Textile Materials – Un Spun Improvements in new materials, processes and finishes are always being developed to meet the needs of consumers. This ‘Un Spun’ work sheet will help you understand more about the range of natural and manufactured fibres improving your knowledge of fabric structure, finish, properties and manufacture. Polymers – Fibres – Microfibres Polymers Polymer = combination of large molecules (these molecules are made from a chain of smaller repeating chemical units called monomers) Natural PolymersRegenerated polymersSynthetic polymers Short fibres – must be combed, lined up and twisted to make longer, usable lengths. Vegetable fibres – Cotton, Linen (Cellulose) Animal fibres – Wool (Keratin) Hair fibres – Cashmere (Keratin) Natural fibres – that need to be processed & manufactured Viscose and Modal – made from the cellulose in wood pulp. It is dissolved in chemicals, pushed through tiny holes in a spinneret & into an acid bath, producing a continuous filament Manufactured from petrochemicals by the polymerisation process to produce long chains of linear fibre polymers. These are melted and pushed through spinnerets forming continuous filaments of synthetic fibre. Acrylic, Elastane

Fibre Fibres are very fine textile raw materials. They are flexible and have a high ratio of length over thickness. Fibres are either natural or manufactured. Natural Staple Fibres – usually very short in length e.g. a few mm (cotton linters) or a metre as in some linen. Synthetic Continuous Filament Fibres – Manufactured to an indefinite length, usually the whole length of the yarn Natural Continuous filament fibres – As long as one kilometre when taken for a silk cocoon

Microfibre Microfibre technology combines a high number of very fine fibres into one yarn of one decitex or less. 10km of filament weigh one gram or less. A microfibre is between 60 and 100 times finer than a human hair. Microfibres can be:  manufactured from polyester, polyamide or acrylic  blended with other synthetic fibres or with natural fibres  used in fabrics that have an enormous variety of appearances and end uses  used in smart and technical fabrics for active wear, all-weather wear and for a range of industrial uses

Vegetable Fibres Cotton, Linen and Sisal are all vegetable fibres. Cotton comes from natural cellulose in the seed of the cotton plant. It is like a flat hollow tube with a natural twist in it and is produced as staple fibre.  Cotton is very absorbent and can hold 65% of its own weight with out dripping  It is non-static because it always contains some moisture  It is naturally breathable, soft to handle, has good drape and dries slowly  It has good strength, abrasion, resistance and durability  It has poor elasticity and creases easily  It is biodegradable and recyclable Typical cotton fabrics include calico, corduroy, denim, gingham and terry towelling. It is used for bed sheets, curtains, towels, shirts, underwear, jeans, tents, work wear etc. The performance can be improved through finishing  Mercerising – for higher strength and lustre  Synthetic resin treatment – for non-iron, crease resist  Stain resist – using Teflon or silicone

Animal Fibres Wool, Cashmere and Silk, are all examples of animal fibres Wool comes from the fleece of sheep. It is produced as a staple fibre. Microscopes show us that the fibre has:  an outer layer of scales called the cuticle, making the fibres interlock during manufacture  an inside core like a tiny cable, called the cortex, giving strength.  The cortex is made up of millions of long cells held together by a strong natural binding material. In between these two layers are thousands of little sealed-in air bubbles, making the wool proof against heat, cold and damp. This three-in-one combination and interlocking fibre of great strength with built-in insulation is what man made synthetic fibre have never been able to imitate.  Wool is hydrophilic – can absorb 1/3 or its weight in water  Naturally breathable – rapidly absorbs moisture vapour  Hydrophobic – repels raindrops  Good crease resistance and 40% natural elasticity stretch  Is biodegradable and recyclable Typical wool fabrics are felt, herringbone, flannel, tartan, and tweed.

Natural Polymers Viscose, Modal and Acetate are all natural polymers. Viscose is a natural cellulose made from wood pulp of Pine or Eucalyptus trees, it is produced as staple and filament yarns. Viscose properties are:  More absorbent than cotton & non static  Naturally breathable, absorbing 11% water vapour  Fine, soft handle with good drape  Not very warm, low ability to trap air  Low strength, low durability - Can tear when wet  Creases easily, poor elasticity  Biodegradable and recyclable, inexpensive Typical fabrics include lustrous crepe fabrics from filament and faux cotton, linen and wool type fabric from staple. Improved performance achieved through finishing can be  Synthetic resin treatment to reduce shrinking and creasing – but absorbency is reduced  Wide range of textures and crimping can be applied

Synthetic Polymers Acrylic, PVC, elastane, nylon and polyester are all synthetic polymers. Acrylic is made from petrochemicals. It is inexpensive to manufacture, can be a filament or spun fibre and can also be spun as a microfibre. Its properties are:  Low absorbency – fast drying but prone to static  Good strength, crease resistant  Soft wool-like handle, with good drape  Warm, easy care  Thermoplastic, sensitive to steam and heat, can result in shrinkage  Non-renewable resource Acrylic can be blended with wool or viscose for winter fabrics and cotton, linen or silk for summer fabrics. Typical end uses might be fluffy knitting yarns, fake fur and fleece fabrics, blankets, curtains, carpets and microfibre performance fabrics.

Synthetic Polymers cont… Nylon is made with petrochemicals and is inexpensive to manufacture. You can produce textured filaments, staple fibres and microfibres from it. Its properties are:  Non absorbent and prone to static, textured filaments transport moisture away from the body  Fineness ranges from microfibre to coarse fibre  Flat filaments trap little air so are cool, textured filaments trap air and provide warmth  Very strong, excellent abrasion resistance & durability  Windproof, hydrophobic, water repellent, easy care, lightweight, flammable, soft, good drape  Good elasticity, so good crease recovery  Dyes well, looses strength with long exposure to sunlight  Resistant to alkalis, solvents, mildew and fungus, but degraded by concentrated acids  Non-renewable source, non-biodegradable Typical uses include carpets, curtains, umbrellas, tights, underwear, night wear, socks, ties, active wear, fleece garments, parachutes, seat belts, tents and ropes Performance can be improved with anti static treatments