sustainability
Closing the loop for PU waste
| Petra Rehmet, Rebecca Böhm
Chemical recycling on an industrial scale
How can PU insulation foams from old refrigerators be recycled despite heavy contamination? Together with BASF, RAMPF, and Remondis, KraussMaffei is developping an industrial recycling process. The continuous extrusion process enables chemical recovery even with heavily contaminated regrind.
Until now, PU from old refrigerators has often been incinerated, for example to generate energy in cement production, but it is foreseeable that the thermal recycling of plastics will be more restricted in the near future.
KraussMaffei is therefore in the process of industrializing a process for the continuous chemical recycling of PU through depolymerization. The project partners are BASF, Rampf (Producer of sustainable recycled polyols) and Remondis (processing and recycling of old electrical appliances).
Contamination levels of up to 30% are possible
In the purity glycoLine PU process, PU insulating foam from the Remondis refrigerator recycling plant is recycled within minutes using a co-rotating twin-screw extruder (ZE BluePower).
Unlike the widely known batch process, this continuous extrusion method can efficiently handle PU regrind with contamination levels of up to 30%, including residues of other plastics and metals.
In order to achieve depolymerization using a glycolysis process modified by RAMPF, the PUR regrind is mixed with depolymerization agents and other additives in the extruder.
The result is an intermediate product from which the aforementioned high proportion of foreign substances can be filtered out directly in-line after the extruder.
KraussMaffei has adapted the filtration technology required for this to the market requirements for polyols in extensive tests at its Innovation Center.
Sustainable cycle thanks to purity gycoLine PU: The PU components of items such as refrigerators are converted into polyol with recycled content (rPolyol) at the end of their service life using an extruder in a continuous chemical process.
The polyols obtained from the extruder can be used at BASF as a component of innovative PU systems for the production of rigid foams with recycled content. What is particularly important here is that the process is already economically attractive today.
At the K trade fair, visitors to the KraussMaffei booth can experience live how the PU system with recyclate content is processed into foamed insulators for beverages.
Metering machine ready for digitalization and autonomous operation
The Reaction Process Machinery team will be presenting another market launch: a RimStar series metering machine with numerous new features in preparation for digitalization and autonomous operation. This will make the machine and process even easier to control, even for less experienced users.
In the future, it should even be possible to completely relieve operators of certain tasks. Digital analysis tools such as the dataXplorer, which records and evaluates all relevant process data, are already integrated for this purpose. In future, its results will serve as the basis for automatic adjustments during the production process
The new RimStar metering machine with new digital features: the machine and process are even easier to control, even for less experienced users.
KraussMaffei at K 2025
Hall 15, Booth C24
