Gettings the plastic out
The relationship between the two companies began in 2018, when STGP initially bought a Hurrikan S mobile windsifter that removes light plastics, film and foils from screened overflow, with a separation efficiency of up to 95 percent. STGP uses the Hurrikan S at their South Mimms site, which has an annual throughput of up to 50,000 tons. “One of the things that really surprised me when we started to use the Hurrikan S, was that due to the integrated magnet roll and roller separation we saw quite a lot of stone and metal being captured, in addition to a high level of plastic,” says Pollington, adding that formerly such oversizes had been sorted out by hand. That is now outdated. “With the Hurrikan the process is definitely safer, cleaner and more efficient,” he says.
This gave Pollington the confidence to invest further in Komptech. “I then purchased a second one for Ardley, which is our other in-vessel composting site, so basically replicated the same process. We could see the benefits clearly. Then from there we purchased two Crambo low-speed shredders.” This was preceded by a demo of a Crambo 5200 direct at STGP’s Wallingford site. Pollington ran it against his existing high-speed shredder to compare the output, and decided to switch to the Crambo after finding fuel savings and increased throughput with higher-end product yields. There were other benefits as well. “Previously, the high-speed shredder would be running all day to get through the amount of waste that the Crambo can do in maybe five, six hours. And the Crambo just opens plastic bags instead of tearing them to bits like the high-speed shredder did. That means they can be captured again by picking.”