Dürr sets up state-of-the-art paint shop at Ford India’s Sanand plant

The Dürr Group, one of the world’s leading machinery and plant engineering manufacturers, has helped set up a modern painting line at the new Ford India manufacturing plant at Sanand in Gujarat. Dürr says its system sets new standards for the Indian market in terms of paint finish quality as well as eco-efficiency.

The new Ford paint shop in India, set up by Dürr, and officially inaugurated on March 26, 2015, claims to be the current benchmark in the Indian market in terms of energy consumption, paint finish quality and cost per unit. "We are not only achieving lower VOC and CO₂ emissions here, but are also realizing the highest paint finish quality, in terms of our customer's individual requirements," says Dr. Hans Schumacher, Head of the Dürr Division Application Technology, outlining the automated paint process in Sanand.

Customised operation
The core components in the new paint shop are, along with pretreatment, cathodic electrocoating and fully automatic paint application, a high-performance pollution control system for reducing VOC emissions, a heat recovery system for oven heating and highly efficient electrical pumps for paint circulation. Dürr process and application equipment was combined with the carmaker's specific standards during planning. For example, the paint line in Sanand was conceptualised by Ford, according to the carmaker’s ‘3-wet-paint’ technology. Three paint layers (primer, base coat and clear coat) are applied one after the other in this paint process, then dried together in a subsequent step. This not only saves space because complete drying can be forgone after the primer painting, but is also highly energy efficient.

Efficiency and quality through rotation
Right from the beginning, the paint process by Ford Sanand is about quality and performance: In pretreatment the white body is initially cleaned, phosphated and provided with a first even coating during the subsequent cathodic electrocoating (EC). Dürr applies its proven Ecopaint RoDip M process here. In this process, the car body is dipped into the dip tank and conveyed through the tank, rotating on its transverse axis. The car body is initially cleaned evenly by this rotation. Subsequently, a high-quality corrosion protection treatment is performed in the EC process, in which primer paint is applied. In the RoDip dip tank, immersion and removal sections standing at steep angles shorten the dip tank by several meters, thus conserving space and resources.

Fully automated sealing plant
After the EC, the individual spot-welded seams of the primed car body are sealed in a Dürr sealing plant. An underbody sealant that protects the vehicle from stone-chipping and corrosion is applied here simultaneously. This process is fully automated with eight EcoRS Dürr standard robots and can be reprogrammed flexibly for other car body types, if necessary.

Following this, the cleaning system Ecopaint Clean removes loose dirt particles from the car bodies. Rotating feathers swipe over the car body's outer skin, gathering and removing the dust lying on it.

For the 3-wet-paint process specific to Ford, the car bodies branch into two lines. A total of 32 paint robots of the type EcoRP L033 apply the primer paint, as well as the base coat and clear coat, in three directly consecutive steps. All robots are equipped for this task with the proven high speed rotating atomizer EcoBell2.

The innovative air conditioning EcoSmart AC ensures optimum air management and thus contributes additionally to the high paint finish quality at Ford in Sanand. Even with the climatic challenges typical for India, such as high temperatures and humidity, the air conditioning performs precisely and is stable long-term. This reduces energy consumption significantly by up to 30% and simultaneously lowers the production costs. The investment in EcoSmart AC pays off within a year.  "This is how, a new benchmark has been set in the Indian market by the interaction of the innovative plant technologies by Dürr and the internal Ford paint process," says Manfred Weil, Head of the Dürr Division Paint and Final Assembly Systems, describing the cooperation with Ford.

Robots work in degrade mode
Should a robot fail, the required cycle time can be still adhered to via the so-called degrade mode. In this case, the other machines take over the painting scopes of the failed robot and thus continue operating at the same cycle speed. This not only prevents downtime, but reduces the cost per unit sustainably.

The final drying booth and the oven after the EC are also equipped with the Dürr air purification plant Ecopure TAR, which dedusts the process exhaust air by combustion. By means of downstream heat recovery systems, residual heat is returned from the cleaned exhaust air to the manufacturing process. This is how the use of resources and CO₂ emissions can be reduced even more.

EcoEMOS software drives production
Durr’s supervisory control system EcoEMOS ensures the control and visual display of the entire production. This software links the production's control level with the plant's job management and creates efficiency through transparency. Thanks to the simple access to process data, the production costs can again be reduced effectively and the production quality increased. 

Once 240,000 passenger cars have rolled off the assembly line at the new Ford factory in Sanand after a year has passed, the vehicles will have undergone a consistently resource-saving paint process of pretreatment, seam sealing, application technology and automation, right up to air pollution control.

According to Girish Kumar, paint area manager of Ford Sanand, "By means of this efficient process, we have succeeded in lowering the consumption of materials and energy significantly, which further cascades to a lower carbon footprint as compared to conventional painting processes."