Conveyor belts are made from layered combinations of rubber, fabric, plastic, or metal, with the exact materials depending on what the belt needs to carry and the environment it operates in. A typical industrial belt has two main components: an outer cover material that contacts the cargo, and an internal reinforcement layer (called the carcass) that provides strength and shape. Some belts skip this layered design entirely and are built from interlocking plastic modules or woven metal wire instead.
The Carcass: Internal Reinforcement
The carcass is the structural backbone of a conveyor belt. It carries the tension load, prevents stretching, and gives the belt its shape. The most common carcass materials are polyester, nylon, cotton, and PVC, woven into plies (layers) that are then bonded together. Many belts use a combination, with polyester running lengthwise for low stretch and nylon running crosswise for impact absorption.
For extreme loads, like those in mining or long-distance overland conveyors, the carcass may use steel cables embedded in rubber instead of fabric. Steel cord belts handle enormous tension over distances that can stretch several kilometers. Aramid fibers offer a lighter alternative with very high tensile strength, though they cost more and are used in specialized applications.
Rubber Cover Compounds
The outer covers of most heavy-duty conveyor belts are made from synthetic rubber compounds, each engineered for a specific threat. The most widespread is SBR (styrene-butadiene rubber), a general-purpose synthetic that resists abrasion well and handles moderate heat. Standard SBR covers work for most bulk material handling, from gravel to grain.
When temperatures climb, the rubber chemistry changes. SBR compounds can handle continuous surface temperatures up to about 120°C. EPDM compounds push that limit to around 160°C for continuous operation and can tolerate brief spikes up to 230°C from hot lumpy materials like freshly processed clinker or sinter. For the most extreme heat environments, EPM compounds can withstand continuous surface temperatures of 200°C and peak material temperatures reaching 400°C. These heat-resistant belts also offer better resistance to ozone and aging.
Natural rubber still appears in applications where high elasticity, tear resistance, and excellent grip matter more than chemical resistance. It wears well under abrasion but degrades faster when exposed to oils, solvents, or UV light.
PVC and Polyurethane Belts
Lighter-duty conveyors, especially in warehouses, packaging lines, and airports, often use PVC or polyurethane (PU) covers instead of rubber. PVC is inexpensive, flame-retardant, and works well for general material handling at moderate temperatures (roughly -20°C to 80°C). Its main weakness is oil: PVC degrades when exposed to greasy or oily materials.
Polyurethane outperforms PVC in demanding environments. PU belts handle oily and greasy conditions without breaking down, resist abrasion better, and tolerate a wider temperature range. They also meet food-safety standards more easily, making them the default choice for meat, dairy, and bakery lines where hygiene requirements are strict. The tradeoff is cost. PU belts are more expensive upfront, though they often last longer in the right application.
Food Grade Materials
Conveyor belts that directly contact food must meet FDA or equivalent safety standards, and several materials qualify. Thermoplastic polyurethane (TPU) is the most common, operating between about -20°C and 100°C. PVC, polyethylene, and thermoplastic elastomer (TPE) belts also come in food-safe versions, each suited to different temperature ranges.
Silicone belts handle a broader range, from -30°C up to 180°C, making them a good fit for baking lines and other heated food processes. For the highest temperatures, PTFE (Teflon) belts work continuously from -70°C all the way to 260°C, with some coated fiberglass versions tolerating peaks near 340°C. PTFE’s nonstick surface also means food releases easily without oils or sprays, which is why it dominates in commercial baking and confectionery production.
Modular Plastic Belts
Not all conveyor belts are continuous loops of layered material. Modular belts are assembled from interlocking plastic links, similar to chainmail, and they can be repaired by swapping out damaged sections rather than replacing the entire belt. The four main plastics used are polypropylene, acetal, polyethylene, and nylon.
Polypropylene is lightweight and chemical-resistant, making it popular in food processing and wet environments. It floats in water. Acetal is denser and stiffer, with better wear resistance and tighter dimensional tolerances, making it the choice for precision conveying. It sinks in water, which is actually the simplest way to tell the two apart. Polyethylene is used primarily in cold storage and freezer applications where other plastics become brittle. Nylon modules offer the highest mechanical strength and work in high-load or high-temperature situations.
Metal Belts
When no polymer can survive the conditions, metal belts take over. Stainless steel mesh belts are standard in industrial ovens, furnaces, and high-temperature drying operations where temperatures exceed what even PTFE can handle. They also appear in food processing for tasks like cooling, freezing, and washing, since stainless steel cleans and sanitizes easily.
Metal belts come in several configurations: woven wire mesh, flat wire (honeycomb patterns), and solid stainless steel strips. Chain-driven metal belts handle heavy loads in automotive manufacturing, glass production, and metalworking. Their main drawbacks are weight, noise, and cost, but nothing else matches their combination of heat tolerance, strength, and hygiene.
How Abrasion Resistance Is Measured
For industries like mining and quarrying, the rubber cover’s ability to resist wear is often the single most important factor in belt selection. Abrasion resistance is measured through standardized testing, with European DIN standards being particularly well-established and widely recognized in the industry. The test itself involves grinding a rubber sample against an abrasive surface and measuring how much volume is lost. That result is then compared against minimum performance thresholds set by international standards. A belt being “tested” to a standard means nothing on its own. What matters is whether the rubber actually passed, and by how much it exceeded the minimum requirement. Higher-grade covers cost more but can double or triple belt life in abrasive environments, so the economics often favor spending more upfront.