Strength Extensibility Elasticity Fineness Electrostatic charge Lustre Thermal

� 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)

FINENESS - SEE PAGE 44 CLOTHING TECHNOLOGY � 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”

l l 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.

l l l 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 gm 2, but sometimes measured in linear metres. Denim is traditionally weighed in oz, such as a 12 oz denim for jeans, a 8 oz 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/brushing Texture � 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 gm 2. 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. ”