Enclosure Manufacturing
A cabinet for a hospital is not a cabinet for a factory. The loads are lower, the volumes are lower, and the drawing usually looks simpler — and yet these are the enquiries that take the longest to quote, because the specification is in the notes rather than the geometry. Disinfectant resistance, cleanability, edge geometry, documentation. Get any one of those wrong and the part is rejected on goods-in, not on the line.
This page covers what we have learned building housings, covers, console frames and chassis for medical and laboratory equipment. It is written for engineers and procurement people who need a supplier that understands why the specification says what it says.
Cleanability is a geometry problem, not a coating problem
The most common reason a medical housing fails review has nothing to do with the paint. It is that the assembly has places a wipe cannot reach:
- External seams that open upward. A joint between two panels where the upper panel’s edge sits proud creates a ledge — it collects fluid and it cannot be wiped clean. The fix is a flushed, sealed seam, or a deliberate drip edge that directs fluid away.
- Exposed screw heads on horizontal top surfaces. Every recess is a reservoir. Where fasteners must be on top, we use domed or low-profile heads with a sealed washer, or move them to a vertical face.
- Sharp internal corners. A 90° internal corner cannot be cleaned to a validated standard. Where the spec allows, we design a radiused internal corner or a coved fillet.
- Gaps at door perimeters. A door designed for IP rating with a retained gasket also seals against fluid ingress during cleaning — but the gasket material has to survive the cleaning agent, which is a separate decision.
Coating: what survives the cleaning protocol
Hospital cleaning agents are aggressive. The question is never “is it painted”, it is “does the film survive being wiped with this chemical, several times a day, for years”.
| Powder coating | Two-component wet paint (2K) | |
|---|---|---|
| Film thickness | Typically 60–80 µm, even coverage including edges | Typically 30–50 µm, thinner and smoother |
| Chemical resistance | Good with the right powder chemistry | Often specified where aggressive disinfectants are used |
| Colour matching | Standard RAL range; custom matches possible | Easier to match an existing branded colour exactly |
| Edge coverage | Excellent — this is powder’s real advantage | Thinner at edges, needs attention to edge radiusing |
| Repair in the field | Hard to touch up invisibly | Easier to repair |
| Lead time / cost | Faster, lower cost, single applicator | Longer, needs a controlled applicator |
Powder coating is applied by our long-standing coating partner, not on a line we own. We specify the pre-treatment and film build, approve a drawdown panel before the batch runs, and check film thickness on receipt. We say this plainly rather than implying a line we do not have — and the same applies if your spec calls for a named two-component wet paint system: we tell you at quotation stage and route it to a controlled applicator, rather than substituting powder and hoping nobody checks. Substituting a finish on a medical device is the kind of shortcut that surfaces during an audit, and we would rather lose the enquiry than be the reason it happens.
Material
- Galvanized sheet (DC01 + ZE, or DX51D Z275) — the standard choice for painted internal housings and covers. The zinc layer protects cut edges, which matters because every cut edge is a corrosion start point under a cleaning regime.
- Cold-rolled steel (SPCC / DC01) — used where the part is fully coated and never exposed bare, and where forming behaviour matters more than corrosion resistance.
- 304 stainless — for trolley bodies, wash-down areas and anything that will be wiped with chlorine-based agents. 316 where chloride exposure is higher.
- Aluminium 5052-H32 — where weight matters, typically mobile equipment and cart-mounted devices.
Thickness for medical housings is usually 1.0–2.0 mm. Thinner looks like a cost saving and often is not: 1.0 mm panels need more returns, more stiffening and more careful handling, and the assembly ends up costing more than a 1.5 mm version that is simply bent.
Documentation your compliance team will ask for
We can supply, as part of the order rather than as a paid extra afterwards:
- Material certificates traceable to the mill, tied to the heat or coil used
- Coating thickness readings recorded per batch, not just “applied”
- First-article inspection report with dimensional results against the drawing
- Photographic build record — useful when the part is assembled and the internals can no longer be inspected
- Change control — if we change a process step, a fastener supplier or a material source, you are told before the batch ships, not after
If your own QMS requires supplier documentation in a particular format, send the template with the enquiry. Retrofitting a certificate format after production is the single most avoidable delay in this sector.
What we need to quote a medical housing
- STEP or DWG plus the assembly drawing
- Coating specification — product name if one is specified, otherwise RAL and any chemical resistance requirement
- Cleaning protocol if known — the agent family is enough (quaternary, chlorine-based, hydrogen peroxide, alcohol)
- Material and whether stainless is required on any face
- Annual quantity and batch size
- Any documentation requirements beyond our standard first-article report
Building a housing for medical or lab equipment?
Send the drawing and the coating spec. We will flag every ledge, exposed fastener and un-hemmed edge that will come back at you during cleanability review — before the first article is cut.
Ningbo Fulei Metal Products Co., Ltd. — laser cutting, CNC bending, TIG and MIG welding, hardware installation and assembly in-house. Powder coating runs on audited partner lines that we specify and inspect. Related: medical device sheet metal housing · stainless console housings · inspection checklist.