Mike Farish reports on the methods being developed to reduce the amount of automotive manufacturing waste being sent to landfill.
A previously derelict parking lot in Detroit, Michigan, now bears the name Cadillac Urban Garden, marking the fact that the 250 plant beds it contains are made from redundant shipping crates donated from GM’s nearby Orion assembly plant for direct use in the community project rather being scrapped or recycled.
This green connection epitomises the holistic approach to modern industrial waste management that manufacturing companies of all sorts will increasingly need to act on. “It is not good enough just to recycle materials. You have got to reach out beyond your own walls on sustainability issues,” says John Bradburn, who manages GM’s waste reduction efforts worldwide. Bradburn, who is based right at the centre of the company in Detroit, explains that the issue is no longer merely technical, it is “informational” and finding effective solutions to specific waste management issues – certainly as part of major strategic company initiative such as GM’s – involves cooperation with a wide range of organisations, especially, but not exclusively materials and component suppliers. A core reason for this is simply to source ideas for the effective re-use of what might otherwise be waste materials.
The initiative that provides a context for all GM’s waste management efforts is its commitment to making all its sites worldwide ‘landfill-free’, be they manufacturing, assembly or logistical. The campaign to do this has its roots in a decision taken as far back as 1997 to embark on a systematic analysis of the waste streams produced by its operations.
The first landfill-free site – the Flint powertrain manufacturing plant in the US – took until March 2005 to achieve, but in June 2012 a parts distribution centre in Lansing, Michigan became the 100th site within the global operation to attain that status. By the beginning of May this year that total had risen to 105 – 85 of them manufacturing sites recycling or reusing an average of 97% of all waste materials, with the remainder converted to energy through incineration.
At the moment, confirms Bradburn, some 2.4 million tons of various materials that might otherwise have gone to landfill are dealt with by one or other of these means.
Curiously, the first US assembly plant to achieve this status, the Fort Wayne truck site in Indiana, did not do so until late in 2011. Bradburn explains that this was due to a legislative requirement relating to the safe disposal of phosphate material used as a pre-paint coating.
Within GM itself, says Bradburn, the initiative is pervasive and involves staff at all levels. “There are environmental engineers in place at almost all our plants, as well as resource managers,” he states. He also emphasises that “plant managers are held accountable” and input is also required from areas such as purchasing and quality management. “It is about managing the total system in a better way,” he states.
Perhaps one of the most striking aspects of GM’s recycling activity is the way it feeds back not just into processes, but quite literally the vehicles themselves, as the company has started to incorporate recycled materials into new cars; materials that derive from the production processes rather than scrapped vehicles. At Fort Wayne, for instance, cardboard packaging is recycled into Buick Lacrosse and Verano headliners to serve as acoustic padding. In addition, absorbent pads used to soak up oil and water from production areas are initially cleaned and re-used up to three times, but will then be processed into Silverado and Sierra air deflectors, which also contain some of the plant’s former plastic packaging material.
Bradburn reveals that GM’s sourcing for such materials can be surprisingly inventive. As well as re-used plastic bottles and former polypropylene matting from production areas, some 25% of the baffles that covered the radiators of the whole of the 2010 production of the Chevrolet Volt was derived from the plastic booms used to help clear up the Gulf of Mexico oil spill that resulted from the accident involving BP’s Deepwater Horizon drilling rig. No less than 227 miles of the material was processed and subsequently utilised.
Beyond the details of such cases there are some more general points to be made. One that Bradburn concedes is that while some sources of recycled material, such as plant packaging waste, may be constant, others such as the boom material are not. Therefore the specification for relevant parts has to be based on performance and not a particular material source. “You have to achieve a consistency of material from a variety of sources,” he states. In turn, a further implication is the need for the involvement of design staff – a confirmation of Bradburn’s observation that effective waste management involves a company-wide range of stakeholders.
Another concern is the relative ease or otherwise with which materials can be recycled. Those with the longest established traditions within the industry and the greatest value as raw scrap – most obviously metals – are the easiest.
Conversely, the most challenging, not merely technically, but also economically, will be those that involve a mix of substances requiring separation from each other and in which the base material will have little intrinsic value in its raw state. The mix of polypropylene filters and used machining coolant fluids is a prime example.
Another material source that Bradburn describes as “particularly challenging” is packaging. The core issue here is the choice between recycling and re-use and the decision is as likely to involve logistics and material properties. Put simply, a global supply chain may well involve logistic costs that will militate against the re-use of transport media such as pallets and instead create a need for recycling. In contrast, a geographically more compact ‘regional’ supply infrastructure is more likely to facilitate a ‘return and re-use’ policy that will entirely obviate any related need for waste management.
It seems evident that there will always be waste materials of some sort to deal with and technology, as well as procedure, will continue to have its uses in dealing with them. At the moment, Bradburn indicates, GM is interested in the potential of two particular techniques; “plasma gasification” and “microwaves”.
The latter, he indicates, could provide a means of dealing with materials containing organic compounds, such as foundry sand, using a lower energy consumption than present methods. The former could provide a means of turning into syngas various materials including cardboard and sludges. It also, perhaps summing up how GM sees waste management, has the potential to handle “varying materials on a continuous basis”.