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Making the Mini

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A new model Mini has led to BMW upgrading its UK manufacturing capacity to ensure a more resource efficient production process

In November, BMW launched its new Mini car range as well as upgrades to its UK manufacturing processes to make it more resource efficient.

The new Mini has a range of technologies to make the drive more efficient. This includes a GREEN mode that makes driving more fuel efficient and reduces use of energy sapping heating and cooling systems as well as a satnav that suggests the most fuel efficient routes.

While the overall weight of the vehicle has been reduced making it lighter than the previous iteration of the Mini leading to greater fuel efficiency.

But it is the manufacturing process where the vehicle has become more resource efficient.

BMW, which owns the Mini brand, has invested £750 million to upgrade the Mini manufacturing plants in Oxford and Swindon with its engine plant at Hams Hall in Birmingham to follow.

“In our Oxford plant’s centenary year (2013), we are continuing the Mini brand success story and starting production of the new model generation,” says BMW Group Board of Management member Harald Krüger.

“Our total investment of £750 million in our British production locations of Oxford, Swindon and Hams Hall between 2012 and 2015 underscores the importance of the Mini production triangle within our global production network.”

The facility in Oxford has received most of this investment with a new state-of-the-art bodyshop that makes manufacturing much more efficient, as well as a new paintshop and improved waste management processes. As a result, there is a reduction in the facility’s carbon footprint with over 1,000 tonnes of CO2 saved from improvements to the paintshop alone.

An army of 1,000 new robots will assemble the bodies of the Mini with new levels of precision enabling less material to be wasted. Smaller panels are now used for the body of the car with 435 typically used in the Mini hatchback. As these panels are spot-welded using Perceptron cameras that measure to an accuracy of 0.05mm (half the width of a human hair), less body panel material is needed reducing the overall weight of the vehicle but providing more rigidity and strength than in previous models.

Another huge manufacturing resource saving has been made in the paintshop.

Although the Oxford plant was the first in the BMW group to use the environmentally friendly Integrated Paint Process, where the primer coat and oven stage are eliminated to reduce paint use and emissions, it has taken this a step further.

The seam-sealing process is now automated after being a manual process before. Key parts such as the welded joints in the car’s interior, engine bay, roof and part of the tailgate aperture are automatically protected against water-ingress with a flexible mastic material applied by a set of 12 robots.

This automation means that the application of the mastic is performed to a consistently high quality and less of the material is needed and less is wasted than if applied by humans.

The application of the top-coat of paint on the vehicle’s door, tailgate and bonnet apertures has also been automated. With robots now applying the paint, a lot less is wasted and the quality of the finish is improved.

BMW has also introduced a new electro-coating facility where an electrically-charged dip ensures that paint reaches every crevice within the body. The previous system featured a three-stage bath, but this has now been replaced by a 12-stage bath system that is able to apply the right thickness of paint to each area of the body. As a result, exactly the correct amount of paint can be applied to the vehicle body leading to savings in both materials and energy while maintaining the required level of protection.

Mini manufactured with resource efficiency in mindA total of 175 energy-saving initiatives have been introduced in Oxford and Swindon including improving air flow at the facilities that has led to a combined 47.8GWh of energy savings. This is roughly equivalent to the energy consumed by 2,390 average UK homes in a year.

In 2008, the Oxford plant was sending 12.2 kg per unit to landfill but by 2011 this had been reduced to 6.6kg per unit. As a result of these efficiency measures at the plent, BMW expects this figure to drop even further.

With BMW having employees in each location responsible for using a waste material information system, it aims to optimise processes and procedures even further by getting a precise overview of the flow of waste materials. This should then help to avoid creating the waste in the first place. 

Category: Manufacturing
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