The Sound of Plastic

There is more than e-waste processing happening in the open-air recycling factory: plastic processing represents a significant portion of Agbogbloshie’s ecosystem and economy.

The plastic processing chain involves various actors (male and female — contrary to e-waste processing which does not employ female workers) and machines:

• Collectors get plastic waste from all around the city and temporarily store them onsite. Dismantlers scrap plastic out of e-waste or other items.
• Men and women sort out plastics based on empirical and heuristic approaches: they separate plastics according to their thickness, malleability (thermoplastics are malleable and can be recycled, while thermoset plastics are not), and by the sound plastics make when workers bang on them with a screwdriver!
• In our interaction, workers in Agbogbloshie did not know about the resin identification code system. However, as observed many locally-made plastics lacked labels, as well as scrap pieces of plastic detached from primary parts in which the label is inset. Thus, if the processing is carried out in a hasty and crude manner, then having resin identification codes may not be overly helpful.

As we learned by watching the documentary film The Electronic Tragedy by Dannoritzer Cosima, in other parts of the globe where informal plastic processing also occurs, heuristic approaches include burning plastics with a lighter and smelling the burnt material – each type of plastic has a different burning temperature. This strategy is more dangerous for the workers’ health than local methods of differentiating between types based on the sound of plastic.

• In Agbogbloshie, it is common knowledge that television cases (made of non-recyclable thermoset plastics) cannot be sold for recycling. And this is also the reason why the item is often used for storage or as a stool. The local workers separate plastics into three main categories (while there are seven identified categories of plastics. PET (bottles) and PVC (pipes) are in addition): “rubber” (e.g. polypropylene, PP), “gallon” (e.g. high density polyethylene, HDPE), and “plastic” (not recyclable). In all, they process Polypropylene PP, High Density Polyethylene HDPE, Low Density Polyethylene LDPE, Polyethylene Theraphalate PET, Polyvinyl Chloride (PVC), and other types such as PP-MD20, and PP-TD30.
• Women remove labels and caps of PET containers (water bottles for example; water bottle c­­­aps are made of another type of plastic). Workers sort recyclable plastics by colors before (loud) shredding using locally fabricated shredding machines. They then sieve the shredded plastics before washing it. The plastic is now ready to be sold to industries – local and global!

Prices vary according to the type of plastic and depends on the market. For our plastic experiments, we purchased the Kg of shredded PET for 3 Cedis and the Kg of PP for 2 Cedis. The workers specialized in plastic processing were rather excited about the business opportunity afforded by our plastic experiments (bricks and tiles made with PP and PET) and we look forward to this knowledge transfer.

Find more pictures on Flickr.