Technical Fabrics

Technical Fabrics

Definition of Technical FabricsFabrics manufactured primarily for their

technical performance and functional properties rather than their aesthetic or decorative characteristics

Methods for producing fabricsWeaving KnittingLace makingNet makingFeltingTuftingNon-woven processes

A 3-D Fabric

Woven Fabric Specifications• Fabric construction

– Warp count x weft count/ ends per inch x picks per inch

• Fabric area density / GSM• Cover factor• Type of weave• Crimp• Fabric width• Thickness

Fabric area density• The loom state cloth area density depends on the

weaving specification, that is, yarns, thread spacing and weave, and on any additives, such as size, which are used to improve the weaving process.

• Finished cloth area density is frequently altered by chemical treatments .

• The area density of the fabric can be varied by changing the linear density or count of the yarns used and by altering the thread spacing, which affects the area covered by the yarns in relation to the total area.

Cloth cover factorCloth cover factor = warp cover factor + weft

cover factorCover factor in SI units =

Cover factor formula by Pierce =

Area density and cover factorLow area density fabrics of open construction

include bandages

Light area density fabrics high cover factor fabrics include medical filter fabrics

Heavy open cloths include Geotextiles fabrics

Heavy closely woven fabrics include cotton awnings.

Plain weave90% technical fabrics have plain weave

Price: 13.40 euro / sq.m.Areal weight: 165 g / sq.m.Weaving style: PlainWidth: 0.91 or 1.27 metersWarp: aramid fiber Kevlar 49, 5.1 ends(threads) / cmWeft: aramid fiber Kevlar 49, 5.1 ends / cm

MECHANICAL PROPERTIES OF ARAMID FIBER USEDTensile strength (MPa): 2900Elongation at break (%): 2.5

ARAMID FABRICARAMID FABRIC

Price: 21.68 euro / sq.m.Areal weight: 205 g / sq.m.Weaving style: Plain Width: 1.27 metersWarp: carbon fiber, Weft: carbon fiber,

MECHANICAL PROPERTIES OF CARBON FIBER USEDTensile strength (MPa): 4900Elongation at break (%): 2.1

CARBON FABRICCARBON FABRIC

Point paper diagram of a plain weave fabric.

Warp-faced plain fabrics

• Generally have a much higher warp cover factor than weft cover factor.

• If warp and weft yarns of similar linear density are used, a typical warp faced plain may have twice as many warp ends as picks.

Weft-faced plain fabrics

Produced by using much higher weft cover factors than warp cover factors

Weft-faced plains are little used because they are more difficult to weave.

Rib fabrics

• The simplest modifications of plain weave fabrics.

• Produced by lifting two or more warp threads and/or two or more picks at the same time.

• It results in larger warp and/or weft covered surface areas than in a plain weave fabric.

Matt fabrics (or hopsack)• The simplest of the matt weaves

is a 2/2 where two warp ends are lifted over two picks

• Matt weave fabrics can be woven with higher cover factors and have fewer intersections.

• In close constructions they may have better abrasion and better filtration properties and greater resistance to water penetration.

• In more open constructions matt fabrics have a greater tear resistance and bursting strength.

Twill fabricsA twill is a weave that repeats on three or

more ends and picks and produces diagonal lines on the face of a fabric.

Such lines generally run from selvedge to selvedge.

The direction of the diagonal lines on the surface of the cloth are generally described as a fabric is viewed along the warp direction.

3 x 3 Twill weaves. (a)2/1 Twill with Z twill line, (b)2/1 twill with S twill line, (c)1/2 twill with Z twill line, (d)1/2 twill with S twill line,(e)four repeats of (a) (2/1 twill with a Z twist line).

When the diagonal lines are runningupwards to the right they are ‘Z twill’ or ‘twill right’ and when they run in the oppositedirection they are ‘S twill’ or ‘twill left’

Twill fabrics• For any construction twills will have longer floats,

fewer intersections and a more open construction than a plain weave fabric with the same cloth particulars.

• Broken twills, waved twills, herringbone twills are extensively used for suiting and dress fabrics.

• The smallest repeat of a twill weave consists of 3 ends x 3 picks.

Satins and sateens in BritainSatin Sateen

• A satin is a warp-faced weave

• Satins normally have a much greater number of ends than picks per centimeter.

• To avoid confusion a satin is frequently described as a ‘warp satin’.

• A sateen, frequently referred to as a ‘weft sateen’, is a weft-faced weave .

• Sateens are generally woven with a much higher number of picks than ends.

Use of Satins and SateensSatins and sateens are widely used in

uniforms, industrial and protective clothing

Triaxial weaves• Two sets of warp yarns are generally inserted at

60° to the weft

Triaxial weavesThe tear resistance, bursting resistance of

Triaxial fabrics is greatly superior to that of standard fabrics

They have a wide range of technical applications including sailcloths, tyre fabrics, balloon fabrics.

Crimp

Classification of Weaving Machines• Single-phase weaving machines

– Machines with shuttles (looms):• Hand operated (hand looms)• Non-automatic power looms (weft supply in shuttle

changed by hand)• Automatic weaving machines

– Shuttle less weaving machines:• Projectile• Rapier• Jet machines

– air (with or without relay nozzles)– liquid (generally water)

• Multiphase weaving machines

In single phase machines, one weft thread is laid across the full width of the warp sheet followed by the beat-up and the formation of the next shed in preparation for the insertion of the next pick.

In multiphase machines, several phases of the working cycle take place at any instant so that several picks are being inserted simultaneously.

Shedding MechanismsCrankCam or tappetDobbiesJacquards

Weft Insertion MechanismsShuttleProjectileRapierAir jetWater jet

Projectile looms…• They are used not only for weaving a vast

range of standard fabrics but also for heavy industrial fabrics of up to 8m wide, for – sailcloth, – conveyor belts,– tyre cord fabrics,– awnings, – Geotextiles, – airbags and – a wide range of filter fabrics of varying area

density and porosity.

L680W series high-efficiency fibre glass rapier cross weaving machine

Suitable for the weaving of various gridding cloth used in civil engineering, hydraulic construction, building materials, chemical engineering ann transportation areas

OMNI plus 800 air jet weaving machine• Gauze

– Gauze is a lightweight, open-texture fabric produced in plain weave, used for bandages, food wrapping etc.

• Parachute – Parachute is industrial, heavy-filament, rib stop

cloths made of fine nylon fibre

• Tyre cord– Tire cord is a fabric used to reinforce the tires

of vehicles

OMNI plus 800 air jet weaving machine• Umbrella cloth

– Umbrella cloth is usually made with a cotton warp and rayon or nylon filling, which is then treated to make it water repellent.

• Camping tent cloth – Camping tent cloth is a fabric used for the

outer covering of tents for recreational camping.

OptiMax rapier weaving machine

Conveyer beltConveyor belt is a continuously moving strip or

surface for transporting a load of objects from one place to another.

Filter clothFilter cloths are mainly made up of

monofilaments and/or multifilament's.

Woven either on rapier or air-jet technology• Sail cloth

– Sail cloth is any heavy, plain-weave canvas fabric, usually made of cotton, linen, polyester, jute, nylon etc. that is used for sails and apparel.

• Seat fabrics– Seat fabrics are used to cover seats in the

transport industry (automotive, aviation, etc.)• Air bags

– Airbag is a heavy denier nylon fabric for personal protection in various forms of transportation.

– Most airbag fabrics are woven with rapier weaving technology.