Plastics recycling in the mechanical engineering industry

The EU WEEE (management of waste electrical and electronic equipment) directive has big implications for mechanical engineering companies, who today incorporate FPGA design and polybrominated plastics into many of the products they create.

While the prohibited metals, such as lead and mercury, are relatively easy to recover and recycle, the recycling of restricted plastics is more difficult. However, recently there have been significant breakthroughs in this department – notably at the TAMARA municipal solid waste combustion (MSWC) pilot plant at the Karlsruhe Research Centre, Germany, which has been trialling machinery for separating the bromine component of brominated plastics.

The trials supported the theory that wet scrubbing systems installed in modern MSCW facilities could be used to liberate bromine from WEEE plastics waste, for example flame-retardant finishes. Bromine – as pure bromine, hydrogen bromide and sodium bromide – is widely used in industry, so it’s a financially viable option. There are enough MSWC facilities in Europe to process all the bromine currently known to exist in WEEE plastics, and commercial plants investing in the necessary equipment would be assured of a regular supply of raw materials, especially as polybrominated waste is a world-wide issue extending far beyond the EU.

Plastics are used in both electronic and mechanical engineering. Used throughout the design process, from housings to circuitry, they reduce size, weight and production costs, enhancing functionality and consumer appeal. With miniaturisation now possible through sophisticated PCB design tools, WEEE has become a complex issue. The average lifespan of hi-tech hardware is shorter than it’s ever been, leading to large volumes of environmentally harmful products, such as lead solder and flame-retardant insulation, ending up in landfill sites.

Flame retardants are often necessary for products to comply with fire safety regulations. However, there are a wide range of alternatives in PCB design, packaging and cabling. These include polymer resins, polyphosphates and organic halogen derivatives. Aluminium phosphate, Zinc stannate, Polyethylene sulphide and tetrabromo phtalimid are just four already in use, with more being developed all the time. This makes following RoHS regulations fairly trouble-free, since these concern the construction of new items. However, the disposal of end-of-life EE (electronic/electrical) plastics presents more of problem, as their composition will affect the recovery process. A comprehensive bill-of-materials is essential no matter how small the component is.

Like lead, hexavalent chromium and mercury, the recycling of polybrominated plastics needs to be done eco-efficiently, so environmental compliance in one area does not impact on another, or make the process economically unviable. However, trials with Polybrominated insulation foams and WEEE plastics have shown that recovery of bromine is a highly efficient waste management operation which satisfies environmental compliance regarding energy emissions, and is commercially viable.

Eco-efficient waste management is a lucrative area for both mechanical engineering companies and FPGA design teams. Bromine recycling adds an exciting new edge to the range of technologies available for WEEE recycling. We at Enventure Technologies offer a wide range of services in the areas of mechanical engineering and PCB design, as well as data management solutions for those struggling with WEEE and REACH legislation.

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