To make the process more economic it is highly important to have machines that can automatically identify each one of the elements, above all in a non- destructive manner. Moreover, in this way it will be less contaminating for the environment and workers will not be exposed to the emission of substances that could be damaging to health.
Investigating the possibilities of classification of different materials, such as iron, lead, stainless steel, aluminium, plastic or brass, it can be observed that, in some cases, it is possible to find a way of identifying them in the visible spectrum. Nevertheless, other metals such as aluminium or stainless steel are impossible to separate by colour.
It is necessary to find other methods and here is where multispectral identification comes in. These solutions can be based on the fact that each pure metal has a spectral reflectivity response which is unique to the element, some of the metals can be identified in the 380-740 nm visible spectrum (as in the case of lead and copper) and others outside this range.
Unlike colour cameras, multi- and hyper-spectral systems can appreciate multiple bands, from ultraviolet to infrared, with very good resolution of up to 2.5 nm between bands, for example, with the ISA camera from the Finnish company, SPECIM. This versatility makes it possible for these systems to detect, classify and identify different materials, overcoming some of the limitations of the colour cameras that operate in the visible range.
The application of this type of technology to the classification of metals is the novel approach which holds out hope for the solution to the problem. It is expected that, in 2015, although it is estimated that electrical and electronic waste generated annually will double to 12 million tons, the amount of material recycled will rise s
|Contact: Irati Kortabitarte|