CONVEYOR BELT TERMS A-Z BELTEDIA
Wearing away by rubbing, scraping. Video. The established abrasion tests, for instance as per ISO 4649, have practical relevance only for grinding kind of applications. The abrasion value alone is no indicator of a belt's wear resistance.
The bonding strength between two materials.
The red glow persisting after extinction of the flame, for instance in certain fire resistance tests.
The exposure to an environment for a period of time.
A compound ingredient used to retard deterioration caused by oxygen.
Code letter E as per DIN 22102 and 22131. Grades K, S and V have a surface resistivity of min. 300 MOhm. Tested as per DIN 22104.
Stands for aromatic polyamide. Its acronym is D. Aramide is a low elongation, light, high-strength fiber with limited applicability for conveyor belts because of its poor fatigue properties and sensitivity to chafing. Expensive. Loses strength under UV radiation (splicing!). Trademarks are Kevlar and Twaron.
Arc of contact
The circumferential portion of a pulley which is engaged by a belt.
Association for Rubber Products Manufacturers, a successor of RMA. Published their conveyor belt handbook in 2011, determining grade 1 with tensile strength of 17 MPa, elongation at break of 400 % and volume loss of 125 mm³.
Beams or metal plates secured transversely to hold the belt in a desired position.
Belt cleaning device
A scraper or rotating device pressed against the belt surface to remove material stuck to the belt.
A device for holding two ends of a conveyor belt together. More.
A classification of the rubber quality and properties as per ISO, DIN or other standards. More...
Usually, every belt length has an embossed individual serial number, plus the belt type and the manufacturer's acronym. The size and positioning of the marking can be agreed between customer and manufacturer. Example
The force per unit width of belt required to produce a stated percentage of elongation, or the ratio of stress to strain. See "Modulus of elasticity".
The amount of vertical deflection of a conveyor belt from a straight line between idlers, usually expressed as a percentage of the center to center spacing of the idlers.
The speed differential between the belt and the pulley surface, accelerating the abrasion of the belt cover.
Belt tear resistance
Or "tear propagation resistance". A belt sample is cut and then further separated. Odditiy: as per ISO 505, the parties must decide with order placement, whether the minimum value required is related to a test with or without belt covers.
Belt training idler
An idler having a belt-actuated swivel mechanism to automatically control side drifting of a conveyor belt.
A system of idlers to turn a belt over (upside down). Illustration.
Wherever possible, standard widths (for instance 1000, 1200, 1400 mm etc.) should be chosen, so they fit to other standardized conveyor components.
The force required to induce bending around a specified radius and, hence, a measure of stiffness.
A pulley used to change the direction of a belt.
A cut of belt ends made diagonally at an angle less than 90 degrees - usually 30° - to the longitudinal axis. Video.
Binder warp yarn
One of the warp systems in a straight warp fabric interlaced with the filling yarn to provide the strength to hold mechanical fasteners.
Migration to the surface of plasticizer, waxes or similar materials to form a film or beads.
A raised spot on the surface or a separation between layers usually forming a void or air-filled space in the vulcanized conveyor belt.
Used in some long conveyors to reduce the power/tension at the drive pulley.
The non-carrying belt side towards the pulleys. Usually thinner than the top cover.
A bow is a longitudinal curve in a belt on its concave side. A bow can be created during manufacture, improper storing, splicing or tensioning. See also Camber.
An extra ply made of fabric or steel for shock absorption to minimize gouging.
The breaking strength of the conveyor belt, either nominal/minimum (e.g. St 2000) or ultimate/actual (e.g. 2197 N/mm). Test
Bucket elevator belt
A transversely rigid belt with buckets attached, for vertical conveying.
Required for determining the troughing angle, the angle of repose and maximum inclination. Table.
The distance between two opposing steel cords in a conveyor belt splice.
A roller mill equipped with three or more internally heated or cooled drums, used to continuously sheet out polymeric compound to wipe it into the interstices of a fabric leaving a small portion of it on the surface of the fabric, or to lay a continuous sheet of compound on a fabric. More...
Describes a crooked conveyor belt ("banana"). More...
The material load on the belt, given in tons per hour (t/h). More...
Carbon black is used to increase strength and abrasion resistance of a rubber compound. Smaller particles provide better reinforcement but are more difficult to process. The Chinese used carbon black 500 years ago to make ink and lacquer.
The fabric plies or steel cords (plus breakers) of a belt, as distinguished from the rubber covers. The carcass provides the tensile strength to move the loaded belt. More...
The material carrying side of a conveyor belt. In most cases thicker than the bottom cover.
A type of flexible belt-carrying idlers with ends supported in pivoted stands.
The most advanced conveyor belt monitoring system, based on radiographic technology. Supplies and processes nonstop live information about any deficiencies of a conveyor belt.
The distance between the center of two pulleys. Sometimes also called "centers" or "center distance" or "conveyor length".
Ceramic pulley lagging
Used for high-capacity conveyors or in slippery environments. Offers higher wear resistance and a higher friction factor.
Highly abrasion resistant elastomeric lining in a chute to protect the metal chute from abrasion wear.
Depending on the friction factor of clamp and belt surfaces and on the (downhill) force. Chart.
A device for removing adherent material from the belt. More commonly used term: Scraper.
Transverse raised sections on a conveyor belt to stabilize material carried up an incline.
See Pipe conveyor belt.
The length coefficient used for calculating the secondary resistances. Chart.
See f value.
Usually, conveyor belts are resistant to up to -30°C. Lower temperatures may be achieved with special compounds. Constant movement of the belt may be required.
The concave radius of a conveyor must be sufficiently large to avoid belt lifting from the conveyor.
The deformation in a material remaining after it has been subjected to and released from a compressive force.
Several strands of yarn twisted together
A fabric with plied or cabled yarns in the warp direction and a light weight filling yarn spaced only sufficiently to process the fabric.
A tool for easy separation of steel cords from the belt as part of the splicing procedure. Requires a winch. More...
Also called "insulation gum". The rubber used for filling the gaps in a steel cord and improving adhesion between the cord and the top and bottom covers.
The weight applied to the take-up assembly to maintain proper belt tension. Take-up length.
The outer rubber (or PVC) component of a belt. Protecting the belt carcass and providing drive friction. There are cover grades for a broad variety of applications. A cover usually consists of a principal polymer and assorted modifiers, carbon black, antioxidants, accelerators, fillers, plasticizers etc. Compounding.
Please follow this link for physical data of the most common cover grades.
A sharp break or fissure in the surface.
The action of a belt alternately losing speed on the driving pulley and gaining speed on the driven pulley.
The waviness of the yarn in a woven fabric or the difference in distance between two points on a yarn as it lies in a fabric, and the same two points when the yarn has been removed and straightened. Expressed as a percentage of the distance between the two points as the yarn lies in the fabric.
A pulley with a greater diameter at the center than at the edges.
A belt tending to form a cup by raising the edges. Depending on severity, it may not be able to be guided by the idlers or even be loaded properly.
The uncovered edge of a belt, created by cutting after vulcanization. The carcass is visible from the sides.
A term used for a troughing angle of 45, rather 60°.
A deleterious change in the chemical structure of a material.
The separation of layers of material, for instance textile ply from top cover.
A yarn sizing system for continuous filament synthetic fibers on the basis of the weight in grams of 9000 meters of the yarn.
The ratio of the mass of a body to its volume or the mass per unit volume of the substance. For ordinary practical purposes, density and specific gravity may be regarded as equivalent.
For Deutsches Institut für Normung, German Institute for Standardization. World's first standards for conveyor belts were published by DIN in Germany.
A fabric coated with rubber compound by passing through a rubber solution and drying.
The energy caused by the drop of the conveyed material onto the conveyor belt. Depending on lump size, drop height etc. See also Impact resistance.
Dynamic splice strength
E' and E''
E' is the dynamic modulus of the rubber which is in phase with the applied strain loading. E'' is the loss modulus, which is out of phase with the applied strain. The ratio of E''/E' = tan delta, which is the internal friction of the rubber. E' is an important factor for low indentation rubber.
Tendency to return to the original shape after deformation.
A measure of how well a material accommodates the transport of electric charge, measured in Ohm (Ω). Photo.
Used for vertical conveying, with buckets mounted to it.
The total belt elongation consists of an elastic (which recovers) and a plastic (which remains) portion. As per ISO 9856 a belt sample is subjected to a sinusoidal cyclic stress that varies from 2 to 10 % of the belt's nominal breaking strength. Test
Elongation at break
The percentage the rubber or belt can be stretched until it breaks.
The length of a closed belt (without splice allowances).
A process whereby rubber is forced through a shaping orifice. More...
Determines the optimum difference between the forces F1 and F2 without belt slip. Equation.
See textile conveyor belts.
See "mechanical fastener".
The weakening of a material occurring when repeated application of stress causes permanent strain.
A belt that discharges material onto another conveyor belt. Often used for belts extracting bulk materials from under a dump hopper or regulating feed to a crusher or screen.
A continuous fiber of discretionary length.
Fire or flame resistance
Retards the burning action of fire or flame. Achieved by adding fire retardants to the compound or by using fire resistant elastomers or plastomers. More...
Flat-to-trough transition zones
The transition length between pulley and deepest trough station. This length must be sufficiently high to prevent major additional tensions in the conveyor belt edges. Influencing the required conveyor belt breaking strength.
A trademark for "woven" steel cord conveyor belts. Belt manufacturers tend to use "Flex" in their own belt names. More.
The resistance to tangential motion between two surfaces. For rubber, the classical laws of friction are not applicable, since rubber has no rigid surface. The individual friction factor must be determined experimentally. In general, higher hardness and abrasion resistance result in lower friction. Chart.
The coefficient f (also called artificial or fictive friction or resistance coefficient) is resulting from the correlation between the weights and the motional resistances of the belt conveyor. A typical f value would be 0,016.
In optimum installations with low rolling resistance belts, even f values of around 0.010 have been found. Chart.
In contrary to DIN and ISO, CEMA works with Kx, Ky and 0.015 instead of f, which f is a sum effect of.
The effect of sharp heavy material falling onto a conveyor belt cover to loosen or tear out pieces of the cover. Photo
There is a wide choice of conveyor belts for all gradients. From normal troughed conveyor belts, via pipe conveyor belts through to vertical elevator belts. Table.
A mechanical system that adjusts for the stretch or shrinking of a conveyor belt automatically by a weighted pulley in the system.
The bars at the loading point absorb the impact energy from the lumps and redirect the (big) lumps to the belt; fines fall on the belt before the lumps.
Lagging with round or angular grooves to minimize material buildup on the pulley.
The pulley at the discharge end of the conveyor.
Normal belts usually are resistant up to 80°C. Special compounds can increase the temperature resistance to around 200°C.
Hooke's law of elasticity states that if a force (F) is applied to an elastic spring, its extension is linearly proportional to its tensile stress σ and modulus of elasticity (E): ΔL = 1/E × F × L/A = 1/E × L × σ
The radius of a horizontal curve is required for the layout of the diameter of a pipe conveyor belt. More...
See Pipe conveyor belt.
A loss of mechanical energy due to successive deformation and relaxation, measured by the area between the deformation and relaxation stress-strain curves. See also "Elongation".
A non-powered roller supporting the belt.
Industrial Internet of Things. Electronic interaction between different components of a belt conveyor. The belt can be integrated digitally by the output of X-ray monitoring systems.
A stroke of a body dropping on the belt.
A belt idler having a resilient roll covering, resilient molded elastomer rings, springs or other means of absorbing impact energy at the place where material falls onto the belt.
The relative ability of a conveyor belt assembly to absorb impact loading without damage to the belt. See also "transverse reinforcement". Test.
The gradient of a conveyor. The maximum (uphill) inclination for non-profiled belts is around 18° for ore. In general, the angle of repose of the conveyed material must be larger than the inclination angle of the conveyor. Chart.
Since the conveyor belt is permanently subjected to many strains and stresses, frequent, regular inspection of it is important. More...
Indentation rolling resistance
The energy consumed by internal friction caused by deformation when the belt moves over idlers. More...
The connection of two belt ends. More common term: splice. More...
A trademark for para-aramide (aromatic polyamide). See Aramid.
A temporary or permanent distortion of belting caused by doubling the belt on itself
A smooth or embossed covering on a pulley to increase friction between belt and pulley.
An open mesh fabric in which the warp yarns are held by the filling yarns, with the filling yarns twisted around alternating warp yarns in opposite direction. Sometimes used as impact breaker.
Defining the belt's sag on the idler gaps. The sag may be an issue for very thin belts and wide gaps. Term widely used in North America.
Low rolling resistance. More...
Conveyor belts are highly strained at the material feeding points. The intensity of the impact energy depends on the lumps' size, weight and shape.
Proper maintenance is very important to get the most out of your belt. Longer belts should be monitored by state-of-the-art systems based on X-ray technology. More...
The highest tension occurring in any portion of the belt under operating conditions.
Any mechanical device used to join the ends of belting. Sometimes also used for temporary emergency repairs. Illustration.
Modulus of elasticity
The force divided by the percent elongation to cause the elongation, related to the belt width. The lower the stretch, the higher the MoE. The MoE, sometimes called belt modulus, is influenced by the textiles (for instance the crimp of the yarn) or steel cords used and the way of belt manufacture, for instance the tension during vulcanisation. Example: The MoE for a 800/St2500 belt is 200 kN/mm. To stretch 1 m of this belt (elongation 0,15 %) by 1,5 mm, a tension of 240 kN is required. This is approximately 12 % of the nominal belt breaking strength.
The belt manufacturer should be consulted for exact figures. Equation.
Essential part of a Preventive Maintenance programme and IIoT. Extends belt life, reduces costs, increases safety. More...
The resistances - "main, additional, inclination, special" - when moving a belt on a conveyor system. Illustration.
A solid rubber belt edge formed in a mould or against edge irons. Another option are cut edges. The technical differences are small. Steel cord conveyor belts always have moulded edges.
A particular aspect of the mechanical response in filled rubbers in which the stress-strain curve depends on the maximum load encountered. The phenomenon can be idealized as an instantaneous and irreversible softening of the stress-strain curve that occurs whenever the load increases beyond its prior all-time maximum value. At times, when the load is less than a prior maximum, nonlinear elastic behavior prevails.
The clearance between two rolls of a calender.
The tension of longitudinal sections of a belt system when moving material.
Cracks caused by exposure to an atmosphere containing ozone.
A discharge over the head of the conveyor.
For textile conveyor belt splicing, plies are overlapped. Illustration.
Impressions of release paper, which is being used for preventing the unvulcanized belt stick to the press platens during the vulcanization process. The impressions look like small cracks on the cover surface. Usually they are abraded after a short time and do not affect the belt's life expectancy or performance.
Is observed under cyclic loading conditions with small strain amplitudes, and is manifest as a dependence of the viscoelastic storage modulus on the amplitude of the applied strain.
Plastic elongation. See "Elongation".
Usually the quality or condition of allowing passage of air through a steel cord to identify the degree of rubber penetration.
Pipe conveyor belt
A closed conveyor belt for tight curves and for protection of the environment. More...
Also called "spacing". The distance between the middle of adjacent steel cords in a conveyor belt.
piw (pounds per inch of width)
A term used in the USA, indicating a belt's "working tension". See also here.
A suspension of a finely divided polymer (PVC) in a plasticizer.
A layer of fabric in a belt.
High-elongation fiber, normally used for the belt's weft for good troughability. As warp recommended only for specific applications because of its poor plastic elongation behavior. Absorbs moisture of up to 10 % of its own weight.
Low-elongation fiber, normally used as belt warp. Almost no moisture absorption, good dimensional stability.
The process that converts monomers into polymers.
The length of a belt that can be cured at one time.
Pressure under steel cords on pulley
As a rule of thumb, the pressure between steel cord and pulley should not be higher than 2 N/mm².
Avoiding premature failures through condition monitoring. More...
There are requirements on the minimum pulley diameter. A bigger diameter can have a positive effect on belt life.
A textile carcass impregnated with PVC compound (plastisol). Illustration.
The minimum belt breaking strength (DIN) of a belt in Newtons per millimeter of belt width (or in kN/m).
In the USA sometimes used as a term for the working tension.
Most conveyor belts are not pollutive because of their organic components.
A conveyor for which the head is at a substantially lower altitude than the tail (downhill conveying), generating power.
There are many repair methods for all kinds of belt damage. It is recommended to contact the belt manufacturer for optimum instructions. The most reliable method is a hot repair. Belt damage that reaches down to the belt carcass should find immediate attention, in order to prevent even more serious consequences. See also Preventive Maintenance.
Part of a conveyor's return/bottom/lower run.
The non-carrying belt side towards the pulleys. Usually thinner than the carry side.
A device to measure the shear stress of rubber under the influence of temperature and pressure under a twisting cone. More...
A system detecting a lengthwise damage of the conveyor belt. Most common are sensor loops embedded in the belt's cover at a certain spacing. See here. Also other external - X-ray, mechanical, radiant or optical - systems can be used.
A system to prevent the intrusion of foreign bodies into the belt and its subsequent slitting. This may be done by a simple breaker (a fabric ply) or single synthetic transverse cords. More...
For Rubber Manufacturers Association. Since 2011, all rights are with ARPM. More...
Absorbs the impact from big lumps by filling the rock box first, so other lumps bounce off of the pile onto the belt. It reduces the free fall of the material to the belt.
Also called indentation rolling resistance. The resistance by deformation that occurs when the conveyor belt moves over an idler. The energy of deformation is greater than the energy of recovery. The hysteresis energy loss is depending on the viscoelastic properties of the belt. More...
Also called Rotocure or Auma. A vulcanizing machine consisting of a rotating, heated drum with a flexible steel band partially encircling the drum, which continuously advances the belt while under pressure and heat between drum and band. Illustration.
See Rotary press.
A short length of belting added to an existing belt (mostly a replacement in case of partial damage or splice failure).
A multiplier applied to the calculated maximum force to which a conveyor belt splice (as the weakest link in a conveyor belt) will be subjected. A factor of safety accounts for imperfections in materials, flaws in assembly, material degradation, and other uncertainties.
Conventional safety factors usually range from 6,7 to 10 for steady operating conditions, related to the splice strength.
Modern steel cord conveyor belts are designed based on more realistic safety factors as per DIN 22101 considering the dynamic splice efficiency as per DIN 22110/3.
The amount of vertical deflection of a conveyor belt from a straight line between idlers, usually expressed as a percentage of the spacing between idlers. More.
A system for removing residues from a conveyor belt. Illustration.
A take-up for a conveyor system in which movement of a pulley-bearing block is accomplished by means of a screw.
A cut edge sealed by heat applied to the protruding carcass fibers.
Secondary Safety device
Temperature sensors on pulleys, slip detectors, sprinklers etc. Of relevance for the determination of the right class of conveyor belt for underground use.
If set under fire the belt will generate gases that extinguish the fire. Test procedures require that a minimum undamaged length remains after the belt has been set on fire. More...
Loop made of conductive material embedded in the belt top or bottom cover to prevent slitting. If they are cut, the conveyor drive will be stopped. See also here.
The strength needed to separate cover and ply and ply from ply. More...
Used in the USA for the ratio between the working tension and the belt breaking strength (f.i. 10:1), not considering the splice efficiency. See Safety factor.
The belt service life depends on many influences like type and quality of the belt and the splice, feeding situation, lump size, weight and shape, tonnage, bendings, velocity, pulley lagging, maintenance, safety factor, starting and stopping etc., and the right monitoring system.
Shelf storage life
The period of time prior to use during which a product retains its intended performance capability. Important consideration for (uncured) splicing material. Usually a couple of months under proper storage conditions.
A belt conveyor having overend discharge, the whole being mounted on a travelling carriage capable of being shuttled backwards and forwards.
A layer of rubber material laid on a fabric but not forced into the weave. For improved adhesion between plies.
In a conveyor system, the vertical or inclined plates located longitudinally and closely above the belt to confine the conveyed material.
A 45° bevel in top and/or bottom cover across the belt width in a splice.
Belting made in wide widths and long lengths for later slitting into narrower widths and cutting into shorter lengths.
A conveyor belt used to carry material along an inclined flight. Sometimes called drift conveyor. See also under "Inclination".
A non-driven pulley located close to the drive pulley to provide a greater arc of contact around the drive pulley.
A single ply ("monoply") interwoven fabric. It is more complex and robust than a straight warp fabric. Illustration.
Additional length required to make a splice. Length depending on number of plies, rectangular or bias press, belt rating, steel cord diameter and pitch etc. Best to consult your supplier. More...
A field splicing engineer.
A conveyor piling bulk material.
The tension necessary to accelerate a belt from rest to normal operating speed.
The resistance which must be overcome to start a body sliding down a belt surface.
Steel cord conveyor belts
Conveyor belts with steel cords as tension members. For long distances. More...
Steel cord pullout strength
The adhesion between rubber and steel cord, usually determined in the "supply status" (Fa) and after additional thermal treatment (Fv). A typical minimum requirement is 15d+15 for Fa and 15d+5 for Fv. Example: 5 mm steel cord diameter times 15 + 15 = 90 N/mm. More...
Or "stage". Describing the number of steel cord steps in a conveyor belt splice - "1-step, 2-step" etc.
Usually made of high tenacy polyester yarns for the warp and polyamide yarns for the weft, both held together by binder yarns. The warp (lengthwise) yarns are essentially uncrimped. See also "Solid woven".
Deformation resulting from a force applied to a body.
Force applied to a body that results in the body being deformed.
In a steel cord conveyor belt, Z and S lay steel cords are used alternately to ensure a straight running behaviour of the belt. More.
The pulley near the loading end of the conveyor system.
A pulley which can move in order to maintain relatively constant tension.
The distance the take-up can move during the belt operation.
The fabric, cord and/or metal reinforcing section of a belt, as distinguished from the rubber cover. See Carcass.
The usual term for the rubber's or carcass' ultimate tensile strength, i.e. the maximum stress that the rubber or carcass material can withstand while being stretched (MPa).
Longitudinal stress on the belt tending to cause extension.
Textile conveyor belts
Conveyor belts with one or more layers of textile. Usually EP (polyester/polyamide) or PP (polyamide/polyamide).
Thermal expansion coefficient
The linear thermal expansion coefficient is used to determine the rate at which a material - for instance the steel cord tensile member in a conveyor belt - expands as a function of temperature. This can be of importance for environments with extremely changing low and high temperatures.
A thin sheet of unvulcanized rubber inserted between plies in vulcanized repairs of splices.
The material carrying side of a conveyor belt. Usually thicker than the bottom cover.
An idler mounted on a mechanical device, actuated by the belt moving against it to make the belt run straight.
The distance between the last fully troughed idler station and the flat driving or discharge pulley. Transition lengths should be generous in order to minimize the edge tension and thus reducing the safety factor. More...
An additional layer of polyamide cords for increased rip and impact resistance.
Resistance to belt deformation in the belt crosswise direction.
A device for discharging material from a belt at some intermediate position.
Trough-to-flat transition zone
The transition length between the deepest trough station and the pulley. This length must be sufficiently high to prevent major additional tensions in the conveyor belt edges.
The property of a belt that permits it to conform to the contour of troughing idlers. More...
A belt-to-belt booster drive to reduce belt tension. Originally from the German term "Treib-Traggurt".
Increases belt wear, maintenance and reduces system availability.
The property of materials that exhibit both viscous and elastic characteristics when being deformed. Viscoelasticity is the result of the diffusion of atoms or molecules inside an amorphous material.
The resistance of a material to flow under stress. The higher the viscosity, the thicker the material. Illustration.
An irreversible process during which a rubber compound, through a change in its chemical structure, becomes elastic. More...
A mobile curing machine for field splicing (also called press). More...
The lengthwise yarns in a woven fabric.
A combination of abrasion and cut resistance. The severity of the wear depends on the nature, size, weight, shape and trip rate of the conveyed material. New test methods are being discussed.
A fabric pattern description denoting a specific relationship of warp and filling yarns at specific locations in the fabric.
The crosswise yarns in a woven fabric.
The belt width is usually given in mm (DIN/ISO: 400, 500, 650, 800, 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2400, 2600, 2800, 3000, 3200. AS/BS: 300, 400, 450, 500, 600, 650, 750, 800, 900, 1000, 1050, 1200, 1350, 1400, 1500 1600, 1800, 2000, 2400, 2600, 2800, 3000, 3200).
The smallest part of a steel cord. More...
Used in the USA to determine the belt rating (piw). It is up to the belt manufacturer to decide on the actual belt breaking strength. More...
An appearance usually resulting from curing with separation paper or cloth.
Most advanced method to scrutinize the entire conveyor belt's condition. More...
The stress per unit strain for elastic materials. Equation.