What etchant does GE recommend for aluminium?

Alkaline sodium hydroxide (NaOH) — typically 8–12% wt with dissolved aluminium load up to 80 g/L, operating at 40–55 °C. A dissolved-aluminium-tolerant inhibitor (often a long-chain alcohol) is added to control undercut on the sidewall. FeCl₃ is unsuitable for aluminium — it pins a hard oxide layer that stops the etch.

Will aluminium etching give burr-free edges?

Yes. The chemistry dissolves the aluminium isotropically and the sidewall has a typical 60–75° slope with no burr or recast. The micro-roughness (Ra 0.5–1.0 µm) is ideal for subsequent anodising or powder coating, where it gives better key than a rolled or machined surface.

What's the tolerance?

±0.02 mm land width on a horizontal precision line; ±0.01 mm positional on vertical precision. For 0.10 mm aluminium foil, the GE thin-plate machine holds ±0.01 mm. Sidewall slope is consistent shot-to-shot because the etch rate is well-characterised across the family.

How do you handle the dissolved aluminium?

Spent NaOH etchant contains sodium aluminate (NaAlO₂). We add a caustic recovery loop that cools the spent liquor and crystallises Al(OH)₃ out — saleable as a feedstock for water-treatment chemicals. Closed-loop NaOH + Al recovery is standard on EU installations; the alternative is to neutralise to Al(OH)₃ sludge and landfill.

What about Al-clad PCB boards?

Yes — GE ships a PCB etching line with a switched chemistry module (NaOH for Al substrate etching, CuCl₂ for Cu surface etching) used in copper-clad aluminium PCB, copper-aluminium hybrid PCB and DC power electronics. Same conveyorised cabinet, two chemistry loops, fully automated controller switch.

Home/Etching Machines/Aluminium

Aluminium etching machine

Photochemical etching for 3003, 5052, 6061, 7075 & aluminium-alloy foils. Alkaline NaOH etchant with closed-loop Al(OH)₃ recovery — ±0.02 mm, burr-free, 0.05–1.5 mm. EV battery enclosures, signage, decor panels, satellite waveguides, nameplates & inverters.

Aluminium is etched in alkaline sodium hydroxide, not acid. The chemistry is mature, the etchant is regenerable, and the sidewall leaves a micro-rough surface that's perfect for anodising. GE aluminium etching lines are widely used for EV battery enclosures (where burr-free edges are a regulatory safety issue), decor panels, and aerospace waveguides.

By grade

Aluminium grades & their machines

🔹 3003 (Al-Mn)

Most common. Mild etch, inhibitor added. Horizontal precision

🔹 5052 (Al-Mg)

Marine grade. Standard NaOH. Bilge & fuel-tank shims.

🔹 6061 (Al-Mg-Si)

Heat-treatable. Structural battery enclosures & cooling plates.

🔹 7075 (Al-Zn-Mg-Cu)

Airframe grade. Slower etch, NaOH + Na₂S activator. Aerospace line

🔹 Aluminium foil 0.05–0.10 mm

Sensor mesh & EMI shields. Super thin-plate

🔹 Clad aluminium (Al-Cu, Al-SS)

Switched chemistry. PCB etching line

Recommended configuration

Aluminium etching machines

Production Double-sided spray etching machine for aluminium

Double-Sided Spray Etching Machine

Working width650 mm × L
Sheet thickness0.10–1.50 mm
Tolerance±0.02 mm
EtchantNaOH 8–12% wt, closed-loop
CabinetPP-lined, FRP shell, full exhaust

Workhorse for decor panels, signage, EV shims.

View family →

Foil

Super Thin-Plate Etching Machine

Etch area400 × 1000 mm
Foil thickness0.02–0.10 mm
Tolerance±0.005 mm
EtchantDilute NaOH, low-flow spray
Best forAl foil, EMI shields

Built for ultra-thin foil that ordinary lines would tear.

View specs →

By application

Aluminium parts on GE lines

EV battery enclosures

6061-T6 aluminium shims & cooling plates. Burr-free. →

Aerospace waveguides

6061 / 7075 slot arrays. ±0.01 mm positional. →

Architectural decor

Anodised panels & elevator cladding, 1.5–3 m wide. →

Nameplates & signs

Anodised aluminium panels, 0.30–1.20 mm. →

GE-AE Series — the lineup

Aluminium etching: pick the right machine

Aluminium is etched in alkaline NaOH (or CuCl₂/ammonia for PCB inner-layers). Three GE machines cover the bulk of programmes.

GE-AE650

GE-AE650 — Conveyorised Alkaline

PCB alkaline etching: ammonia-based chemistry for HDI / multilayer boards.

Etching process	Ammonia-based alkaline (CuCl₂ + NH₃)
Applications	Double-sided PCBs, LED, multilayer, thin copper
Power	40 kW / 380 V / 50 Hz
Working width	650 mm
Working height	850 mm (+/-50 mm)
Min / Max board	120 × 80 mm / 650 × 650 mm
Develop type	Double-spray oscillating
Workpiece thickness	0.2–3.2 mm
Working temperature	35–55 °C
Conveyor speed	0.5–6 m/min
Heater / cooling	Titanium pipe
Dimension	8000 × 1700 × 1850 mm

Process flow: Load → CuCl₂/ammonia etch → regeneration → pressure water wash → squeeze → cold/hot dry → unload.

GE-JM650-NaOH GE-JM650 NaOH etching line for aluminium sheet

GE-JM650-NaOH — Sheet Aluminium Line

Heavy-duty NaOH etching for 1.0–1.5 mm aluminium panels and nameplates.

Power	15 kW / 380 V / 50 Hz
Etching width	650 / 1000 / 1220 / 1550 mm
Thickness	0.20–3.0 mm
Tolerance	±0.05 mm
Spray	Double-side oscillating, 4 kW ×2
Tank volume	800 L PP-lined
Cabinet	PP, ≤100 °C
Dimension	3850 × 1650 × 1550 mm

Includes an Al(OH)₃ precipitation loop — turns sodium aluminate to sellable aluminium hydroxide.

GE-TS650

GE-TS650 — Vertical Precision Aluminium

For 650 × 650 mm decorative and signage work.

Power	5.5 kW / 380 V / 50 Hz
Etching size	650 × 650 mm
Thickness	0.05–5.0 mm
Spray	Top & bottom oscillating
Tank volume	400 L
Cabinet	PP
Dimension	1850 × 1650 × 1550 mm

Aluminium — the smelly chemistry

Aluminium is etched in alkaline NaOH (or ammonia-based for PCB inner-layer copper). The reaction releases H₂ gas — that's why every GE aluminium line ships with a sealed tank and a forced-exhaust hood. The H₂ also carries an aerosol of NaOH droplets, so the cabinet isn't optional. NaOH by itself is corrosive but not toxic; the ammonia version is worse on the nose and requires a wash-down module to drop NH₃ below 25 ppm before discharge.

The GE-AE650 was built originally for PCB inner-layer etching — the multiple-lane conveyor, the regenerable CuCl₂/ammonia loop and the dual-temperature zones are all PCB legacy. We adapted it to aluminium sheet by substituting the chemistry and dropping the lane-count; most aluminium-decor customers run one or two lanes at 0.5 m/min and never push the full 6 m/min capability.

Related etching lines & guides

Six things to read next — same chemistry, similar tolerances, or the next step in your process.

Planning an aluminium etching line?

Tell us your alloy (3003 / 5052 / 6061 / 7075), sheet thickness and volume. We'll spec the NaOH loop, the Al(OH)₃ recovery and the cabinets.

Request a Quote Etching 101 →