Fengfan DPE-III is a polyamine condensate — poly(dimethylamine-co-epichlorohydrin-co-ethylenediamine) — supplied as a colorless to yellowish liquid for cyanide-free zinc electroplating. It is dosed at 2–5 g/L and does one job in the bath: it levels and brightens the zinc deposit, so that a part reads the same from the high current density edge to the recessed face once it leaves the plating process.
The effect is easiest to see on parts that are passivated after plating. A deposit that is slightly rough or uneven takes the passivation film unevenly too, and the colour drifts from part to part; a leveled deposit takes it uniformly. That is why lines supplying visible components keep a leveling component in the package rather than relying on brightness alone, and why the same addition reduces the number of parts that go back for re-plating.
Two kinds of buyer use this intermediate. The first is a plating shop running alkaline cyanide-free zinc on rack or barrel lines that wants a brighter, more even finish without rebuilding its whole additive set. The second is a formulator that builds its own brightener concentrates and buys intermediates rather than finished additives; for that buyer the CAS number, pH, density and molecular formula matter more than the drum.
Chemically it is an organic polymer, not a metal salt, so it does not change the zinc content of the bath. It can be introduced into an existing line one addition at a time, with everything else held constant so that the effect can be read on your own parts.
Baths in this family run without free cyanide, which is the main reason shops move to them: waste treatment is simpler, the operator exposure profile is easier to manage, and most automotive and electronics customers now expect it. Running without cyanide also puts more weight on the organic components, and the leveling intermediate is one of the parts that has to be right. This is not one of the acid zinc plating chemicals — it is built for the alkaline side, where the bath is held at pH 9.0–11.0 and the polymer has to stay in solution and keep working at the cathode.
| Property | Value |
|---|---|
| Chemical name | Poly(dimethylamine-co-epichlorohydrin-co-ethylenediamine) |
| CAS No. | 42751-79-1 |
| Molecular formula | C7H20ClN3O |
| Molecular weight | 197.71 |
| Physical form | Colorless to yellowish liquid |
| Polymer type | Cationic amine condensate, supplied as an aqueous solution |
| pH (as supplied) | 9.0–11.0 |
| Density | 1.00-1.05 |
| Solubility | Soluble in water |
| Function | Leveling agent and brightener in cyanide-free zinc plating baths |
| Addition level | 2–5 g/L |
| Packing | 25 kg drum |
| Storage | Cool and dry place, drums kept closed and upright |
A cyanide-free alkaline zinc bath is rarely a single additive. Most lines run a carrier or wetting agent, a base brightener, a top brightener and one or more leveling components, balanced against each other, against the zinc concentration and against the current density the work needs.
This intermediate belongs to the leveling part of that stack. It does not replace the carrier, which controls how the bath wets the part and how the deposit builds on complex geometry, and it does not replace the base or top brightener, which set the overall gloss. What it adds is the smoothing: the deposit fills the fine structure of the substrate more evenly, so the other components have a flatter surface to work on.
For a first trial, hold the rest of the package constant and change only this addition. A bath that has absorbed a new component while three others were also changed tells you nothing about which one moved the result. Once the response is known, the product can run alongside the existing carrier, brightener and wetting system without further adjustment.
As a polymeric surface active agent it behaves differently from the inorganic salts in the bath: it acts at the boundary between the solution and the growing deposit, and it tolerates baths that already contain several organic additives.
Bath type matters more than any other single factor. A zinc nickel plating line controls alloy ratio as well as brightness and uses a different additive set, so this product is not a drop-in for those baths. Lines that also run acid zinc plating chemicals keep those baths and their additives completely separate, because the operating pH and the conductivity of the two systems have nothing in common.
Keep drums closed, upright and under cover, in a cool dry store away from direct sunlight. The intermediate does not need temperature control beyond normal warehouse conditions, but long exposure to strong heat or to frost is worth avoiding: a drum that has been frozen and thawed should be inspected and rolled before it is dosed from.
Label discipline carries more weight than it sounds. In a busy metal plating plant a drum can sit on the line for weeks, and a container decanted into an unmarked pail is the usual source of a wrong addition. Keep the original label readable, keep the lot's batch number alongside the bath log, and store the intermediate apart from acids and from zinc nickel plating or other lines' additives so that a drum cannot be picked up by mistake at a shift change.
Rotate stock oldest first, and check the batch number against the batch records before opening a drum that has been in store for a while. Rinse emptied drums before disposal and send them through the plant's chemical waste route rather than general refuse; local rules decide what happens after that.
A drum is only as good as the record behind it, and in a plating shop that record has to answer two questions: whether this lot matches the last one, and what can be handed to a customer's auditor.
Our pilot plating laboratory is where a change is proved before it reaches a tank. When a formulation or a supply source changes, the new material is plated on panels and read across the current density range, so the comparison against the previous lot rests on a deposit from your own plating process rather than on a specification sheet. Production runs under clean production verification approval and safety in production standardization, with 6S scene management and standard management governing how the line is set up and how a batch is signed off.
Batch identity is the thread through all of it. Quote the batch number when you raise a question about brightness, dose or a passivation result — it is how the batch record and the panel are pulled together. Keep the same number in the bath log beside the date and the addition, and the next shift can see what changed.
Storage and dispatch go through a classified logistics system, which is what keeps an alkaline intermediate apart from acids and from the additives of a zinc nickel plating line while the drums are still in the warehouse.
For paperwork, name the destination country when you order. Safety data sheets and lot documentation are prepared per market, and raising it at quotation stage is quicker than discovering at the port that the version on file was issued for another country.
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.
Use it at 2–5 g/L in a cyanide-free zinc plating bath, where it works as the leveling agent and brightener. The lower end suits a new make-up or a bath that only needs a small correction to appearance; the upper end suits a bath whose low current density area still looks dull on a test panel. Holding the addition inside that band is what keeps the deposit uniform and bright, especially in baths that run without free cyanide.
Yes. We support custom formulations and batch qualification trials, and we work from the bath you actually run — the zinc source, the current density range, the part geometry and the appearance target. Tell us what the current package is doing and where it falls short, and a trial on your own panels is normally the quickest way to settle the dose.
In a cool, dry place, in the original closed drum, away from direct sunlight and away from acids. Keep the label readable and the batch number together with the bath log, so that any change in deposit appearance can be traced to a lot if it ever needs to be. Avoid freezing, and roll a drum that has been through very cold weather before dosing from it.
Production runs under clean production verification approval and safety in production standardization, with 6S scene management, standard management and a classified logistics system covering storage and dispatch. Our pilot plating laboratory supports qualification trials, so a new formulation can be checked on panels before it reaches a customer's line.
No on both counts. It is an organic intermediate, so it adds no zinc — the metal comes from the zinc source the bath is made up with, as in any metal plating process. It also does not replace the carrier or the base and top brighteners; it works with them. The clearest way to judge it is on a Hull cell panel, where the effect of the addition shows across the whole current density range.
This product is documented for cyanide-free zinc baths. Zinc nickel plating controls alloy ratio as well as brightness and uses a different additive set, so this intermediate is not a drop-in for those baths. If your plant runs both, confirm the pairing with our technical team before substituting anything.
No, and the difference comes from the bath rather than the drum. This intermediate is a cationic amine condensate built to stay in solution and reach the cathode in an alkaline zinc electrolyte, so its behaviour is tied to that chemistry. An acid zinc bath runs at low pH with a different conductivity and buffering profile, and the brightener and carrier components in it are selected to work in that environment; a polymer tuned for the alkaline side has no defined role in that set, so swapping one for the other tells you nothing about the result. Adding it to an acid bath is not a like-for-like replacement — expect it to sit largely inactive, and it may cloud the bath or leave organic load you then have to carbon-treat out before the deposit settles again. If your plant runs an alkaline line and an acid line side by side, keep the two additive sets apart: dedicated dosing vessels and lines, clearly labelled drums, and a rinse between make-ups so drag-in does not carry one system into the other. For an acid sulfate line, ask for a brightener formulated for that bath rather than forcing this one to fit. If you are trying to reproduce a finish you already get on an acid line, send us the bath parameters and a plated sample, and confirm the response in a bench trial on your own solution before any production dosing changes. Shops that run both systems usually keep the acid zinc plating chemicals and the alkaline intermediates on separate shelves for exactly this reason.
