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Agricultural Conveyor Belts: Grain, Fertiliser and Silage Duty

2026-10-09

A conveyor that has carried wheat for four seasons without a splice failure can start peeling top cover within a month of being switched to blended fertiliser. The frame is unchanged, the gearbox is unchanged, and the pulleys still run true. What changed is the material touching the rubber, and with it the entire set of conditions the cover has to survive. Buyers still send us enquiries for "a belt for the agricultural line" as though farm duty were one specification, and that single assumption is where most of the wasted spend sits. Grain, granulated fertiliser, wrapped silage, oily pelleted feed and fragile seed each attack a belt in a different way, and one of them will normally force a change of compound, cover grade, or even carcass.

This page is deliberately not a sector overview, because that ground is already covered on our agricultural conveyor belt systems hub. What follows is the working question that keeps arriving from feed mills, inland grain ports and livestock farms: when one machine has to run more than one material, what has to change before the new belt is ordered? We answer it with cover grades, standard numbers and the field consequences of getting it wrong.

Tell us the materials your line runs and we will match the cover grade to each one

01A Belt Change Starts with the Material, Not the Machine

Manufacturers and farms do not replace belts because the calendar says so. They replace them because the cover has lost thickness, because a splice has opened, or because a quality team has rejected a batch that picked up residue from a cracked surface. All three of those events trace back to the material stream far more often than to a worn pulley or a tired drive. A belt selected for dry cereal on a long horizontal run is, in most cases, the wrong belt for damp silage on the same frame, and the mismatch shows up as cover loss rather than as a dramatic break.

So the first habit worth building is to treat every material as a hazard set, not as a category.

The hazard set has four parts. There is the mechanical attack, which is abrasion and impact from the particle itself. There is the chemical attack, which comes from salts, acids, oils and moisture that sit against the cover for hours at a time. There is the electrical question, which matters whenever a fine combustible dust is present. And there is the hygiene question, which decides whether the surface can be cleaned between grades of seed or feed. On one mixed feed mill I surveyed, a 1,000 mm EP belt on the fertiliser run lost roughly 2 mm of top cover in seven months, while the same specification on the adjacent grain line was still inside tolerance after two years. Same frame geometry, same trough angle, same 1.6 m/s.

A general-purpose rubber conveyor belt is an excellent starting point for cereal, and a poor one for fertiliser, and the table below explains why the difference is not marketing but chemistry.

Material stream	What attacks the belt	Cover property that decides service life	Reference point to quote	Typical failure when the wrong belt is fitted
Dry cereal such as wheat, maize and soybean	Free-flowing abrasive grain plus fine dust that migrates into open splices and pulley lagging	High-abrasion cover with controlled hardness and a tight, well-cured splice	DIN 22102 grade W, abrasion loss not more than 90 mm³ by ISO 4649	Cover polishing followed by splice edge lift, usually between month 12 and month 18
Granulated NPK and urea fertiliser	Nitrate and phosphate salts held against the cover by residual moisture and a light oil coating	Oil and chemical resistant compound, anti-static where dust clouds can form	Volume swell by ISO 1817, surface resistance not more than 3×10⁸ ohm by ISO 284	Cover swelling, then surface cracking, plus an ignition risk in any enclosed gallery
Wrapped silage and cut forage	Organic acids and effluent that keep the cover wet for long shifts and creep into cut edges	Acid and moisture tolerant cover with a protected, sealed edge	Acid exposure checked to ISO 1817, edge construction agreed in writing	Cover delamination and edge fraying inside a single silage season
Pelleted feed carrying added fats	Vegetable and animal oils at 8 to 12 percent inclusion, plus warm pellets that soften the surface	Nitrile-based oil resistant cover that resists softening at working temperature	Volume swell target not more than 10 percent after 72 h at 23 °C	Cover softens and grains off along the return run where it passes the scrapers
Seed and other delicate product	Almost no abrasion, but contamination risk and static cling on fine, dry fractions	Smooth clean-release surface, food-contact formulation where the process demands it	Surface finish and cleanability agreed jointly with the quality team	Seed lodged in a cracked cover, which turns into a rejected batch at the next changeover

Read down the last column and the pattern is obvious. None of those failures announce themselves as a broken belt. They arrive as cover loss, swelling, or a batch rejection, and by then the belt has to come off anyway.

02Grain Duty: Abrasion, Throughput and Dust

Grain is the material most farm conveyors are actually designed around, and it is also the one people underestimate because it feels harmless in the hand. Dry wheat at speed is abrasive. The dust it sheds is combustible, it packs into every crevice, and it will find any open splice within a few thousand cycles. A general-purpose industrial conveyor belt will run grain for years if the tension is right and the loading point is controlled, but "run" and "run economically" are not the same target.

The trap is the loading zone.

Drop height is what kills grain belts on farms and inland silos, not total tonnage. On a 900 mm belt moving 250 t/h I have watched a single 2.5 m fall create enough impact at the loading point to break belt fabric in the first ply, months before cover wear was even visible. Fitting impact idlers under the chute, cutting the fall to under 1 m and adding a skirt with a settled material cushion usually removes that failure at a fraction of the cost of a heavier belt. Thicker is not always the answer here, because the fabric damage happens with the cover largely intact.

For the same grain line, the drive end matters as well. A farm conveyor is often belt-driven from a shaft-mounted gearbox, and if the V-belt manufacturer supplied wrapped belts with the wrong section for the pulley groove, slip shows up as heat and noise long before anyone connects it to belt tension. That is a cheap part of the system to get right on the first order.

agricultural conveyor belt moving grain through a farm handling hall

Dust is the other half of grain duty, and it changes the belt specification rather than just the housekeeping routine. Grain dust is combustible, so any belt running inside an enclosed gallery or a silo transfer tower should be electrically conductive enough to drain static. ISO 284 sets a surface resistance ceiling of 3×10⁸ ohm for anti-static belting, and your grounding scheme has to be continuous through the splice. We have seen more static-related incidents on plants where the belt was anti-static but the splice used a non-conductive gum strip than on plants running fully general-purpose belts in open air.

Tracking finishes the grain picture. Cereal dust builds on idler surfaces and pulleys, which effectively enlarges them on one side and starts to steer the belt. That is why we suggest a couple of training idler stations on the carrying run and self-aligning idler sets on the return, on any grain line that runs more than one grade through the same machine.

Duty parameter	Typical grain figure	What it forces onto the belt	How we account for it	Consequence when it is ignored
Bulk density of cereal	Wheat near 0.78 t/m³, maize near 0.72 t/m³, barley near 0.60 t/m³	Load per metre, and therefore the working tension and the required ply count	Tension from throughput, density, friction and lift, checked against the belt rating at 1.0 service factor minimum	Belt runs slack at the drive, slips under load, and spills at the transfer
Throughput against belt width	250 to 400 t/h on belts from 800 mm to 1,200 mm	Belt width, trough angle and surcharge, all decided together	Cross-section from 20° or 35° troughing, checked against machine speed rather than guessed	Running too fast to make capacity, which drives dust, wear and spillage together
Grain temperature after drying	Commonly 45 to 60 °C directly off the drier	Cover compound that holds hardness as it warms, and a carcass that does not creep	Heat-resistant cover above 60 °C, with the adhesion verified, not just the cover grade	Cover softens, grain sticks, and the return run drags material back to the tail
Combustible dust and static	Fine fractions below 500 microns, worst in dry, low-humidity weather	Anti-static belt plus a continuous conductive path through the splice and the frame	Surface resistance verified to ISO 284 and earthing measured on site, not assumed from the certificate	Static discharge in an enclosed gallery, which is the scenario every dust hazard study is written around
Inclination of the run	Grain settles on the surface at around 20 to 25 ° of repose in a moving trough	Either a steeper trough design or a profiled belt surface	Beyond roughly 18 to 20 °we move to a profiled surface rather than simply raising speed	Material rolls back down the incline and the belt does less work than the motor suggests

None of these five parameters belongs to a different machine. They all belong to the one grain conveyor sitting in front of you, and they all move the moment the material changes.

03Fertiliser and Salt Duty: Oil, Chemistry and Static

Fertiliser is where cereal-selected belts go to die. The granules look dry, but most blends are hygroscopic and pull moisture out of the air until a thin film of saturated solution is sitting against the cover for the whole shift. Add the oil coating many prills carry to stop caking, and you have a mild chemical and oil bath running continuously across the top cover. That is a different job from grain, and it is why a oil resistant conveyor belt grade is the starting point here, not an upgrade.

Chemistry decides the compound.

Urea is only mildly alkaline, but it is very soluble and keeps the surface wet, which weakens adhesion at any splice over time. Ammonium nitrate is the opposite problem and a far more serious one, because it is an oxidiser and its dust is a recognised explosion hazard. On those lines we specify anti-static belting to ISO 284 together with a flame-retardant cover verified to ISO 340, and we treat the splice as part of the electrical path rather than as a mechanical joint. A chemical resistant conveyor belt compound handles the chloride salts in muriate of potash, which will attack a general cover faster than people expect because the salt stays on the surface and keeps working.

Two practical points come up on almost every fertiliser enquiry. The first is that the same silo often stores more than one product, so the belt sees urea in spring and a potash blend in autumn, and the compound has to survive both. The second is that fertiliser dust is far more aggressive to bearings than to the belt itself, which is why enclosed, sealed roller assemblies earn their keep on these lines even though the belt gets all the attention. When we quote a fertiliser line through a conveyor belt supplier network, we ask for the product list and the storage rotation before we ask for a belt width, because those two facts change the recommendation more than tonnage does.

There is also a compliance angle that a conveyor belt factory can support but cannot decide for you. Enclosed fertiliser galleries usually fall under a dust hazard study, and the study will state which zones need conductive belting and flame-retardant covers. Order the belt to match that document. A fire resistant conveyor belt cover that satisfies ISO 340 is not automatically anti-static, and the two certificates are frequently requested together because the hazard needs both.

Product and exposure	Chemistry actually present	Cover and compound response	How to verify before ordering	Cost of a wrong choice
Ammonium nitrate prills	Hygroscopic oxidiser with a combustible, static-sensitive dust fraction	Anti-static compound plus flame-retardant cover, with a conductive splice	Certificates to ISO 284 and ISO 340 on the same article, plus a site earth continuity test	An ignition source in the one product where a dust explosion is genuinely credible
Urea	Very soluble, mildly alkaline, keeps the cover damp for long periods	Moisture and chemical tolerant cover with high wet adhesion at the splice	Adhesion values after water immersion, not just the dry figure on the datasheet	Splice adhesion fails first, usually as a peeling lap rather than a clean break
NPK blends with an oil coating	Vegetable or mineral oil film over soluble nitrates and phosphates	Nitrile-based oil resistant cover that also resists salt carry-over	Volume swell by ISO 1817 in the actual blend, because blends differ from the raw salts	Cover swells, loses tensile strength, and starts leaving rubber on every scraper
Muriate of potash and sulphate of potash	Chloride salts that stay on the surface and keep attacking while damp	Chemical resistant cover with a dense, low-porosity surface	Immersion testing in a saturated salt solution at working temperature	Surface crazing that traps salt, which accelerates the next round of attack
Multi-product stores with seasonal rotation	Whatever was stored last, plus the residue left in the transfer points	One compound that must cover every product in the rotation, not just the main one	A written product list and rotation calendar supplied with the enquiry	A belt that suits the headline product and fails on the second one, every season

04Silage, Forage and Feed: Acids, Fats and Cleaning

Silage duty combines three attacks that no single grain belt is built to withstand at once. The material is wet, it is acidic, and it is often abrasive because chopped stalk and grit travel with it. Grass silage sits at 65 to 75 percent moisture and carries the organic acids that fermentation produces, so the cover is wet for hours and the cut edges are permanently exposed to effluent. Maize silage adds a harder, more abrasive stalk. If your farm runs one conveyor through both, the belt has to satisfy the harsher of the two, not the average.

Edge construction is where silage belts fail.

We have repeatedly seen a belt survive a full grain season and then fray at the edges inside a single silage campaign, because the effluent wicks into the cut edge and loosens the fabric. A sealed or moulded edge, and a carcass chosen for wet adhesion, add a small amount to the unit price and remove that failure entirely. On the same site, a warm pelleted feed containing 8 to 12 percent added fat will soften a general cover until it grains off along the return run, so the compound needs nitrile chemistry rather than a standard blend. The oil resistant conveyor belt grades we recommend for feed duty are the same family used on fertiliser, but selected for a different reason and tested against a different fluid.

Cleaning decides the rest. Feed and silage lines are usually washed or scraped between batches, and a rough or cracked cover defeats both. Any belt that will be cleaned in place should have a smooth, low-porosity surface and a splice that is flush enough to pass under a scraper without lifting. When a plant buys through a conveyor belt manufacturer that also has to support the cleaning regime, the splice specification changes to match the scraper, and that detail belongs in the original enquiry rather than in a call after the first failure.

Feed mills also run more than one line off a single purchase, which is why wholesale conveyor belts ordered as a mixed set should carry a written matrix of which belt goes on which line. A plain, stored specification can quietly migrate onto the wrong conveyor during an emergency change, and that is a slow-motion version of the same material mismatch this page is about.

Material and condition	The aggressive agent at work	Belt response that is actually required	Construction or sizing note	Failure signature to watch for
Grass silage at 65 to 75 percent moisture	Lactic and acetic acids plus silage effluent that keeps the cover wet and wicks into cut edges	Acid and moisture tolerant cover with a sealed or moulded edge	Wet adhesion checked after immersion, and a carcass that resists wicking between plies	Edge fraying followed by cover delamination, typically within one silage season
Maize silage and chopped forage	Hard, abrasive stalk and grit travelling with an acidic wet load	Abrasion resistant cover of the same order as a cereal belt, combined with acid tolerance	Cover grade to DIN 22102 W, abrasion loss not more than 90 mm³ by ISO 4649, checked with the acid exposure	Cover wears through to the carcass faster than expected because two attacks run together
Molasses-treated feed	Sticky sugar film that adheres to the cover and cannot be scraped clean	Smooth clean-release surface with a flush splice that passes a scraper freely	Splice finished and trimmed flush, with the scraper setting agreed around the joint	Heavy carryback that builds up under the return run and misaligns the belt
Warm pelleted feed with added fats	Vegetable and animal oils at 8 to 12 percent, arriving at 50 to 70 °C	Oil resistant nitrile cover that holds hardness at working temperature	Heat ageing checked to ISO 188, alongside volume swell to ISO 1817	Cover softens and grains off along the return run under the scrapers
Rough handling of baled or block feed	Sharp corners and occasional impact from dropped bales or frozen lumps	An impact and cut resistant conveyor belt construction with a breaker ply	Impact idlers under the loading zone and a controlled drop below one metre	Localised cuts and ply damage at the loading point that spread into a tear

05Seed and Delicate Product: Cleanliness and Contamination

Seed handling flips the whole problem on its head. There is almost no abrasion and often no aggressive chemistry, so the belt that survives fertiliser would run here for a decade. What seed lines care about is contamination, and that is a surface and splicing question rather than a wear question. A cover with a crack, a void, or a proud splice will hold a few grams of the previous variety, and a few grams is enough to fail a purity test when the next lot is a different cultivar.

Cleanability is a specification, not an opinion.

For seed and food-adjacent duty we agree the surface finish and the cleaning method in writing before the belt is built, because "washable" means different things to a maintenance team and a quality auditor. Where the process is genuinely food-contact, the compound selection goes further and follows the same logic used on our food and packaging conveyor belt lines, with the documentation trail that a quality system expects. That trail is also why quality assurance records should follow the belt, not just the batch.

The splice matters more here than anywhere else on a farm. An open, stepped splice is a trap for fine seed, and a raised overlap is a scraper's worst enemy. For delicate product we prefer a flush, well-cured joint and a carcass that holds its geometry so the splice stays flat under tension. A general EP rubber conveyor belt is usually the right carcass for these lighter duties, because the load is gentle and low-stretch performance is not the limiting factor.

There is one more consideration that surprises buyers on mixed farms. The same building often contains both the seed line and an oilseed or feed line, and the drive arrangements differ. Where a line is driven by a synchronous drive rather than a V-belt or a shaft-mounted unit, the transmission side is a separate selection, and our timing belts range covers those cleaner, non-slip drives. Getting the conveying belt and the drive belt from one conveyor belt distributor keeps the two selections consistent and removes the guesswork when a drive is later re-rated.

Contamination control also has a static dimension with fine, dry seed, though a milder one than on fertiliser. A dry seed fraction moving at speed can build a charge that makes light particles cling to the cover and to the chute, which shows up as uneven flow and as product left on the belt at shutdown. A lightly conductive surface and good earthing usually settle it.

06Turning Duty into Numbers: Cover Grades and Compounds

Everything discussed so far has to end up as a line on a purchase order, and cover grades are how that happens. The useful move is to stop describing duty in words and to start quoting the standard that the cover will be tested against. When a buyer tells us "it runs fertiliser and it is wet", we translate that into an abrasion figure, an oil swell limit, a surface-resistance ceiling and a flame test. Once those four numbers exist, two suppliers quoting against the same specification are genuinely comparable, and a quotation that cannot name them is not.

The numbers are not arbitrary.

They come from a small set of published tests that the whole industry recognises, so a buyer with no rubber background can still hold a supplier to account. Abrasion is measured as volume loss in cubic millimetres on a rotating drum, oil and chemical resistance as a percentage volume swell after immersion, anti-static behaviour as a surface resistance in ohms, and flame resistance as a test that either passes or does not. If a datasheet quotes a cover as "heavy duty" without one of those figures behind it, treat the claim as a description of thickness rather than of quality.

For grain and maize silage the governing figure is usually abrasion, and the family of abrasion resistant conveyor belt covers is where a farm belt for hard, dry product should sit. For grain arriving hot off a drier, the limiting property moves to heat, which is a separate selection that belongs with our heat resistant conveyor belt range. Where the load carries oils, as on fertiliser and on fat-enriched feed, the deciding figure is volume swell, and that is a compound choice rather than a cover-thickness choice.

agricultural conveyor belt with abrasion and oil resistant cover grades

It is worth saying plainly that a thicker cover is not a substitute for the correct compound. Adding a millimetre of the wrong rubber delays the failure and does not prevent it, and it adds weight and cost to the carcass at the same time. Buyers who buy on millimetres alone usually pay twice, once for the extra thickness and once for the replacement. On the drive side of these same machines, the equivalent discipline applies to the belts that turn the pulleys, and a transmission belt manufacturer worth using will quote section, profile and power rating rather than just a length.

Cover grade and standard	Abrasion loss limit	Oil and chemical position	Where it fits in agriculture	What you trade away
DIN 22102 grade W, high abrasion resistance	Not more than 90 mm³ by ISO 4649	Standard oil resistance only, suited to dry product	Dry grain, maize silage, and any hard, abrasive farm load	A higher unit price, and no benefit if the real problem is oil rather than wear
DIN 22102 grade X, abrasion resistance	Not more than 120 mm³ by ISO 4649	Standard, adequate for cereal without oils	General grain handling where wear is moderate and speed is controlled	Some wear life compared with grade W, in exchange for a lower price
DIN 22102 grade Y, general purpose	Not more than 150 mm³ by ISO 4649	Standard, not oil or chemically resistant	Light seed and clean, low-abrasion product on short runs	Rapid cover loss the moment abrasive grain is introduced
DIN 22102 grade Z, heat resistance	Abrasion checked separately, heat ageing to ISO 188	Standard, with retention of properties at temperature	Grain straight off the drier, typically 60 to 100 °C	Cost, and it is not a fix for an oil problem at the same time
Nitrile-based oil resistant compound	Abrasion stated on the datasheet, often to grade X order	Volume swell to ISO 1817, commonly under 10 percent after 72 h	Fertiliser with an oil coating, and feed carrying added fats	Slightly lower abrasion resistance than a pure grade W cover
Anti-static and flame-retardant cover	Abrasion whatever the base grade allows	Surface resistance to ISO 284 and flame test to ISO 340	Enclosed fertiliser galleries and any combustible dust zone	Cost, and the discipline of a conductive splice to keep the path intact

Two of those rows can be needed on the same belt, and that is normal. A fertiliser line in an enclosed gallery usually wants an oil-resistant, anti-static, flame-retardant compound all at once, and the grade table is simply a way of confirming that every one of those requirements was specified rather than assumed.

07Splices, Edges and Tracking on Short Farm Conveyors

Farm conveyors are short, which changes the economics of the joint. On a 2 km overland line a splice is a small part of the total cost, but on a 30 m farm conveyor the splice is a large share of both the price and the downtime, and it is also the part most likely to fail first. The splice you choose has to match the material, not just the belt, because silage effluent and fertiliser salts both attack an open joint far faster than they attack the cover.

The joint is a material decision.

A hot-vulcanised stepped splice gives the highest efficiency and the best resistance to moisture wicking, and it is what we specify where wet, acidic silage or damp fertiliser is involved. A finger splice suits thinner belts and lighter seed duty, where a flush joint that passes a scraper cleanly matters more than raw strength. Cold-bonded joints are convenient on site but their adhesion is temperature and cure-time sensitive, so they are a poor choice on a line that runs hot grain or works in a cool, damp climate. Mechanical fasteners have their place when a belt must be shortened in the field, but on a washable food or seed line the staples and hinge pins are exactly where product lodges.

Edge construction follows the material in the same way. Cuts expose the fabric, and anything wet and acidic will travel along that exposed edge faster than it will travel through the cover. A sealed edge is not a luxury on silage; it is the difference between a belt that lasts a campaign and one that frays out of it. The same argument explains why the chevron conveyor belt profiles used on steep grain or forage inclines should have their cleats bonded and their edges finished to the same standard, since a lifted cleat presents the same exposed fabric as a torn edge. Where a steeper incline needs a continuous wall rather than discrete cleats, the sidewall conveyor belt construction takes over, and again the base belt edge and the wall bond are the weak points to inspect.

agricultural conveyor belt splice and edge detail on a farm conveyor

Tracking is the last piece, and on short machines it is unforgiving because there is little length over which a belt can correct itself. A belt that is slightly out of square, or a splice that is a few millimetres off-perpendicular, will run to one side within a single revolution. That is why we recommend a conveyor pulley pair that is confirmed square and level before a new belt is fitted, and we ask for the pulley diameters so that we can check any transition requirement on a short centre. Good conveyor rollers and a couple of aligning stations usually finish the job, provided the belt itself was cut straight to begin with.

Splice method	Typical joint efficiency	Where it fits on farm duty	Skill and tooling required	Failure mode when it is mismatched
Hot-vulcanised stepped splice	Highest of the field methods, typically quoted near belt strength	Wet, acidic silage and damp fertiliser where wicking must be stopped	Press, heating and trained fitters, best done in a workshop or under cover	Poor cure shows as a soft joint that creeps and then peels from the end
Hot-vulcanised finger splice	High, and notably flush across the running surface	Thinner belts on seed and light feed duty, and lines with close scrapers	Careful cutting and pressing, with a finger pattern suited to the carcass	Fingers cut short leave thin sections that crack under repeated flexing
Cold-bonded splice	Lower, and dependent on site temperature and cure time	Emergency repair and short, light runs where a press is not available	Clean, dry surfaces and a genuine cure window before the belt is loaded	Adhesion never develops, and the joint opens on the first heavy start
Mechanical fastener	Lowest, and creates a leak path through the belt	Field shortening of a belt on a non-food, non-washdown line only	Basic tools, so it is tempting, but the material must tolerate the gap	Product lodges in the hinge, and on food or seed duty that alone fails a batch

08The Change-Material Checklist Before You Swap a Belt

When the same machine is about to run a new material, the belt decision can be reduced to a short list of questions that a buyer can answer from the plant without any rubber expertise. Work through them in order and most of the selection falls out before you ever open a catalogue. The point is not to make the choice complicated; it is to stop the choice being made by whoever happens to have a spare belt on the shelf.

Start with the material and the moisture, because those two facts drive almost everything else.

Next comes the acceptance standard. If the line feeds a quality system, the cleaning method and surface finish are fixed by the auditor and not by the belt supplier, so collect those first. Then confirm whether the environment is an enclosed dust zone, because that alone can add an anti-static and a flame-retardant requirement that a general farm belt will not meet. Finally, decide the splice before you order, not after the belt arrives, so that the workshop has the right press and the right cure time available.

If any of those answers is genuinely unknown, the honest move is to test rather than guess. A short immersion test of cover samples in the actual material, run for a week at working temperature, will settle most oil and chemical questions at almost no cost. We would rather quote against a tested answer than against an assumption, and a good service team will help you set that test up. Where a line combines a heavy-duty carcass requirement with a specialised cover, as it sometimes does on long grain runs, the choice may reach into a steel cord conveyor belt construction for tension rather than for the cover. That is a length and duty decision, not a material one, and it should not be allowed to distract from the cover selection that the material demands.

Question to answer	Why it changes the belt	Data to collect	What a good answer looks like	What it rules out
What is the new material, precisely?	Abrasion, oil, acid and static all follow from the material and its moisture, not from tonnage	Product name, moisture content, oil or fat content, and particle size	A named product with a moisture figure, not "some fertiliser"	Reusing the previous grain-grade belt without any review
Is the environment an enclosed dust zone?	Combustible dust brings anti-static and flame-retardant requirements into the cover	The dust hazard study or zone drawing for the gallery or tower	A stated zone, with the required anti-static and flame tests identified	Any general-purpose belt, however hard wearing
Will the line be washed or scraped?	Cleaning method fixes the surface finish and the level of the splice	Scraper type, wash temperature, and the chemicals used in cleaning	A surface and splice that pass the scraper without lifting	Rough finishes and any raised mechanical fastener
Does another product share the line?	The compound must cover every material in the rotation, not just the loudest one	A full product list and the seasonal order in which they run	One belt that satisfies every product, or a stated plan to swap belts each season	A belt optimised for a single product that fails on the next one
What is the temperature of the load?	Hot product softens the cover and can change the required compound family	Product temperature at the loading point, and the ambient range	A measured figure rather than an assumption of "ambient"	Standard covers on grain that leaves a drier still warm
Which splice can the site actually make?	Joint strength and wicking resistance depend entirely on the splice method chosen	Available press, skilled fitters, and the time window for a cure	A method matched to the material and to the site's real capability	A high-efficiency splice the workshop cannot actually produce

Answer those six questions and you have the material list, the cover family, the environment requirement and the joint, which between them decide the belt. Nothing on the list requires a rubber chemist on site, and every item on it is cheaper to settle before the order than after the failure.

Send us your material list and we will confirm the cover and splice

09Frequently Asked Questions

Can the same belt really run both grain and fertiliser on one machine?

Sometimes, but only when the compound is chosen for the harder of the two materials rather than the one that happens to arrive first. A nitrile-based, oil-resistant cover can carry oil-coated fertiliser without swelling and still handle dry grain, and if the line sits inside an enclosed gallery it also needs to be anti-static. What will not work is a plain general-purpose cover that was selected for cereal and then left in place when the store rotates to fertiliser. If the two materials are physically separated in time and the plant is willing to stock two belts, running a grade W cover on grain and an oil-resistant cover on fertiliser is usually the cheaper long-run answer, because each belt then works only in the way it was designed to.

Why did the cover wear out so quickly after we switched the line to fertiliser?

In most of the cases we are asked about, abrasion was not the cause and the cover was not wearing out in the usual sense. It was swelling. Fertiliser carries moisture and often an oil coating, and both sit against the rubber for the whole shift. A cover that suits dry grain absorbs a little of that, softens, loses tensile strength and then starts leaving rubber behind on the scrapers. The pattern looks like heavy wear, but a grade W abrasion figure would not have prevented it. Volume swell to ISO 1817 in the actual blend is the test that answers the question, and it is quick to run on cover samples before a full belt is ordered.

Is a thicker cover a safe way to handle a switch to a harder or hotter material?

No. Extra thickness buys time, not immunity, and on a material that attacks the cover chemically it buys very little time at all while adding weight and cost to the whole belt. Where the new material is genuinely more abrasive, the sensible change is the cover grade, moving from a general-purpose cover toward a grade W cover with an abrasion loss under 90 mm³. Where the new material is hotter, as with grain straight off a drier, the change is to a heat-resistant compound with its ageing verified to ISO 188. Thickness is the last variable to adjust, and it should follow the compound decision rather than replace it.

Do we need anti-static belting on an open farm conveyor?

Usually not on an open, well-earthed conveyor in the open air, where any charge has room to dissipate and the dust is not confined. The requirement appears when the same material runs inside an enclosed gallery, a silo transfer tower or a covered store, because a combustible dust cloud plus a static discharge is the scenario that safety studies are written around. In those locations we specify a surface resistance to ISO 284, and we treat the splice as part of the conductive path rather than as an ordinary joint. A flame-retardant cover to ISO 340 is a separate property and is often requested alongside the anti-static one, but one certificate does not imply the other.

Which splice should we choose for wet silage or damp fertiliser?

For anything wet and acidic, a hot-vulcanised stepped splice is the right default because it offers the highest joint efficiency and it seals the plies against moisture travelling along the joint. A finger splice is a good alternative on thinner belts and lighter duty, especially where the running surface has to stay flush under a scraper, but it needs careful cutting so no finger is left short. Cold-bonded splices are best kept for emergency repairs, because their adhesion depends on site temperature and on a cure window that a busy plant often cannot respect. Whatever the method, pair it with a sealed or moulded edge, since a wet material will travel along an exposed cut edge much faster than it will move through the cover.

How do we know our cleaning routine suits the belt we bought?

Agree the surface finish and the splice level with the supplier before the belt is built, and write them into the order. A smooth, low-porosity cover and a splice trimmed flush are what let a scraper clean the belt without lifting the joint, and they are also what stop fine seed lodging in a crack between batches. If the line washes down, give the wash temperature and the cleaning chemicals as well, because some cleaning agents are as aggressive to the cover as the product is. When those details are agreed up front, the belt and the cleaning regime support each other; when they are not, the belt becomes the thing that stops the line passing its next audit.