| A-F |
| Abrasion |
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. |
| Adhesion |
The bonding strength between two materials. |
| Ageing |
The exposure to an environment for a period of time. |
| Aramid |
Stands for aromatic polyamide; a low elongation, high-strength fiber (More). |
| Arc of contact |
The circumferential portion of a pulley which is engaged by a belt. |
| Belt clamp |
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. |
| Belt fastener |
A device for holding two ends of a conveyor belt together (More). |
| Belt modulus |
The force per unit width of belt required to produce a stated percentage of elongation. See "Modulus of elasticity". |
| Belt sag |
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. |
| Belt slip |
The speed differential between the belt and the pulley surface, accelerating the abrasion of the belt cover. |
| Belt training idler |
An idler having a belt-actuated swivel mechanism to automatically control side drifting of a conveyor belt. |
| Belt turnover |
A system of idlers to turn a belt over (upside down) (Illustration).(Minimum Lengths). |
| Bending modulus |
The force required to induce bending around a specified radius and, hence, a measure of stiffness. |
| Bend pulley |
A pulley used to change the direction of a belt. |
| Bias cut |
A cut of belt ends made diagonally at an angle less than 90 degrees - usually 30° - to the longitudinal axis. |
| 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. |
| Bleeding |
Migration to the surface of plasticizer, waxes or similar materials to form a film or beads. |
| Blister |
Phoenix Designation |
| Belt modulus |
A raised spot on the surface or a separation between layers usually forming a void or air-filled space in the vulcanized conveyor belt. |
| Booster drive |
Used in some long conveyors to reduce the power/tension at the drive pulley. |
| Breaker |
An extra ply made of fabric or steel for shock absorption to minimize gouging. |
| Breaking strength |
The breaking strength of the conveyor belt, either nominal/minimum (e.g. St 2000) or ultimate/actual (e.g. 2197 N/mm). |
| Bucket elevator belt |
A transversely rigid belt with buckets attached, for vertical conveying. |
| Calender |
A machine equipped with three or more heavy drums revolving in opposite directions (Illustration). |
| Capacity |
The material load on the belt, given in tons per hour (t/h). |
| Carcass |
The fabric, cord and/or metal reinforcing section of a belt, as distinguished from the rubber cover. The carcass provides the tensile strength to move the loaded belt (Carcasses). |
| Catenary idler |
A type of flexible belt-carrying idlers with ends supported in pivoted stands. The tube or rollers sag under the weight of the load to form trough. |
| Center-to-center |
The distance between the center of two pulleys or idlers. Sometimes also called "centers" or "center distance" or "conveyor length". |
| Ceramic pulley lagging |
Used for high-capacity conveyors or in slippy environments. Offers higher wear resistance and a higher friction factor. |
| Clamping force |
Depending on the friction factor of clamp and belt surfaces and on the (downhill) force (Chart). |
| Cleaner |
A device for removing adherent material from the belt. |
| Cleat |
Transverse raised sections on a conveyor belt to stabilize material carried up an incline. |
| Coefficient C |
The length coefficient used for calculating the secondary resistances (Chart). |
| Cold resistance |
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. |
| Cord fabric |
A fabric with reduced elongation by means of the weft yarn twist. |
| Compression set |
The deformation in a material remaining after it has been subjected to and released from a compressive force. |
| Counter weight |
The weight applied to the take-up assembly to maintain proper belt tension. |
| Cover |
The outer rubber (or PVC) component of a belt. Protecting the belt carcass and providing 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. |
| Cracking |
A sharp break or fissure in the surface. See also "wrinkle". |
| Creep |
The action of a belt alternately losing speed on the driving pulley and gaining speed on the driven pulley. |
| Crimp |
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. |
| Crowned pulley |
A pulley with a greater diameter at the center than at the edges. |
| Cut edge |
The uncovered edge of a belt, created by cutting after vulcanization. The carcass is visible from the sides. |
| Degradation |
A deleterious change in the chemical structure of a material. |
| Delamination |
The separation of layers of material. |
| Denier |
A yarn sizing system for continuous filament synthetic fibers on the basis of the weight in grams of 9000 meters of the yarn. |
| Density |
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. |
| Dipped fabric |
Coated with rubber compound by passing through a rubber solution and drying. |
| Dutchman |
A short section of belting mechanically spliced into a length of belting and removed when the take-up allowance is exceeded. |
| Dynamic splice strength |
The test and evaluation method is described here. Usual dynamic splice strengths are given in table 10 of DIN 22101 (see here). |
| Dynamometer |
An apparatus capable of inducing various loads for evaluation of dynamic belting properties. |
| Electrical conductivity |
A measure of how well a material accommodates the transport of electric charge, measured in Ohm (Ω). |
| Elongation |
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 Equations. 2 - 10 %, because this is a typical operating range for textile conveyor belts. After 200 cycles, the amount of permanent elongation of the test piece and the amount of elastic elongation produced by the force differential are recorded from a force-elongation. Typical permanent elongation values: Polyamide (P): 1,0-2,5%, Polyester (E): 0,5-1,5%, Aramide (D): 0,25-0,75%, Steel: 0,1-0,25%. Click here to see a hysteresis curve. Other (static) tests, e.g. as per DIN 22102, require a reference tension of 10% of the nominal belt breaking strength. The maximum total elongation for EP belts is 1,5, 2,5 or 3,0 %, depending on belt class. |
| Elongation at break |
The percentage the rubber or belt can be stretched until it breaks. |
| Endless length |
The length of a closed belt (without splice allowances). |
| EOB |
Low energy consuming belt with reduced indentation rolling resistance (More). |
| Extrusion |
A process whereby rubber is forced through a shaping orifice. |
| Eytelwein's equation |
Determines the optimum difference between the forces F1 and F2 without belt slip (Equation). |
| Fatigue |
The weakening of a material occurring when repeated application of stress causes permanent strain. |
| Feeder belt |
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. |
| Filament |
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). |
| Friction |
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 (Table). |
| f value |
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). Contrary to DIN and ISO, CEMA works with Kx, Ky and 0.015 instead of f, which f is a sum effect of. |
| G-K |
| Gauge |
The thickness of a belt or its individual elements. |
| Gouging |
The effect of sharp heavy material falling onto a conveyor belt cover to loosen or tear out pieces of the cover. |
| Gravity take-up |
A mechanical system that adjusts for the stretch or shrinking of a conveyor belt automatically by a weighted pulley in the system. |
| Hardness |
Degree of resistance to indentation (°Shore A). |
| Head pulley |
The pulley at the discharge end of the conveyor. |
| Heat resistance |
Normal belts usually are resistant up to 80°C. Special compounds can increase the temperature resistance to some 200°C. |
| Hooke's Law |
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 δ and modulus of elasticity (E): ΔL = 1/E × F × L/A = 1/E × L × δ |
| Hysteresis loss |
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". |
| Idler |
A non-powered roller supporting the belt. |
| Impact |
A stroke of a body dropping on the belt. |
| Impact idler |
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. |
| Impact resistance |
The relative ability of a conveyor belt assembly to absorb impact loading without damage to the belt. See also "Transverse reinforcement" |
| Inclination |
The gradient of a conveyor. The maximum (uphill) inclination for non-profiled belts is 18° for ore in a Peruvian gold mine. In general, the angle of repose of the conveyed material must be larger than the inclination angle of the conveyor. |
| Joint |
The connection of two belt ends. |
| Kevlar |
A trademark for para-aramide (aromatic polyamide). |
| L-P |
| Lagging |
A smooth or embossed covering on a pulley to increase friction between belt and pulley. |
| Load support |
Defining the belt's sag on the idler gaps. The sag maybe an issue for very thin belts and wide gaps. Term widely used in North America. |
| LRR |
Low rolling resistance. |
| Maximum tension |
The highest tension occurring in any portion of the belt under operating conditions. |
| Mechanical fastener |
Any mechanical device used to join the ends of belting (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. The belt manufacturer should be consulted for exact figure (Equation). |
| Motion resistance |
The resistances - "main, additional, inclination, special" - when moving a belt on a conveyor system (Illustration). |
| Moulded edge |
A solid rubber belt edge formed in a mould. Another option are cut edges. The technical differences are small. |
| Mullins effect |
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. |
| Nylon |
See "polyamide". |
| Ozone cracking |
Cracks caused by exposure to an atmosphere containing ozone. |
| Overend discharge |
A discharge over the head of the conveyor. |
| Payne effect |
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. |
| Permeability |
Usually the quality or condition of allowing passage of air through a steel cord to identify the degree of rubberization. |
| piw (pounds per inch of width) |
A term used in the USA, indicating a belt's "working tension". See also here. |
| Plastisol |
A suspension of a finely divided polymer (PVC) in a plasticizer. |
| Ply |
A layer of fabric in a belt. |
| Polyamide |
High-elongation fiber, normally used for the belt's weft for good troughability. As warp recommended only for specific applications because of its plastic elongation behavior. Absorbs moisture of up to 10% of its own weight. |
| Polyester |
Low-elongation fiber, normally used as belt warp. Almost no moisture absorption, good dimensional stability. |
| Q-U |
| Rating |
The minimum belt breaking strength (DIN) of a belt in Newtons per millimeter of belt width.In the USA sometimes used as a term for the working tension. |
| Recycling |
Most conveyor belts are not pollutive because of their organic components. However, it is suggested to have them recycled. This is possible for all kind of conveyor belts. |
| Regenerative conveyor |
A conveyor for which the head is at a substantially lower altitude than the tail (downhill conveying), generating power. |
| Return idler |
Part of a conveyor's return run. |
| Rheometer |
A device to measure the shear stress of rubber under the influence of temperature and pressure under a twisting cone. |
| Rip detection |
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 - mechanical or optical - systems can be used. |
| Rip protection |
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 sophisticated systems like single synthetic transverse cords. |
| Rolling resistance |
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. See also here. |
| Safety factor |
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 splicing efficiency as per DIN 22110/3. |
| Screw take-up |
A take-up for a conveyor system in which movement of a pulley-bearing block is accomplished by means of a screw. |
| Sealed edge |
A cut edge sealed by heat applied to the protruding carcass fibers and/or rubber frictioned on the edge. |
| Self-extinguishing |
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. |
| Service factor |
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. |
| Service life |
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. |
| Shelf storage life |
The period of time prior to use during which a product retains its intended performance capability. Important for (uncured) splicing material. |
| Shuttle conveyor |
A belt conveyor having overend discharge, the whole being mounted on a travelling carriage capable of being shuttled backwards and forwards. |
| Skim coat |
A layer of rubber material laid on a fabric but not forced into the weave. Normally laid on a frictioned fabric. |
| Skirt board |
In a conveyor system, the vertical or inclined plates located longitudinally and closely above the belt to confine the conveyed material. |
| Skiver |
Grinding equipment to bevel belt ends for an overlap splice. There are sanding belt, drum and disk skivers in use. |
| Slab belting |
Belting made in wide widths and long lengths for later slitting into narrower widths and cutting into shorter lengths. |
| Slope belt |
A conveyor belt used to carry material along an inclined flight. Sometimes called drift conveyor. See also under "Inclination". |
| Snub pulley |
A non-driven pulley located close to the drive pulley to provide a greater arc of contact around the drive pulley. |
| Solid woven |
A single ply ("monoply") interwoven fabric. It is more complex and robust than a straight warp fabric. |
| Splice allowance |
Additional length required to make a splice. |
| Splicer |
A field splicing engineer. |
| 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. |
| Straight warp |
Made of high tenacy polyester fibres for the warp and weft polyamide yarns, both held together by a polyamide composite yarn. The warp (lengthwise) yarns are essentially uncrimped. The yarns are thicker and locked together. |
| Tail pulley |
The pulley near the loading end of the conveyor system. |
| Take-up pulley |
A pulley which can move in space in order to maintain relatively constant tension. |
| Tensile member |
The fabric, cord and/or metal reinforcing section of a belt, as distinguished from the rubber cover. |
| Tensile strength |
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). |
| Tension |
Established belt manufacturers are testing all parameters agreed in the purchase order of every belt produced before shipment. Independent test labs can be consulted to review the results. |
| Testing |
Cracks caused by exposure to an atmosphere containing ozone. |
| Tie gum |
A thin sheet of unvulcanized rubber inserted between plies in vulcanized repairs of splices. |
| Training idler |
An idler mounted on a mechanical device, actuated by the belt moving against it to make the belt run straight. |
| Transition length |
The distance between the last fully troughed idler 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. |
| Transverse reinforcement |
An additional layer of single polyamide cords in custom-made pitch and diameter for increased rip and impact resistance. |
| Tripper |
A device for discharging material from a belt. |
| Troughability |
The property of a belt that permits it to conform to the contour of troughing idlers. |
| TT drive |
A belt-to-belt booster drive to reduce belt tension. Originally from the German term "Treib-Traggurt".Increases belt wear, maintenance and system availability. |
