Cleaner running applies as much to manufacturing processes as to finished automotive products – more so, in the case of water and chemicals used in manufacturing
One of the pleasures of a new car is its smell – the odour that says ‘it’s new, no-one has been in this vehicle’. Unfortunately, the smell is not an unalloyed positive. It comes from new materials, yes, but the aromas come from a cocktail of chemicals, some of which are not good at all; they damage the environment and are harmful to health.
In the report, Toxic at Any Speed: Chemicals in Cars and the Need for Safe Alternatives (Gearhart, Posselt; contributors Dempsey, Costner, Griffith and Juska; The Ecology Center, 2006), the authors note that exposure to polybrominated diphenyl ethers (PBDEs) from the interior of a car during a 90-minute journey equates to eight hours in a workplace.
PBDEs are known to cause neuro-developmental damage and thyroid hormone disruption, while animal testing has returned evidence of liver poisoning with extended exposure.
PBDEs are traditionally used in fabrics, for insulation of electrical cables, for electronic enclosures and in a variety of plastic parts. The report also considered the presence of phthalates, used to soften plastics and found extensively in PVC products – of which there are a lot in the average car. Phthalates have been associated with birth defects and cognitive problems in laboratory testing, as well as being a potential cause for early-onset puberty.
PVC is related to dioxin, a by-product in its production chain. Veterans of the Vietnam war who were exposed to it – in the form of Agent Orange – have demonstrated a variety of symptoms including abnormal liver functions and a range of cancers.
The reality is that chemicals, useful as they are, can have some unpleasant side effects. Most companies accept that poisoning customers is not a good business model; sick people don’t tend to be repeat purchasers. The challenge for the automotive industry is to find less- or even non-toxic alternatives, removing the potentially harmful materials from the manufacturing process and finished article.
There are alternatives: PLA (polylactic acid), which is derived primarily from corn (maize), doesn’t use chlorine, contains virtually no toxic chemicals and generates lower emissions of greenhouse gases. Thermoplastic polyolefins (TPOs) – which have the added advantage of being easier to recycle – are gaining share at approximately 10 per cent a year.
The use of TPOs is higher in European and Japanese cars, where recyclability is a prerequisite. They are replacing polyurethanes, PVC and thermoplastic elastomers in bumper facias, air dams, cills, exterior trim and underbody parts. Traditional degreasing compounds can be replaced with less volatile alternatives. But do the replacements do the job as well as the originals, and what is the cost involved? If too high, customers will not be interested. Chemical usage in Europe is governed by the EU’s REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulation 190/227, which was enacted in 2007 with deadlines coming into effect in 2008. Substances that have been identified as posing a risk because they are of ‘high concern’ will have to be replaced with safer alternatives.
The main obligation falls on manufacturers, OEMs in particular, but importers and all downstream users must also ensure compliance. The initial list of substances that will have to be authorised will be made available by the European Chemicals Agency by June 2009. Whatever is included, it will be the responsibility of the industry to generate and evaluate substance data, assess exposure limits and agree appropriate risk management measures with downstream suppliers; and for downstream suppliers to identify the use of substances and communicate them upstream.
That could create a different working scenario, as more clarity will be required than in the past. Supply chains will have to adapt to the new environment.
Ford took a lead in taking volatile chemicals out of its cars; the company’s Focus C-Max was the first vehicle that complied with allergy-free interior standards established by the TUV Rheinland Group. The carmaker has tried to avoid using latex, chrome, nickel and any other materials known to provoke allergic reactions.
The Focus saloon and hatchback and the S-Max and Galaxy MPVs have also attained TUV certification and Ford intends for more product lines to follow the same path. Its Volvo brand is already ahead of the game; the Ecology Centre report found that it was the leader of all companies surveyed in total phthalate usage and second only to Hyundai in low PBDE levels. The standard involves extensive analysis of passenger compartment air quality and examining the concentration of organic substances including formaldehyde, phenols, phthalates and solvents. The maximum level for phthalates is 30 micrograms per cubic metre.
The ACEA (European Automobile Manufacturers’ Association), CLEPA (European Association of Automotive Suppliers), SMMT (Society of Motor Manufacturers and Traders), VDA (German Automotive Industry Association), AIAG (Automotive Industry Action Group), JAMA (Japanese Automobile Manufacturers’ Association) and KAMA (Korean Automobile Manufacturers Association) have created a REACH task force, which has drawn up a set of automotive industry guidelines to provide a common understanding of definitions, scope, deadlines, key impacts and risk analysis.
In Japan, JAMA is driving the reduction of volatile organic chemicals (VOCs) in cars, with particular emphasis on the passenger sector. From model year 2007, JAMA’s voluntary code set a maximum for 13 VOCs. The level for di-(2-ethylhexyl) phthalate (DEHP), also known as dioctyl phthalate (DOP), was set at 7.6 parts per billion in interior air, in line with recommended standards from the Japanese Ministry of Health, Labour and Welfare.
When plastic is not so fantastic
DEHP is used as a softener in PVC and has been associated in some studies with birth defects, and other conditions. The EU meanwhile, (Commission Communication C/2008 34/1, February 7, 2008) has assessed that it poses no health risk to humans. Its use in children’s toys and childcare items has been banned in Europe since January 2007 and possible risks to workers in factories, the local environment around production plants and in some medical devices have also been identified.
America’s Food and Drug Administration issued an advisory public health notification as long ago as July 2002 on the use of medical devices containing DEHP, with recommendations against use in certain treatments and procedures. Where the use of PVC is unavoidable, there is a wide choice of alternative plasticisers to DEHPs, including adipates, citrates and trimellitates, although they are all more expensive.
European manufacturers have tended towards diisononyl phthalate (DINP), which was shown not to have environmental or health risks when assessed. GM has been using BASF Elastoskin – a polyurethane elastomer skin – on instrument panels and interior doors in its high-end Oldsmobile and Cadillac models; however, in general, GM cars made in the EU under its Vauxhall and Opel brands tend to have more environmentally-friendly plastics than their American counterparts.
In Europe, Denmark has removed PBDEs from foams typically used in car seats. Volvo’s leadership is hardly surprising in this regard. Chlorinated phosphate esters and halogen-free polyphosphates containing ammonium are used, as well as phosphorus polyols.
Some metal suppliers that used to have ammonium cracking plants on site have done away with them and buy the component hydrogen and nitrogen gases from thirdparty suppliers, a relatively easy decision as the economics became feasible.
Chemicals used in the manufacturing process aren’t all covered by REACH, but that isn’t a reason to use them profligately. Anything less than careful disposal of machine lubricating oils, for example, can bring a hefty fine, even if they go to the right place at the right time. BP Castrol has been working with clients across the world to help them manage their consumables better, with less waste and improved performance. In some cases, it has even created new compounds, specifically to reduce pollution, downtime and waste disposal expense.
Caterpillar has an environmental policy to achieve zero emissions to landfill by 2010. Working with the company’s Perkins Engines subsidiary in Peterborough, UK, it has cut consumption of cutting-machine coolant by more than 90 per cent. The two transfer systems at the Peterborough plant have an annual output of 20,000 cylinder heads and blocks. A cylinder head machining line supplied by Renault produces 80,000 units, while a bearing cap machining facility produces 150,000 sets for a variety of engines.
Following a Six Sigma study to assess the potential for outsourcing all fluid management, the company opted for Castrol’s proposal for a specific project: installation and management of coolant reprocessing and laundering equipment in the main metal cutting facility that produces cylinder blocks and heads. The project started in May 2004, at which time the Peterborough facility was disposing 466,000 litres annually. By October 2006, it was down to 45,000 litres and Perkins was able to meet its targets two years ahead of schedule.
“We’re not selling products, we are selling solutions,” says Adam Cavanagh, who had lead responsibility for the Perkins partnership. “Hydraulic and other oils manage to find their way into the cooling system. The oil is run through a laundering unit, which takes the solids out, then the free-floating tramp oils, and another unit kills off bacterial infection. From there, the fluid goes back to a 20,000-litre clean tank.” The quality of the ‘laundered’ oil, including pH levels, is monitored weekly. “The oil can be recycled several times. In fact, with the exception of events like mass ingress, it can be done indefinitely.”
“Historically, engine lines have used a second-tier product, a single-pack, mineral-based coolant,” says Wayne Thorne, Contract Manager for Castrol at the plant. “We are offering Hysol EM400, which is a twin-pack.” One of the issues involved with coolants is organic pollutant growth, including bacteria. The answer is biocides, but the disadvantage is that these and other chemicals result in variable concentration, which affects performance.
“Castrol’s Hysol EM 400 is a vegetable-oil based, two-pack product. This means there is a lubricity phase, containing a vegetable-oil based ester with certain additives, and a water phase containing water and other additives. The advantage is that the system can be topped-up with whichever phase is depleted,” says Thorne. “The two-pack approach gives more control over the coolant concentration and, therefore, its machining performance. Our team monitors all the coolant and washes for bacteria and pH levels on a weekly basis.
We’re able to deliver tighter concentration control and less variation. It’s also kinder to the operators.”
It’s also more cost-effective. “Because we’re able to monitor and control it so tightly, we can get concentrations down from 12 per cent, which is what you’d have with a typical coolant, to six per cent, with two per cent biocide. That’s a saving of 50 per cent of the oil cost, and you can use it for longer,” says Thorne. This was stage one of the project. Stage two was compatible hydraulic and slide way oils.
High levels of tramp oils in central coolant systems create a number of problems. They can significantly reduce the performance of water-soluble metal working fluids, leading to increased oil misting and fluid losses via drag out and, if left untreated, can result in the central system having to be emptied and refilled with new coolant.
“We’ve converted the whole engine line to vegetable based oils, which are compatible with Hysol EM400,” says Thorne. The compatible nature of the chemistry used across the product platform ensures that tramp oil becomes part of the oil phase of the water-soluble metal working fluid.
This compatible lubricant system has been running for two years. “We’ve seen significant reductions in dumps of effluent because of tramp oil. On some systems we expect the vegetable-based oil will give five years plus service, which you’d never get with a conventional system with high tramp oil ingress. It saves money and saves effluent, but that’s just the tip of the iceberg, as it also improves health and safety standards and results in less misting, less waste and less downtime. Previously, if tramp oil concentration got too high, you’d have to shut the line down for anything up to 48 hours; the vegetable-based hydraulic oil doesn’t pollute the coolant – it effectively tops it up,” says Thorne.
Stage three will address the washing system that, by its nature, will become contaminated. Castrol has developed a wash medium that’s compatible with the coolant. A Clarisep ultra-filtration unit will be used to filter out esters that have transferred to the wash. This recovers them and reuses them in the coolant. “The wash medium is also compatible with the coolant water phase,” he says. “A 300,000-litre system could have up to 100,000 litres of top-up water added weekly.
Historically, a washing system would inevitably have oil build-up. It would give about three or four months’ service before becoming totally saturated.”
“The Clarisep extends the lifecycle enormously,” says Thorne. “During summer shutdown, the machine would be cleaned and the wash medium would be dumped. Now, it’s sent to the coolant system. It all helps to reduce plant discharge, but it depends on water quality. We’re looking at implementing a water treatment system for incoming water to remove chlorides and control the water hardness. That will also help us to maintain concentrations and keep the product stable.”
As the project is rolled out across the group, other plants are benefiting from the initial work done. It has identified a 70 per cent reduction in rejection rate on one engine line; five per cent increase in jobs per hour; filter and chemical usage has been cut in conrod grinding, while total industrial fluid usage has been reduced by 60 per cent. The line previously used 400,000 litres of metalworking fluid annually; that’s now down to 150,000 litres of the vegetable oil coolant products.
Ford Motor Company has been paying a lot of attention to another area of fluid use – water. It is not alone among the ‘Detroit Three’ in improving its environmental performance – for example, Cadillac Products Automotive is ISO 14001 certified and has been recognised as a Michigan Clean Corporate Citizen for its efforts in reducing adhesive waste by 15 per cent.
Ford’s global water strategy was announced in 2000 and by 2005 had seen water consumption cut across its operations by almost 19 per cent, or more than five million gallons. Some basic steps have produced big savings – its Kansas City plant, which assembles pickups and SUVs, cut annual water consumption by 126m gallons through the implementation of leak detection and a total fluids programme that monitors and manages cooling-tower water use. Output has increased by 30 per cent.
Its Saarlouis, Germany, plant has implemented advanced technologies to boost the reuse of water. Water from phosphate treatments containing dissolved waste particles, grease and salts, is initially processed along with waste water from other areas in the plant’s regular waste treatment facility.
The first level is the decomposition of biodegradable pollutants by targeted bacteria. Subsequently, it undergoes nano-filtration through an ultra-thin membrane, which removes all but the tiniest particles. The third stage involves reverse osmosis to finish off waste extraction; clean water is then returned to the production process. The goal is to achieve a zero discharge of water.
Across the world from Saarlouis is Caparo’s Chennai plant in Sriperumbudur, Tamil Nadu, India, where water is recycled for subsequent use in domestic flushing and gardening. Step one is collection; water is aerated with external blowers. Urea and di-ammonium phosphate are added to develop mixed liquor suspension solids and the suspension is transmitted to a secondary clarifier, where sludge is settled by gravity.
Treated water flows to the clarified water tank and is passed through a multi-grade filter to remove suspended particles. In the final stage, it is passed through an activated carbon filter to remove odour.
India has long had an incentive to save as much water as it can. Tamil Nadu is semi-arid, and every drop is vital. In the developed world, closed-loop systems can save massive amounts of money. Similarly, removal of harmful chemicals makes sense in three ways: it makes for a better working environment, it saves money in disposal costs and it’s not just a good idea – it’s increasingly the law.
