Optimizing pre-treatment and processing in mechanical recycling: A case study on waste stream DSD310

Description

In mechanical recycling processes for plastics, the pre-treatment stage plays a key role, as the quality of the input waste material has a significant impact on the output material quality. In addition, once the waste has been cleaned, the next step to improve the material quality is to convert the material into granulate, i.e., plastics processing. To address the common phrase "bad material in, bad material out", this study focuses on mitigating unwanted inputs by optimizing the washing step. Despite its industry-wide implementation, a lack of dedicated effort to determine the optimal combination of temperature, time, and detergent was observed. Furthermore, the influence of double filtration in the material conversion process on the material properties has been investigated. This research involves a systematic investigation of pre-treatment and processing using the specific plastic film waste stream “DSD310”, which contains a high amount of large format plastic films such as bags, carrier bags, shrink films, etc. The chosen washing parameters include temperatures of 25°C and 80°C, along with varying durations of 5 and 15 minutes, and sodium hydroxide (NaOH) contents ranging from 0% to 2.5%. Filtration was performed using a laboratory-scale co-rotating twin-screw extruder and two filter sizes. To assess the impact of these combinations, key performance indicators such as melt mass-flow rate (MFR), ash content, oxidative-onset temperature (OOT), optical contaminant detection (OCD), tensile properties, and puncture resistance were measured. The results show that processing has a greater effect on the material than pre-treatment.

Period	02 Oct 2024
Event title	European Regional Meeting of the Polymer Processing Society PPS-2024
Event type	Conference
Location	SpainShow on map