Case Study: Automotive Interior UV Curing Line
Summary
A fast-cure liquid coating line for a Brazilian supplier of automotive interior parts to VW, Stellantis and other regional OEMs, producing centre consoles, vents and door-handle trims at a 15-second cycle and 4,000–5,000 pieces per day. Electrostatic bell-cup spraying of high-gloss paint is followed by infrared pre-heating at 60 °C and a lamp cure, so plastic substrates never exceed 80 °C. Film gloss is ≥90 GU at 60° with 2H hardness and a 99.5% visual pass rate. Figures as reported after commissioning in 2024.
Project Background
The client is an automotive interior parts supplier in Brazil for VW, Stellantis, and other regional OEMs, producing center consoles, vents, and door handle trims. Their existing thermal curing line couldn't meet the cycle time required for new vehicle programs.
The Challenge
Automotive interior parts require top visual quality (B-class surface) — no particles, no sagging, no orange peel allowed. Plastic substrates can't tolerate high heat (≤80 °C), so traditional thermal drying doesn't work.
MUSI's Solution
MUSI deployed a UV curing solution: electrostatic liquid spray of high-gloss UV paint → IR pre-heating (only 60 °C) → UV lamp combination cure (mercury + LED), from spray to full cure in just 90 seconds.
Equipment Configuration
| Line type | Overhead chain UV coating line |
|---|---|
| Spray method | Electrostatic bell cup (fine atomization) |
| UV lamps | Mercury 200 W/cm × 4 + LED 365 nm × 2 |
| Curing time | 30 seconds |
| Cycle time | 15 sec/piece |
| Film gloss | ≥90 GU (60° angle) |
| Film hardness | 2H |
| Daily capacity | 4,000-5,000 pcs |
Equipment used on this line
- Automatic spray coating lines — overhead chain, floor belt and robotic flexible lines
- Liquid spray lines — water-based, solvent-based, electrostatic and 2K mixing systems
Implementation
60-day delivery. UV curing is a new process — MUSI process engineers and the client's tech team tested for 3 weeks before settling on the optimal UV cure profile.
Results
Cycle time 5x faster than thermal cure. CapEx per unit area reduced 30%. Visual pass rate 99.5%. The client won supplier nomination for popular new EV models (BYD South America, Renault Latam).
Client Feedback
"UV curing was new for automotive interior in our region. MUSI's process solution is mature and proven. Our capacity bottleneck disappeared overnight."
— Project Manager, Client Side
Selection logic: why this configuration
A lamp-cured coating was chosen over thermal drying because interior plastics cannot exceed 80 °C and the new-programme cycle time could not be met with a long convection oven. Electrostatic bell-cup atomisation was preferred to air spray for the B-class surface requirement, where orange peel and particles are rejects. Infrared pre-heating at 60 °C was added so that the paint flows out before the cure without heating the substrate.
Scope of supply and key components
| Item | Specification | Notes |
|---|---|---|
| Overhead chain conveyor | 15 s cycle | |
| Spray station | Electrostatic bell cup, fine atomisation | |
| Pre-heat | Infrared, 60 °C substrate | |
| Cure | Lamp cure, 30 s | Combination lamp array |
| Booth air | Filtered supply, controlled overspray extraction |
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 | International tier-one spray gun, pump and 2K proportioner brands |
| Booth ceiling and intake filter media | Freudenberg Viledon, AAF SureStop, Camfil, MANN+HUMMEL |
| 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 |
| Conveyor gear motors | SEW-EURODRIVE, NORD DRIVESYSTEMS, Bonfiglioli, Siemens, Sumitomo Drive Technologies |
| Sensors and temperature controllers | SICK, Pepperl+Fuchs, OMRON E5CC, Honeywell UDC, Yokogawa UT, ifm, KEYENCE |
| Dust collector filter cartridges | Donaldson Ultra-Web, Parker BHA, Camfil, MANN+HUMMEL |
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 |
Results: before and after
Figures are those published on this page; measurement party, sample size, test date and method are not on record here and are left blank rather than estimated.
| Metric | Before | After | Change | Measured by | Single / average | Samples | Test date | Method / instrument |
|---|---|---|---|---|---|---|---|---|
| Cycle time | thermal cure | 15 s per piece (5× faster) | 5× | |||||
| Visual pass rate | — | 99.5% | — | |||||
| Capex per unit area | baseline | −30% | −30% |
Applicability and limits
The 15-second cycle and 90 GU gloss apply to small plastic interior parts with a lamp-cured high-gloss system and a clean-room-grade booth. Large parts, deep-draw shapes that shadow the lamps, or paint systems not formulated for lamp cure will need a different cure section and cycle time.
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
How do you coat plastic parts that cannot take oven heat? With a lamp-cured paint system: infrared pre-heat at 60 °C to flow the film, then a 30-second lamp cure. Substrate temperature stays under 80 °C throughout.
What surface quality does the line reach? Gloss ≥90 GU at 60°, pencil hardness 2H and a 99.5% visual pass rate to the OEM B-class surface standard.
How fast is the line? Fifteen seconds per piece, 4,000–5,000 pieces per day, about five times the throughput of the previous thermal-cure line.
Why electrostatic bell cups rather than guns? Bell cups give finer, more even atomisation and higher transfer efficiency on small parts, which is what keeps orange peel and particles off a visible interior surface.
How long did commissioning take? Sixty days delivery, then three weeks of joint trials with the client to fix the cure profile before production.
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.
Provided by Lin Cong, Technical Director, MUSI Technology · Published 2026-05-02 · Updated 2026-09-30 · Last technical review: 2026-09-30
QQuestions buyers ask before ordering
quotation · price · lead time · installation · warranty
What information do you need to prepare a quotation?
Send part drawings or photos, the largest part size and weight, the material, the required output per shift, the paint or powder type and number of colours, and the available floor space, ceiling height and power or gas supply. MUSI engineers reply within 24 hours; a recommended configuration and quotation follow once your part data is complete.
How much does this equipment cost?
Budget depends on part size, throughput and the level of automation. Indicative ex-works ranges are published in our complete coating line cost guide; a configured quotation is prepared from your part data. Published indicative ex-works ranges: a complete powder coating line is roughly USD 75,000–230,000 semi-automatic, USD 200,000–600,000 for a standard automatic line and USD 600,000–2,000,000 for a high-throughput automated plant.
What is the lead time?
Standard configurations ship in 30–60 days from contract signing and down payment; custom configurations take longer. The delivery date is fixed in the contract.
Do you install and train operators overseas?
Yes. MUSI engineers carry out on-site installation and commissioning and give 3–5 days of operator and maintenance training. MUSI has delivered 800+ coating lines to customers in 36 countries.
What warranty and after-sales support are included?
12 months full-machine warranty, 36 months on critical components and up to 60 months on structural parts. International customers get 24-hour phone response and 72-hour on-site arrival; spare parts ship from the Changzhou headquarters.
Can the environmental equipment be supplied with the line?
Yes. VOC treatment (RTO, RCO, activated carbon, zeolite rotor), dust collection and paint wastewater treatment are supplied with the coating line under one contract; MUSI has equipped 50+ coating facilities whose projects all passed local environmental compliance reviews.
Get a Similar Solution
If your industry and requirements match this case, contact MUSI to schedule a free consultation. We'll design an optimal solution based on your specific workpieces, capacity, and facility.