Ever wondered what happens to a beverage container after you place it into a reverse vending machine? We had the opportunity to observe one of the key stages of the process at the sorting center for refundable bottles in Kočovce, Slovakia.
Slovakia implemented the Deposit Return System back in 2022. Nowadays, the country and its DRS operator, Správca Zálohového Systému, can claim a staggering collection rate of 92%.
The entire life cycle of a PET bottle or aluminum can placed into a reverse vending machine (RVM) can be described in the following steps, from start to a new life:
- Beverage consumption
- Deposit and return
- Material bundling
- Transport to a sorting facility
- Sorting
- Transport to a recycling facility
- Recycling and production of new packaging
The facility in Kočovce is responsible for the sorting phase, which is more complex than it might initially appear. Let’s delve into the life cycle of beverage packaging and explore the processes involved. Bear in mind that the whole process might vary from country to country.
1. Beverage consumption
The first step to consider is purchasing beverages with a logo indicating the option for reverse recycling. Consumers buy beverages in bottles or cans, typically paying a deposit for the container. This process initiates the recycling loop, as the containers are meant to be returned after use, helping to reduce waste.
2. Deposit and Return
After consumption, consumers return their empty beverage bottles to vending machines, collection bins, or stores equipped for the deposit return system. These return points are designed to be user-friendly, often scanning barcodes to identify eligible items and confirm the deposit refund. The system operates on a simple yet effective principle: the deposit paid at purchase is refunded only when the bottle is returned, ensuring a closed-loop process. Vending machines typically sort the returned beverage containers into categories, such as plastic bottles and aluminum cans, streamlining the subsequent steps of material handling and recycling.
3. Material bundling
Both bottles and cans are simply compressed and placed into large bags to streamline handling. Flattening them significantly reduces their volume, optimizing storage and transport efficiency. This process minimizes the space required for storage, making it easier to manage and transport the materials to sorting facilities. When bottles are picked by hand (often from smaller shops), they’re placed into plastic bags. In such cases, the bottles must be carefully counted, as the number is verified by staff at the sorting center.
During our visit, an employee showed us a bag with a green plastic tag attached to it. When the tag was scanned, it revealed exactly where the bag came from and how many bottles it was supposed to contain. Surprisingly, this bag had one bottle less, which can happen, as plastic bottles now possess certain value and people sometimes try to profit from them. The sorting center must then confront this issue and investigate further.
4. Transport to Sorting Facilities
The bags of beverage packaging are transported by trucks to recycling centers designed to handle large volumes of material. This transportation ensures that the materials are delivered to the appropriate sorting facilities, where they undergo detailed processing. The sorting facility in Kočovce plays a crucial role in managing returned beverage containers. With a storage capacity of 1,800 to 2,000 tons, the facility efficiently stores large volumes of returned bottles and cans. Equipped with advanced sorting technology, it ensures that the materials are properly categorized for further recycling, contributing significantly to the recycling loop.
5. Sorting
The first phase of the processing stage involves guiding plastic bottles and cans onto separate paths, as each type requires different processing methods. At the sorting facility, containers are sorted by material type using a variety of advanced technologies:
- Optical Sorting: Cameras and infrared sensors are used to identify different polymers and colors. This allows clear plastics (PET) to be separated from colored plastics (HDPE, PVC), which require different processing techniques. The purity rate is approximately 95%. While most bottles are accurately separated, occasional imperfections may occur, such as two bottles of different colors getting stuck together.
- Magnetic Separation: Magnetic fields are used to separate steel cans from other materials, ensuring that ferrous metals are effectively removed.
- Eddy Current Separation: Non-ferrous metals, such as aluminum cans, are separated using induced magnetic fields that repel them, isolating them from other materials.
Once sorted, the materials are compressed into large processed blocks, with plastics grouped by color. The sorting facility in Kočovce has the capacity to process approximately 90 tons of bottles and cans daily, ensuring a continuous and efficient flow of recyclable materials. This sorting ensures that only the cleanest, most homogeneous materials are sent for recycling.
6. Transport to Recycling Facilities
Once the containers are sorted, they are transported to specialized recycling facilities for further processing. This transport is carefully managed to ensure that the materials are delivered efficiently and without contamination. In Kočovce, 90% of bottles are sent to the Kollarovo GP recycling facility for further processing. However, aluminum cans cannot be processed locally in Slovakia and are instead exported to other countries, primarily Germany, where they are recycled into new products.
7. Recycling and Production of New Packaging
At recycling plants, the materials undergo the following processes based on their material:
- Plastics: After being collected, plastics are first ground and washed to remove dirt and glue. This results in clean PET flakes. These flakes are then cleaned and decontaminated in a reactor. Next, the material is heated in an oven before being injected into molds to create new products. Clean plastic material is also added during the process to ensure high-quality output.
- Aluminum: Small pieces of aluminum are cleaned with a strong magnet to remove steel debris, then chemically and hot-air cleaned to remove paint and ink. The cleaned aluminum is melted in a furnace and cast into ingots or sheets. These can be used to create new products like cans, foils, or spare parts. When they reach the end of their life, the recycling process starts again.
Once the recycled materials, whether plastic or aluminum, are processed into new products like bottles, cans, or other goods, the cycle begins anew. These newly created products are then returned to the market, ready for use by consumers. This ongoing cycle of collection, recycling, and repurposing not only reduces waste but also conserves valuable resources, contributing to a more sustainable future. By participating in the reverse bottle system, consumers play a key role in this closed-loop process, helping to reduce environmental impact and support a circular economy.
