A look inside Nissan’s Smyrna paintshop, opened earlier this year with the aim of setting new standards for quality, efficiency and environmental ‘footprint’

Nissan’s Smyrna plant in Tennessee is one of three operations in the country for the Japanese car maker, the other two being the powertrain assembly plant in Dechard, also Tennessee, and a second assembly plant in Canton, Mississippi.

Beginning with the new Nissan Altima and continuing this winter with the launch of the Rogue, Nissan is set to introduce five core-volume models in 15 months in the US. Those launches will cover more than 75% of showroom volume. The shift of Rogue production to the US is part of Nissan’s broader strategy to localise production. By 2015, the car maker aims to have 85% of its products which are sold in the US also manufactured in North America. It was the recent start of Infiniti JX and LEAF production and the planned addition of the Rogue to its vehicle assembly lines in Smyrna that made Nissan realise it would need to upgrade its paintshop there. With help from the US Department of Energy, the company opted to try to create the most advanced paint plant in the world.

Setting new benchmarks

Nissan claims that facility Paint 4 sets new benchmarks for quality, efficiency and environmental ‘footprint’, being capable of reducing energy consumption by 30% compared with its predecessor, as well as carbon emissions by 30% and volatile organic compound (VOC) emissions by 70%.

“With the volume increases that we see coming our way, the opening of the new paintshop earlier this year was good timing,” says Mike Clemmer, director of paint plant at Smyrna. “The quality of the vehicles coming from this plant will be unmatched and that’s really our goal. Aside from the increased energy efficiency we have vastly increased our throughput by reducing cycle times. The paint cycle for the new plant is five-and-a-half hours compared to the nine to ten hours that it took in the old facility.

“The new paintshop is designed to achieve Infiniti paint standards. We were able to achieve those standards in the old shop by manually sanding the vertical surfaces after prime to yield a super smooth surface to lay down base and clear over. That manual process is no longer required. Total processing time through the plant has been reduced by 40%.”

BASF’s three-wet process

The plant uses an innovative three-wet paint process developed by BASF that applies all three paint layers before the vehicle goes into the oven; the previous painting process required two baking sessions. In the new method, these layers are applied wet-on-wet and then dried. This shortened process leads to compressed production time, reduced energy consumption and lower emissions.

The first step in the new sequence is the application of phosphate to provide corrosion protection and adhesion for the subsequent E-Coat. Application of the E-Coat involves electro-deposition of a paint layer onto the car body for corrosion protection. The car is then baked and sealer application occurs before a further bake. Topcoat prep follows and then the topcoat itself in the three-wet process: primer; heated flash-off; basecoat; heated flash-off; clearcoat; and topcoat bake. After a manual touch-up, the trim parts are applied (blackout, chrome sash mouldings and adhesiveapplied parts).

“The old paintshop used the conventional paint process with all solvent-borne paint,” Clemmer explains. “The new shop is a ‘compact-appli’ three-wet system with waterborne primer and basecoat.”

Automated sealing

Clemmer says that the sealer is applied by automated procedures except for the hem sealer around the closures; Liquid Applied Sound Deadener (LASD) and Stone Guard Coating (SGC) are also applied robotically. “The topcoat booth utilises ABB IRB55000 FlexPainter robots with RB1000 applicators,” he states. “The prime and basecoat zones incorporate the cartridge bell system with an integrated fill station that cleans and fills a cartridge with the next colour paint while the robot is painting the current colour. Colour change waste is virtually eliminated.”

The Nissan Green Program 2016

The facility comprises Nissan’s Showcase Project which has been undertaken as part of the US Department of Energy’s Better Buildings Better Plants Challenge, in which Nissan has committed to reducing energy intensity at its three US plants by 25% by 2020.

This effort is part of Nissan’s broader global environmental initiative, the Nissan Green Program 2016, which focuses on reducing the environmental impact of corporate activities and harmonising resource consumption and ecology by promoting and widening the application of innovative green technologies, energy management and fuel-efficient vehicles.

In May 2012, the Smyrna Vehicle Assembly Plant attained the ISO50001 energy management standard and Superior Energy Performance (SEP) certifications.

Planning for the paintshop dates back to 2010, when Nissan set about replacing its old paint plant. The new 250,000ft2 facility, which is located next to the vehicle assembly plant, was designed to incorporate the latest innovative features to make it more efficient, flexible and productive in a way that incremental measures could not achieve.

"We are going to be the global benchmark for quality"– David Johnson – Nissan

Brennan says Nissan is pursuing “global strategies of zeroemission leadership and corporate social responsibility to employees, stakeholders and customers".

Paint 4 is one of three

Paint 4 is now one of three paintshops at the Smyrna site, which account for approximately 70% of the energy consumed by the whole plant. The figures are typical for the automotive industry and emphasise why efforts in this area can produce a significant reduction in energy consumption in vehicle manufacturing.

The three-wet process in Paint 4, for instance, eliminates one high temperature oven bake step with a typical 30 minute cycle time and replaces it with a three minute cycle time low temperature flash-off oven. Ovens typically represent 30% of the electrical power use and more than 40% of the fuel consumption in paintshops, so the elimination of a high temperature bake step is a significant improvement.

The paintshop also features a compact spray booth design which saves space and requires less supply air. In consequence, exhaust air systems are smaller and use less electricity, reducing conditioning costs. Older style spray booths use more than 30% of the total electric power and 35% of the fuel use in a paint plant. The energy consumption associated with the spray booth design in Paint 4 has been reduced through the recirculation of 75% of the booth air in all three of the prime, base and clear zones.

Furthermore, the plant benefits from a lower temperature phosphating process, saving on energy used to heat the bath. In addition, all of the fan and pump motors in the facility that can benefit from speed adjustment are controlled by variable frequency drives which optimise motor speed to match load requirements.

It is not only the paint process and equipment which contribute to the facility’s energy efficiency, but the building itself. The roof is made of white polyvinyl chloride (PVC), which absorbs less sunlight than a dark roof and thus reduces heat ingress and energy expended on air-conditioning.

Paint 4 requires chilled water all year round to control the humidity of the returning booth air. However, energy efficiency improvements at the Canton vehicle plant enabled two water-cooled chillers to be re-deployed to the new facility in place of air-cooled chillers. This re-purposed equipment saved on capital outlay as well as contributing to energy cost reduction for the life of the project.

Elsewhere, multiple small natural gas hot water generators are used instead of large steam boilers. Moreover, since individual processes are served by their own dedicated boilers, each process uses only what it needs, when it needs it.

But the core of the new paintshop’s performance is provided by the three-wet system. Laurent Vaucenat, global account manager for Nissan at BASF’s Coatings Division, says it was technological innovation which convinced longterm customer Nissan to extend its collaboration with BASF in Smyrna.

An energy-efficient future

“We will be able to paint the vehicles in a more energy efficient manner,” confirms David Johnson, paint shop manager at Smyrna. “We can work with a short lead time, supply better quality and produce a very, very glossy paint finish,” he states.

Johnson makes it plain that Nissan’s ambition for the new facility is nothing less than worldwide in scope: “We are going to be the global The new paintshop is designed to achieve Infiniti paint standards benchmark for quality.”