Industry Insight | Surface Treatment & Coating Technology

June was a landmark month for Li Auto. With weekly sales reaching 10,900 vehicles and holding the #1 position among China's new-energy brands for seven consecutive weeks, Li Auto also broke into the top three luxury brands in the Chinese market — a remarkable milestone for a company still scaling production.

What made it even more extraordinary was the speed: from the April 18th launch of the Li L6, to the 10,000th production unit rolling off the line on May 15th, to the 20,000th on May 31st — all within less than two months. This vertical production ramp at Li Auto's Changzhou Intelligent Manufacturing Base is now being called the "Li Auto Speed."

We take you inside the four core workshops of this multi-billion yuan smart factory — with a close look at the coating process that brings every vehicle's finish to life.

Workshop 1 — Stamping

Covering 22,000 m², the stamping shop is the first step in vehicle production, responsible for 26 large-scale core stamped body panels — including all exterior and closure components. Fully automated high-speed stamping lines and blue-light 3D scanning ensure identical quality from the first unit to the millionth.

Workshop 2 — Welding & Body Assembly

The Li L6 body contains over 6,000 connection points. The welding workshop — spanning 53,000 m² with 21 fully automated lines and over 600 FANUC robots — achieves 100% automation on critical joining processes including spot welding and self-piercing riveting. Real-time cloud monitoring through Li Auto's proprietary Lianshan Quality Platform tracks every vehicle on the line.

Workshop 3 — Coating & Paint Shop

This is where surface treatment science truly shines.

Achieving the perfect finish on a vehicle — rich color, even film thickness, flawless consistency — demands precision at every stage of the coating process. Li Auto's Changzhou paint shop integrates several advanced technologies:

• Nano-scale zirconium pretreatment — replacing traditional phosphating for superior adhesion and corrosion resistance
• Proprietary electrocoating (e-coat) film prediction technology — self-developed algorithms that model and control primer film build in real time
• 3D vision-guided automatic wax sealing — robotic application of cavity wax with millimeter-level positioning
• X-Rite MA-T6 multi-angle spectrophotometer — for color consistency verification across every body panel

The result is 100% automated spray painting — enabling consistent, defect-free delivery of signature colors like the popular "Little Elephant Grey" on the Li L6.

For surface treatment professionals, this is a compelling case study in how nano pretreatment, electrophoretic coating control, and automated color measurement work together to achieve zero-compromise finish quality at scale.

Workshop 4 — Final Assembly

The most complex of the four workshops, final assembly is where every component converges. Li Auto's proprietary Li-MOS system, station terminals, and Lianshan platform connect all assembly data and workflows end to end. A highlight: the industry-first automated wheel-end assembly line — handling automatic pickup, inspection, and torquing of wheel assemblies — replacing manual processes still common across most OEMs.

Every torque value, down to a single bolt, is monitored in milliseconds. Any anomaly triggers an automatic alert. The standard: 100% assembly consistency, zero defects.

What This Means for the Coatings Industry

Li Auto's Changzhou facility is more than a showcase of automotive ambition — it's a blueprint for where industrial coating and surface treatment is heading: fully automated application, data-driven process control, advanced pretreatment chemistry, and real-time quality assurance from primer to topcoat.

At ShengTai Powder Coating Equipment, we follow these developments closely. The same principles driving excellence in automotive OEM painting — precision, consistency, environmental responsibility — are at the heart of what we deliver through our powder coating solutions for industrial applications worldwide.

Interested in how advanced powder coatings can elevate your surface treatment line? Explore our product range or get in touch with our technical team.

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