Cleated Conveyor Belt Guide for Reliable 2025 Selection

5. Key Factors Affecting the Lifespan of Cleated Conveyor Belts: Manufacturing Process

For cleated conveyor belts, the quality of the base belt is crucial. However, under the same base belt conditions, lifespan differences often stem from the design and manufacturing process of the cleats themselves: how they are made, how they are fixed, the rationality of the root transition, and their compatibility with different material systems. This chapter focuses solely on the manufacturing process of cleats and crossbars.

5.1 Key Manufacturing Points for Rubber Cleats

Rubber cleats are primarily used in medium-to-heavy load applications, with lifting angles typically ranging from 18° to 40°. The key here is not how the rubber is molded into a belt, but rather how the cleats are integrated with the rubber base belt.

(1) Small Height Cleats (≤ Approximately 6 mm)

These small protrusions or shallow cleats are usually integrally molded directly from the rubber base belt during vulcanization. They are more akin to anti-slip patterns, used for small inclination angles, anti-slip, and guidance, rather than as the main support structure bearing heavy loads.

There are only two key control points:

• • • Mold precision and rubber flow to ensure consistent geometric dimensions;

• • • No sharp corners should appear in the transition area with the base strip to avoid stress concentration and cracking.

(2) Medium-High Rubber Cleats

Once the cleats reach the actual “supporting material” zone, they are usually not completed in one step during base strip vulcanization. Instead,

• • • Cleaats are vulcanized separately;

• • • Base strip is vulcanized separately;

• • • Cleaats are bonded to the base strip using a special adhesive and hot-press curing.

The key process points here are:

• • • Sufficient effective bonding area at the bottom of the cleats;

• • • A smooth transition adhesive layer at the root, rather than a 90° right angle;

• • • One or more reinforcing fabric layers are added to the bottom of the cleats depending on the working conditions to disperse the peeling force;

• • • The bonding interface must be free of bubbles, impurities, and oil stains.

In short, the process goal of rubber cleats is: under conditions of repeated material impact and periodic loading, to ensure that the failure point of the cleats occurs as late as possible after the normal lifespan of the base belt, rather than being ripped off from the root after only a few months of operation.

5.2 Key Processing Points of Cleats in Corrugated Sidewall Conveyor Belt

This article focuses only on the parts directly related to cleats for corrugated sidewall conveyor belts.

(1) Skirt and Base Belt

The skirt is generally made of rubber material. Through surface treatment, adhesive bonding, and vulcanization pressure, it forms a high-strength bond with the rubber base belt, not simply by gluing it on. This relates to lateral sealing capability and overall structural stability, but it is still only an “environmentally supportive structure.”

(2) Connection Method of Cleats and Skirt

The cleats here are essentially also a type of cleat, but they work in conjunction with the skirt to form a “grid” or “bucket-like” support structure. There are three key points:

• • • The diaphragms cannot be directly “welded” to the skirt through vulcanization. In actual engineering, mechanical connections are commonly used: bolts, rivets, plate clips, etc.

• • • During connection, pressure plates, gaskets, and other structures are used to firmly clamp the diaphragms to the skirt and/or the skirt reinforcement layer;

• • • The diaphragms are not necessarily vertical in design; sometimes they are tilted forward or backward to better adapt to the material flow state, inclination angle, and loading method.

(3) Process details requiring special attention

• • • The bolt hole positions must be symmetrical, and the bolt preload must be kept stable to avoid loosening after operation;

• • • The rubber thickness in the contact area between the diaphragm and the skirt should not be too thin to avoid local “cutting” by the bolts;

• • • The spacing and angle of the diaphragms need to match the inclination angle and material particle size; otherwise, material accumulation, jamming, or premature tearing may occur.

In other words, the quality of the crossbar construction on a corrugated sidewall conveyor belt determines whether the system can stably support materials at an inclination angle of 40-70° over a long period.

5.3 Welding Process of PVC/PU Cleats

PVC and PU cleats do not use a vulcanization system; they are thermoplastic materials. The most common cleat fixing methods are high-frequency welding or hot air welding.

(1) Basic Logic of High-Frequency Welding/Hot Air Welding

• • • The base belt and cleats are made of the same PVC or PU material;

• • • The contact area is heated by a high-frequency electric field or hot air, causing its surface to “melt”;

• • • Cooling is performed under a certain pressure, allowing the two to re-bond into one unit.

Advantages:

• • • Smooth seams, easy to clean, suitable for food, packaging, and other applications;

• • • No extra foreign matter layer between materials, good overall flexibility, suitable for small roller diameters;

• • • Mature process, suitable for mass standardized production.

(2) Common Failure Modes and Process Correlation

• • • Insufficient welding temperature → cleats gradually lift and curl at the edges during operation;

• • • Excessive temperature → Material becomes brittle, yellows, and hardens on the surface;

• • • Uneven pressure → One side of the cleats is well welded, while the other side has a weak weld, leading to skewed stress.

In PVC/PU systems, an empirical judgment is:

If the edges of the cleats start to turn white and lift under normal load, it is mostly due to unstable welding process or process window control, rather than a problem with the material itself.

5.4 Direct Impact of Cleats Process on the Lifespan of Cleated Conveyor Belts

To make the key points clearer, the impact of the cleats process on lifespan can be understood as three inspection lines:

(1) Whether the connection method matches the material system

• • • Rubber → vulcanization molding + vulcanization bonding;

• • • PVC/PU → high-frequency welding or hot air welding;

• • • Corrugated sidewall conveyor belt partitions → mainly mechanical connection.

If the material system and connection method are mismatched, the lifespan is often uncontrollable.

(2) Does the root design avoid stress concentration?

• • • Does the rubber cleats have rounded corners and a reinforcing layer at the root?

• • • Are the welds on the PVC/PU cleats wide enough?

• • • Is the adhesive layer thickness at the crossbeam connection reasonable?

A poor root design is most typically a case of “breaking from the root.”

(3) Can the process stability cover real-world working conditions?

• • • Load, impact, tilt angle, temperature, and speed all fluctuate;

• • • Cleats need to maintain a “firm fit and stable shape” over a long period amidst these fluctuations.

As long as the cleats process is conservative, the service life of the entire cleated conveyor belt will be closer to the upper limit that the base belt can withstand, rather than being prematurely worn down by the cleats.