BKNL-65 GOST 20-85

BKNL-65 Conveyor Belt

The BKNL-65 rubber-fabric conveyor belt is the primary type of traction and load-bearing web used in the agro-industrial complex and light industry. Unlike heavy rubber-cable or synthetic belts for mining (such as TK-200), this type of web is designed specifically for transporting bulk cargoes of low and medium abrasiveness - grain, grain processing products (flour, bran), compound feeds, and seeds. The abbreviation "BKNL" is a technical designation of the fabric structure that forms the basis of the reinforcing carcass:

• B (Б) - Belting (type of thread weave)
• K (К) - Combined (use of a blend of natural and synthetic fibers)
• N (Н) - Thread/Yarn
• L (Л) - Lavsan (polyester fiber in the warp)
• 65 - nominal tensile strength of one ply 65 kgf/cm

The use of a combined thread (polyester + cotton) provides the material with the necessary balance of flexibility and strength. Unlike the obsolete B-820 fabric (pure cotton) used on old elevators, the BKNL-65 carcass has significantly higher resistance to moisture and biological degradation (mold, rot). At the same time, the main advantage of the material remains its ability to effectively wrap around small-diameter drive drums without cracking, retaining elasticity even at low temperatures.

Differences between BKNL-65 and TK-200

When choosing components, it is important to distinguish between the spheres of application of different carcass types. The BKNL-65 belt is often visually similar to more powerful analogues like TK-200 (Nylon Fabric), but their operational properties differ significantly:

1. Thickness and Flexibility
A BKNL ply has a thickness of about 1.2 mm, while TK-200 is over 1.5–1.8 mm (plus thicker rubber layers). BKNL is significantly softer, allowing it to work on pulleys with a diameter from 200 mm (grain throwers, small bucket elevators), whereas the more rigid TK belt is subjected to excessive bending stresses on such small radii, leading to rapid delamination of splices.

2. Weight
BKNL-65 is lighter than synthetic analogues - this reduces the dead load on bearing units and the gearbox, which is critical for equipment, especially when operating on Soviet-era models (ZAV, NTs) designed for lower traction forces.

3. Temperature Regime
Due to the presence of cotton in the composition, BKNL behaves better at low temperatures and does not stiffen ("get oaky") as much as fully synthetic nylon carcasses.

4. Load Abrasiveness
TK-200 is designed for heavy conditions (crushed stone, coal, ore), while BKNL-65 is a specialized solution for "light" bulk loads (grain, flour, compound feed).

Thus, the choice in favor of BKNL-65 is the most rational decision for the majority of tasks in the agricultural sector. The application of heavy mining belts (TK) on elevators without appropriate project justification is a common mistake that entails hidden losses. Such a belt not only costs more to purchase but also leads to constant overconsumption of electricity, as the drive has to expend more power to overcome the resistance of the rigid carcass during bending. Moreover, excessive rigidity of the web destroys the mechanics of a standard bucket elevator - poor contact with the drum causes intensive abrasive wear of its surface (lagging), and attempts to compensate for this with high tension create a critical load on bearing units and the gearbox, reducing their service life several times over.

Spheres of Application for BKNL-65

Thanks to its versatility and price-quality balance, the BKNL-65 belt is the most common rubber-technical material in the agricultural sector. Main areas of use:

1. Vertical Transport (Bucket Elevators)
Used as the basic traction component on bucket elevators of low and medium load (NTs-5, NTs-10, NTs-20, NTs-50, NTs-100), as well as on unloading units of ZAV and KZS complexes.

2. Grain Loading Machinery
Serves as the base for belts of grain throwers such as ZM-60, ZM-90, ZM-120 (trimmer belts, including those with welded ribs/chevrons). The flexibility of the BKNL carcass is a critical parameter for operation on high-speed small-diameter drums installed in the trimmers of this machinery.

3. Technical Equipment and Lining
The material is also widely used for manufacturing sealing gaskets, splash guards, flexible inserts, as well as for lining (padding) gravity chutes and bunkers to reduce grain damage upon impact with metal.

Main Physico-Mechanical Parameters of BKNL-65

Reference data for calculation and belt selection are provided below.

Production Service and Engineering Support from Zavod Moroza

Cooperation directly with the manufacturer is, first and foremost, an opportunity to order a traction unit individually prepared for the technical requirements of a specific assembly. If necessary, the production lines of Zavod Moroza allow for high-precision longitudinal cutting (slitting) and forming coils of any non-standard width with perfect edge geometry. This option is critically important for servicing imported grain dryers or modernized elevators, where specific sizes are often required - for example, 130 mm, 175 mm, or 450 mm. Industrial slitting excludes the appearance of irregularities characteristic of manual cutting - this ensures perfect centering of the web on the drum immediately after installation, guaranteeing stable belt tracking and preservation of edge integrity throughout the entire service life.

A separate advantage for our partners is access to the qualified expertise of the plant's design department. In cases where you are unsure about the parameters of standard equipment or plan a modernization, our engineers are ready to recalculate loads based on the shaft height and planned capacity. This approach helps to mitigate risks associated with changing operating conditions, as often after installing more voluminous polymer buckets or increasing speed, old passport calculations lose relevance. Under such conditions, a standard belt may prove either too weak for the new load or excessively heavy. Upon request, we will help determine the optimal number of BKNL fabric plies and cover type to ensure a balance between safety margin and drive energy efficiency. However, our competencies are not limited to the belt alone - we are ready to offer comprehensive solutions for traction unit renovation, for example, calculating the efficiency of switching to polymer buckets or implementing "bottomless" bucket technology. Such an engineering approach allows for significantly increasing elevator productivity and reducing grain breakage, effectively obtaining new equipment characteristics without expensive capital reconstruction.

For those aiming to simplify installation work as much as possible, we offer a full pre-sale preparation service for the BKNL-65 belt. The assembly shop can perform automated product perforation - punching holes for buckets with precise adherence to the specified pitch, saving the installation team days of painstaking manual labor. Also available is the option of full order completion with accompanying materials - from specialized elevator bolts and nuts to reinforced splice fasteners, selected specifically for the thickness of the chosen belt. Entrust the technical side of the issue to the specialists at Zavod Moroza. This will ensure a reliable operational resource for your equipment, allowing you to focus on the main thing during the peak season - effective reception and processing of the harvest with the stable, predicted operation of all elevator units.