N220 and N330 carbon black are not interchangeable. Here is what actually changes.
Ask two suppliers to quote “50% carbon black masterbatch” and you can get two prices thirty per cent apart for what looks like the same product. The loading is rarely the reason. Which furnace black is inside the bag is — and in most quotations nobody writes down which one it is.
By Zoe Lin, Export Manager, E-LUCK (Guangdong Yijuyuan Plastic Industry Technology Co., Ltd.)
The two grades side by side
Both are oil-furnace carbon blacks classified under ASTM D1765. The number is not a quality ranking. It sorts them into families by how nitrogen adsorbs on the surface, which tracks particle size — and therefore how much light a kilogram of pigment can remove from a part.
| Grade | Series | Nominal particle size | Character | Where you notice |
|---|---|---|---|---|
| N220 | ISAF — intermediate super abrasion furnace | ~20–25 nm | Finer, higher surface area | Deeper jetness at the same loading; denser UV screening; needs more shear to wet out |
| N330 | HAF — high abrasion furnace | ~28–36 nm | Coarser, easier to wet | Lower filter pressure at the same loading; runs cooler; gives up some blackness |
The particle sizes are nominal values for the grade families, not measurements of a particular batch. Batch figures belong on a certificate of analysis, not in a brochure.
What N220 buys you
Jetness. Finer particles mean more surface to absorb light per kilogram. At the same let-down you get a deeper black. Turn that around and it means you can often reach the colour you want with less masterbatch — and less masterbatch means less carrier resin going into every part.
UV screening. In buried service — pressure pipe, geomembrane, drip irrigation — the pigment is doing structural work, not cosmetic work. Denser screening is the difference between decades and years. Several polyethylene pipe material specifications also set a limit on primary particle size, and N220 sits inside those limits more comfortably than N330 does.
What N220 costs you
All of that surface area has to be wetted and broken apart first. Higher surface area means higher shear demand, and if your extruder cannot supply it the consequences are measurable rather than theoretical:
- Filter pressure climbs, and screen packs blind sooner than they did.
- Melt temperature rises to win the output back, which costs energy and can shorten the thermal stability margin.
- In thin film and fine filament, agglomerates show up as specks, gels or breaks — a reject rate problem rather than a colour problem.
This is why “more black per kilo” can end up costing more per finished part. The pigment is not cheaper to use just because a smaller dose reaches the same colour.
What N330 buys you
Easier wetting and easier dispersion. In practice that reads as a lower filter pressure value, longer screen life, cooler running and steadier output through a long order. In thin blown film — anything at roughly 20 µm and below — dispersion quality decides your reject rate well before colour does.
The trade is honest: to reach the deep black that N220 gives at a given loading, you generally load a little more N330. Whether that trade pays depends entirely on what you are making and what your customer measures. How to price a let-down properly →
Where each one tends to land
| Application | What actually decides it | Usually lands on |
|---|---|---|
| Buried pressure pipe, conduit, geomembrane | UV lifetime plus the material specification window | N220 |
| Thin blown film and bags | Specks, gels, filter pressure, screen changes | N330 |
| Automotive interior trim | Deep black at low loading, with low odour and dispersion limits to meet | Either — decided with your dispersion and emission targets |
| General injection moulding | Cycle time, dispersion stability, cost per part | N330 |
| Conductive and anti-static compounds | A different kind of carbon black altogether | Neither — ask about conductive grades |
These are starting points, not recipes. The right answer depends on your resin, your screw and the test your customer runs on the finished article.
How to check what you are actually being sold
Three asks, none of which cost anything:
- Ask for the ASTM D1765 grade on the data sheet, not wording like premium furnace black. The answer should read N220 or N330. Anything vaguer usually means the grade is allowed to move between batches.
- Ask for it on every batch certificate, next to the filter pressure result, the mesh size and the test polymer. A carbon black grade without its dispersion result is only half an answer — what to look for on a CoA →
- Verify it yourself in twenty minutes. Compare jetness at the let-down you actually run, or measure carbon black content by TGA. Both are short tests, and both are described in our note on carbon black content testing.
What we run, and what we will tell you
We run both N220 and N330. Which one a given grade uses is stated on that grade’s data sheet and on its batch certificate of analysis — the technical data page carries the same statement, and so does the grade chart.
Tell us what the part has to survive — buried UV, thin-wall extrusion, food contact, an automotive emission limit — and we will put in writing which carbon black we would offer and why. We do not publish our pigment suppliers’ trade names; those are commercial, and if your approval process genuinely requires the mill we disclose it under NDA before you commit.
Anything we claim is something we will put on a certificate. If you ask for a number we do not measure, we say so rather than fill the space.
Related
- Technical data — both carbon blacks, the twelve grades, and what we release when
- Black masterbatch for pressure pipe — how pipe actually fails and what we evidence
- How to read a black masterbatch CoA
- Gels, streaks and specks — when the problem is dispersion, not pigment
- Compare the 12 grades
Questions buyers ask
What is the difference between N220 and N330 carbon black?
Both are oil-furnace carbon blacks classified under ASTM D1765. N220 is the finer of the two, with a nominal primary particle size of around 20–25 nm, so it gives deeper jetness and denser UV screening at the same loading. N330 is coarser at around 28–36 nm, so it wets out and disperses more easily and tends to run at a lower filter pressure. You pay for N220 in shear and dispersion effort.
Which carbon black does E-LUCK use?
Both N220 and N330, depending on the grade. Which one a given grade uses is stated on that grade’s data sheet and on its batch certificate of analysis. Tell us what the part has to survive and we will confirm the grade — and the reason for it — in writing with the quotation.
How can I tell if my supplier changed the carbon black?
Ask for the ASTM D1765 grade and the filter pressure value on every batch certificate, with the mesh size and test polymer stated, then compare jetness at the let-down you actually run. A shift in colour at the same loading, shorter screen-pack life or a rising filter pressure are usually the first signs that the pigment changed even though the loading did not.
Do I need N220 for pressure pipe?
Usually, yes. Buried pressure pipe has to survive decades of UV exposure and slow crack growth, and several polyethylene pipe material specifications set both a carbon black content window and a limit on primary particle size. N220 sits inside those limits more comfortably than N330. We supply the formulation data and batch certificate your certifying body asks for; we do not claim pipe-level approvals on a masterbatch.