Fiber & Textile Glossary

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A

Abrasion Resistance — The ability of a fiber, yarn, rope, or textile to resist surface wear caused by friction.

Adhesion — The ability of a fiber or coating to bond to another material such as rubber, resin, or polymer.

After-Treatment — Any finishing process applied to a fiber, yarn, or textile after its primary manufacturing step to improve performance or handling.

Air-Textured Yarn — A yarn produced by using compressed air to create bulk and texture in continuous filaments.

Alignment — The degree to which fibers or polymer chains are oriented in the same direction.

Amorphous Region — The less ordered area within a polymer structure that can influence flexibility, moisture absorption, and thermal behavior.

Annealing — A controlled heating process used to relieve internal stress and improve dimensional stability in fibers or polymer components.

Anisotropic — A material property indicating that performance differs depending on direction. Many fiber-reinforced composites are anisotropic.

Anti-Wicking Finish — A treatment applied to reduce fluid travel along yarns or fibers in cables, ropes, or textiles.

Areal Weight — The weight of a textile or reinforcement material per unit area, often expressed in oz/yd² or g/m².

Aramid Fiber — A class of high-performance synthetic fibers known for high strength, heat resistance, and durability. Examples include Kevlar® para-aramid fiber and Nomex® meta-aramid fiber.

Aramid Yarn — Yarn produced from aramid fibers such as Kevlar® or Nomex®, commonly used in protective textiles and industrial applications.

Aromatic Polyamide — The chemical class of polymers that form aramid fibers.

Aspect Ratio — The ratio of a fiber’s length to its diameter. This is especially important in chopped fiber reinforcement applications.

Autoclave Curing — A composite processing method using heat and pressure to consolidate resin and reinforcement materials.

Axial Strength — Tensile strength measured along the fiber axis.

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B

Backbone — The primary molecular chain structure of a polymer that defines many of its core material properties.

Ballistic Fiber — Fibers engineered for impact resistance and energy absorption in ballistic protection systems.

Base Fiber — The primary fiber used to create a yarn, cord, rope, or textile construction.

Basis Weight — The weight of a textile material expressed over a given area, often used for fabrics and nonwovens.

Basket Weave — A woven fabric pattern in which two or more warp yarns interlace with two or more weft yarns together.

Berry Amendment Compliance — A U.S. sourcing requirement for certain government and defense purchases requiring qualifying domestic materials and manufacturing.

Benzene Ring — A six-carbon aromatic ring structure found in polymers such as para-aramid and meta-aramid fibers.

Bias — A fabric direction that runs diagonally to the warp and weft.

Binder Yarn — Yarn used to hold fibers, cables, or components together during processing or in the final construction.

Bi-Component Fiber — A fiber made from two different polymers combined in a single filament.

Braided Cord — A textile structure formed by interlacing multiple yarns diagonally to create a flexible and durable cord.

Braid Angle — The angle formed between braided yarns and the axis of the finished braided construction.

Break Elongation — The percentage a fiber or yarn stretches before breaking.

Breaking Strength — The maximum load a fiber, yarn, or rope can withstand before failure.

Bundle — A grouping of fibers or filaments collected together for processing.

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C

Cable Lay — The direction and configuration in which yarns, strands, or subassemblies are twisted together in a cable construction.

Capstan — A driven wheel used in fiber processing, coating, winding, or tension-controlled manufacturing lines.

Carbon Fiber — A high-strength fiber composed primarily of carbon atoms arranged in crystalline structures used in composite materials.

Carding — A process used to separate, align, and clean staple fibers before spinning.

Centinewton per dtex (cN/dtex) — A common metric unit used to express normalized fiber strength.

Chain — A load-bearing hardware component often paired with synthetic fiber rope in marine and mooring systems.

Chemical Resistance — The ability of a fiber or textile to maintain performance when exposed to chemicals.

Chopped Fiber — Fiber cut into short, controlled lengths for use in composites, coatings, friction materials, and thermoplastics.

Coating — A surface-applied material used to improve abrasion resistance, adhesion, UV resistance, moisture resistance, or processability.

Coefficient of Friction — A measurement describing the friction between two surfaces.

Cohesion — The tendency of fibers in a yarn or bundle to hold together.

Composite Material — A material formed by combining fibers with a matrix such as resin to create enhanced structural properties.

Compression Molding — A process used to form composite or polymer parts under pressure and heat.

Consolidation — The process of compressing and bonding fibers and matrix materials into a dense composite structure.

Continuous Filament — Fibers produced in continuous lengths rather than cut into staple lengths.

Copolymer — A polymer made from more than one type of monomer.

Cord — A construction made by twisting or braiding yarns together to form a stronger load-bearing element.

Cordage — A general term for cords, ropes, and similar load-bearing flexible textile constructions.

Core — The central load-bearing or functional portion of a rope, braid, yarn package, or composite structure.

Core-Sheath Construction — A structure in which one material forms the inner core and another forms the outer covering or sheath.

Cover Factor — A measure describing how much of a surface is covered by yarns in a woven or braided construction.

Creep — The gradual elongation of a material under constant load over time.

Crimp — A waviness or undulation in fibers that affects bulk, stretch, and processing behavior.

Cross Section — The shape of a fiber when viewed perpendicular to its length, such as round, trilobal, or flat.

Crosslinking — Chemical bonding between polymer chains that can improve durability and heat resistance.

Crystallinity — The degree of ordered molecular alignment within a polymer structure.

Curing — The chemical or thermal process that hardens a resin system in composites or coatings.

Cut Length — The specified length of chopped fiber pieces used in compounds, coatings, and composites.

Cut Resistance — The ability of a fiber or textile to resist cutting forces.

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D

Decitex (dtex) — A unit of linear density equal to one gram per 10,000 meters of fiber.

Degassing — The removal of entrapped air or volatile components from a resin, coating, or matrix system.

Delamination — Separation of layers within a laminated composite or textile-reinforced structure.

Denier — A unit describing the linear mass density of fibers. One denier equals one gram per 9,000 meters.

Denier per Filament (DPF) — The linear density of individual filaments within a multifilament yarn.

Dimensional Stability — The ability of a material to maintain size and shape under load, temperature change, or moisture exposure.

Directional Strength — Strength that is concentrated along a particular axis because of fiber orientation or construction design.

Dispersion — The distribution of chopped fibers or additives throughout a matrix such as resin or polymer.

Dispersion Quality — The uniformity with which chopped fibers or additives are distributed throughout a matrix system.

Doff — To remove a finished yarn package, spool, or bobbin from manufacturing equipment.

Double Braid — A rope construction in which one braid forms the core and another braid forms the cover.

Drape — The ability of a textile or reinforcement fabric to conform to a shape or contour.

Draw Ratio — The amount a fiber is stretched during manufacturing to align polymer chains and increase strength.

Dry Fiber — Reinforcement fiber that has not yet been impregnated with resin or matrix material.

Durometer — A measure of hardness, commonly used for elastomers and certain coatings rather than fibers themselves.

Dyneema® — A brand of ultra-high molecular weight polyethylene fiber known for extremely high strength-to-weight ratio.

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E

Edge Fray — The unraveling or loosening of yarns at the edge of a textile structure.

Elastic Recovery — The ability of a fiber to return to its original length after being stretched.

Elongation — The amount a fiber or yarn stretches when subjected to tensile loading.

End — A single yarn or strand in a textile construction.

End Count — The number of yarn ends per unit width in a woven or warp-based textile structure.

Engineering Fiber — Fibers designed primarily for structural or industrial performance rather than apparel use.

Epoxy — A common thermoset resin used in composite materials.

Extruded Coating — A polymer coating applied by extrusion over a fiber, rope, or cable structure.

Extrusion — A process in which polymer material is forced through a die to form filaments, fibers, or coated constructions.

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F

Fatigue Resistance — The ability of a material to withstand repeated loading or bending cycles without failure.

Fiber — The smallest structural component of a textile material with a high length-to-diameter ratio.

Fiber Architecture — The arrangement and orientation of fibers in a yarn, rope, braid, or composite reinforcement system.

Fiber Diameter — The thickness of a single filament, usually measured in microns.

Fiber Orientation — The alignment of fibers within a composite structure.

Fiber Volume Fraction — The percentage of fiber present within a composite relative to the total volume of the composite.

Filament — A continuous fiber strand of indefinite length.

Filament Count — The number of individual filaments contained within a yarn.

Filament Yarn — Yarn made from continuous filaments rather than staple fibers.

Filtration Media — A textile or fiber-based structure used to remove particles from air or liquids.

Finish — A surface treatment applied to fibers or yarns to improve processing, sewing, adhesion, abrasion resistance, or appearance.

Finish Pickup — The amount of finish or coating retained on a fiber or yarn after application and drying.

Flame Resistance — The ability of a material to resist ignition, burning, or flame propagation.

Flex Fatigue — Fatigue caused by repeated bending or flexing of a fiber or yarn.

Flexural Strength — The ability of a material or composite to resist bending forces before failure.

Float — A portion of yarn in a woven fabric that passes over multiple perpendicular yarns before interlacing again.

Flocking — A process that applies short fibers to a surface to create texture or functional properties.

Friction Material — A material used in applications such as brake pads or clutch materials where controlled friction is required.

Fuzz — Loose or broken fiber ends projecting from the surface of a yarn, thread, or rope.

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G

Gauge Length — The specified test length between grips used during tensile testing.

Gel Spinning — A manufacturing process used to produce highly oriented UHMWPE fibers with exceptional strength.

Glass Transition Temperature — The temperature range where a polymer changes from a glassy state to a more rubber-like state.

Grab Strength — A measure of the force required to break a textile specimen when only part of its width is clamped.

Graphitic Structure — Ordered carbon atom layers that contribute to the stiffness of carbon fiber.

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H

Hand — The tactile feel or softness of a textile or yarn.

Heat Resistance — The ability of a fiber or textile to maintain integrity at elevated temperatures.

Heat Setting — A controlled heating process used to stabilize a fiber or textile structure.

High Modulus Fiber — Fibers characterized by very high stiffness and resistance to elongation.

HMPE — High modulus polyethylene fiber, commonly used interchangeably with UHMWPE.

Hybrid Composite — A composite structure that uses more than one fiber type, such as carbon with aramid or glass with UHMWPE.

Hydrogen Bonding — Intermolecular attraction that contributes to the strength and rigidity of polymers such as para-aramids.

Hydrophobic — A material property indicating resistance to water absorption.

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I

Impact Resistance — The ability of a material to absorb energy from sudden loading without failing.

Impregnation — The process of saturating fibers or textiles with resin, coating, or another matrix material.

Industrial Yarn — Yarn designed for technical or structural applications rather than clothing.

Inherent Flame Resistance — Flame resistance that is built into the fiber chemistry rather than added through a finish.

Insertion Loss — In cable or fiber optic systems, the reduction in signal resulting from components or construction changes.

Interfacial Bonding — The adhesion between a fiber surface and the surrounding matrix in a composite or coated structure.

Interlacing — The crossing and locking of yarns in a woven or braided structure.

Isotropic — A material property indicating essentially uniform performance in all directions.

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J

Jacket — The outer protective layer on a cable, rope, or cord.

Jumbo Spool — A larger yarn or thread package used for longer production runs and reduced changeovers.

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K

Kevlar® — A para-aramid fiber brand known for high tensile strength, cut resistance, and structural reinforcement performance. See Kevlar® product page.

Knot Strength — The retained strength of a rope or yarn after a knot is tied.

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L

Laminated Composite — A composite made from multiple bonded layers of reinforcement and matrix material.

Laminate — A composite built from multiple bonded layers of reinforcement and matrix material.

Lap Joint — An overlap joint commonly used in composite, textile, or structural assemblies.

Lay — The direction or twist of strands or yarns in a rope or cord construction.

LCP Fiber — Liquid Crystal Polymer fibers such as Vectran™ known for dimensional stability and low creep.

Line Speed — The rate at which material travels through a manufacturing process, usually expressed in feet or meters per minute.

Linear Density — Mass per unit length of a fiber or yarn.

Load Bearing Fiber — Fibers engineered to carry structural loads in cables, ropes, or composites.

Load Transfer — The movement of mechanical stress from a matrix to reinforcing fibers in a composite.

LOI (Limiting Oxygen Index) — The minimum oxygen concentration required to support combustion of a material.

Low Creep Fiber — A fiber that resists gradual elongation under constant load.

Low Elongation Fiber — A fiber that stretches very little under load, often desirable in structural or precision applications.

Lubricant Finish — A finish applied to yarn or thread to improve sewing or processing performance.

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M

Marine Rope — Rope designed for marine applications such as mooring, towing, rigging, and offshore handling.

Matrix — The surrounding material, often a resin or polymer, that supports and binds reinforcement fibers in a composite.

Matrix Compatibility — The suitability of a fiber surface for bonding with a specific resin, polymer, or coating system.

Mechanical Properties — Properties describing how a material responds to forces such as tension, compression, bending, or impact.

Melt Point — The temperature at which a thermoplastic material softens and transitions to a melt state.

Meta-Aramid — A type of aramid fiber designed primarily for flame resistance and thermal stability. Nomex® is the most widely recognized example.

Microfiber — Extremely fine fibers with very small diameters.

Migration — The movement of additives, finishes, or low molecular weight components through or out of a material over time.

Modulus — A measure of stiffness indicating resistance to deformation under load.

Mooring Line — A rope or line used to secure a vessel, platform, or floating structure in position.

Moisture Regain — The amount of moisture a fiber absorbs from the air under standard conditions.

Monofilament — A single continuous filament used as a yarn or line.

Multifilament Yarn — Yarn composed of many continuous filaments grouped together.

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N

Needle Punching — A nonwoven manufacturing method that mechanically entangles fibers using barbed needles.

Nomex® — A meta-aramid fiber brand known for flame resistance, thermal stability, and protective textile applications. See Nomex® product page.

Nonwoven — A textile structure made by bonding or entangling fibers rather than weaving or knitting them.

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O

Offgassing — The release of volatile materials from a fiber, coating, or polymer over time.

Open-End Spinning — A yarn spinning process distinct from ring spinning, commonly used for certain staple fiber yarns.

Outgassing — The release of trapped gases or volatile compounds from a material, especially important in aerospace and vacuum applications.

Oxidation — A chemical reaction with oxygen that can degrade certain materials at elevated temperatures.

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P

Package Build — The winding shape and geometry of a yarn package.

Package Density — The compactness of yarn wound on a spool, cone, or bobbin.

PAN Precursor — Polyacrylonitrile precursor fiber used in the production of most commercial carbon fibers.

Para-Aramid — A class of aramid fibers known for extremely high tensile strength and stiffness. Kevlar® is the most widely recognized example.

PBI Fiber — Polybenzimidazole fiber known for exceptional heat and flame resistance.

PEEK — Polyether ether ketone, a high-performance thermoplastic often used in advanced composite and industrial applications.

Pick — A single weft yarn inserted across the width of a woven fabric.

Pick Count — The number of weft yarns per unit length in a woven fabric.

Pilling — The formation of small fiber balls on the surface of a textile caused by abrasion or wear.

Pitch-Based Carbon Fiber — Carbon fiber produced from petroleum or coal-tar pitch, often associated with very high modulus grades.

Plain Weave — The simplest woven fabric structure in which each warp yarn alternates over and under each weft yarn.

Ply — One of two or more single yarns twisted together to form a stronger yarn or thread.

Plied Yarn — Yarn formed by twisting together two or more single yarns.

Polyethylene Fiber — A class of high-strength fibers including UHMWPE used in ropes and ballistic materials.

Polymer Chain — Long molecular chains that form the backbone of synthetic fibers.

Porosity — The presence of voids or empty space in a textile, composite, coating, or matrix system.

Post-Cure — Additional heating applied after initial curing to further improve resin or composite properties.

Pot Life — The usable working time of a reactive resin or coating mixture before it begins to gel or harden.

Precursor Fiber — The starting fiber used to produce another fiber type, such as PAN precursor used in carbon fiber production.

Preform — A shaped fiber reinforcement prepared before final resin impregnation or molding.

Precision Cut Fiber — Fiber chopped into tightly controlled lengths for more consistent reinforcement and dispersion.

Proof Load — A predetermined load applied to verify that a component or rope meets minimum performance requirements.

Protective Textile — A textile designed to resist heat, flame, cut, abrasion, or ballistic threats.

Pultrusion — A continuous manufacturing process used to create composite profiles by pulling reinforcement through resin and a heated die.

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Q

Quasi-Isotropic — A composite layup designed to provide more uniform properties in multiple directions.

Quench — A rapid cooling step used during certain polymer or fiber manufacturing processes.

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R

Recovery — The ability of a material to return to its original condition after deformation or loading.

Reel — A cylindrical holder used to wind and package yarn, cord, or rope.

Reinforcement Fiber — Fibers used to strengthen composite materials.

Resin — A polymer matrix material used to bind fibers in a composite.

Resin Content — The amount of resin present in a composite relative to the total composite weight or volume.

Retained Strength — The remaining strength of a material after exposure to heat, UV, moisture, or aging.

Ripcord — A high-strength yarn embedded in a cable to enable the jacket to be opened without damaging internal components.

Ring Spinning — A staple yarn spinning process that produces strong, relatively fine yarns.

Rope Construction — The method used to combine yarns or strands into cords or ropes through twisting or braiding.

Rope Lay — The direction and pattern in which strands are twisted to form rope.

ROV Umbilical — A tether system used for remotely operated vehicles that may include optical, electrical, and load-bearing elements.

Roving — A collection of untwisted or lightly twisted continuous filaments, often used in composites.

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S

Saltwater Resistance — The ability of a material to maintain performance when exposed to marine environments.

S-Twist — A twist direction that slopes in the same direction as the center of the letter S.

S-Twist Yarn — A yarn or thread with twist inserted in the S direction rather than the Z direction.

Satin Weave — A woven structure with longer floats that can improve drape and surface smoothness.

Scour — To clean a textile material and remove oils, finishes, or contaminants.

Secondary Backing — An additional backing layer applied to a textile product for support or dimensional stability.

Shear Strength — The ability of a material to resist forces that cause sliding failure between layers or surfaces.

Sheath — The outer covering surrounding a rope core, cable, or textile structure.

Shrinkage — The reduction in dimension of a textile or polymer after heat, moisture, or processing exposure.

Single End — One individual yarn, strand, or tow used by itself in a construction or process.

Sizing — A coating applied to fibers to protect them and improve compatibility with a resin or matrix.

Slippage — Movement of yarns relative to one another within a textile construction under load.

Sliver — A loose, untwisted strand of staple fibers produced during carding or drawing.

Soft Twist — A relatively low twist level used to improve flexibility or processability.

Specific Gravity — The ratio of a material’s density to the density of water.

Specific Modulus — Modulus normalized by density, used to compare stiffness-to-weight performance.

Specific Strength — Strength normalized by density, used to compare strength-to-weight performance.

Spectra® Fiber — A UHMWPE fiber brand known for extremely high strength and low density.

Spinning — The process of converting fibers into yarn.

Splice — A method of joining rope or cord by interweaving strands or ends.

Staple Fiber — Fibers cut into short lengths and spun together to form yarn.

Static Load — A constant or slowly applied load that remains relatively steady over time.

Strand — An intermediate textile element made from one or more yarns, often used in rope constructions.

Strength Member — A structural textile element used to carry load in a cable, rope, or composite construction.

Strength-to-Weight Ratio — A measure comparing material strength relative to its weight.

Stress Relaxation — The reduction in stress experienced by a material held at a constant strain over time.

Surface Energy — A material property influencing wetting, adhesion, and coating behavior.

Surface Treatment — A modification applied to fibers to improve adhesion, handling, dyeability, or durability.

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T

Take-Up — The winding or collection stage of a fiber, yarn, or coating process.

Technora® — A high-performance para-aramid fiber developed by Teijin known for excellent fatigue resistance and durability.

Tenacity — Fiber strength normalized by linear density, often expressed in grams per denier or centinewtons per dtex.

Tensile Strength — The maximum stress a fiber can withstand before breaking.

Tex — A unit of linear density equal to one gram per 1,000 meters of fiber.

Thermal Aging — The long-term effect of elevated temperature exposure on a material’s properties.

Thermal Conductivity — The rate at which a material transfers heat.

Thermal Stability — The ability of a material to maintain performance at elevated temperatures.

Thermoplastic — A polymer that can be melted and reshaped repeatedly.

Thermoset — A polymer that cures irreversibly and cannot be remelted like a thermoplastic.

Tow — A bundle of continuous filaments, commonly used in carbon fiber and other reinforcement materials.

Tow Size — The number of filaments in a tow, often designated as 1K, 3K, 12K, and so on.

TPI (Twist Per Inch) — The number of twists inserted into yarn per inch of length.

TPM (Twists Per Meter) — A metric unit describing twist level in yarn or cord constructions.

Tracer Yarn — A colored or otherwise identifiable yarn used to mark or identify a construction.

Tubular Braid — A braid formed as a hollow cylindrical structure without a separate core.

Twist — The spiral arrangement inserted into a yarn, strand, or cord to hold fibers together.

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U

UHMWPE — Ultra-high molecular weight polyethylene, a high-performance fiber known for extremely high strength-to-weight ratio.

Ultra High Molecular Weight Polyethylene — A polymer used to produce fibers such as Dyneema® and Spectra®.

Umbilical — A combined cable and strength-member system used in subsea, ROV, and offshore applications.

Uniformity — The consistency of fiber, yarn, coating, or textile properties throughout a product.

UV Resistance — The ability of a material to resist degradation caused by ultraviolet radiation.

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V

Vectran™ — A liquid crystal polymer fiber known for very low creep, excellent dimensional stability, and high strength. See Vectran™ product page.

Virgin Fiber — New fiber material that has not been previously processed or recycled.

Void Content — The percentage of trapped air or empty space in a composite or coated system.

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W

Warp — Yarns that run lengthwise in woven fabrics.

Warp Knit — A knitting construction in which loops are formed primarily in the warp direction.

Weathering — The combined effects of UV, moisture, oxygen, heat, and environmental exposure on material performance.

Weave — The pattern created by interlacing warp and weft yarns in a fabric.

Weft — Yarns that run across the width of woven fabrics.

Wet-Out — The ability of a resin or liquid to fully surround and penetrate fibers in a composite or coating system.

Wet Strength — The strength retained by a material when wet or after water exposure.

Wicking — The ability of fibers to transport moisture along their surface.

Windability — The ease with which a yarn or thread can be wound onto a package without defects.

Winding — The process of collecting yarn, cord, or rope onto a spool, cone, tube, or reel.

Working Load Limit (WLL) — The maximum load that should be applied to a product under normal service conditions.

Workmanship — The quality and consistency of manufacturing, including defects, winding quality, and construction uniformity.

Woven Fabric — A textile created by interlacing warp and weft yarns.

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Y

Yarn — A continuous strand of fibers or filaments used to make textiles, cords, ropes, or composites.

Yarn Count — A numerical description of yarn size or linear density.

Yield — The length of yarn or rope obtained per unit of weight.

Yield Point — The stress level at which a material begins to deform permanently.

Young’s Modulus — A fundamental measure of stiffness defined as stress divided by strain in the elastic region.

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Z

Z-Twist — A twist direction that slopes in the same direction as the center of the letter Z.

Z-Twist Yarn — A yarn or thread with twist inserted in the Z direction rather than the S direction.

Zylon® — A PBO fiber known for very high strength and modulus, though with important environmental durability limitations.