Industrial recycling of PU with a high proportion of foreign matter
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.
This serves as a starting material for new applications and can be processed in the metering machine without any adjustments.
PU is also frequently used for insulating applications such as refrigerators, and at the end of the appliances' life, the question of disposal arises. 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).
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. KraussMaffei has adapted the filtration technology required for this to the market requirements for polyols in extensive tests at its Innovation Center.
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.
Metering machine ready for digitalization and autonomous operation
RimStar metering machine with new digital features: the machine and process are even easier to control, even for less experienced users.
The vision for the future is autonomous operation.
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.
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 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.
