Belting Glossary - Conveyor Belt Terms and Meanings
There are currently 730 names in this directory
Accelerated aging
Intensive exposure to operating conditions to obtain an early change in physical properties of an elastomer.
Accelerated life test
A method designed to approximate in a short time the deteriorating effects obtained under normal service conditions.
Across the line starting tension
Tension developed in a belt when full electrical power is applied to the drive system.
Adhesion
Basically, the adhering, clinging, bonding or sticking of two material surfaces to one another, such as rubber to rubber, rubber to metal, rubber to wood, rubber to fabric, etc.
Adhesive
A material which, when applied, will cause two surfaces in contact with each other to stick together.
Adhesive coating
A coating applied to a surface to create or increase its bond to an adjoining surface.
Adhesive fabric
A fabric with a surface treatment which will bond two surfaces together when interposed between them.
After-cure
A continuation of the process of vulcanization after the cure has been carried to the desired degree and the source of heat removed.
Air bomb aging
Means of accelerating changes in physical properties of materials by exposing them to the action of air at elevated temperature and pressure.
Air checks
The surface markings or depressions which occur due to air trapped between material and mold or press surface.
Air curing
Vulcanization of rubber products in air opposed to vulcanizing in a press or steam vulcanizer.
Air oven aging
Means of accelerating a change in physical properties of rubber compounds by exposing them to the action of air at an elevated temperature but normal atmospheric pressure.
Angle of repose
The angle to the horizontal plane which a grainy material will naturally assume when dropped in a pile.
Anti-static
A belt’s capability to dissipate and therefore reduce build up of static electricity while running.
Apex crown
A pulley crown that continuously increases in diameter from the edges of a pulley towards the center, creating an undesired ridge in the center. See also crowned pulley.
Arc of contact
(1) The portion of a curved surface which is engaged.
(2) In belts, it refers to the portion of a pulley which is engaged by the belt and is usually expressed in degrees.
(2) In belts, it refers to the portion of a pulley which is engaged by the belt and is usually expressed in degrees.
Armored belt
A conveyor belt with crosswise insertions in the cover such as steel cables to minimize gouging or tearing of the cover by sharp objects.
Artificial weathering
Exposure to cyclic laboratory conditions involving changes in temperature, relative humidity and radiant energy, with or without direct water spray, attempting to produce changes in the material similar to that observed after long-term continuous outdoor exposure.
Atmospheric cracking
Small fissures in the surface of a belt cover caused by exposure to atmospheric conditions.
Automatic take-up
A mechanical device to maintain proper tension in a belt automatically compensating for belt stretch or shrinkage in service.
Backstop
A mechanical device for preventing a loaded, inclined conveyor or elevator belt from running backwards after the belt has been stopped.
Banbury mixer
A specific type of internal mixer used to incorporate filler and other ingredients in rubber or plastic operations.
Bare duck
The duck surface of a fabricated article wherein the exposed duck surface is free of any covering.
Bareback surface
A belt surface where the textile surface is without any coating. It is usually the back or pulley side of the belt, but the top side could be bareback, as well.
Base belt
The portion of a closed belt in a closed belt conveyor which remains flat and provides the necessary tensile strength.
Basic tension bearing yarns
One of the two warp systems in a straight warp fabric where the warp yarns are substantially without crimp and provide the tensile strength for the belt.
Basket weave
A fabric with ends of yarn side by side in both the warp and filling in a plain weave construction.
Bead rubber
An extruded polymeric compound used to fill the void between butted joint of two pieces of fabric.
Belt
A flexible reinforced band placed around two or more pulleys to carry materials from one place to another.
Belt clamp
Beams or metal plates secured transversely on both sides of belt ends to hold the ends 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 conveyor
A mechanical system composed of suitable head, tail, bend pulleys and belt idlers or a slider bed to handle bulk materials, packages, or other objects placed directly upon it.
Belt drive
An assembly of power-driven pulley(s) used to transmit torque when initiating and maintaining motion to a conveyor or elevator belt.
Belt duck
An open weave duck made from plied yarns with strength predominately in the warp direction. Used primarily in the manufacture of conveyor belts.
Belt fastener
A mechanical device for holding the ends of belt together. There are a lot of different fasteners on the market.
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 tracking switch
A limit switch actuated by the edge of a conveyor belt when the belt moves to either side of its centered path.
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 pulleys arranged to turn a belt over. Frequently used to prevent building-up on return idlers by turning the dirty side (carrying side) up. See also twist.
Belting deflector
A mechanism which deflects the conveyed material off of the belt at specific points along the conveyor.
Bench test
A modified service test in which the service conditions are approximated by means of a simulation in the laboratory.
Bending modulus
The force required to induce bending around a specified radius and, hence, a measure of stiffness.
Bias angle
The smaller included angle between the warp yarns of a fabric and the diagonal line across the warp yarns.
Bias cut
A cut of a textile material or belt ends made diagonally at an angle less than 90 degrees to the longitudinal axis.
Bias laid
Material laid on or wrapped around so the warp yarns are at an angle less than 90 degrees to the longitudinal direction.
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. See also Bloom.
Blisters
A raised spot on the surface or a separation between layers usually forming a void or air-filled space in the vulcanized or laminated article.
Bloom
A discoloration or change in appearance of the surface of a rubber product caused by the migration of a liquid or solid to the surface. Examples: sulfur bloom, wax bloom. Not to be confused with dust on the surface from external sources.
Bolted plate hinge fastener
Steel plates both sides and both ends of two belt ends to be fastened together (secured to the belt with bolts with the ends of the plates constructed into a circular hole for accepting a hinge pin to secure the two ends of the belt(s) together.
Bootlegging
(1) Progressive ply delamination.
(2) The separation of plies in belting due to flexing.
(2) The separation of plies in belting due to flexing.
Bottom cover
The protective rubber cover on the surface contacting the driving mechanism of a conveyor belt.
Bow
(1) Curvature from the flat plane on the surface.
(2) The deviation from the straight line of the fill yarn in fabric.
(3) The deviation from the straight line of a product when unrolled and laid on a flat surface.
(2) The deviation from the straight line of the fill yarn in fabric.
(3) The deviation from the straight line of a product when unrolled and laid on a flat surface.
Brand
A mark or symbol identifying or describing a product and/or manufacturer: may be either embossed, inlaid, or printed.
Breaker ply
An open weave fabric used next to the carcass fabric and/or in the cover to improve the attachment of the cover to the carcass and to improve cover cut and gouge resistance.
Buckled ply
A deformed ply, usually the result of a fold or wrinkle, which distorts it from its normal plane.
Bumping
In the operation of a flat press, the alternative application and release of ram pressure to vent trapped air and gases.
Butt strap joint
The connection of elevator belt ends with a piece of belting the width of the elevator belt placed over the butted belt ends, usually extending under at least two buckets and secured with bolts to the belt.
Calculated center distance
In belt drives, the distance between two shaft centers calculated from pulley diameters and belt length being used.
Calender
A machine with three or more internally heated or cooled cylinders used to (1) continuously sheet out polymeric compound or fused PVC (2) to wipe polymeric compound into the interstices of a fabric leaving a small portion of it on the surface of the fabric, or (3) to lay a continuous sheet of compound on a fabric.
Capacity
The maximum number of pieces, volume, or weight of material a belt conveyor can handle in a given time interval and belt speed.
Capped edge
A rubber protective edge placed around a product internally reinforced with textile or other material.
Carcass
The fabric, cord and/or metal reinforcing section of any rubber product such as a belt, as distinguished from the rubber cover.
Carrying run
The portion of a conveyor that carries the load between the loading and discharge points.
Castfilm
A film made by depositing a layer of plastic, either molten, in solution, or in a dispersion onto a surface, solidifying and removing the film from the surface.
Catenary idler
A type of flexible belt-carrying idler with ends supported in pivoted stands. The tube or rollers sag under the weight of the load to form trough.
Cemented edge
An application of cement around the edge of a fabricated product with or without internal reinforcement for protection or adhesion. (A form of Capped Edge.)
Center-to-center
The distance between the center of two pulleys or idlers. Also called centers or center distance.
Centrifugal bucket elevator
A type of bucket elevator having a belt which travels at sufficient speed to discharge material from the buckets by centrifugal force.
Chafer duck
A relatively open weave duck of approximately square woven construction made with single or ply yarn.
Chalking
Formation of a powdery surface condition due to disintegration of surface binder or elastomer due in turn to weathering or other destructive environments.
Checking
Short shallow cracks on the surface generally due to effect of destructive action of environmental conditions.
Chevron
A ridge or profile arranged in a Vee shaped configuration on a belt carrying cover to stabilize material carried up an incline.
Chute lining
Highly abrasion resistant elastomeric lining in a chute to protect the metal chute from abrasion wear.
Cleated belt
Transverse raised sections on a conveyor belt to stabilize material carried up an incline.
Closed belt conveyor
A moving, endless conveyor belt formed into a tubular shape by joining its edges while carrying material, and opening the edges while in motion to receive and discharge material.
Coefficient of friction
The ratio of the force required to move a package across a belt surface to the weight of the package.
Cogged V-belt
A V-belt cut or produced with a series of evenly spaced V-shaped indentations in the inner face to increase the belt’s flexibility.
Coil
Usually a squared end belt piece of full manufacturing length but not full manufacturing width. See also slab belting.
Cold splice/bond
Usually the joining of two or more sub-straits together, using a two-part cement that is chemically cured without using supplemental heat from an external source.
Commercially smooth
A degree of smoothness of an article which is acceptable in accordance with industry practice.
Compound
A mixture of a polymer(s) and other materials to give the desired chemical and physical properties in the elastomeric components of a belt.
Compression set
The deformation in a material remaining after it has been subjected to and released from a compressive force.
Contact stain
When staining occurs on the area of an object directly in contact with the rubber article it is known as “contact stain”.
Continuous bucket elevator
A bucket elevator belt that discharges by gravity over the inverted bottom of the preceding bucket on the descending side of the elevator.
Control
A material or a product of known characteristics included in a series of tests to provide a basis for evaluation of other products.
Conveyor
A system for the continuous movement or transport of bulk materials, packages or objects along a predetermined path.
Conveyor belt package deflector
A mechanical diverter placed at an angle across the belt to deflect packages off the belt at specific locations.
Conveyor belt stretch
The increase in belt length which occurs when tension is imposed. Stretch is either elastic or permanent. Elastic stretch is a temporary change in length which varies directly with the pull. Permanent stretch is the residual change in length after tension has been removed; it generally accumulates over a period of time.
Copolymer
A substance consisting of molecules characterized by the repetition of two or more types of monomeric units.
Cord fabric
A fabric with plied or cabled yarns in the warp direction and a light weight filling yarn spaced only sufficiently to process the fabric.
Count
In a fabric, the number of warp ends, the number of filling picks, or both in a square inch of fabric.
Counter weight
In conveyor belting, the weight applied to the take-up assembly to maintain proper belt tension.
Creep
(1) The deformation occurring with the lapse of time in both cured and uncured rubber, in a body under stress in addition to the immediate elastic deformation. Some related terms and properties are stress-relaxation, hysteresis, damping, flow, compression set and viscosity. See Cold Flow.
Creeper drive
An auxiliary drive, usually consisting of a small motor and speed reducer, used to keep a belt conveyor in motion at a very low speed during non-operating periods in extremely cold weather. It is used to prevent freezing of a belt and other components.
Crowned pulley
A pulley with a greater diameter at the center, or other points, than at the edges. There are radial and trapezoidal crowns. Apex crowns are not recommended for industrial belts.
Crystallization
A change in physical properties resulting from the crystalline reorientation caused by temperature.
Cure time
Time required, at a given temperature, to produce optimum physical properties in an elastomer.
Curl
The action of the edges of a belt bending upward on the carrying run and downward on the return run. Also called cupping.
Cut edge
The uncovered edge of a laminated product, such a belt, created by cutting after vulcanization.
Data code
Any combination of numbers, letters, symbols, or other methods used by a manufacturer to identify the date of manufacture.
Deflector
A board or plate at an angle across the path of a belt traveling over a flat surface to transfer material off the belt.
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.
Diameter
The length of a straight line from the periphery passing through the geometric center to the other side of the periphery of an object.
Dielectric strength
The measure of electric potential strength of a rubber product. Measure of its ability as an insulating compound to resist passage of a disruptive discharge produced by an electric stress. Measured as volts per mil of thickness.
Dip coat
A thin coat on a surface obtained by dipping the material to be coated into the coating materials.
Double plate bolt fastener
Two ends of belting joined together with a plate on both sides across both ends of the joint.
Drive factor
A numerical factor used for calculating the belt minimum slack side tension required for a given driving condition and or configuration.
Drive snubbed pulley
An non-driven pulley located close to the drive pulley to provide a greater arc of contact around the drive pulley.
Drive-on hinged fastener
Two ends of belting joined together with a pre-packaged fastener assembly having prongs for driving through the belt end.
Drive-on plate fastener
Two ends of belting joined with a single plate, across the top cover joint, with rivets or sharp teeth clinched over on the bottom cover side of the belting.
Drop ply
The omission of a reinforcing ply for a specified distance from each edge. Usually the bottom or next to bottom ply in flat conveyor belting.
Duck
A tern applied to a wide range of medium and heavyweight fabrics, commonly made of cotton, including the heaviest and strongest of all, single-woven fabrics. There are three main types number duck, army-type duck and flat duck.
Durometer hardness
An arbitrary numerical value which measures the resistance to penetration of the indentor point of the durometer. Value may be taken immediately or after a very short specified time.
Dutchman
A short section of belting mechanically spliced into a length of belting and removed when the take-up allowance is exceeded.
Dynamic fatigue
Loss in properties of a material when continually subjected to flexing and or cyclic stress.
Dynamometer
An apparatus capable of inducing various loads for evaluation of dynamic belting properties.
Effective tension
Difference between the tight side and the slack side tension at the drive pulley providing the necessary pull to move the load.
Elastic limit
The limiting extent to which a material may be deformed and yet return to approximately its original shape after removal of the deforming force.
Elasticity
The property of an article which tends to return it to its original shape after deformation.
Equivalent free fall
The calculated vertical distance material falls from the discharge point to end of a belt.
Extensible conveyor
An adjustable conveyor system with a loop of belting between the carrying idlers and the return idlers for changing the center distance.
Extraction test
A test in which certain components are separated from a solid by dissolving them in a liquid solvent under suitable conditions.
Extrusion
A process whereby heated or unheated plastic forced through a shaping orifice becomes a continuously formed piece.
Fabric design
The combination of size and numbers of fibers or yarns, in both warp and filling, and the manner in which they are processed.
Fabric impression
A pattern in the cover of a belt formed by contact with a fabric during processing.
Fabric rating
The maximum tension per ply of fabric a belt should be operated under ideal conditions.
Fiber
A unit of matter having a length at least 100 times its diameter and which can be spun into a yarn.
Filler seam
Extruded polymeric compound used to fill the void between two pieces of belt cover or fabric.
Finger tipping tool
Equipment similar to a sodering iron to fix fingers of a thermoplastic belt splice in place prior of putting the belt into a watercooled press.
Flame retardance
Intensity of flame diminished by fire retardant ingredient(s) in the plastic compound.
Flame test
A means, under specific condition, for establishing the flame performance of a belt. This will not indicate the performance of the belt in any fire in which the belt may be involved.
Flanged pulley
A pulley with a raised rim at the edges for the purpose of keeping the belt on the pulley.
Flash
Material protruding from the surface of a molded part, appearing at the mold parting line or mold vent points.
Flat belt
(1) A belt the cross section of which is in the general form of a rectangle; (2) A belt which operates on a smooth flat bed or straight idlers or rollers.
Flat press
A belt finishing press with flat platens, between which the belt is heated and compressed.
Flex life test
A laboratory method used to determine the life of a plastic product when subjected to dynamic bending stresses.
Floating breaker
A leno or cord breaker embedded in a belt cover with a distinct layer of elastomer separating the breaker from the carcass.
Flow crack
A surface imperfection caused by improper flow and failure of a compound to blend with itself during the moulding operation.
Frequency factor
The duration of time in minutes required for one complete cycle of a conveyor belt.
Friction
(1) The resistance to motion of a belt due to the contact between two surfaces. (2) Improperly used to indicate the bond between two surfaces.
Friction coat
An impregnation of rubber material calendered by friction motion to a fabric so that the material is forced into the weave of the fabric.
Friction surface
The exposed portion of a belt finished with a layer of impregnated plastic as distinguished from being completely covered with a layer of plastic.
Friction, coefficient of
The ration between the force pressing the surfaces together and the force required to move it.
Fusion
An irreversible process during which a PVC compound or platisol undergoes a physical change and becomes a homogeneous mixture by the mutual solvation of the PVC resin and the plasticizer in the compound, as result of heating to an appropriate temperature.
Gouging
The effect of sharp heavy material falling onto a conveyor belt cover to loosen or tear out pieces of the cover.
Grab test
A tensile test for woven fabric using specimens considerably wider than the jaws holding the ends of the test specimen.
Grade
The ration of incline or decline of a conveyor expressed a s percent of the vertical height to the horizontal distance.
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.
Head-tail drive
A belt driving system using one or more powered pulleys at or near both the head and tail pulleys with each pulley independently driven.
Heat mark
Extremely shallow depression or groove in the surface of a plastic visible because of a sharply defined rim or roughened surface.
Heavy weight belt
A belt with a rated maximum working tension equal to or greater than 160 pounds per inch width, when operating under ideal conditions.
Herringbone weave
The longitudinal appearance of a row of parallel lines slanting at an angle in the opposite direction to another row of slanting parallel lines.
Hinged fastener
A fastener attached independently to each of the belt ends designed with an opening in the end of the fastener to accept a pin through the opening to complete the joint.
Holland cloth
A filled sheeting (usually starch filled) with a smooth, glossy finish on both sides, used as separating medium.
Horizontal belt curve
The portion of a conveyor system which deviates from a straight line in the same horizontal plane as the rest of the system.
Hugger belt conveyor
Two belt conveyors whose conveying surfaces combine to convey loads up steep inclines or vertically.
Hysteresis
A loss of energy due to successive deformation and relaxation. A measurement of the area between the deformation and relaxation stress-strain curves.
Idler
(1) A non-powered pulley around which a belt travels (2) a non-powered roll or rolls supporting a belt.
Immediate set
The amount of deformation measured immediately after removal of the load causing the deformation.
Impact
The single instantaneous stroke or contact of a moving body with another either moving or at rest, such as a large lump of material dropping on a conveyor belt.
Impact energy
The effective combination of force (weight of the body and height) when one body falls on another.
Impact idler
A belt idler having a resilient roll covering, resilient molded elastomer rings, pneumatic tires, springs or other means of absorbing impact energy at or close to the place where material contacts the belt.
Impact rating
The maximum rating of a belt construction based on the fabric, impact rolls, design of loading, size of material falling on the belt, relative speed of the material and the belt, etc. to withstand the energy of impact loading.
Impact resistance
The relative ability of a conveyor belt assembly to absorb impact loading without damage to the belt.
Impression
Design formed during vulcanization in the surface of any rubber article by a method of transfer, such as fabric impression or molded impression.
Indentation
(1) The extent of deformation by the indentor point of any one of a number of standard hardness testing instruments; (2) A recess in the surface of a belt cover.
Installation allowance
The amount by which the center distance can be adjusted so a belt can be installed without damaging.
Interstice
A small opening, such as between fibers in a cord or threads in a woven or braided fabric.
Interwoven conveyor belt
A type of conveyor belt construction similar to that of a solid woven belt, with plies interwoven such that it is impossible to separate them.
Irons
Strips of metal at the edges of a belt in a flat press to confine the edge elastomer for making a molded edge or to obtain uniform thickness of the edges of a slit edge belt near its edges.
Lap joint
An elevator joint where one end of the belt laps over the other end with the leading edge on the bucket side.
Lap seam
A seam made by placing the edge of one piece of material extending flat over the edge of the second piece of material.
Lateral misalignment
Offset of pulleys, idlers, or structure from a design longitudinal reference line.
Leno weave
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.
Life test
A laboratory procedure used to determine the resistance of rubber article to a specific set of destructive forces or conditions.
Light weight belt
A belt with a rated maximum working tension of less than 160 pounds per inch width.
Lined bolt holes
Bolt holes which have been given a protective coating to cover the exposed carcass.
Liner
A separator, usually cloth, plastic film, or paper, used to prevent adjacent layers of material from sticking together.
Live rolls
A series of rolls over which objects are moved by application of power to all or some of the rolls.
Load support
The ability of a fully loaded conveyor belt to bridge the idler gap without creasing into the idler gap and carry material without excessive sag between the carrying idler pulleys.
Loop edge
A selvage formed by having the filling loop around a catch cord or wire, which is later withdrawn, leaving small loops along the edge of the cloth.
Low temperature flexibility
The ability of belting to be bent or flexed at low temperatures without loss of serviceability.
Master batch
A preliminary mixture of two or more compound ingredients for purposes of more thorough dispersion or better processing, and which will later become part of the final compound in a subsequent mixing operation.
Maximum ply
(1) The maximum number of plies permissible that will permit for satisfactory troughability; (2) The maximum number of plies permissible to satisfactorily operate around a pulley of a given diameter.
Migration
The transfer of an ingredient in a rubber compound from one layer to an adjacent layer or to the surface.
Migration stain
When staining occurs on the area of an object adjacent to the rubber article it is known as “migration stain”.
Mildew
Growth on organic matter produced by fungi, generally in textile components of rubber articles. Usually causes deterioration.
Mill
A machine with two horizontal rolls revolving in opposite directions used for the mastication or mixing of rubber.
Minimum accelerating time
The least time allowed to accelerate a conveyor belt from rest to normal speed without exceeding its maximum safe working stress.
Minimum braking time
The least time allowed to decelerate a conveyor belt from normal speed to rest without exceeding the maximum safe working stress or causing the belt to double up on itself.
Minimum ply
The least number of plies that will support the load on a belt without damaging deformation.
Modified grab test
A tensile test for woven fabric using specimens wider than the jaws holding the specimen cut midway between the jaws to the warp yarns held by the jaws. Minimizes warp yarn popout experienced by raveled specimen test.
Modulus of elasticity
The force divided by the percent elongation (divided by 100) to cause the elongation.
Modulus, belt
The force per unit width of belt required to produce a stated percentage of elongation.
Mold lubricant
The material used to coat the surfaces of a mold to prevent the rubber adhering to the metal during vulcanization.
Mold mark
An indentation or embossment on the surface of a molded product caused by irregularities in the mold surface.
Mooney viscosity
A measure of the plasticity of a polymeric compound determined in a Mooney shearing disc viscometer.
MSHA flame retardant test
Flame test procedure for underground conveyor belting prescribed by the Mine Safety & Health Administration of the U.S. Department of Labor.
Narrow disc idler
A flat pulley with discs attached around the pulley at certain intervals across the pulley.
Needle punched
Non-woven fabric punched with a hack latched needle to improve its strength and stability.
Net endless length
The manufactured length necessary to provide proper initial fit and tensioning of a belt on a specified drive.
Norway type elevator bolt
Flat top, squared shoulder bolt for attaching elevator buckets to elevator belts.
Offset idler
The center carrying roller which is offset and transversely lapping the troughing idlers.
Oil resistant
Withstands the deterioration effect of oil(generally refers to petroleum) on the physical properties.
Oil well splice
Two ends of a belt each bent 90 degrees around a steel form and bolted together through the belt and steel form.
Oligomer
A polymer consisting of only a few monomer units such as in dimer, a trimer, a tetramer etc. & their mixtures.
One side
Pertains to one of the two outward faces or surfaces of a conveyor belt (not the edges of the belt).
Operating tensions
The tension of longitudinal sections of a belt system (tight side and slack side) when moving material, as distinguished from tension when the belt is running empty.
Optimum cure
The time, temperature and compression of vulcanization or of fusion at which a desired combination of properties is attained in an elastomer.
Organosol
A suspension of a finely divided plastic in a plasticizer with a volatile organic solvent.
Oven
A low pressure hot air chamber used for the purpose of heating, drying, baking or vulcanizing rubber products. See Aging.
Oxidation
The reaction of oxygen on a rubber product, usually detected by a change in the appearance or feel of the surface or by a change in physical properties.
Oxygen bomb aging
A means of accelerating change in the physical properties of rubber compounds by exposing them to the action of oxygen at an elevated temperature and pressure.
Permanent set
The amount by which an elastic material fails to return to its original form after deformation.
Permeability
The quality or condition of allowing passage of liquids or gases through a rubber layer.
Pitch line
The plane within a belt which undergoes neither stretching nor compression when the belt rounds the pulley, i.e., the neutral plane of the belt structure.
Plain weave
The simplest type of weave with both adjacent warp and filling yarns crossing over and under each other.
Plastic
A material that contains as an essential ingredient one or more organic polymeric substances of large molecular weight, is solid in its finished state, can be shaped by flow.
Plasticizer
A compounding ingredient which can change the physical and chemical properties and processibility of a polymeric compound.
Ply adhesion
The force required to separate two adjoining strength reinforcing members in a rubber product.
Polymer
A macromolecular material formed by the chemical combination of monomers having either the same or different chemical composition.
Portable vulcanizer
A vulcanizer readily moved from one place to another, usually used for making field splices and repairs.
Pot life
The period of time during which a reacting polymeric compound remains suitable for its intended use after having been mixed with a reaction-initiating agent.
Powered roller conveyor
A term used by the U.S. Postal Service to mean a live roller conveyor. See live roller conveyor.
Press
A machine consisting of two or more heated plates which can be brought together and separated by hydraulic pressure or mechanical action.
Press marks
Irregularities in the surface of a vulcanized product caused by the press ends or by corresponding irregularities in the press surface.
Pricker marks
Small marks in the cover of a vulcanized belt where a roll with sharp needles had penetrated the uncured belt to allow trapped air in the uncured belt composite to escape.
Profile top cover
Belt surface having a series of continuous or interrupted, straight or curved ridges, across the belt at regular intervals to enhance the belts ability to move materials up inclines or down declines.
Pure gum compound
A natural rubber or isoprene compound containing only the ingredients necessary to process it, to protect it from aging, and to cause vulcanization.
Qualification conformance inspection
The examination of samples from a production run to determine conformance to a given specification.
Qualification inspection test
The examination of samples from a typical production run to determine conformance to a given specification for approval to become a supplier.
Recovery
The degree an elastomeric material returns to its original dimensions after being stressed.
Reinforcement agent
An ingredient in a polymeric compound not basic to its vulcanization used to increase its chemical and physical properties.
Resistance
The property or ability of matter to withstand the effects of force, pressure, heat or chemical action.
Ribbon blender
A type of internal mixer used to mix powders and liquids into a dry powderous viscous or liquid mass.
Ribs
Transverse configurations on the carrying side of a belt to facilitate carrying material on an incline.
Riveted plate joint
A mechanical fastener with rivets projecting through a plate on both sides of the belt.
Roll belting
Belting made to ordered width but of nominal lengths for cutting later into shorter lengths.
Rotary press
A vulcanizing machine consisting of a rotating, heated drum with a flexible steel band partially encircling the drum, which continuously advances a material while under pressure and heat between drum and band.
Rough top
A belt made with projections in the carrying surface to improve the ability of the belt to carry material on inclines.
Safe working strength
The manufacturer’s recommended maximum working tension for a conveyor belt operating in ideal conditions.
Safety factor
The ratio of the maximum stress that a belt or a belt splice can withstand to the maximum stress recommended for it by the manufacturer. The ratio of breaking strength to rated working tension.
Sag
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.
Sag belt tension
The minimum tension in any portion of the carrying run of a belt necessary to prevent excessive sag of the belt between idlers.
Seam
The place where two edges of fabric or elastomer are adjacent to each other to form a single ply or layer.
Seaming strip
A strip of polymeric material laid over and/or in a seam to fill any voids between the adjacent plies of material.
Self-aligning idler
An idler having a belt-activated swivel mechanism to control the side movement of an operating conveyor belt.
Service factor
The amount by which the normal rating of a unit is altered to compensate for specific service requirements.
Service test
A test in which the product is made to operate under service conditions in the actual equipment.
Set
The amount of deformation remaining after complete release of the load producing the deformation.
Sheeting
A form of plastic in which the thickness is very small in proportion to length and width and in which the plastic is present as a continuous phase throughout.
Shelf storage life
The period of time prior to use during which a product retains its intended performance capability.
Singles yarn
The product from aligning and twisting together fibers or twisting together filament fibers.
Skim or 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.
Skive
A cut or grinding action made on an angle to the surface to produce a tapered or feathered end.
Slab belting
Belting made in wide widths and long lengths for later slitting into narrower widths and cutting into shorter lengths.
Slack side tension
The lessor of the tensions in a belt on an operating conveyor. Usually immediately following the drive pulley.
Slider bed conveyor
A conveyor belt operating all, or in part of its length, over a flat support surface as opposed to being supported by a series of rollers.
Slip
The action that takes place, causing a differential movement between the pulley surface and the belt.
Slip and sequence system
An interlocking belt conveyor system that stops the system when the speed of the conveyor belt drive pulley exceeds a certain speed of the conveyor belt.
Snub pulley
A pulley adjacent to a drive pulley that increases the arc of contact on the drive pulley to increase the effectiveness of the drive.
Solid woven belt
A type of conveyor belt wherein the carcass is a single ply consisting of multiple layers of warp and filling yarns interwoven. The carcass usually is impregnated and/or coated with polymeric compound.
Spread
To apply a thin coat of liquid material over a surface by means of a knife, bar, or doctor blade.
Spread coat
To apply a thin coat of material over a surface determined by means of a knife, bar, or doctor blade.
Spread coated fabric
A fabric coated with a liquid plastic by a spreading process and then heated to fuse the coating.
Spring take-up
A mechanical device on both sides of the conveyor system where a variable force spring is secured to the conveyor structure and to the tail pulley block for the purpose of maintaining a uniform tension in the belt.
Staple
A textile fiber of relatively short (1″ to 3″) length which when spun and twisted forms a yarn.
Static electricity
Electrical potential resulting from two surfaces rubbing together or parting one from the other.
Steel cord belt
A conveyor belt having a tension bearing member of steel cords lying in the same plane with a definite spacing between the cords, elastomer between the cords and an elastomeric cover on both sides of the belt.
Step ply
A conveyor belt having a plied textile carcass in which the upper ply or plies are set back toward the edges to increase the cover gauge in loading area.
Stepped splice
The joint of one end of multi-ply belting with plies of fabric removed so respective ply ends will butt together and overlap adjacent plies of fabric.
Stitching
A method of butting or joining two pieces of material together, usually by means of a stitcher roller.
Stock roll
A belt made to some nominal length and width for subsequent cutting to required length and width.
Straight warp weave
Two warp yarn systems and a filling yarn system where one warp system is essentially without crimp and is the tension bearing member, while the other warp system is interlaced with the filling yarn and provides mechanical fastener holding capability.
Striated cover
A cover having grooved or channeled lines, due to transfer of irregularities from contact with surfaces of forming or finishing equipment.
Strip test
In fabric testing, a tensile strength test made on a strip of fabric with cut edge or raveled down to a specified number of threads or width of fabric, all of which are firmly held in gripping jaws wider than the test piece.
Sun check
Fine cracks and crazing of an elastomeric surface primarily due to the sun’s ultraviolet rays.
Take-up pulley
A pulley which can move in space due to gravity, a spring, or other forces in order to maintain relatively constant tension in a specific strand of a belt.
Tape line measurement-maximum length
The inside circumference of a belt measured around the pulley surfaces when the take-up idler(s) are moved out to where they take up all the belt slack their movement permits.
Tape line measurement-minimum length
The inside circumference of a belt measured around the pulley surfaces when the take-up idler(s) are moved in for the installation of the shortest belt possible.
Tear down
The removal of a ply of fabric in a multi-ply fabric belt to prepare the stepped down configuration for a stepped splice.
Telescoped roll
At the outside end of a roll of belting, turns of the belting progressively loosened and moved outward from the remainder of the evenly wound turns of the belting.
Tension minimum
The lowest tension occurring in a belt in a conveyor or elevator system under operating conditions.
Tension ratio
In an operating belt system, the ratio of the larger to the smaller tension as the belt approaches and leaves a driving or driven pulley.
Tension, slack side
In a belt system, where the two portions of the length of a belt on either side of a driving or driven pulley have different tensions, the slack side tension is the smallest of the two.
Tension, slope
The tension in an inclined belt caused by the weight of the material being elevated in addition to the belt weight and independent of friction and other sources of tension.
Tension, take-up
The amount of tension in each of the runs of belting approaching and leaving the take-up pulley, the total of which is the force exerted by the take-up device.
Tension, tight side
In an operating conveyor system, the greater of the tensions as the belt approaches and leaves the drive pulley.
Textile
A general term applied to yarn, cord, non-woven, or woven fabric made from a fibrous material.
Thermoplastic
Capable of being repeatedly softened by heating and hardened by cooling and in the softened state can be shaped by flow.
Tie gum
A thin sheet of un-vulcanized rubber inserted between plies in vulcanized repairs of splices.
Tire bead wire
Steel wire placed in or beneath the top cover to minimize rips in the belt by objects that penetrate the belt.
Top cover wear
The protective rubber cover on the material conveying surface or surfaces of a conveyor belt.
Training
The process of adjusting idlers, pulleys, and loading conditions to insure the belt runs straight.
Training idler
An idler mounted on a mechanical device, actuated by the belt moving against it to make the belt run straight.
Transition distance
The distance between the last fully troughed idler and the flat driving or discharge pulley.
Transition idler
A troughed belt idler having a lesser degree of trough than the previous carrying idlers.
Transverse seam
The joint, across the belt, of two ends of a fabric ply in the belt or cover material.
Traveling deflector
A mechanism which moves over the carrying surface of the belt and deflects the conveyed material off of the belt.
Tripper
A fixed or moveable mechanism at some intermediate place in the conveyor system to discharge material from the belt.
Troughability index
The ratio of the deflection of a freely supported transverse section of a belt to the distance between the freely supported ends.
Troughed belt
A belt operating in a conveyor system with inclined side idlers to cause the belt edges to turn up and increase the amount of material carried while minimizing side spillage of the material.
Troughing angle
The angle troughing idlers are to the horizontal extension of the flat carrying idler.
Troughing idlers
An idler system which supports a belt in a troughed configuration. Usually it consists of a center horizontal roll with an inclined roll on each side. See also catenary idler.
Twist
The rotation of a belt on its longitudinal axis. A 180 degree twist is used as a means of inverting a belt through the zone of the twist.
Undercure
A less than optimal state of vulcanization which may be evidenced by tackiness or inferior physical properties.
Void
The absence of material or an area devoid of materials where not intended. See also blister and sink.
Vulcanization
A process over a range in temperature during which a polymeric compound, through a change in molecular structure (e.g., crosslinking) becomes less plastic and causes changes in the physical and chemical properties of the resulting elastomer.
Watercooled press
A belt press that includes water passages right below the heating plates to allow rapid cooling of the heated press and belt joint.
Weathering
Surface deterioration, evidenced by cracks and crazing of an elastomer, during outdoor exposure.
Weave
A fabric pattern description denoting a specific relationship of warp and filling yarns at specific locations in the fabric.
Winged pulley
A pulley with radial vanes extending from a supporting structure to the center shaft to minimize trapping material that otherwise would build up and damage the belt.
Wire hook fastener
A mechanical fastener consisting of wires capable of being driven through the belt end and bent back into the belt by a special tool device.
Woven fabric
A flat structure composed of two series of interlacing yarns of filaments, one parallel to the fabric and the other transverse.
