanger systems. The American Food and Drug Administration has approved the system combination for food grade, so that PO regranulates from defined input streams (e.g., Commercial Post Consumer LL/LLDPE stretch and shrink film) may be used in proportions of up to 100% in food packaging.

Currently, there is no food-grade approval for polyolefins in Europe. Since October 2022, EU Regulation 2022/1616 has offered the possibility of granting early approval to new recycling technologies for direct food contact via a "novel technology" (see information box). EREMA supports recycling companies in generating data and providing evidence for the EFSA (European Food Safety Authority) assessment procedure.

Source:- Erema