Glossary: Common Biomedical Textile Terms

A

Abrasion Resistance - The ability of a fiber or fabric to withstand surface wear and rubbing.

Air Jet Spinning - A spinning system in which yarn is made by wrapping fibers around a core stream of fibers with compressed air.

Air Permeability - Porosity, or the ease with which air passes through material. Air permeability determines fiber characteristics such as the wind resistance of sailcloth, the air resistance of parachute cloth, and the efficiency of various types of air filtration media.

Alternating Twist - A texturing procedure in which S and Z twist are alternately inserted into the yarn by means of a special heating apparatus.

Aramid Fiber - A manufactured fiber in which the fiber-forming material is a long chain synthetic polyamide with at least 85% of its amide linkages (-NHOCO-) attached directly to two aromatic rings.

Autoclave - An apparatus for the carrying out of certain finishing operations, such as pleating and heat setting, under pressure in a superheated steam atmosphere.

 

B

Balanced Cloth - A term describing a woven fabric with the same size yarn and the same number of threads per inch in both the warp and the fill direction.

Basket Weave - A variation of the plain weave in which two or more warp and filling threads are woven side-to-side to resemble a plaited basket.

Beam - A cylinder of metal, usually with a circular flange on each end, on which warp yarns are wound for slashing, weaving, and warp knitting.

Beaming - The operation of winding warp yarns onto a beam usually in preparation for weaving or warp knitting. This process is also called warping.

Beating-Up - The last operation of the loom in weaving, in which the last pick inserted in the fabric is “beat” into position against the preceding pick, usually by a comb-like device called a reed.

Bicomponent Yarns - Spun or filament yarns of two generic fibers or two variants of the same generic fiber.

Bi-directional Fabric - A fabric with reinforcing fibers in two directions, i.e., in the warp (machine) direction and filling (cross-machine) direction.

Blend - 1. A yarn obtained when two or more staple fibers are combined in a textile process for producing spun yarns.
2. A fabric that contains a blended yarn in both the warp and filling direction.

Blending - The combining of staple fibers of different physical characteristics to assure a uniform distribution of these fibers throughout the yarn.

Braid - A narrow textile band, often used as trimming or binding, formed by plaiting several strands of yarn. The fabric is formed by interlacing the yarns diagonally to the production axis of the material.  Two types of braids follow:

  • Biaxial Braid - Braided structure with two yarn systems running in one direction and a third in the opposite direction.
  • Triaxial Braid – Braided structure with axial yarns running in the longitudinal direction.

Braid Angle - The acute angle measured from the axis of the fabric or rope to a braiding yarn.

Braided Fabric - A narrow fabric made by crossing a number of strands diagonally so that each strand passes alternately over or under one or more of the other strands.

Braiding - The interwinding of three or more strands to make a cord or narrow fabric.

Break Factor - A measure of yarn strength calculated as: 1) the product of breaking strength times the indirect yarn number; 2) The product of breaking strength times the reciprocal of the direct yarn number.

Breaking Strength -1. The maximum resultant internal force that resists rupture in a tension test.
2. The load (or Force) required to break or rupture a specimen in a tensile test made according to a specified standard procedure.

Breaking Tenacity - The tensile stress at rupture of a specimen expressed as Newton’s per Tex (cN/tex).

Broadcloth - A fabric so named because it is woven in widths exceeding 29 inches.

Broad Goods - Woven fabrics 18 inches or more in width.

Broken End - A broken, untied warp thread in a fabric. Broken ends can result from slubs, knots, improper shuttle alignment, a shuttle hitting the warp shed, excessive warp tension, faulty sizing, and rough reeds, heddles, dropwires and shuttles.

Broken Pick - A broken filling thread in a fabric. Broken picks can result from excessive shuttle tension, weak yarn, or filling that comes in contact with a sharp surface.

 

C

Cabled Yarn - A yarn formed by twisting together two or more plied yarns.

Cabled Twist - A construction of thread, yarn, cord, or rope in which each successive twist is in the same direction opposite the preceding twists; i.e., an S/Z/S, or Z/S/Z construction.

Calender - A machine used in finishing to impart a variety of surface effects to fabrics. A calender essentially consists of two or more heavy rollers, sometimes heated, through which the fabric is passed under heavy pressure.

Calendering - A mechanical finishing process for fabrics used to produce special effects such as high luster, glazing, moiré, and embossed effects.

Carbon Fiber - A high-tensile fiber or whisker made by heating rayon or polyacrylonitrile fibers or petroleum residues to appropriate temperatures. Fibers may be 7 to 8 microns in diameter and more than 90% carbonized.

Cloth - A generic term embracing all textile fabrics and felts. Cloth may be formed out of any textile fiber, wire, or material.

Coated Fabric - A fabric to which a substance has been applied in firmly adhering layers to provide certain properties, such as water impermeability.

Coating - The application of a semi-liquid material to one or both sides of the textile material. Once the coating has dried (cured), it forms a bond with the fabric.

Composite - 1. An article or substance of two or more constituents, generally with reinforcing elements dispersed in a matrix or continuous phase.
2. Hard or soft constructions in which the fibers themselves are consolidated to form structures rather than being formed into yarns.

Conditioning - A process of allowing textile materials to reach equilibrium with the surrounding atmosphere.

Cone - A conical package of yarn, usually wound on a disposable paper core.

Coning - The transfer of yarn from skeins, bobbins or other types of packages to cones.

Core Spinning - The process of making a core-spun yarn. It consists of feeding the core yarn into the front delivery roll of the spinning frame and of covering the core yarn with a sheath of fibers during the spinning operation.

Core-Spun Yarn - A yarn made by twisting fibers around a filament or a previously spun yarn, thus concealing the core.

Creel - A framework arranged to hold yarns so that many ends can be withdrawn smoothly and evenly without tangling.

Creeling - The mounting of supply packages in a creel to feed fiber to a process, i.e., beaming, warping or weaving.

Crimp - 1. The waviness of a fiber expressed as crimps per unit length.
2. The difference in distance between two points on an unstretched fiber and the same two points when the fiber is straightened under tension.
3. The difference in the distance between two points when the yarn has been removed from the fabric and straightened under specific tension expressed as a percentage of the distance between the two points as the yarn lies in the fabric.

 

D

Density - Mass per unit volume usually expressed as grams per cubic centimeter (g/cc). Also known as specific gravity.

Denier - Officially, the weight in grams of 9000 meters of yarn. Denier is a direct numbering system in which the lower numbers represent the finer sizes and the higher numbers the courser sizes. In countries other than the USA, Denier is replaced by the Tex system.

Denier per filament (dpf) - The denier of an individual continuous filament or an individual staple fiber if it were continuous.

Yarn Denier - The denier of filament yarn. It is the product of the denier per filament and the number of filaments in the yarn.

Total Denier - The product of the denier per filament and the number of filaments in the tow.

Denier Variation - Usually variation in diameter, or other cross-sectional dimension, along the length of a filament or bundle of filaments. Malfunction or lack of process control in fiber manufacturing causes denier variation.

Dent – On a loom, the space between the wires of a reed.

Dimensional Stability - The ability of textile material to maintain or return to its original geometric configuration.

Dobby - A mechanical attachment on a loom that controls the harness to permit the weaving of geometric figures.

Doff- A set of full packages, bobbins, spools, etc. produced by one machine.

Doffing - The operation of removing full packages, bobbins, spools, etc. from a machine and replacing them with empty ones.

Double End - Two ends woven as one in a fabric. It may be intentional or accidental.

Drape - A term to describe the way a fabric falls while it hangs; the suppleness and ability of a fabric to form configurations.

Drawing-in - In weaving, the process of threading warp ends through the eyes of the heddles and the dents of the reed.

Drop Wires - A stop-motion device utilizing metal wires suspended from warp or creeled yarns. When a yarn breaks, the wire drops, activating the switch that stops the machine.

 

E

Elastomers - Synthetic polymers with properties of natural rubber such as stretchability and recovery.

Electrical Conductivity - a measure of the ease of transporting electric charge from one point to another in an electric field.

Elongation - The deformation in the direction of load caused by a tensile force.  Elongation is measured in units of length (inches, millimeters) or calculated as a percentage of the original specimen length. Elongation may be measured at a specific load, or at the breaking point.

Elongation at Break - The increase in length when the last component of the specimen breaks. Usually expressed as %.

End - An individual warp yarn. A Warp is composed of a number of ends.

End Out - A void caused by a missing warp yarn.

Entering - The process of threading each warp yarn on a loom beam through a separate drop wire, heddle, and reed space in preparation for weaving.

Extractables - The material that can be removed from textiles by means of a solvent (water can often be a solvent).

Extraction - Removal of one substance from another, often accomplished by a solvent.

 

F

Fabric - A planar textile structure produced by interlacing yarns, fibers, or filaments.

Fabric Construction - The details of structure of fabric. These include such information as style, width, type of weave or knit, threads per inch in warp and fill, and weight of goods.

Fabric Crimp - The angulation induced between a yarn and a woven fabric via the weaving or braiding process.

Fiber - A unit of matter, either natural or manufactured, that forms the basic element of fabrics and other textile structures.

Fiber Number - The linear density of a fiber expressed in units such as denier or Tex.

Filament - A fiber of an indefinite or extreme length such as silk. Manufactured fibers are extruded into filaments that are converted into filament yarn, staple, or tow.

Filament Count - The number of individual filaments that make up a thread or yarn.

Filament Yarn - A yarn composed of continuous filaments assembled with or without twist.

Filling - In woven fabric, the yarn running from selvage to selvage at right angles to the warp. Each crosswise length is called a pick. In the weaving process, a shuttle, rapier, or other type of yarn carrier carries the filling yarn.

Finish -1. A substance or mixture of substances added to textile materials to impart desired properties.
2. A process, physical or chemical, performed on textile materials to produce a desired effect.

Finished Fabric - fabric that is ready for packaging, having passed through the required finishing process.

Finishing - All the processes through which fabric is passed after construction. in preparation for  use.

Float - A weaving defect consisting of an end lying or floating on the fabric surface instead of being properly woven in.

 

G

Gauge - A generic term for various measurement instruments such as pressure of thickness gauges, also the thickness of a knitting needle, and the number of wales per inch in a knitted fabric.

Gauge Wire - Used with an extra filling yarn during weaving, this type of standing wire controls the height of fabric pile.

Greige Fabric - (pronounced gray) An unfinished fabric just off the loom or knitting machine.

 

H

Hand - The tactile qualities of a fabric, e.g., softness, firmness, elasticity, fineness, resilience and other qualities perceived by touch.

Heat Resistance - A property of certain fibers (Ex: PEKK & PEEK) or yarns whereby they resist degradation at high temperatures.

Heat Setting - The process of conferring dimensional stability and other desirable properties (wrinkle resistance and improved heat resistance) by means of either moist or dry heat.

Heat Stabilized - A term to describe fiber or yarn heat-treated to reduce the tendency of the fiber to shrink or elongate under a load or at elevated temperatures.

Heddle - A cord; round steel wire; thin, flat steel strip with a loop; or eye near the center through which one or more warp threads pass on the loom, so that the thread movement may be controlled in weaving. The heddles are held at both ends by the harness frame.  They control the weave pattern and shed as the harnesses are raised and lowered during weaving.

Herringbone - A broken twill weave characterized by a balanced ziz-zag effect produced by having the rib run first to the right, and then to the left for an equal number of threads.

High Modulus - A term that refers to a material with a higher-than-normal resistance to deformation.

Hollow Filament Fibers - Manufactured, continuous filament fibers with voids created by introduction of air or other gas in the polymer solution or melt spinning through specially designed spinnerets.

Impregnated Fabric - A fabric in which the interstices between the yarns are completely filled, as compared to sized or coated materials where the interstices are not completely filled.

 

I

Implantable Textile – A textile composed of materials suitable for long-term implant in the body.  All implantable textiles must be post-processed to meet requirements for biocompatibility.

Industrial Fabric - A broad term for fabrics used for non-apparel and non-decorative uses. They fall into the following classes:

  • Fabrics employed in industrial processes (e.g., filtration, polishing and absorption)
  • Fabrics combined with other materials to form a different material (e.g., rubberized fabric for hose, belting, tires, timing gears, bearings, and electrical parts)
  • Fabrics impregnated with adhesive and dielectric compounds

Fabrics developed for industrial use cover a wide variety of widths, weights and construction.

Inspection - The process of examining textiles for defects at any stage of manufacturing and finishing.

 

J

Jacquard - A system of weaving that utilizes a highly versatile pattern mechanism to permit the production of large, intricate designs and shapes. The weave controls the action of one warp thread for the passage of one pick.

 

K

Kink - In fabrics, a place where a short length of yarn has spontaneously doubled back on itself.

Kinking - The doubling back of a yarn on itself to relieve torque imparted by twisting or texturing.

Knit Fabric - A structure produced by interlooping one or or more ends of yarn or comparable material.

Knitting - A method of constructing fabric by interlocking series of loops of one or more yarns. Knitting Types:

  • Warp Knitting – A type of knitting in which the yarns generally run lengthwise in the fabric. The yarns are prepared as warps on beams with one or more yarns for each needle. Examples include Raschel, Crochet and Tricot.
  • Weft Knitting – A common type of knitting, in which one continuous thread runs crosswise in the fabric, making all of the loops in one course. An example is:
  • Circular Knitting, where the fabric produced on the knitting machine is in the form of a tube, the threads running continuously around the fabric.

 

L

Leno Weave - A weave in which the warp yarns are arranged in pairs with one twisted around the other between picks of filling yarn. This type of weave gives firmness and strength to an open-weave fabric and prevents slippage and displacement of warp and filling yarns.

Let-Off Motion - A device for controlling the delivery and tension of the warp during weaving.

Leveling - Migration leading to uniform distribution of dye in a dyed material. Leveling may be a property of the dye or it may require chemical assistance.

Loom - machines for weaving fabric by interlacing a series of vertical parallel threads (the warp) with a series of horizontal parallel threads (the filling). The warp yarns from a beam pass through the heddles and reed, and the filling is shot through the “shed” of warp threads by means of a shuttle or other device and is settled into place by the reed and lay. The primary distinction between different types of looms is the manner of filling insertion.

Lot - A unit of production, or group of other units, or packages that is taken for sampling, or statistical examination, having one or more common properties and being separable from other similar lots.

Lubricant - An oil or emulsion finish applied to fibers to prevent damage during textile processing, or to knitting yarns to make them more pliable. (Spin Finish)

 

M

Machine Direction - The long direction within the plane of the fabric, i.e., the direction in which the fabric is being produced by the machine.

Manufactured Fiber - A class name for various fibers (including filaments) produced from fiber-forming substances, which may be polymers synthesized from chemical compounds (acrylic, nylon, polyester, polyethylene), modified or transformed natural polymers (cellulose-based fibers like acetate and rayon). The term “manufactured” usually refers to chemically produced fibers to distinguish them from truly natural fibers such as silk.

Melt Index - The weight in grams of a thermoplastic material that can be forced through a standard orifice within a specified period of time.

Melting Point - The temperature at which the solid and liquid states of a substance are in equilibrium; generally the temperature at which a substance changes from a solid to a liquid.

Microdenier - refers to fibers having less than 1 denier per filament, or 0.1 Tex per filament.

Mispick - A weaving defect in which a pick is improperly interlaced, resulting in a break in the weave pattern.

Modulus - The ratio of change in stress to change in strain following the removal of crimp from the material being tested.  In other words, the ratio of the stress expressed in either force per unit leaner density, or force per unit area of the original specimen, and the strain expressed as either a fraction of the original length or percentage elongation.

Moisture Regain - A measure of the increase in weight due to the adsorption of water by a fiber vs. its initial dry weight. Usually expressed as %.

Monofilament - Any single filament of a manufactured fiber, usually of a denier higher than 14. Rather than a group of filaments extruded through spinnerets to form a yarn, monofilaments are usually spun individually.

Monomer - the simple, unpolymerized form of a compound from which a polymer can be made.

Mullen Bursting Strength - An instrument test method that measures the ability of a fabric to resist rupture by pressure exerted by an inflated diaphragm.

Multifilament - A yarn consisting of many strands, as opposed to Monofilament, which is one strand. Most textile yarns are multifilament.

 

N

Narrow Fabric - Any non-elastic woven fabric, 70mm or less in width.

Needle Loom - A narrow fabric-weaving machine (loom) that uses a needle to insert filling across a warp. A needle loom uses a catch cord system to make a selvage on one edge of the weave and to return the pick after anchoring it within the selvage.

Nylon Fiber - A manufactured fiber in which the fiber-forming substance is a long chain synthetic polyamide with recurring amide groups (-NH-CO-) as an integral part of the polymer chain.

 

O

Olefin Fiber - A manufactured fiber in which the fiber-forming substance is any long chain synthetic polymer composed at least 85% by weight of ethylene, polyethylene, or other olefin unit. Olefin fibers combine low weight with high strength and abrasion resistance.

Orientation - In linear polymeric structures, the degree of parallelism of the chain molecules.

Orifice - Generally, an opening. Used specifically to refer to the small holes in spinnerets through which the polymer flows in the manufacture of fibers.

 

P

Packages - A large selection of forms for winding yarn onto. Examples include a cone, cheese, and pirn package.

Pattern - 1. An arrangement of form or weaving designs.
2. A model, guide, or plan used in making things

Pick- A single filling thread carried by one trip of the weft-insertion device across the loom.  The picks interface with the warp ends to form a woven fabric.

Pick Count - The number of filling picks per inch, or per centimeter of fabric. Pick and end counts are two fabric specifications needed to design a fabric.

Pick Counter - 1. A mechanical device that counts the picks as they are inserted during weaving.
2. A mechanical device equipped with a magnifying glass used for counting picks and/or ends in finished fabrics.

Pirn - 1. A plastic support; cylindrical or slightly tapered, and with or without a conical base, on which yarn is wound.
2. The double-tapered take-up yarn package from drawtwisting of nylon, polyester and other melt spun yarns.

Plain Weave - One of the three fundamental weaves: plain, satin and twill. Each filling yarn passes successfully over and under each warp yarn, alternating each row.

Ply - 1. The number of single yarns twisted together to form a plied yarn, or the number of plied yarns twisted together to form a cord.
2. One of a number of layers of fabric.

Polyester Fabric - A manufactured fiber in which the fiber-forming substance is any long chain synthetic polymer composed of at least 85% by weight of an ester of dihydric alcohol and terephthalic acid. It is high in strength and resistant to shrinking and stretching.

Polyethylene Fiber - A manufactured fiber made of polyethylene, often in monofilament form as well as in filament form. The fibers have low specific gravity, very low retention of moisture, the same tensile weight wet or dry.

Polyamide Fiber - Fully imidized, manufactured fiber formed from the condensation polymer of an aromatic anhydride and an aromatic diisocyanate. A polyamide fiber is a high shrinkage fiber.

Polypropylene Fiber (PP) - A manufactured olefin fiber made from polymers or copolymers of polypropylene. This is a very tough fiber with a tenacity of 8.0 to 8.5 grams/denier and a melting point of 165° C. It is so light in weight that it floats and is highly resistant to mechanical abuse and chemical attack.

Polytetrafluoroethylene (PTFE) Fiber - A fluoride containing manufactured fiber characterized by high chemical stability, relative inertness, and high melting point. The fiber has moderate tensile strength and resistance to chemicals and high temperature. It has very low frictional characteristics and a slippery hand.

Post-production processes – A range of processing that includes heat setting, coating, forming, packaging, sterilization, slitting/cutting, sewing, scouring, and more.

 

Q

Quill - A light, tapered tube of wood, metal, or plastic on which the filling yarn is wound for use in the shuttle during weaving.

Quilling - The process of winding filling yarns onto filling bobbins or quills in preparation for use in the shuttle for weaving.

 

R

Radial Strength – Fabric’s resistance to compression in the radial direction.  Radial strength can be improved by adding yarn or wire elements in the radial or helical direction of a structure.

Reed - A comb-like device on a loom that separates the warp yarns and also beats each succeeding filling thread against that already woven. The space between two adjacent wires of the reed is called a dent. The fineness of the reed is calculated by the number of dents to the inch. The more dents to the inch, the finer the reed.

Roll Goods - Fabric rolled up on a core after it has been produced. It is described in terms of weight and width of the roll and length of the material on the roll.

 

S

Satin Weave - One of the basic weaves, (plain, satin, and twill). The face of the fabric consists almost completely of warp or filling floats produced in the repeat of the weave. Satin weave fabric has a characteristic smooth, luxurious surface and has a considerably greater number of yarns in the set of threads (either the warp or filling) that forms the face than in the other set.

Scouring - An operation to remove spinfinish and manufacturing particulate.

Scrim - 1. A lightweight, open-weave, course fabric.
2. Fabric with open construction used as base fabric in the production of coated or laminated fabrics.

Seamless - A term that describes a tubular knit or woven fabric without seams, e.g., seamless woven tube.

Section Beam - 1. A large flanged roll upon which warp yarn is wound at the beam warper in preparation for slashing.
2. Small flanged or unflanged beams placed side by side on the shaft of a warp beam for further processing.

Selvage - The narrow edge of woven fabric that runs parallel to the warp. It is made with stronger yarns in a tighter construction than the body of the fabric to prevent raveling.  A fast selvage encloses all or part of the picks, and a selvage is not fast when the filling threads are cut at the fabric edge after each pick.

Shuttle - A boat-shaped device usually made of wood with a metal tip that carries filling yarns through the shed in the weaving process.

Shuttless Loom - A loom in which some other device than a shuttle is used for weft insertion.

Sinker - In weaving design, a blank square indicating a filling thread over a warp thread at the point of insertion.

Skein - A continuous strand of yarn, fabric, or cord in the form of a collapsed coil. It may be any specified length and is usually obtained by winding a definite number of turns on a reel under prescribed conditions.

Slub - A yarn defect consisting of a lump or thick place on the yarn caused by lint or small lengths of yarn adhering to it.

Slug - A thick place in a yarn, or a piece of lint entangled in yarn, cord, or fabric.

Spinneret - A metal disc containing numerous minute holes used in manufactured fiber extrusion. The spinning solution or melted polymer is forced through the holes to form fiber filaments.

Splicing - The joining together of two ends of yarn or cordage.

Staple - Natural fibers or cut lengths from filaments. The staple lengths of natural fibers vary from less than 1-inch, while manufactured staple fibers are cut to definite length. The term staple (fiber) is used in the textile industry to distinguish cut length manufactured fibers from filament.

Static- The accumulation of negative or positive electricity on the surface of fibers or fabrics because of inadequate electrical dissipation during processing.

Stiffness - The property of a fiber or fabric to resist bending or to carry a load without deformation.

Stop Motion - Any device that automatically stops a textile machine’s operation on the occurrence of a yarn break, high defect count, etc.

Strand - A single fiber, filament, or Monofilament.

Stuffers - Extra yarns running in the warp direction through a woven fabric to increase the fabric’s strength and weight.

Surfactant - A surface-active agent, i.e., a product that acts by modifying the surface or boundary between two phases.

 

T

Take-up (Twist) – the change in length of a filament, yarn, or cord caused by twisting, expressed as a percentage of the original (untwisted) length.

Take-up (Yarn in Fabric) – The difference in distance between two points in a yarn as it lies in a fabric and the same two points after the yarn has been removed from the fabric and straightened under specified tension, expressed as a percentage of the straightened length.

Tape- A narrow woven fabric not over 70mm in width.

Tear Strength - The force required to begin or continue a tear in a fabric under specified conditions.

Tensile Strength - In general, the strength shown by a specimen subjected to tension as distinct from torsion, compression, or shear.

Tensile Test - A method of measuring the resistance of yarn or fabric to a force tending to stretch the specimen in one direction.

Tenter Frame - A machine that dries fabric to a specified width under tension. The machine consists essentially of a pair of endless chains on horizontal tracks. The fabric is held firmly at the edges by pins or clips on the two chains that diverge as they advance through the heated chamber, adjusting the fabric to the desired width.

Tex - 1. A unit for expressing linear density, equal to the weight in grams of one kilometer of yarn, filament, fiber or other textile strand.
2. The system of yarn numbering based on the use of Tex units.

Textile - Originally, woven fabric.  Now applied generally to any one of the following: staple fibers and filaments able to be converted into woven, knit, or braided fabrics.

Textile Materials - A general term for fibers, yarn intermediates, yarn, fabrics, and products made from fibers.

Textile Processing - Any mechanical operation used to translate a textile fiber or yarn into a fabric or other textile material. This includes such operations as opening, carding, spinning, plying, twisting, texturing, coning, quilling, beaming, weaving, braiding, and knitting.

Texture - A term describing the surface effect of a fabric, such as dull, lustrous, stiff, soft, fine, course, etc.

Textured Yarns - yarns that develop stretch and bulk on subsequent processing.

Thermal Shrinkage - The amount of shrinkage of a fiber measured in dry air vs. that measured in its saturated state. Usually expressed as a %.

Thermoplastic - A term used to describe a plastic material that is permanently fusible, such as manufactured fibers that will soften at higher temperatures.

Thermoset - A term used to describe a plastic that, once formed, will not melt.

Thread - 1. A strong, slender strand or cord, especially one designed for sewing or other needlework.
2. A general term for yarns used in weaving and knitting

Thread Count - The number of ends (wales) and picks (courses) per inch in a woven or knitted fabric.

Three-dimensional Weaving - To produce three-dimensional textiles, yarns are simultaneously woven in three directions (length, width and thickness), rather than in the conventional two.

Throwing - The operation of doubling or twisting silk or manufactured filament yarn.

Throwster - A company that specializes in putting additional twist in yarn.

Transition Temperature - A temperature at which some radical change (usually a phase change) in the appearance or structure of a substance occurs, i.e. melting point or boiling point.

Traveler - A C-shaped, metal clip that revolves around the ring on a ring-spinning frame. It guides the yarn onto the bobbin as twist is inserted into the yarn.

Twill Weave - A fundamental weave characterized by diagonal lines produced by a series of floats staggered in the warp direction.

Twist - The number of turns about its axis per unit of length of a yarn or textile strand. Twist is expressed as turns per inch (tpi), turns per meter (tpm), or turns per centimeter (tpc).

Twist, Direction of - The direction of twist in yarns and other textile strands is indicated by the capital letters S and Z. Yarn is S-twisted if, when it is held vertically, the spirals around its central axis slope in the same direction as the middle portion of the letter S (i.e. to the right).  Yarn is Z-twisted if they slope to the left, (i.e. the middle section of the Z).

Twist Multiplier - The ratio of turns per inch to the square root of the yarn count.

Twist Setting - A process for fixing the twist in yarns to deaden torque and to eliminate kinking during further processing. This process usually involves heat.

 

U

Undrawn Yarn - Extruded yarn (filaments), the component molecules of which are substantially unorientated. An undrawn yarn exhibits predominantly plastic flow in the initial stages of stretching and represents an intermediate stage in the production of a manufactured yarn.

 

V

Vectran® Fiber - Manufactured fiber spun from Hoechst Celanese Vectra® liquid crystal polymer. These fibers have high-temperature resistance, high strength and modulus, and a high resistance to moisture and chemicals, with good property retention in hostile environments.

 

W

Warp - The set of yarn in all woven fabrics that runs lengthwise and parallel to the selvage and is interwoven with the filling.

Warp Beam - A large spool or flanged cylinder around which the warp threads, or ends, are wound in a uniform and parallel arrangement.

Warp Drawing - A process in which a number of thread lines are orientated under essentially equal mechanical and thermal conditions by a stretching stage using variable speed rolls, then directly wound onto the beam. This process gives uniform end-to-end properties.

Waterproof - A term applied to materials that are impermeable to water; waterproof fabrics have all of their pores closed and are also impermeable to air and very uncomfortable.

Water-Repellent - A term applied to fabrics that can shed water, but are permeable to air.

Weave - A system, or pattern of intersecting warp and filling yarns. There are three basic two-dimensional weaves: Plain, twill and Satin.

Weaving - The method or process of interlacing two yarns of similar materials so that they cross each other at right angles to produce woven fabric.

Webbing - Strong, narrow fabric, closely woven in a variety of weaves and principally used for belts and straps that can withstand strain.

Weft Insertion - Any one of various methods: shuttle, rapier, water jet, etc. for making a pick during weaving.

Width - A horizontal measurement of a material. In woven fabric, it is the distance from selvage to selvage, and in knitted fabric, from edge to edge.

Winding - Winding is the process of transferring yarn, or thread from one type of package to another.

Woven Fabric - Generally used to refer to a fabric composed of two sets of yarns, warp and filling, that is formed by weaving, which is the interlacing of these sets of yarns.

 

Y

Yarn - A generic term for a continuous strand of textile fibers, filaments, or material in a form suitable for knitting, weaving, braiding, or otherwise intertwining to form a textile fabric.

Yarn Construction - A term used to indicate the number of single yarns and the number of strands combined to form each successive unit of plied yarn, or cord.

Yarn Number - A relative measure of the fineness of yarns.

Young’s Modulus - A property of perfectly elastic materials, it is the ratio of change in stress to change in strain within the elastic limits of the material. The ratio is calculated from the stress expressed in force per unit of cross-sectional area, and the strain expressed as a fraction of the original length.

 

Z

Zero Twist - twistless, devoid of twist.

Z Twist - See Twist, Direction of.

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Biomedical Structures and MPC to Jointly Exhibit at BIOMEDevice Boston 2014

Synergy Supports Full Spectrum of Value-added Design and Contract Manufacturing Solutions WHO: Biomedical Structures LLC (BMS), provider of biomedical textiles for medical devices and other clinical applications, and Modified Polymer Components (MPC), which specializes in the design, rapid prototyping and manufacture of reliable, highly precise polymer components for medical device OEMs. WHAT: BIOMEDevice Boston is […]