Blogs

CEMA idlers are bought and sold on a two-word label, and this page deals with that label alone. It explains what a class actually governs: the load a roller is built to carry, the service life it must reach, and how bearings, shaft, shell and seal are assembled to hit that target. The four classes, B through C, D and E, are opened up as design envelopes rather than bearing sizes, then the American lettered convention is set against DIN and ISO practice to show why the two do not convert. A site condition, tonnage, belt width and speed, dust, moisture and intermittent running, is mapped onto a class, and it closes on writing the specification and accepting what arrives.

Most wear advice in English is written about rubber, so this page stays with the plastic belt body instead. It separates the two ways a belt resists abrasion, a polymer body that keeps its own surface against a rubber cover that is meant to be sacrificed, and shows why that split decides how each one fails. The thermoplastics used in belting are compared: acetal and polyamide, polyethylene and UHMWPE, plus the coated PVC and polyurethane builds. Sliding, impact and gouging are treated as three different problems. It closes on turning load, speed, particle sharpness, heat and cleaning agents into a written specification, and on the conditions that send you back to a rubber-covered belt.

Written for machine-tool swarf, not bulk materials. It treats a chip conveyor as a different duty entirely - intermittent slugs, birds-nest bundles, hot and fluid-soaked loads - and explains why a mine-style specification fails on a CNC lathe. It works through the three main belt styles: hinge-type steel belts for mixed and curled swarf, scraper conveyors for fine and powdery chips, and magnetic conveyors for cast iron and ferrous grinding fines. Selection by swarf form and workpiece material follows, then the effect of cutting fluid, pH and temperature on belts, hinges and chains. The last sections cover jam and pull-through prevention, and what to write in a purchase specification.

A decision guide. It sets out when a jointless endless conveyor belt beats a spliced one, clearing up the words endless, jointless and spliced, including belts sold as endless that still carry one seam. It explains why the seam is the weak point: fatigue at the splice edges, tracking drift and hygiene traps. Then it marks where a jointless loop earns its price: washdown lines, thin belts, high-speed sorting and long-life duties. Length limits, lead times, and the choice between moulded, field-vulcanised and mechanically fastened loops follow. It closes on specifying length tolerance and edges, running in a jointless loop, and when an endless belt is the wrong answer.

This piece covers only the support structure of an agricultural conveyor: the idlers, frames, stringers, legs and brackets that hold a grain line in place and in line, not the belt. It opens with the four load cases that support must survive - gravity, chute impact, misalignment as the belt drifts, and slow moisture. It works through idler selection for grain duty: troughing, impact, return and self-aligning rollers and their spacing on 800 to 1,400 mm belts. Frame and stringer rigidity, trough angle and roll diameter, and how legs and bents stand the line on real ground follow. It closes on labyrinth sealing in grain dust, tracking on long gallery runs, and coatings that survive washdown.

A double belt sandwich conveyor carries material between two belts pressed together, so the load rides an incline an open surface could never hold. This first guide to the method explains how clamping actually holds the load, then puts numbers on it: the line pressure that sets the whole design. It looks at the cargo that suits a clamped pocket, the fine, dry and free-flowing materials that dominate the installed base, and the steep incline envelope of angle, speed and capacity. A comparison with chevron, cleated and sidewall belts marks the boundary where each is the better answer, and the article closes with the cases where a double belt is simply the wrong choice.

Selecting a belt for hard-rock service starts with the ore, not the brochure. This hub works through the four measurements that decide everything: the largest lump at the loading point, the quartz content that sets abrasiveness, the surface moisture or clay fraction, and the free-fall height from the chute. Each is tied to a belt family, from high-tension carcass builds for long overland hauls to multi-ply fabric ones for shorter spans. The load then runs through impact and abrasion at the loading zone, the pulley geometry that quietly shortens belt life, and the idlers and rollers that cost least but decide most. Cleaning, tracking and acceptance checks close the guide.

A wrapped V-belt looks much the same today as it did a decade ago, which is why buyers still award these orders on unit price alone. This guide reads the rubber transmission belt market from the supply side. It explains what a grade name actually promises, how power rating and service factor leave or remove margin, and why one supplier quotes far less than another for the same section. It shows where the days in an eight-week lead time really go, breaks a quotation into its cost blocks, and sets out how batch size and moulds change the arithmetic of a minimum order. Storage, substitution and field practice are covered too.

Most cleated belt complaints arrive as one sentence: it is slipping, or the ribs are coming off, or we are shovelling material out of the boot. This troubleshooting guide splits those complaints into symptoms that can be measured, then traces each one back to its causes. Slippage on an incline has four causes that look identical at the head pulley, and the fix for one quietly worsens another. Profile damage is separated into peeled tips, torn shoulders and bond-line failure under the rib, with a field test that tells a manufacturing bond fault from a geometry fault. Carry-back, tracking asymmetry, unsquared splices, and the rollers and skirts that punish cleated belts, are each covered.

Roller selection on a mining site starts with what will kill the roller first. This guide matches roller grade to the ore, the dust and the water rather than to a price list. It explains how to read ore abrasiveness and particle size before choosing a shell, how sealing classes are chosen for high-fines circuits, and how washdown chemistry and coastal sites change the shaft and end-cap specification. It then ties shell wall, bearing and shaft to load and speed, sets out spacing, trough angle and transition zones in abrasive duty, and lists the deliverables that matter after the roller itself: dimensional records, bearing lot declarations, seal drawings and torque data.

A warehouse conveyor belt is usually bought in a hurry, and the hurry is where the trouble starts. This guide splits the duty into four cases: high-rate sortation and induction, packing and accumulation benches, chilled and frozen transfers, and light cleaning duties. It explains how to specify friction, tracking and static dissipation for sorters, why a general-purpose PVC cover cracks at the load point in a cold store, and how splice type and tension take-up decide belt life on very short centres. Later sections cover hygienic design, construction and joints for warehouse layouts, the rollers and pulleys around the belt, and the belt register a whole building should keep.

Ordering one custom belt is easy; the tenth copy of it, three years later, is where procurement failures surface. This audit works through twelve checks that make a bespoke order repeatable. It opens with drawing release and interface data, then covers tooling, mould and splice control, and the four dimensions that decide tracking: finished length, width, gauge and camber. Later sections take in sampling and first-article approval, compound and carcass traceability, batch consistency across repeat orders, and the marking and packing rules that keep a mixed shipment traceable. Each check is tied to a measurement you can take at goods-in.