Sorting technology

It is not tme either that vinyl is the problem in municipal recycling because it contaminates other resins. Contamination occurs whether or not vinyl is present. Other resins are just as much a contamination problem as vinyl. Except for commingled plastics apphcations, different plastic materials caimot be mixed successfiJly in most recycled products apphcations. This is why it is cmcial to separate efficientiy one plastic from another. Because of the chlorine that is present in it, vinyl lends itself very weU to automated sorting technology. 

Sorting Ni-Cd batteries from collected streams is a critical operation for those composition where zinc batteries are dominating. Industrial sorting technologies are in operation in Europe (Euro Bat Tri - 2000 and Wiaux -2000) but not in all eountries and not with the same efficieney. It is believed that a significant fraction of Ni-Cd batteries collected are still processed with zinc batteries and are not accounted separately. 

There is no shortage of examples that we could cite sorting technologies do exist, but they need to be improved and used in accordance with the particular source at hand. It is fruitless to put sensors in place to eliminate bromide plastics if we have NO polypropylene (PP) fiem waste electrical and electronic equipment (WEEE or W3E) in the sources of EOL plastics. W3E does often contain bromine, unlike other sources. 

Stream of bottles for presentation to the detector and air ejectors (a blast of air is usually used to eject an identified bottle off of a moving belt downstream fi om the detector) is an important part of the overall ID and sorting technology. 

The Environment and Plastics Industry Council (EPIC) of Mississauga, ON, and Corporations Supporting Recycling commissioned a study of plastic sorting technologies in 2002. An update to the original study was released in 2005. It reported that the main manufacturers of mass-feed plastic bottle sorting equipment for the North American market... 

Cirko, C. and B. Graham, Plastic Sorting Technologies Under the Microscope, Resource Recycling, June 2003, pp. 16-19. 

All in all, new sorting technologies in combination with large-scale slaughtering lower the degree of asset specificity between pork producers and processors. In the Danish example, farmers and their local abattoir are heavily dependent on each other by the use of special genetic. Toennies reaches a similar output without contracts on a spot-market basis or, at best, long-term relationships with their suppliers. 

The manual sorting method is labor intensive and requires operators to monitor an assembly line and sort out clear plastic bottles (PET) from the milk containers (HDPE) and colored plastic containers (LDPE, PP, PVC). The automated method can employ one of several analytical techniques, including X-ray fluorescence, mass spectroscopy, Fourier Transform Near Infrared (FT-NIR) spectroscopy, Fourier Transform Medium Infrared (FTIR) spectroscopy, or tribo-electric analysis, on the recycled plastic materials. The state of Rhode Island has a single stream process to sort out the recycled materials with optical sorting technology. The recycled materials include cardboard, paper, glass, metal, and plastics (Rhode Island 2013). 

An alternative is to use mechanised sorting technologies. This works by utilising differences in material properties. For example, the densities of some common plastics are shown in Table 5.3. 

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