Strength Extensibility Elasticity Fineness Electrostatic charge Lustre Thermal insulation Flammability Moisture absorption Shrinkage

Very strong – polyester, polyamide Good strength – elastane, acrylic, silk,

cotton (*stronger when wet*), linen Medium strength - wool Low strength – viscose (*significantly

lower than cotton* and also poor wet strength), acetate

Elasticity is the property which allows a fibre to recover to its length after it has been extended.

Very good – wool due to natural crimp in the fibre; silk; polyester; polyamide; elastane (lycra); acrylic

Poor – cotton (creases easily); linen (creases badly); viscose (creases easily)

Measured in units of tex or decitex (dtex). The smaller the number the finer the fibre.

Remember with tights that a 40 denier tight is thicker than a 10 denier

Textile fibres can be classified into coarse, fine and microfibres

Microfibres are mainly synthetics with a linear density of less than 1 dtex.

Finer fibres make for softer, denser and more comfortable fabrics with better drape.

Microfibre is fiber with strands less than one denier. Microfiber is the perfect blend of polyester and polyamide. Fabrics made with microfibers are exceptionally soft and hold their shape well. When high quality Microfiber is combined with the right knitting process, it creates an extremely effective cleaning material. This material can hold up to seven times its weight in water. They are also used for some cleaning applications, because of their exceptional ability to absorb oils.

sythnetic fibres generally have an electrostatic charge due to their low moisture absorption. Remember that when you wear a polyester skirt and nylon tights that you often get static cling and the skirt “rides” up your legs.

Natural and regenerated fibres rarely have an electrostatic charge because the moisture present conducts the charge away.

Silk has a typical lustre due to the trilobal cross section of the fibre

Viscose, can range from high lustre to matt depending on the cross section and the addition of delustrants.

Polyester and polyamide can range from high lustre to matt depending on the cross section and the addition of delustrants.

Cotton can be given lustre by a treatment with caustic soda called mercerizing that makes the cross section more circular meaning that light can be reflected.

Warm to wear – wool, acrylic, Cool to wear – cotton, silk (*but also

provides good insulation and is used in thermal underwear), linen,

low warmth - viscose, acetate, polyester unless texturised yarns, polyamide unless texturised yarns, elastane (but also used in blends)

Very flammable and ignite with a naked flame– cotton, linen, viscose

Wool – does not burn easily and is used for protective clothing

Synthetic fibre tend to shrink away from the flame and melt

A blend of cotton/polyester burns dangerously as the cotton ignites and the polyester melts creating a “scaffold” effect”

Is measured as the standard moisture regain (SMR%) of a fibre. The test is carried out in a special room at 20ºC and at 65%RH (relative humidity)

Synthetic fibres have poor moisture absorption (remember high static). They are hydrophobic and fast drying.

Natural fibres have good moisture absorption properties (low static).

Cotton can absorb up to 20% of water vapour without feeling wet.

Wool is hygroscopic – it can absorb up to a third of its weight in water vapour without feeling wet! Water vapour is absorbed, but water droplets are repelled – this behaviour is known as hydrophobic!

Silk, like wool it can absorb up to one third of its weight in water vapour.

Viscose is slightly more absorbent that cotton. Due to its absorbent nature viscose is used in sanitary wear, nappies, household wipes etc.

Strength This is the degree to which a fabric will resist

strain. A strong fabric will not tear easily and will have a

high tenacity value.Durability This means the fabric does not wear out easily. It is resistant to abrasion, rubbing and friction. Chemicals in detergents and anti-perspirants may

reduce durability. Ultra-violet light may break it down.

Elasticity This is the ability a fabric has to stretch. The fabric: has the ability to recover to its original shape and size Easily sheds creases and crushing gives added comfort in wear is resilient and recovers well after stretch.Flammability This is the degree to which a fabric will catch fire or burn. Non-flammability may also be achieved by a special chemical

finish.Thermal qualities - Warmth/thermal insulation Fibres trap air, preventing passage of heat away from body. Construction of knitted fabric laminates and membranes lend

themselves to trapping air and preventing passage of heat away from the body.

Crease resistance This means the fabric: sheds creases easily keeps good appearance requires little ironing/tumble drying. Crease resistance may be improved by the addition of a

chemical finish.Absorption/absorbency This means the fibre can readily soak up/absorb

water/moisture. The absorbency of a fibre is measured as its SMR% (standard moisture regain).

The fibres are termed hydrophilic, water loving. For example, cotton and viscose.

In contrast, some fibres are naturally water repellent. These fibres are termed hydrophobic, water hating. For

example, polyester, nylon and acrylic. Polyester is so hydrophobic that it attracts and absorbs fats,

oils and greases. It is termed olephilic, oil loving. This can make it difficult to remove grease stains.

Stretch/elasticity – This is the ability a fabric has to stretch. The fabric: has the ability to recover to its original shape and size Easily sheds creases and crushing gives added comfort in wear is resilient and recovers well after stretch.Formability

Easy care This means the fabric can be easily laundered without damage. The

fabric: allows soiling to be removed easily is not damaged by detergents does not lose colour when washed does not lose shape when washed does not shrink when washed dries easily/quickly can be tumble dried requires little ironing does not require special care/dry cleaning.

Handle this means how a fabric feels to the touch and is

subjective. Fabric can be described as having a crisp hand, firm hand, soft hand, slippery hand, silky hand etc. Silk has a characteristic “scroop”

Drape this means how a fabric falls, hangs or drapes. Drape can

be recorded in laboratory tests. Weight this is the weight of the fabric usually measured as gm2,

but sometimes measured in linear metres. Denim is traditionally weighed in oz, such as a 12oz denim for jeans, a 8oz denim for shirting.

Pattern repeat this applies to fabric that can be either a printed woven or

knitted fabric (i.e. floral print) or yarn dyed woven (i.e. unbalanced check) or a fancy weave (i.e. jacquard)

Directional pile - also refer to pile weave/knits Pile runs in one direction. Fabric has a rich, luxurious appearance and feel. Fabric appears lighter if pile runs down. Fabric appears darker/richer if pile runs up. Pile is easily marked/flattened by water/staining As the surface of the fabric is raised, extra consideration

should be given to layout, cutting, assembly and finishing to avoid disturbing the pile.

Examples Carpet Chenille Corduroy Fake fur Fur fabrics Novelty pile fabrics Terry towelling Velour Velvet Velveteen

Nap Direction of pile/brushingTexture this refers to the surface texture of a fabric. Fabric

such as knitted fleece can have a wool fleece like texture. Brocade and jacquards have their texture woven into the fabric as their design/pattern.

Lustre is used to describe the sheen/shine of a fabric Traditionally synthetic fibres/fabric are shiny,

however, delustrants can now be added to the synthetic chip/molten polymer to make the fibres matt in appearance. In industry a de-lustred fibre would be referred to as being semi-dull or full-dull.

In industry testing of materials to determine appropriate properties in relation to chosen end use is carried out a various stages of the process. Raw materials/fibre Yarn Weaving/knitting/non-woven Griege fabric - Dyed/Printed/Finished fabric Fibre composition Fabric performance Product performance

Raw materials/fibre would be tested to ensure that quality standards are met. If you are a spinner of woollen yarn then you need to know that you have been supplied with 100% wool fibre from a specific breed of animal

Yarn will be tested to ensure that quality standards are met. The strength and perhaps elasticity and extension of the yarn will be tested. The yarn will be checked to see that it has the correct number of twists per cm etc.

Weaving/knitting/non-woven. During the fabric manufacuturing process that fabric will be tested to check that it is the correct weight per gm2. The strength of the fabric might be tested at this stage. Poor strength could be an indicator that there is a problem with the greige fabric.

Fibre composition of a blend, mixture will need to be tested to determine if the fabric meets the standard. Luxury fibres such as cashmere (Nobel fibres), are also tested to ensure that the consumer is not deceived with an inferior fibre.

Dyed/Printed/Finished fabric. The fabric mill will test the performace of the fabric to deterime if it meets the correct quality standards. Common testing at this stage will include Strength Shrinkage/stability Colourfastness to washing Colourfastness to rubbing Any key promotional claims such as water repellency,

waterproof, breathability, crease resistance, wrinkle free, stretch,

Fabric performance. The garment maker might carry out their own testing to determine if the agreed standard of performace has been met. Failure for the bought fabric to met the standard can result in orders being cancelled.

Product performance. Finished products are also tested. By law Childrens nightwear and upholstery must be tested for flammability. Promotional claims must also be tested, such as a product being promoted as “waterproof.”