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Painting Parts

Surface Treatment · Coating · Finishing

Custom Painting Parts —
Professional Industrial Surface Coating

Jiafeng delivers industrial-grade painting parts services from our fully in-house coating facility in Zhejiang, China. Our dual powder-coating lines, 21-slot phosphating pre-treatment system, and ceramic conversion line produce finishes that meet 500–1,000 h neutral salt-spray standards (ISO 9227). Every painted component passes CMM and colour-matching inspection before shipment.

What Are Painting Parts?

Painting parts (also referred to as coated metal components or surface-finished parts) are metallic or composite workpieces that have undergone one or more controlled coating processes to enhance their corrosion resistance, mechanical durability, electrical insulation, and aesthetic appearance. According to ISO 12944-1:2017 – Paints and varnishes: Corrosion protection of steel structures by protective paint systems, the coating system must be selected based on the corrosivity category (C1–C5-M) of the operating environment. For manufacturing applications, ASTM B117 (salt-spray test) and ISO 9227 (neutral salt-spray test) define the standard durability benchmarks all industrial painting parts must pass.

In precision manufacturing, painting is never the final afterthought — it is an engineered process step with rigorous pre-treatment, application parameters, and cure specifications. At Jiafeng, every painting part goes through a documented sheet metal manufacturing workflow before entering the coating line, ensuring surface cleanliness, dimensional accuracy, and process traceability meet customer specifications.

Jiafeng's Painting Parts Process — Step by Step

  1. 01

    Surface Degreasing & Cleaning

    Parts are immersed in an alkaline degreasing bath to remove cutting oils, stamping lubricants, and oxidation. Our stainless-steel / aluminium cleaning line measures 2,400 mm × 750 mm × 1,500 mm over a 46,000 mm run — eliminating surface contaminants that would otherwise cause adhesion failure or blistering in service. (Reference: ASTM D3359 – Adhesion by Tape Test)

  2. 02

    Phosphating Pre-treatment (21-Slot Line)

    Iron or zinc phosphate conversion coating is applied in a 21-slot immersion line (single-slot: 1,300 H × 2,500 L × 3,000 D mm). Phosphating creates a micro-crystalline interface layer that dramatically improves powder-coat adhesion and provides a secondary corrosion barrier. Per ISO 9717:2017 – Metallic and other inorganic coatings: Phosphate conversion coatings, crystalline weight for zinc phosphate should fall between 1.5–4.5 g/m² for optimal powder adhesion.

  3. 03

    Ceramic Conversion Coating (Optional, 7-Slot Line)

    For aluminium and light-alloy painting parts, a chrome-free nano-ceramic conversion treatment is performed on our dedicated 7-slot line (single-slot: 1,300 H × 2,300 L × 1,700 D mm). This process complies with RoHS 2015/863/EU by avoiding hexavalent chromium, while providing 300–600 h salt-spray protection and excellent adhesion for electrostatic powder coatings. This aligns with MIL-DTL-5541F Type II (non-chromate) specifications widely used in aerospace and defence supply chains.

  4. 04

    Electrostatic Powder Application

    Thermosetting powder (polyester, epoxy-polyester hybrid, or polyurethane) is electrostatically charged (–40 to –80 kV) and sprayed onto grounded parts. Wrap-around effect ensures uniform coverage on recesses and edges. Film build is maintained at 60–100 µm per ISO 2360 – Measurement of coating thickness by eddy-current methods. Our dual coating line spans W = 900 mm × 200,000 mm of conveyor length, supporting continuous high-volume production of painting parts.

  5. 05

    Curing in Vertical Ovens

    Parts travel through three vertical curing ovens at 180–200 °C for 15–25 minutes, cross-linking the powder into a hard, continuous film. Oven dimensions accommodate parts up to 6,000 mm × 1,500 mm × 2,980 mm — handling large enclosures and structural frames in a single pass. Cure quality is verified per ASTM D2794 – Resistance of organic coatings to the effects of rapid deformation.

  6. 06

    Inspection & Quality Sign-off

    Finished painting parts are inspected for film thickness (ISO 2360), adhesion (crosshatch, ISO 2409), gloss (ISO 2813), colour deviation (ΔE ≤ 1.0 against RAL standard, CIE L*a*b*), and salt-spray hours. Non-conforming parts are stripped, re-processed, and re-inspected. Our precision machining and mechatronics integration teams also use painted components as final-state sub-assemblies requiring zero rework.

Painting Parts Methods — Technical Comparison

The table below compares the four industrial coating methods Jiafeng supports, drawing on industry benchmarks from ISO 12944, ASTM B117, and EN 13438 (powder coatings for galvanised or sherardised steel).

Method Film Thickness (µm) Typical Salt-Spray (h) VOC Emissions Material Transfer Rate Best For
Electrostatic Powder Coating 60 – 120 500 – 1,000+ Zero (solvent-free) 95 – 99 % (reclaim system) Sheet metal enclosures, cabinets, heavy frames
Liquid Wet Painting (Solvent-borne) 25 – 80 200 – 600 High (requires extraction) 30 – 60 % Complex shapes, colour gradients, OEM branding
Water-borne Liquid Painting 20 – 70 300 – 700 Low (< 250 g/L VOC) 40 – 65 % Automotive, medical device housings
Electrocoating (E-coat / KTL) 15 – 35 240 – 500 Very low 95 – 98 % Primer coat for complex cavities, automotive sub-frames
Zinc Electroplating + Powder Top-coat Zn 8–12 µm + PC 60–100 µm 800 – 1,500+ Zero (powder stage) — Outdoor structural parts, corrosivity category C4–C5

Data derived from ISO 12944-5:2019, ASTM B117-19, and EN 13438:2013. Salt-spray hours are indicative; actual performance depends on pre-treatment, substrate, and film thickness.

Jiafeng Painting Parts Equipment Specifications

All coating equipment listed below is operated in-house at our Jiashan County, Zhejiang facility. No outsourcing. Production continuity is guaranteed by dual-line redundancy.

Equipment / Line Specification / Dimension Capacity / Notes
Powder Coating Line (×2) W = 900 mm × 200,000 mm (conveyor length) Dual-line for redundancy; supports all RAL colours
Phosphating Pre-treatment 21 slots; single slot: 1,300(H) × 2,500(L) × 3,000(D) mm Iron + zinc phosphate; handles steel & galvanised substrate
Ceramic Conversion Line 7 slots; single slot: 1,300(H) × 2,300(L) × 1,700(D) mm Chrome-free; RoHS compliant; for aluminium painting parts
Vertical Curing Ovens (×3) Max part size: 6,000 × 1,500 × 2,980 mm 180–200 °C; 15–25 min cure cycle
Silkscreen / Pad Printing 3,500 mm × 750 mm UV-cure inks; logos, serials, warning labels on painted surfaces
Stainless / Aluminium Cleaning Line 2,400 × 750 × 1,500 mm; 46,000 mm run Alkaline degreasing; removes cutting oils & oxides
Electroplating Line (Zinc) 3,000 × 750 × 1,500 mm; 56,000 mm run Blue-white zinc; 96–128 h salt spray; used as painting parts primer

Painting Parts — Quality & Performance Standards

All painting parts produced by Jiafeng are evaluated against the following internationally recognised standards. Test reports are available upon request.

Test / Property Standard Jiafeng Specification Pass Criterion
Neutral Salt Spray (NSS) ISO 9227 / ASTM B117 500 h (standard) / 1,000 h (premium) No blistering, creep ≤ 1 mm from scribe
Film Thickness ISO 2360 / ASTM D7091 60 – 100 µm (powder) ±10 % of nominal on all measurement points
Adhesion (Cross-cut) ISO 2409 / ASTM D3359 GT0 – GT1 ≤ 5 % detachment (Class GT1 or better)
Hardness (Pencil) ISO 15184 / ASTM D3363 ≥ H (standard); ≥ 2H (hard finish) No cutting through film
Impact Resistance ASTM D2794 Direct: 80 in·lb; Reverse: 40 in·lb No cracking or adhesion loss
Gloss Level ISO 2813 / ASTM D523 Matt 10–20 GU / Gloss 80–90 GU @ 60° ±5 GU from nominal
Colour Accuracy CIE L*a*b* / ISO 11664-4 ΔE ≤ 1.0 vs RAL master Imperceptible colour deviation
RoHS / Hazardous Substance EU 2015/863 / IEC 62321 Pb, Cd, Cr⁶⁺, Hg, PBB, PBDE below threshold Verified by in-house ROHS analyser (1–10 ppm)

Supported Substrates & Colour Options for Painting Parts

Substrate Material Pre-treatment Required Recommended Coating Available Finishes
Cold-Rolled Steel (SPCC / DC01) Zinc phosphate (21-slot line) Polyester powder coat Any RAL; matt, gloss, textured
Galvanised Steel (SGCC / DX51D) Iron phosphate or ceramic Epoxy-polyester hybrid powder Any RAL; textured wrinkle
Aluminium Alloy (5052 / 6061) Ceramic conversion (7-slot line) Polyester or polyurethane powder Any RAL; anodised look
Stainless Steel (304 / 316) Passivation + light abrasive Epoxy primer + polyester top Custom RAL; hygienic white
Zinc-Plated Steel (SECC) Chromate seal → direct coat Epoxy-polyester powder Any RAL; anti-static options

Industrial Applications of Jiafeng Painting Parts

Painted surface finish is a functional requirement in virtually every industrial sector. The following table maps our painting parts output to the industries and product types we serve, aligned with our broader sheet metal manufacturing and mechatronics integration capabilities.

Industry Typical Painting Parts Critical Coating Requirement Corrosivity Class (ISO 12944)
Power & Energy Switchgear cabinets, battery module frames, transformer housings IP54+, arc-flash resistance, ≥ 1,000 h salt spray C3 – C4
Telecom & Networking Base-station shelters, 19-inch rack enclosures, antenna mounts EMI shielding continuity, outdoor durability C3 – C5-M
Medical & Healthcare Imaging equipment shells, surgical trolleys, infusion pump casings Chemical resistance, low-particulate, hygienic white RAL 9016 C2 – C3
Industrial Automation Robot cell guarding, PLC cabinets, servo drive enclosures Impact resistance, anti-chip, consistent RAL colour identity C2 – C3
Retail & Vending Vending machine outer shells, refrigerated display doors High-gloss finish, brand colour matching (ΔE ≤ 1.0) C2
New Energy / EV EV charging station housings, solar inverter enclosures IP65+, UV resistance, outdoor weathering ≥ 2,000 h C4 – C5

Why Choose Jiafeng for Painting Parts?

In-house End-to-End

From raw steel blanking through laser cutting and bending to powder coating and final inspection — no third parties, no scheduling gaps. Single-factory traceability across all painting parts.

Large-Part Capability

Vertical curing ovens handling parts up to 6,000 × 1,500 × 2,980 mm — among the largest in-house painting parts capacity available from a Zhejiang contract manufacturer. Ideal for machine guards, kiosk frames, and EV charging stations.

RoHS & Eco Compliance

Chrome-free ceramic conversion, zero-VOC powder coating, and in-house ROHS analyser (1–10 ppm sensitivity) ensure all painting parts meet EU RoHS 2015/863/EU and REACH SVHC requirements.

Precision Colour Matching

Spectrophotometer-verified colour (ΔE ≤ 1.0 against RAL, NCS, or Pantone masters). Consistent across batches — critical for branded vending machines, medical devices, and retail kiosks requiring identical finish lots.

Integrated Downstream

Painted parts flow directly into mechatronics integration and precision machining assembly on the same floor — eliminating transit damage, handling marks, or moisture ingress during part transfer.

Volume Flexibility

Prototype runs of 10–50 painted parts through to monthly volumes exceeding 100,000 pieces. Standard lead time 7–15 business days. Dedicated production cells available for blanket order programmes with call-off flexibility.

Frequently Asked Questions — Painting Parts

What is the difference between powder coating and liquid painting for metal parts?

Powder coating is a dry, solvent-free process where electrostatically charged thermosetting polymer powder is sprayed onto grounded parts and cured at 180–200 °C. It produces a thicker (60–120 µm), more uniform, and more durable film than most liquid coatings, with zero VOC emissions and a material transfer rate up to 99% with reclaim. Liquid (wet) painting uses solvent- or water-borne resins applied by spray gun; it offers greater flexibility for complex colour effects and thinner films (25–80 µm) but generates VOC emissions and typically achieves lower salt-spray resistance unless combined with a zinc primer. For most industrial painting parts, powder coating is the preferred choice per ISO 12944-5 guidance for corrosivity categories C2–C4.

What pre-treatment does Jiafeng use before painting metal parts?

For steel and galvanised steel painting parts we use a 21-slot zinc or iron phosphate immersion pre-treatment line. For aluminium and light-alloy parts we apply a chrome-free nano-ceramic conversion coating on our dedicated 7-slot line, which is RoHS compliant and provides 300–600 h salt-spray resistance before the powder top-coat. Both lines meet ISO 9717 and customer-specific phosphate-weight requirements. A separate stainless-steel / aluminium alkaline degreasing line handles initial cleaning for all substrates.

What is the maximum size for painting parts at Jiafeng?

Our vertical curing ovens can accommodate parts up to 6,000 mm (length) × 1,500 mm (width) × 2,980 mm (height). The powder-coating conveyor line spans W = 900 mm × 200,000 mm. For parts exceeding these dimensions, our engineering team can discuss modular sub-assembly painting and re-joining strategies. Contact us with your part drawing.

Can Jiafeng match a specific RAL or Pantone colour for painting parts?

Yes. We support any RAL Classic or RAL Design colour, NCS, and Pantone references. Colour is verified by spectrophotometer to ΔE ≤ 1.0 against the master swatch (CIE L*a*b* per ISO 11664-4). Batch-to-batch consistency is maintained through controlled powder-supply agreements with major powder manufacturers. Custom colour formulation is also available for high-volume OEM programmes.

Are Jiafeng's painting parts RoHS and REACH compliant?

Yes. All powder coatings and pre-treatment chemicals used in our painting parts process are screened against EU RoHS 2015/863/EU (10 restricted substances) and REACH SVHC. Our chrome-free ceramic conversion pre-treatment eliminates hexavalent chromium (Cr⁶⁺). All incoming coating materials are tested by our in-house ROHS X-ray fluorescence analyser with a detection sensitivity of 1–10 ppm, RSD < 5%. View our certifications.

Ready to Discuss Your Painting Parts Project?

Send us your drawings or DXF files and we'll respond within one business day with a DFM review, coating recommendation, and budgetary quote. Our engineering team is fluent in ISO 12944, ASTM B117, and RoHS requirements.