Reconstruction of the recycling line

In Slovakia, however, the situation is difficult because glass containers for sorting by colour have been abolished. Furnace Manager Ján Kebísek explains: “Mixed brown, green and white cullet isn't suitable for melting white glass, and the line that has been operating since 2008 was unable to separate out enough white glass from the mix. That's why we decided to convert the line for recycling cullet, so we could boost capacity and maximise the yield of used white glass.”

Converting the line saves over 4,000 tonnes of raw material

The line's capacity is now 50 percent higher, so around 140,000 tonnes of cullet can be processed each year. Ján Kebísek expects the glassworks to save about 4,100 tonnes of original raw material – and what's more, CO2 emissions will be slashed by 550 tonnes. For ten percent more cullet in the volume of glass, energy savings are about three percent and carbon dioxide is reduced by seven percent. Thanks to this investment, the Nemšová glassworks is helping to reduce environmental pollution. At the same time, it is the only processor that is meeting the Slovak Republic's current and future requirements for the recycling of used glass.

To achieve the highest yield for white cullet, the plant has installed a dryer with an upstream unit for removing paper labels. Cullet that has undergone this treatment then reaches the optical separators that remove unwanted materials such as porcelain, ceramics, glass-ceramics and other components. However, usable glass is also separated out in this process, so the waste passes through the newly-built optical sorter, which returns usable glass to the sorting flow. Yet another sorting unit has been installed to clean the white glass and separate out any remaining glass-ceramic and leaded glass. An additional belt conveyor has been added at the very end of the line – so now, the flows of both colours (white and mixed used glass) can be fed into the storage silos simultaneously.

Glass is the only material that can be recycled infinitely with no loss of quality. Time after time, it can be transformed into safe food and beverage packaging – which, ideally, should consist of 98 percent recycled glass. This makes it very important to ensure that cullet processing meets high quality standards.