In order to effectively and efficiently recycle packaging glass, Maltha developed – both on its own and in collaboration with e.g. the Technical University of Delft and various mechanical engineers - unique advanced processing installations. In its plants - in Heijningen, Emmen and elsewhere - Maltha has enough capacity to process 1.3 million tonnes of packaging glass per year.
While one can make coloured glass from white glass, it doesn´t work in the other direction, and that makes white glass more valuable than mixed glass. It is therefore extremely useful to sort packaging glass by colour. This is why waste collectors use containers and collection vehicles with separate colour compartments.
When it arrives at Maltha, packaging glass contains various types of contaminants. There are glass-associated contaminants (such as labels, covers, corks) as well as other types of contamination. In particular ceramic, stone, porcelain, metals and plastics constitute a problem for the process of producing new glass and so they have to be carefully removed.
The glass passes through a series of advanced steps in order to remove the various contaminants. Thus the cullet passes through magnets, sieves, cyclones, eddy current separators, laser and camera technology and even x-ray detection facilities. The result is that ultimately each 1,000 kilos of glass still contain only 10 to 25 grams of contaminants.