As is known, printer toner cartridges must not be thrown in the household waste. The fine toner dust inside the cartridge is not only harmful to health, but it also tends to ignite when it is shredded. “There has been no complete recycling for this material so far,” Doppstadt project developer Leonhard Boscheinen explains. “Although manufacturers and recycling enterprises refill empty cartridges, this does not include damaged and outdated cartridges.” In the end, the only solutions are export or incineration, which is forbidden in Germany according to the ElektroG, the Electrical and Electronic Equipment Act. “This will result in unnecessary costs and valuable raw materials will be wasted. The percentage of metals in the cartridges amounts to 50 %. Furthermore, the plastics, mainly polystyrenes, are much in demand on the market,” Boscheinen continues.
Patented processing concept for toner cartridges
Under Leonhard Boscheinen’s direction, Doppstadt Systemtechnik GmbH has developed a patented processing concept to meet this challenge. Instead of removing the carcinogenic dusts via a special de-dusting plant, the cartridges are put into an oven, which melts the particulate matter. After that the melted toner is no longer explosive. “This thermal pre-treatment replaces the complicated ex-zone categorization and de-dusting equipment,” Boscheinen says. Both the tempering process and the toner itself, which has been transformed by this method, are protected by patents owned by the Doppstadt Group.
After the tempering process, a Doppstadt high-performance shredder combined with state-of-the-art separation technology can process the material. The aims are to recover the metals and to condition the plastics for further processing.
For both processes Doppstadt prioritized health and safety the most. The risk assessment by the independent consulting firm INBUREX confirms that the dust emissions generated during the patented process are harmless. “As the expertise has demonstrated, there is no danger of explosion associated with the recycled toner cartridges,” Boscheinen says. Furthermore, Doppstadt is investigating the separation of different types of plastic in order to recycle them – this also applies to the agglomerated toner. The recovered re-granulates could for instance be used to produce new toner cartridges.
With this method Doppstadt Systemtechnik GmbH provides an efficient and economical solution to meet the legal requirements. “We enable our customers to reduce waste costs significantly and create an added value,” Boscheinen concludes.