Structural Principle and Engineering Application Analysis of Patterned Conveyor Belt and Sidewall Conveyor Belt in Belt Conveyors

        In the bulk material conveying industrial system, belt conveyors are widely used in mining, ports, chemical industry, grain, building materials and other industries due to their advantages of continuity, high efficiency and low energy consumption. Ordinary flat conveyor belts are only suitable for horizontal and small‑angle (≤15°) conveying conditions, and have obvious shortcomings in large‑inclination climbing, easily sliding materials, and anti‑spillage conveying scenarios. Patterned conveyor belts and sidewall conveyor belts, as two types of specially modified belts, solve the industry pain points of material slippage, large‑angle conveying, and material spillage through structural optimization, and are core supporting components for differentiated conveying working conditions. Based on mechanical design and material conveying mechanics principles, this paper systematically and rigorously analyzes the two types of belts from aspects such as structural characteristics, classification parameters, working mechanisms, applicable scenarios, process advantages and disadvantages, and selection criteria, providing technical references for engineering selection and equipment operation and maintenance.

1.Patterned conveyor belt: anti‑slip and friction‑increasing special conveying component

        The patterned conveyor belt is a modified anti‑slip flat belt. Its core design logic is to increase the contact friction between the belt surface and the material through integrally molded raised pattern structures on the belt surface, suppressing relative sliding of the material, thereby improving the climbing conveying capacity of the belt conveyor. There is no side containment structure throughout, retaining the open conveying characteristics of a flat belt.

    1.1  Core structure and molding process

        The patterned conveyor belt as a whole is integrally vulcanized from a base belt and a raised pattern layer. The base belt adopts the traditional conveyor belt skeleton structure, including tensile layers such as canvas, polyester (EP), and steel cord, ensuring overall tensile strength and structural stability, and is compatible with various standard belt conveyor frames. The raised pattern layer is made of wear‑resistant rubber material, which is integrated with the base belt through high‑temperature and high‑pressure vulcanization, with no risk of delamination or detachment. The surface is wear‑resistant, anti‑aging, and impact‑resistant, suitable for harsh working conditions such as mines and open‑air plants. Compared with modified belts with patterns glued on afterwards, the integral vulcanized structure has the core advantages of longer service life, higher operational stability, and better resistance to repeated bending.

    1.2 Main pattern types and performance parameters

        According to differences in working inclination, material particle size, and material moisture, the industry has formed a standardized pattern system. The core commonly used types and their matching parameters are as follows:

Herringbone (V‑type) pattern: The most widely used general‑purpose pattern in the industry, divided into open and closed structures. According to industrial standards, it has three fixed pattern height grades for different inclination conditions. The low pattern height is 3–5 mm, suitable for 15°–25° small‑angle anti‑slip conveying; the medium pattern height is 6–10 mm, suitable for 25°–35° medium‑angle conveying; the high pattern height is 11–18 mm, with an extreme adaptation for 35°–45° large‑angle conveying. The raised pattern can effectively block the material sliding tendency. The open type is suitable for dry granular and lump materials, while the closed type is suitable for slightly moist and easily crushed materials. It is widely used for conveying bulk materials such as ore, gravel, and coal.
Mold and size restrictions: 3–18 mm is the conventional mold cavity height for herringbone patterns, which is the common vulcanization mold for most manufacturers. Above 18 mm (20/25/28 mm) are deep‑pattern dedicated custom molds, which are not universal, have low vulcanization yield, require a thicker base rubber layer, and are not regular supply specifications.

Constraint relationship with the number of fabric plies: There is no mandatory one‑to‑one national standard mapping between pattern height and ply count, but there is a clear minimum matching requirement based on the process—during vulcanization molding, the flow pressure of the rubber compound acts on the base belt skeleton:

- ≤5 mm low herringbone pattern: minimum 3 fabric plies (CC/NN/EP) allowed;

- 6–10 mm medium herringbone pattern: minimum recommended 4 fabric plies;

- 11–18 mm high herringbone pattern: must have ≥5 fabric plies for the base belt; using a 3‑ply thin base belt is prohibited, otherwise the rubber squeeze during vulcanization can cause canvas wrinkling, skeleton shifting, insufficient rubber at the pattern root, and bending fatigue cracking;

- 18 mm custom deep pattern: requires dedicated mold + ≥5–6 ply thickened base belt + pre‑vulcanization process, not applicable to ordinary flat‑bed vulcanization.

        At the same time, the pattern spacing must match the belt width standard. The conventional spacing is 20–40 mm; narrow spacing tends to accumulate material, while wide spacing results in insufficient anti‑slip uniformity.

Straight‑strip, U‑type, and L‑type patterns: These are lightweight anti‑slip structures with a standardized pattern height of 2–5 mm. The structure is low and flat with low running resistance, mainly used for small‑angle anti‑slip and preventing slight material sliding. They are suitable for grain, chemical granules, light powder and similar materials, with a maximum conveying angle ≤25°. Their advantages are that they do not easily accumulate material and are easy to clean and maintain.
Mold and size restrictions: The pattern height for this type must not exceed 5 mm; the general‑purpose mold has a maximum of 5 mm. Exceeding this increases running friction resistance and equipment power consumption, and the pattern is prone to squeeze deformation during belt turnaround. The raised pattern thickness must not be less than 1.5 mm; insufficient thickness leads to rapid wear and fracture, significantly shortening service life.

Constraint relationship with fabric ply count: The 2–5 mm shallow pattern exerts little pressure on the base belt and can be adapted to 3‑ply light fabric cores, but is only suitable for conventional light belt conveyors with belt widths of 500–1400 mm. For heavy‑load, wide‑width, and high‑tension conditions, ≥4 plies are recommended; 2‑ply base belts are not recommended.

Diamond and dot patterns: These are micro‑anti‑slip structures, belonging to shallow surface patterns with a standardized height of only 1.5–3 mm. The surface has uniform concavities and high flatness, mainly used to solve material slipping and belt misalignment on flat belts, not for large‑angle conveying. They are mostly used in light assembly lines, small‑scale bulk material transfer, and packaged material conveying.

Mold and size restrictions: All are shallow‑cavity general‑purpose molds, with pattern height not exceeding 3 mm maximum. Exceeding this will destroy belt flatness, causing small items to jolt or shift. The diameter of dot patterns and the side length of diamond patterns should be controlled within 5–10 mm; too large makes anti‑slip points sparse, too small causes rapid wear and failure. This type has no large‑angle conveying capability and is only suitable for horizontal or slight‑inclination (≤15°) conveying.

Constraint relationship with fabric ply count: The 1.5–3 mm shallow pattern hardly changes the total thickness of the top cover rubber. It is generally compatible with 2–3 ply light‑duty base belts; PVC/PU light conveyor belts may even use 1–2 plies. There is no mandatory minimum ply count; selection should prioritize tensile strength requirements.

Supplementary: Core logic summary of pattern height and fabric ply count
        There is no one‑to‑one binding relationship between the two; the ply count is primarily determined by belt width, tension, load, and roller diameter according to GB/T 7984 and HG/T 3714 strength selection. However, the pattern height imposes a process constraint on the minimum base belt thickness / minimum ply count:

•  The essential constraint comes from the integral vulcanization molding process: the pattern is an upward raised rubber layer, and the pattern root must retain sufficient base rubber thickness before transitioning to the fabric layers. If the base belt has too few plies and insufficient total thickness, the rubber squeeze flow during high‑pressure vulcanization will push the fabric layers, causing displacement, wrinkling, adhesion failure, and cracking at the pattern root along the fabric layers after repeated bending during operation.
•  More plies and thicker base belt do not necessarily mean high patterns must be used; but high patterns (>10 mm) cannot be matched with thin, low‑ply base belts. This is the core boundary for manufacturers to use different molds and process controls.
•  Steel cord patterned belts are not subject to the above fabric‑ply rules; only the cover rubber thickness needs to match the pattern height.

When the conveying inclination ≤40°, the material is dry granules/lumps, there is no strict anti‑spillage requirement, and low operation and maintenance cost is pursued, patterned belts are preferred. 

        Strictly match the pattern specification to the inclination: for ≤15° slight inclination, use 1.5–3 mm diamond/dot patterns (≥2 plies); for 15°–25° small inclination, use 2–5 mm straight‑strip, U‑type patterns and 3–5 mm low herringbone patterns (≥3 plies); for 25°–35° medium inclination, use 6–10 mm medium herringbone patterns (≥4 plies); for 35°–45° large inclination, use 11–18 mm high herringbone patterns (≥5 plies). Deep patterns >18 mm belong to dedicated custom molds and are strictly prohibited from being selected on 3/4‑ply conventional base belts.

    1.3 Core advantages and applicable limitations

        In terms of advantages, patterned belts have a simple structure, low cost, and strong versatility. The belt has good overall flexibility and excellent bending performance, can adapt to conventional roller diameters, and has extremely low operation and maintenance costs. The surface pattern has no dead corners, with no material accumulation or dirt trapping during conveying, low material residue, and suitability for continuous production lines. At the same time, the integral vulcanized structure is wear‑resistant and durable, capable of long‑term resistance to material impact and friction loss.

        In terms of limitations, this type of conveyor belt has no side guard structure and can only rely on friction for anti-slip protection; it cannot prevent lateral spillage of materials. Therefore, it is strictly prohibited for use in high-inclination applications or for conveying fine powders or light, easily airborne materials. Even under steep inclination conditions, a small amount of material sliding back or backflow may still occur, making vertical or near-vertical conveying unachievable.

2.Sidewall conveyor belt: large‑angle anti‑spillage special conveying component

        The sidewall conveyor belt, full name wave‑shaped sidewall baffle conveyor belt, is a three‑dimensional closed conveying structure. It is specially designed to solve the pain points of large‑angle, vertical conveying, and fine powder anti‑spillage. Its core design is to add flexible wave‑shaped sidewalls on both sides of the base belt, with transverse baffles installed at intervals in the middle, forming independent material holding compartments, completely breaking through the inclination limit of flat belts. It is the core equipment for high‑angle, no‑spillage conveying conditions.

2.1 Core structure and molding process

        The sidewall conveyor belt consists of three core components: the base belt, wave‑shaped sidewalls, and transverse baffles, with strong structural synergy. The base belt is made of high‑strength wear‑resistant rubber, PVC, PU, etc., and can be adapted with food‑grade, oil‑resistant, corrosion‑resistant, high‑temperature‑resistant and other special properties according to industry needs. The two side wave‑shaped sidewalls are flexible rubber structures in corrugated form, capable of bending with the belt and deforming around rollers without cracking or detachment. The transverse baffles are vertically fixed on the base belt, dividing the belt into multiple independent compartments, completely preventing overall material sliding.
        High‑end industrial sidewall belts adopt high‑temperature hot vulcanization or high‑frequency welding processes, achieving molecular‑level fusion among sidewalls, baffles and the base belt, with strong integral structure, high resistance to stretching and bending, and not prone to detachment, deformation or cracking. Food‑grade PU sidewall belts use seamless welding technology, with no splicing gaps, no material trapping, easy cleaning, suitable for food and pharmaceutical clean working conditions.

2.2 Core classification and performance parameters

• By structural form: divided into no‑baffle sidewall belts and with‑baffle sidewall belts. No‑baffle sidewall belts rely only on sidewalls for protection, suitable for small‑angle, large‑particle, non‑easily‑sliding materials, mainly preventing lateral spillage. With‑baffle sidewall belts are the standard industrial type, dividing compartments by baffles, enabling 0°‑90° full‑angle conveying, including vertical conveying.
• By material: rubber sidewall belts are wear‑resistant, impact‑resistant, and have strong load capacity, suitable for heavy‑load harsh conditions such as mining, building materials, and heavy industry; PVC/PU sidewall belts are lightweight, clean, and corrosion‑resistant, suitable for food, chemical, light industry and other fine conveying scenarios.
• Customized parameters: sidewall height, baffle height, and baffle spacing can all be customized according to material particle size, conveying capacity, and inclination angle, accurately matching the full range of materials from light powder to heavy lump materials.

2.3 Core advantages and applicable limitations

        On the advantage side, firstly, the conveying inclination can be very large, even achieving vertical lifting, greatly reducing equipment footprint and suitable for production lines with limited space. Secondly, the anti‑spillage and dust‑suppression effects are excellent; the closed compartment structure completely solves spillage and dust issues during conveying of fine powder and light materials, reducing material loss and environmental pressure. Thirdly, operational stability is strong; materials remain relatively static within independent compartments, with low breakage rate, ensuring material integrity.
        On the limitation side, the structure is complex and manufacturing cost is much higher than that of patterned belts. The bending parts of sidewalls and baffles tend to accumulate and stick material, making cleaning and maintenance difficult. It is not suitable for oversized lumpy or sharp hard materials, as they can easily tear the sidewalls and deform the baffles. At the same time, the belt flexibility is restricted, requiring dedicated large‑diameter rollers, with higher equipment compatibility requirements.

3. Core technical differences and working condition comparison between the two types

        To accurately distinguish the engineering application boundaries of the two types, a standardized comparison is made from dimensions such as core performance, working condition adaptability, cost and maintenance. The core differences are as follows:

• Different anti‑slip principles: Patterned belts rely on surface raised structures to increase friction resistance, passively suppressing material sliding; sidewall belts rely on three‑dimensional closed compartment structures to physically fix materials, actively preventing sliding and spillage.
• Different maximum conveying inclinations: Patterned belts have a limit of 30°‑45°, unable to achieve vertical conveying; sidewall belts can achieve 0°‑90° full‑angle conveying, including vertical lifting.
• Different material adaptability: Patterned belts are suitable for dry lumpy, granular, and large‑particle materials, but not fine powder or light easily‑sliding materials; sidewall belts are suitable for fine powder, granular, light materials, moist materials, and can achieve full‑category bulk conveying, but are not suitable for oversized sharp hard materials.
• Different operation and maintenance costs: Patterned belts have a simple structure, no vulnerable accessory parts, extremely low failure rate, easy cleaning, and low maintenance cost; sidewall belts have many accessory parts, are prone to wear and material accumulation at bending points, require regular maintenance, and have higher replacement costs.
• Different site adaptability: Patterned belts are suitable for conventional open spaces and small‑to‑medium inclination climbing production lines; sidewall belts are suitable for space‑limited sites requiring vertical lifting and dust/spillage prevention.

4.Core selection principles for engineering

        In engineering applications, selection must be accurately based on material characteristics, conveying inclination, site conditions, capacity requirements, and operation/maintenance costs, to avoid insufficient adaptability or resource waste. The core selection principles are as follows:

1. When conveying inclination ≤40°, material is dry granules/lumps, no strict anti‑spillage requirement, and low O&M cost is pursued, patterned belts are preferred. Strictly match the pattern specification to inclination: ≤15° slight inclination → 1.5–3 mm diamond/dot patterns; 15°–25° small inclination → 2–5 mm straight‑strip, U‑type patterns and 3–5 mm low herringbone; 25°–35° medium inclination → 6–10 mm medium herringbone; 35°–45° large inclination → 11–18 mm high herringbone. Over‑height and over‑specification selection is strictly prohibited.

2. When conveying inclination >45°, vertical lifting is required, material is fine powder/light dust‑prone, there is anti‑spillage requirement, and site space is limited, sidewall baffle belts must be used. Choose rubber or PU material according to the industry working condition, and custom‑match sidewall and baffle parameters.

3. For heavy‑load, high‑frequency, harsh working conditions (mining, gravel, building materials), preference is given to integrally vulcanized thickened patterned belts and high‑strength rubber sidewall belts. For clean, fine, food/pharmaceutical working conditions, preference is given to seamless welded PU sidewall belts.

4. Oversized lumpy and sharp hard materials are prohibited from using sidewall belts to avoid structural damage. High‑wear large‑pattern belts can be selected instead, with reasonable inclination design to ensure conveying stability.

5. Conclusion

        Patterned conveyor belts and sidewall conveyor belts are two types of complementary special conveying components; there is no superiority between them, only differences in working condition adaptability. Patterned belts, with their core advantages of anti‑slip, simplicity, low cost, and easy maintenance, solve the material slipping problem at small‑to‑medium inclinations. Sidewall belts, with their core characteristics of large inclination, anti‑spillage, full‑condition adaptability, and space saving, solve the problems of extreme angles and fine material conveying. In industrial production selection, accurately grasping the structural principles and adaptation boundaries of the two types can effectively improve belt conveyor operational stability, reduce material loss and O&M costs, and achieve efficient, energy‑saving, and safe operation of the conveying system.