What NN300 Conveyor Belt Means
NN300 Conveyor Belt is a nylon fabric reinforced rubber belt with a nominal tensile strength of 300 N/mm per ply. In many workshops and procurement lists it is also called nylon conveyor belt NN300 or NN300 rubber belt. The “NN” stands for nylon warp and nylon weft, which gives the carcass high strength and good fatigue resistance. This belt is widely used in mines, coal preparation plants, cement kilns, power stations, sand and gravel yards, and bulk material handling lines.
Construction and Common Specifications
The belt is built from a nylon fabric core, bonded with rubber covers on both sides. The cover compounds can be selected for different duties, such as abrasion resistance, heat resistance, oil resistance, flame retardance, or antistatic performance. A typical NN300 belt may have 2 to 6 plies, and the cover thickness is often given as top cover plus bottom cover, for example 4+2 mm, 5+2 mm, or 6+2 mm. Belt widths commonly range from B500 to B2000, depending on the conveyor design and material size.
| Property | Common Range |
|---|---|
| Belt type | NN nylon conveyor belt |
| Nominal strength | NN300 (300 N/mm per ply) |
| Number of plies | 2 to 6 |
| Belt width | B500, B650, B800, B1000, B1200, B1400, B1600, B1800, B2000 |
| Cover thickness | 3+1.5 mm, 4+2 mm, 5+2 mm, 6+2 mm, 8+3 mm |
| Surface form | smooth, patterned, chevron, corrugated sidewall (as needed) |
Where It Is Used
In mining, NN300 Conveyor Belt handles crushed ore, coal, and waste rock. In cement plants, it conveys limestone, clinker, and gypsum. Power stations use it for coal and ash transport. Sand and gravel plants rely on it for aggregate and sand. These belts run over idler rollers, drive pulleys, tail pulleys, and bend pulleys. The belt is supported by conveyor brackets and frames along the line. Because nylon stretches less than cotton and absorbs shock better than some rigid carcasses, NN300 is a practical choice for medium to long conveyors with moderate impact loads.
Selection and Buyer Checklist
When choosing an NN300 belt, the buyer should confirm the actual tensile strength, ply count, cover grade, and belt width required by the conveyor design. The pulley diameters, especially the drive pulley, tail pulley, and bend pulley, must match the belt’s recommended minimum pulley diameter. These pulleys are not interchangeable, so each position should be specified separately. The idler roller spacing and trough angle also affect belt life. For hot materials, a heat-resistant cover is needed; for dusty coal, antistatic and flame-retardant properties may be required. Always ask the supplier for the exact cover compound and ply configuration, because a general NN300 label does not define every working condition.
Maintenance and Handling Notes
Proper tension, alignment, and loading are key to long service. Material should be loaded centrally to avoid edge damage. Regular inspection of idler rollers, pulleys, and brackets helps prevent belt mistracking. If the belt shows edge wear, cover cracking, or ply separation, repair or replace it before failure. Storage should be dry, away from direct sunlight and ozone sources. For very abrasive or high-impact duties, a thicker cover or a different carcass type may be considered, but NN300 remains a versatile choice for many bulk handling lines.
