Carbon Black ASTM Grade N330 is a high-abrasion furnace (HAF) black that serves as the industry standard, general-purpose reinforcing carbon black. It offers an optimal balance of high tensile strength, good tear resistance, low heat buildup, and excellent processing performance in rubber compounds. Due to its balanced properties, N330 is widely used in tire treads, sidewalls, carcass compounds, conveyor belts, rubber hoses, and molded industrial goods.
Carbon Black ASTM Grade N330 belongs to the N300 series of furnace blacks characterized by medium-fine primary particle size (~28–36 nm) and standard structure. Under ASTM D1765 classification:
N indicates a normal curing rate.
3 designates the medium particle size group.
30 denotes standard structure characteristics.
N330 is often considered the benchmark grade in the rubber industry because it balances strong reinforcement with ease of mixing, smooth extrusion, and broad processing latitude.
Balanced Reinforcement: Provides high modulus, tensile strength, and good abrasion resistance without excessive compound stiffness.
Excellent Processability: Lowers compound viscosity relative to finer grades (like N220), allowing for smooth extrusion, reduced mixing energy, and better die swell control.
Low Heat Generation: Exhibits moderate hysteresis, keeping heat buildup low under dynamic stress cycles.
Versatile Compatibility: Highly compatible with natural rubber (NR), styrene-butadiene rubber (SBR), polybutadiene (BR), and EPDM.
| Property / Parameter | Typical Value | Unit | Test Standard |
| Appearance | Black Granular / Pellets | — | Visual |
| Iodine Adsorption Number | $82 \pm 5$ | g/kg | ASTM D1510 |
| Nitrogen Surface Area (NSA) | $78 \pm 5$ | $\text{m}^2/\text{g}$ | ASTM D6556 / D3037 |
| STSA (Statistical Thickness Surface Area) | $75 \pm 5$ | $\text{m}^2/\text{g}$ | ASTM D6556 |
| Oil Absorption Number (OAN / DBP) | $102 \pm 5$ | $\text{cm}^3/100\text{g}$ | ASTM D2414 |
| Compressed Sample OAN (COAN) | $88 \pm 5$ | $\text{cm}^3/100\text{g}$ | ASTM D3493 |
| Tinting Strength | $104 \pm 5$ | % | ASTM D3265 |
| Pour Density | $380 \pm 20$ | $\text{kg}/\text{m}^3$ | ASTM D1513 |
| Heating Loss (Moisture) | $\le 1.5$ | % | ASTM D1509 |
| Ash Content | $\le 0.5$ | % | ASTM D1506 |
| 45 $\mu\text{m}$ Sieve Residue | $\le 0.1$ | % | ASTM D1514 |
Tire Manufacturing: Passenger tire treads, truck tire sidewalls, carcass compounds, apex, and inner liners.
Industrial Rubber Products: High-durability conveyor belts, industrial hoses, rubber rollers, and engine mounts.
Molded & Extruded Goods: Cable jackets, weatherstripping, seals, gaskets, and shoe soles.
Plastics & Coatings: Base pigment and UV protection agent in masterbatches and utility coatings.