Closed Loop – Going round and round
PET bottles are essential to today‘s society. There are abundant reasons for that, as they‘re durable, lightweight, waterproof and cheaply available to make everyone‘s life easier. Careless disposal causes a multitude of issues, though. Plastic products don‘t degenerate which is a strain on the environment, and what is perhaps most important, some valuable material gets lost that could be used over and over again. That‘s why we set ourselves the goal to innovate to bring it full circle. We at STF Group are a driving force behind Closed Loop systems in all their facets.
Collection and Logistics: We are a certified waste processing specialist transporting PET products safely from wherever they arise to our facilities. We take care of all logistics services via our centralized logistics department. You get one person in charge of all transportational matters.
Guaranteed quality: Each and every incoming delivery is checked scrutinisingly. The material gets to proceed through the process only as soon as the quality meets our high expectations. All following steps are surveilled by our laboratory and quality control department; a high level of care and diligence guarantees the best possible quality. We are happy to provide the analysis results to our customers at every time, along with certifications by renowned external authorities.
Sorting: At first, we start with a rough parting of the constituent fractions. PET products get separated from foreign materials such as bags, metal cans and other pollutants. After that, coloured and clear bottles are divided into their respective fractions.
Grinding: Bottles get ground to flakes with a diameter of approximately ten millimetres.
Washing: A thorough washing process follows. Any remaing pollutants get removed. As soon as that is done, the flakes dry and are put into either Big Bags or silos. The quality of the resulting pre-sorted materials is continuously monitored by our laboratories before further processing.
Pelletizing: The flakes are heated in our state-of-the-art machinery. A vacuum is created in order to remove all gaseous substances from the process. The flakes are then molten and pushed through a perforated plate, creating a thread of PET that is cut to small pellets promptly. The result is flawless recyclate.
Decontamination: For even greater quality, the recyclates are processed in a solid state polycondensation reactor. Absolute purity is ensured by another vacuuming of gases, as is the creation of the Intrinsic Viscosity (IV) value the customer expects. Our extrusion uses modern SSP reactors to ensure high purity of the resulting granulate material which typically exceeds our customers‘ requirements by far and which allows for food-grade reuse.
PET flakes: PET flakes created in such a recycling process are suitable for immediate reuse in production processes, for example as a base material for clothing fibres.
PET pellets: Our granulate material is especially suited for creation of new food packaging, as all relevant food-grade requirements are met or exceeded. Depending on individual customer requirements, even special production runs can be implemented.