Doğa PET, a new recycling venture by Doğa Holding is using TOMRA Recycling’s sensor-based sorting solutions to produce high-quality PET flakes and rPET granules which are suitable for food and textile applications.
TOMRA
Located in northwestern Türkiye, Doğa PET’s plant currently processes more than 4,200 tons of PET bottles monthly, producing 3 1,000 tons per month of PET flakes and 2,000 tons per month of rPET granules. The facility incorporates TOMRA’s full range of machines for plastics sorting: four of the company’s sorting all-rounder AUOSORT, two INNOSORT FLAKE and two AUTOSORT FLAKE units for advanced flake sorting and purification. This combination of units optimises both product quality and processing capacity.
Depending on Doğa PET’s customer requirements, the premium PET flakes – produced in various quality grades – are used for PET sheet production, while the rPET granules are mainly aimed at bottle-to-bottle recycling and high-quality textile applications. The company plans to export its recycled products, primarily to European countries.
Achieving exceptional purity levels with TOMRA technology
Dr. Selçuk Gökhan Gerlikhan, General Manager of Doğa PET, comments: “Instead of recycling PET waste into lower-value materials, it is crucial to use advanced technological infrastructure to recover it and produce materials with properties closely resembling those of virgin raw materials. TOMRA has been an invaluable partner since the start of this project. TOMRA’s solutions are widely recognised as industry benchmarks by our customers, so we plan to invest in additional sorters as we develop our lines.”
He continues, "We separate purity levels into two categories: polymer and colour. Our target for polymer purity was 99.998% for the final product, and we achieved this. For colour, our goal was to reach a purity level of 99% transparent PET in the final product. This includes reducing other colours, such as light blue PET, to below 1%. We have already exceeded expectations by achieving colour variations below 0.5%."
While producing clear flakes, Doğa PET aims to minimise the loss of light blue PET material and, when necessary, separates the light blue material from the clear one. The blue bottles, which are ejected when processing clear PET, can be a valuable resource for other applications.
Doğa PET is the first facility in Türkiye to successfully separate light blue material from clear material, regardless of the infeed product. During the sorting process, light blue products are separated from all infeed materials and recovered for reuse as needed.
Serkan Orhan, Sales Manager for TOMRA Recycling Sorting in Türkiye and the Middle East, explains the full process: "The plant’s production line features four AUTOSORT units which pre-sort the PET bottles. The first three sort by material and color before sending them to the subsequent crushing and washing line. The fourth AUTOSORT unit re-sorts the rejected products from the first three units, sending recoverable materials back to the first AUTOSORT to improve efficiency and material recovery.
“After pre-sorting, the material is crushed, washed and dried before being sorted by target colours using the INNOSORT FLAKE, TOMRA’s highly flexible colour and polymer flake sorting machine. Finally, the flakes are sent to the AUTOSORT FLAKE unit, a specialist solution for high-end flake sorting applications such as food-grade bottle-to-bottle recycling. At this sorting stage, the targeted high purity is achieved thanks to the reliable separation of colour, polymer and metal contaminants, virtually eliminating all traces of PVC, PC, PS and other unwanted polymers.”
Advanced waste analysis
Doğa PET is required to prove that less than 5% of the input material for its washing process consists of non-food grade PET to produce food-grade pellets. To meet this requirement and enhance material recovery across its sorting lines, the company has invested in a state-of-the-art waste analyser powered by PolyPerception, a solution that uses cameras for real-time material analysis and classification at key points in the sorting plant. At Doğa PET’s plant, the analyser is positioned before the last of four AUTOSORT units. It continuously monitors and analyses the quantity of non-food grade PET bottles destined for the washing line.
By providing data per batch or shift, the analyser enables Doğa PET to certify the food-grade quality of material from each specific production period, offering crucial reassurance to its customers and relevant certification bodies. This transparency is particularly vital for end customers purchasing these pellets from a Turkish PET facility. Exporting its high-quality product to Europe, Doğa PET relies on this assurance to meet its customers' stringent compliance requirements.
The crucial role of quality in filament-grade textiles
While Doğa PET invests in high-quality food-grade rPET granules for bottle-to-bottle recycling, the company also applies the same approach to supplying raw materials for the textile industry. Dr. Gerlikhan comments: "The filament sector in textiles demands very high purity levels and color stability. The durability, aesthetics and functionality of the final fiber product depend heavily on the proper management of the PET recycling process when producing high-quality rPET granules. Accurate sorting is critical for increasing rPET granule purity. For us, using TOMRA's state-of-the-art sorting systems is crucial as they ensure efficient and fast recycling processes."
Serkan Orhan concludes: “We are delighted to have been by Doğa's side from the very beginning on this project, consulting on the feasibility study. Achieving the desired capacity and quality levels in such a short period of time with such vast inputs has been a great achievement which demonstrates how advanced sorting technology contributes to achieving virgin-like material qualities."