As the technologies to recycle post-consumer waste plastics have improved tremendously over the past few years, interest in their use is rapidly growing. Unlike post-industrial plastic waste, however, using post-consumer waste tends to be accompanied by additional challenges, one of which is odour.
According to Austrian recycling machinery manufacturer Erema, the increase in demand for high-quality post consumer recyclates can be easily measured by a quick glance at the order books. The company, who has developed and marketed an odour-reduction solution called the ReFresher, reported that, out of a total of the more than 25 ReFresher modules sold, 19 were ordered in the past 18 months alone.
"Odour is a typical problem with contaminated household waste such as LDPE films, HDPE containers and PE closures. It is essential that odour is removed if the PCR material is to be reused in high quality packaging for cosmetic products or food," said Clemens Kitzberger, Erema Group Business Development Manager for Post Consumer Applications.
The increased demand for PCR is being driven by two factors, he explained. The first is the ambitious recycling goal set by the European Union, specifying that by 2025, 50 percent of plastic packaging waste must be recycled. It has been calculated that this will mean reusing 10 million tonnes of recyclates in new products every year in future. In the second place, recycling technologies are becoming more and more efficient, making applications possible that were unimaginable a few years ago, a trend that is set to continue.
Erema has already produced a shower gel bottle made from 100 percent PCR-HDPE, that was launched as a world-first in 2019. The recyclate was produced using a combination of its IntaremaTVEplus RegrindPro machine with a ReFresher module.
The company has also demonstrated that packaging and serviceware for direct contact with food and beverages can successfully be produced from PCR-HDPE, in proportions of up to 100 percent, using recyclate produced using that same combination.
The process was initially certified by the FDA in August 2019 as being suitable for the production of milk and juice bottles, as well as meat trays, disposable tableware and cutlery, provided the input material originated from milk and juice bottles. The FDA then, in November 2020, expanded this to include the HDPE closures belonging to HDPE, PP and PET beverage bottles. Currently, material containing up to 100 percent recyclate may be used in the production of containers for direct contact with food of all kinds.
"In order to produce a recyclate of such high quality from PCR material, the recycling machine needs to deliver very high decontamination performance," explains Thomas Hofstätter, Process Engineer at Erema GmbH. "While the high degassing extrusion system removes mainly highly volatile, low molecular weight substances, the ReFresher ensures a significant reduction of the low volatile, high molecular weight organic compounds in the recycled pellets. At the same time, the thermo-physical process works in a particularly energy-saving way, because it makes use of the thermal energy of the recycled pellets that are still warm after the extrusion process."
The combination of the extruder with the ReFresher was a key factor in obtaining FDA approval, according to Michael Heitzinger, managing director of Erema GmbH. "This super-clean process produces high-quality recycled pellets that will open up new, economically viable sales markets that can be developed by working together with partners from all along the value chain,” he said.
Customers can test the extruder-ReFresher combination on an industrial scale at Erema’s Customer Centre in Ansfelden (Austria). For carrying out tests at the customer's plant, Erema offers a compact and mobile ReFresher module that can be integrated into the on-site recycling process.