Case Study: Vehicle Body Painting Line, Mexico
Summary
A vehicle body painting line for the Mexican assembly plant of a major Chinese automaker in the state of Hidalgo, which started production in 2017 with SUVs and by 2025 was assembling more than twenty models including pickups, light trucks, vans and an electric car. The line is built around controlled booth air, with filtered supply and exhaust keeping the booths clean and balanced, viewing windows for operators, and a body conveyor carrying each body through pretreatment, painting, drying and cooling in a fixed sequence. The line serves vehicle production at the plant in 2026.
Project Background
The client is the Mexican assembly plant of a major Chinese automaker, in the state of Hidalgo. It started production in 2017 with SUVs and by 2025 was assembling more than twenty models, from SUVs and pickups to light trucks, vans and an electric car, with an expansion under way to double its capacity. MUSI supplied a body painting line for the plant.
The plant assembles and distributes vehicles for the JAC brand in Mexico, currently the J4, SEI2 and SEI3 models with further models in preparation, and has announced an investment to double its capacity.
The Challenge
Vehicle bodies are the most visible painted surface a car plant produces. Every panel has to come out with the same colour, gloss and film build, dust must be kept off the wet paint, and the paint shop has to keep pace with an assembly plant that is adding models and lines.
MUSI's Solution
MUSI supplied a body painting line built around controlled booth air: filtered supply air and exhaust keep the booths clean and balanced, viewing windows let operators watch the spraying, and the conveyor carries each body through pretreatment, painting, drying and cooling in a fixed sequence.
Equipment Scope
- Pretreatment for vehicle bodies
- Paint booths with filtered air supply and exhaust
- Drying ovens and cooling
- Body conveyor
- Exhaust and VOC treatment
Results
The line serves vehicle production at the plant, painting bodies for the models assembled there.
Selection logic: why this configuration
Booth air balance was made the design centre because on a body line dust in the film and colour drift between panels are the reject causes, and both come from unbalanced or unfiltered booth air. A fixed-sequence body conveyor was specified rather than transfer carts because an assembly plant adding models needs a steady takt, and viewing windows were included so operators check spraying without entering the booth.
Scope of supply and key components
| Item | Specification | Notes |
|---|---|---|
| Pretreatment | For vehicle bodies | |
| Paint booths | Filtered air supply and exhaust, viewing windows | |
| Drying ovens | With cooling | |
| Body conveyor | Fixed sequence through pretreatment, paint, dry, cool | |
| Exhaust and VOC treatment |
Key components
Key components are available from international brands, configurable per customer specification, so that spare parts can be sourced locally over the life of the line. Brand names below are the usual options for this type of equipment; the brands actually fitted are fixed in the contract specification.
| Component | Brands available on request |
|---|---|
| Automatic liquid guns, pumps and 2K proportioners | Graco ProMix 2KS, Sames Airmix, WAGNER AirCoat, Nordson, Binks (Carlisle Fluid Technologies) |
| Painting robots | ABB IRB 5500, FANUC P-350iA, Yaskawa MOTOMAN MPX series, KUKA, Kawasaki |
| Booth ceiling and intake filter media | Freudenberg Viledon, AAF SureStop, Camfil, MANN+HUMMEL |
| Oven and dryer gas burners | Riello RS series, Weishaupt monarch WM-G, Baltur TBG, Honeywell Maxon OVENPAK, Eclipse |
| PLC and HMI | Siemens SIMATIC S7-1500, Mitsubishi Electric MELSEC iQ-R, Schneider Electric Modicon, OMRON NX, Rockwell Automation Allen-Bradley |
| Variable-frequency drives | ABB ACS580, Siemens SINAMICS G120, Danfoss VLT, Schneider Electric Altivar, Yaskawa, Mitsubishi Electric |
| Pretreatment pumps and chemistry | Grundfos CR, KSB Etanorm, Xylem; Henkel BONDERITE, Chemetall Gardobond, PPG Zircobond, Nippon Paint |
| RTO ceramic media and burners | Lantec MLM, Honeywell Maxon line burners, Riello RS, Eclipse |
Not included in the scope of supply
- Civil works, foundations and pits
- Building services up to the battery limit: power supply, gas, compressed air, water and drainage
- Local permits, emission approvals and third-party inspections
- Paint or powder supply, unless stated in the contract
Services included with every line: engineering design, manufacturing, shipping documentation, installation supervision, commissioning, operator training, warranty and spare parts.
Typical programme
The durations below are typical for equipment of this class and are given for planning; they are not the recorded schedule of this project. A complete line usually runs 90–180 days from contract to acceptance, a single unit 30–60 days.
| Stage | Typical duration | What happens |
|---|---|---|
| Site survey and workpiece review | 5–10 days | Remote review of drawings and photos, or an engineer visit |
| Layout and detail design | 15–30 days | Layout drawing, utilities list and specification sign-off |
| Manufacturing | 45–90 days | Booths, ovens, conveyor, pretreatment and controls built and pre-assembled at the works |
| Shipping | 20–45 days | Sea freight; equipment shipped in sections for on-site assembly |
| Installation | 15–40 days | MUSI supervision with the client's installation crew or MUSI crew |
| Commissioning, training and acceptance | 7–15 days | Trial runs on the client's parts, operator training, acceptance record |
Applicability and limits
The line is sized to the body dimensions and takt of this plant; a plant with a different model mix or a higher line rate needs its own booth count and oven length. The paint system and colour range are set by the automaker and are not part of the equipment scope.
Results shown in this case study reflect the stated operating conditions and should not be interpreted as guaranteed performance under different feed, production, environmental, or site conditions.
After-sales and spare parts
Warranty on a MUSI coating line runs from acceptance: 12 months on the complete line excluding consumables, 36 months on critical components such as motors, drives and the PLC, and 60 months on structural parts such as steel structure, ducting and oven bodies. Failures within warranty, excluding misuse, are repaired free of charge.
Support starts remotely: the service line is staffed around the clock, a preliminary diagnosis with recommendations is given within 2 hours, and where a site visit is needed an engineer reaches any major city within 72 hours. A spare-parts inventory is held at the Changzhou headquarters with same-day shipping, and customers can keep a dedicated parts stock at MUSI for emergencies. Details are on the after-sales service page.
FAQ
What matters most on a vehicle body paint booth? Air: filtered supply, balanced exhaust and a steady downdraft, so dust stays out of the wet film and every panel receives the same conditions.
Why viewing windows on the booths? So operators and quality staff watch spraying in real time without entering the booth and disturbing the air.
How does the body move through the line? On a body conveyor in a fixed sequence: pretreatment, painting, drying and cooling, so every body follows the same route at the plant takt.
Which vehicles does the plant build? JAC-brand models assembled and distributed in Mexico, including the J4, SEI2 and SEI3, with more models planned as capacity doubles.
Does the scope include the paint? No; the automaker specifies the paint system and colours. MUSI supplied the booths, ovens, conveyor and air handling.
Next step: a configuration proposal for a similar line
If your parts, volumes or plant conditions are close to this project, MUSI can return a line configuration and layout proposal. To prepare it we need four things:
- Photos and dimensions of the workpieces, with weight and material
- Required output (pieces per hour or per day, and shifts)
- Number of colours and how often colour changes are needed
- Available floor space and ceiling height, with the utilities on site
Message us on WhatsApp with these details, or use the quotation form.
Published 2026-09-26 · Updated 2026-09-30 · Last technical review: 2026-09-30
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Provided by Lin Cong, Technical Director, MUSI Technology