ZN-100 is a composite additive for cyanide-free alkaline zinc plating that does the work of both the brightener and the additive in the same bath. Plating shops reach for it when they want a bright, well-levelled zinc deposit without a cyanide-based brightener sitting behind it.
It is dosed into a bath built on zinc oxide and sodium hydroxide and runs on rack and barrel lines alike. Fastener plants, hardware finishers and job shops in industrial metal plating use it where the finish has to look the same across a mixed workload, not only on the faces nearest the anode.
The additive belongs to Fengfan's electroplating chemicals range, alongside the acid zinc, cyanide zinc and zinc-nickel systems, so a line that already buys chemistry from us can add or change a process without opening a second supplier file.
Most of the work is fastener zinc plating: small parts with straightforward geometry that need a bright finish quickly rather than a heavy build. On that kind of part the metal plating process earns its keep by turning work around fast and keeping appearance consistent from barrel to barrel.
| Bath ingredient | Non-cyanide bath | Low-cyanide bath |
| Zinc oxide (g/L) | 9~12 | 7~12 |
| Sodium cyanide (g/L) | — | 1~8 |
| Sodium hydroxide (g/L) | 100~130 | 100~120 |
| ZN-100 brightener (g/L) | 4~8 | 4~8 |
| Alkaline zinc plating throwing-power agent (g/L, added or not according to the situation) | 4 | 3~5 |
| Aldehyde content | Not contained | Not contained |
| Chelating agents | Not contained | Not contained |
Most plants on an industrial electroplating line come to this additive because of a sodium cyanide bath. It was built so that a cyanide zinc bath can move to a non-cyanide alkaline bath without scrapping the tank, and so that a plant which cannot stop using cyanide in one step still has a brightener that works while it gets there.
The bath table above sets out both routes — a fully non-cyanide bath and a low-cyanide bath — which means the metal plating process can be changed across several production cycles instead of being done over a weekend.
The additive tolerates alkaline zincate chemistry and trace cyanide. That tolerance is what makes the staged route practical: cyanide carried over from the old bath does not spoil the new one, and the brightener keeps performing while the level is walked down.
On the non-cyanide route there is no free cyanide to charge, monitor or destroy, and the housekeeping on the line changes with it — the bath behaves like the rest of the alkaline cell rather than like a cyanide tank with extra rules bolted on.
Plan the changeover with us rather than around us. Local discharge limits, the rinse train downstream and the parts you run all affect how quickly the cyanide level can come down and how steady the plating process stays while it does.
| Setting | Value |
| Temperature | 5~40 °C |
| Cathode to anode ratio (SK : SA) | 1 : 1.5~2 |
| Anode | 0# zinc ingot |
| Rack plating cathode current density | 0.5~4 A/dm² |
| Rack plating cathode movement | 8~12 times/min |
| Barrel plating cathode current density | 0.5~3 A/dm² |
| Barrel plating barrel rotation | 6~8 times/min |
| Brightening on light work | A few minutes in the bath is enough where no heavy build is needed |
| Downstream step | What ZN-100 provides | What to agree with your supplier |
| Chromate passivation | A bright, compact and uniform zinc layer suited to industrial metal plating; the conversion film forms evenly and the final colour develops in the chromate bath | Target shade plus the chromate type, concentration, pH, temperature and immersion time |
| Rack or barrel colour control | Consistent response across the current-density range helps the shade repeat | Contact marks and nesting on barrel work; rack colour-critical parts individually |
| Rinse discipline | A clean zinc surface going into passivation | Rinse stages free of alkaline drag-in, which can lift chromate pH and cause a patchy or dull film |
| Sealer or topcoat | A dense zinc base beneath the passivated film | That the sealer suits the chromate film and will not shift the agreed colour or soften the film |
| Salt-spray performance | The passivated zinc layer carries the corrosion result | Neutral salt-spray testing on your own parts under the customer's specified conditions, not a generic hour figure |
| Cyanide-free changeover | A route away from free cyanide without replacing the passivation stage | A trial batch first, because the cyanide-free deposit can behave differently in the chromate tank |
Choosing the right match is where most sourcing decisions stall. As a trading supplier, we keep one point of contact from first enquiry to after-sales: tell us what you are making and the conditions you work under, and we shortlist the closest matches from our supplier network, compare specifications and arrange samples before you commit to a bulk order. If something does not behave as expected, we work with the supplying partner on the cause and a practical fix, and stay with the case until it is settled. Email, WeChat or WhatsApp enquiries get a reply within 24 hours.
99% minimum, on the additive as supplied. If you are changing over from another brightener on an industrial metal plating line, send us your current bath analysis and we will confirm the dosing for your tank.
Yes. It is compatible with other brighteners and additives, so it can go into an existing alkaline bath rather than only into a freshly made-up one. Run a trial batch first and judge the appearance against your current standard — that is the quickest way to see how it behaves inside your own metal plating process.
The bath contains no aldehyde and no chelate. Those are the two constituents that normally make zinc rinse water stubborn to break down, so the effluent from these plating chemicals is simpler to treat than a cyanide or chelated system.
Yes. ZN-100 deposits a dense, even zinc layer that takes a chromate conversion film cleanly, and the colour develops in the passivation step rather than coming out of the plating tank. Which shade you get — clear or blue-bright, iridescent yellow, olive or black — is set by the passivation chemistry you choose and by its concentration, pH, temperature and immersion time, so agree the target shade with your chromate supplier before the job runs.
Because the deposit stays uniform across a wide current density window, colour tends to hold from part to part, which matters most on barrel work where parts nest against each other and contact marks can show. For colour-critical parts, racking them individually usually gives a cleaner, more even film than barrel plating.
Rinsing between the plating tank and the passivation tank is the most common reason a colour turns patchy: alkaline drag-in lifts the pH of the chromate bath and dulls the film. Keep the rinse stages clean and the passivation bath inside the range its own supplier specifies, and the shade will repeat.
What the passivated finish then survives depends on the zinc thickness you plate, the passivation type chosen, and how the film is dried and handled afterwards. Rather than assume a salt-spray result, run a test on your own parts under the conditions your customer actually specifies, then set the line around what that test shows.
Worth confirming as well: that the chromate you plan to use is accepted in the markets you ship to, and that any sealer or topcoat applied after passivation is compatible with the film. If you are moving across from a cyanide zinc bath, the same passivation stage carries over, so the colour you already know can be reproduced on the new deposit.
Fengfan supplies several cyanide-free alkaline systems, including the ZN-500 brightener. Which one fits depends on your bath make-up, the parts and whether you run with no free cyanide at all or keep a low-cyanide bath — send us the bath analysis and the part list and we will tell you which one suits.
