powder coating
One-stop precision sheet metal manufacturing
One-stop OEM partner for powder coating: MetlTek runs precision sheet metal, mechanical assembly and complete unit delivery from a single plant in Kunshan, China. Founded in 2001, the factory runs three laser cutting machines (a Trumpf 3030 plus two Hongshan machines, the largest 6000 x 2540 mm), a 6.5 m CNC gantry machining center, a Salvagnini P2Lean bending center, Panasonic and Fronius welding robots and an 8 m rail-mounted welding cell. Finished goods ship to industrial customers across Europe and North America.
Every order starts from your drawings. We quote from STEP, DWG or DXF files, build a first-article sample, then run series production on the same line. Typical sheet thickness runs from 0.5 mm to 12 mm in cold-rolled steel, galvanised steel, stainless steel 304/316 and aluminium.
What you get when you order
Three commitments we are judged on by every customer, on every order.
Round-the-clock response
Send drawings at any hour — an engineer replies within one working day, not an automated ticket.
Factory-direct pricing
No trading layer in between. You buy from the plant in Kunshan that actually cuts, bends and welds the parts.
Delivery you can plan around
Committed lead times, serialised inspection records and export packing that survives ocean freight.
Typical specifications
| Material | Cold-rolled steel DC01, galvanised steel, stainless steel 304 / 316, aluminium |
|---|---|
| Sheet thickness | 0.8 – 6.0 mm |
| Tolerance | ± 0.05 mm (laser cut, all machines), ± 0.25° (Salvagnini / TRUMPF bending), ± 0.3 – 0.5° (conventional brakes) |
| Surface finish | Powder coating to RAL (2 automatic lines), zinc plating, brushed or polished |
| Minimum order | 1 piece for prototypes, series from 50 pieces |
| Lead time | Sample 7–10 working days · series 3–5 weeks |
Production Equipment
Riveting, grinding & sealing
| Array | ||
|---|---|---|
| Hargreavers press / riveting machines (USA) | 3 | precision riveting, studs & nuts |
| SG630-4WB brushing / deburring machine (China) | 2 | 800 W · surface brushing |
| Shanjia sealing machine (China) | 1 | seam sealing |
| Plate rolling machine (custom, China) | 1 | rolling |
Powder coating (2 automatic lines)
| Array | ||
|---|---|---|
| Automatic powder coating line — flow coater | 1 | oven 1200×800×2000 mm · small standard parts |
| Automatic powder coating line — batch oven | 1 | oven 2500×3500×3000 mm · large structures, complete machines |
All parameters match the factory nameplates and can be verified during customer audits.
Why powder coating deposits more of what it sprays
Powder coating is electrostatics doing the work. The gun charges atomised powder negative; the part hangs on an earthed conveyor and is therefore positive. Charged particles follow the field lines and wrap around the part — including back faces and inside corners that a spray gun would never reach — and electrostatic attraction holds the coating in place until the part reaches the oven, where it melts, flows and cross-links into a continuous film. There is no solvent, so there is no VOC and no flash-off tunnel. The transfer efficiency is the number that changes a project's cost: a well-set electrostatic powder line deposits around 90% of the powder it charges, against 30–60% for conventional air spraying, where most of the paint misses the part and ends up in the filter. Across a full enclosure programme that is not a rounding error — it is powder, labour, booth time and waste disposal. The one constraint is that the part has to conduct, which is why metal substrates are the natural home for this process.
Electrostatic powder vs conventional air spray
| Powder deposited on the part | ≈ 90% with electrostatic application |
|---|---|
| Powder deposited, conventional air spray | 30–60% — the balance is overspray, recovered or filtered out |
| Throughput | several guns fire at once; 1–3× the rate of conventional spraying on volume work |
| Solvent content | zero — powder contains no solvent, so no VOC and no flash-off |
| Film build | a continuous film built up in one pass, with no primer layer underneath |
| Edge and recess coverage | the wrap-around effect coats edges and inside corners that line-of-sight spraying misses |
| Substrate requirement | the part must conduct — steel and aluminium do; plastics, wood and glass need a conductive pre-treatment first |
| Cure | stoved in an oven at 180–200 °C, where the film cross-links rather than air-drying |
Pre-treatment and the other finishes we apply
| Phosphating | a conversion coating that turns the steel surface into a crystalline phosphate layer. It anchors the powder and adds a second line of corrosion defence under the film, which is why it sits immediately before coating rather than being skipped. |
|---|---|
| Blasting | compressed air drives an abrasive at the surface, cleaning it and leaving a controlled profile for the next stage to key into. It also lifts fine burrs, weld scale and old coating. |
| Zinc and chromium plating | electrochemical deposition of a metal layer. Zinc — clear, blue-white, black or trivalent — is the workhorse for corrosion protection on cold-rolled and hot-rolled steel. Chromium is used where hardness or a bright decorative finish is the point. |
| Abrasive brushing | grinding a directional grain into the surface with belts. It creates the finish and, at the same time, removes fine scratches, tool marks and handling damage. The grain is chosen so the direction reads consistently across every panel in the batch. |
| Anodising | an electrochemical conversion of the aluminium surface itself into a dense oxide layer. Clear or black, aluminium only, and integral to the metal rather than applied on top of it. |
| Silkscreen printing | ink forced through a photographic stencil for logos, ratings, legends and warning marks. Flexible across multiple faces, and it holds outdoors. |
| Dispensing and potting | programmed dispensing of adhesives, gaskets and potting compounds for sealed assemblies and for bonding in components that must not be fastened through the skin. |
| Seam sealing | a gasket or sealant bead run along joints and apertures to reach a rated seal where the sheet metal alone cannot. |
Coating defects and how they are prevented
Coating problems are nearly always traceable to pre-treatment, film thickness or oven settings. All three are measured, not estimated.
Orange peel
A film that cures too fast or is applied too thin will not flow out before it gels. Film thickness and oven profile are set per powder type, and checked on coupons.
Pinholes and outgassing
Trapped air or moisture escaping through the film as it cures. Causes are usually an incomplete pre-treatment or a galvanised or cast substrate that needs a higher pre-heat. The substrate decides the pre-heat, so we ask before we assume.
Colour drift between batches
Powder is a manufactured material and lots vary. Repeat programmes get a retained standard and are matched against it, rather than eyeballed against a memory of the last run.
Poor adhesion or flaking at an edge
Almost always pre-treatment, not powder. Phosphate coverage and rinse quality are the controls, and a bend-and-tape check on a sample confirms the film before the batch ships.
Runs and sags on vertical faces
Too much film on a face that cannot hold it. Film build is set by gun movement and line speed, and vertical faces are checked separately from horizontal ones.
Zinc burn-off on galvanised parts
Cutting and welding galvanised sheet damages the coating locally. Parts that will be coated are cut with nitrogen to limit it, and the damaged zone is cleaned before pre-treatment.
What gets coated here
- Electrical enclosures and control cabinets to a specified RAL colour
- Outdoor telecom and charging cabinets needing UV-stable, weather-resistant film
- Machine guards and covers where appearance and wear resistance both matter
- Stainless assemblies that are brushed or polished rather than coated
- Panels needing printed legends, ratings and warning marks applied in the same route
Built for buyers who audit their supply chain
Four things that decide whether a metal enclosure project lands on time and on budget.
Tolerances we can hold
±0.1 mm on laser-cut features and ±0.3 mm on formed parts, verified before dispatch.
Quality you can audit
ISO 9001 processes, first-article inspection and a measurement report with every series batch.
One supplier, five processes
Cutting, bending, welding, coating and mechanical assembly under one roof — no hand-offs between vendors.
Built for export
Export-grade packing, customs documentation and container loading planned for Europe and North America.
From your drawing to a delivered container
A four-step process, with a defined deliverable and a defined owner at each step.
Send drawings
STEP, DWG, DXF or PDF — tell us material, surface finish and quantity.
Engineering review
We flag manufacturability issues and return a quotation with lead time and tooling cost.
Sample and approval
A first-article sample in 7–10 working days for dimensional and finish sign-off.
Series production and shipping
Batch production with inspection records, then export packing and container loading.
Product lines
Frequently asked questions
What is the minimum order quantity?
There is no fixed MOQ. Prototypes and small batches from one piece are accepted, and unit prices fall as volume grows. One-off tooling cost is quoted separately.
Can you work from our drawings and keep them confidential?
Yes. We regularly work under NDA and produce strictly to customer drawings. Files stay on an internal server and are never shared with third parties.
How long does production take after the sample is approved?
A first-article sample is typically ready in 7–10 working days, and series production runs in 3–5 weeks depending on quantity and surface finish.
Send your drawings and quantity — an engineer, not a sales script, comes back with a quotation covering material, tooling, surface finish and lead time.
Send your drawings and quantity — you will get a quotation with lead time, not a sales script.