AQA GCSE Textiles Revision
- Created by: amycook3999
- Created on: 23-05-16 11:37
Types of Fibre
Yarns are threads made from tiny 'hairs' called fibres.
Fibres can either be in:
- Short/Staple lengths which are spun to make yarns and give a hairier finish.
- Long/filament fibres which can be spun into yarns, or used as they are, they make smooth yarns.
Fibres can be:
- Natural- come from plants and animals, usually staple lengths (except silk). Renewable & biodegradable. Are absorbant and strong, but poor resistance to biological damage.
- Regenerated- made from natural materials (e.g. cellulose) then treated with chemicals. Tencel is example of recyclable ones. Renewable origin, synthectic chemicals. Similar properties to natural but can be changed by chemicals.
- Synthetic- man made fibres made from polymers. Non-renewable therefore less sustainable. Can be given manny different properties, in general resistant to biological damage and can't be changed by heating. But not very absorbant so hard to dye.
Fabric Construction- Weaves
Made up of two yarns: warp (up) & weft (across)
Plain weave
- Weft yarn passes over & under alternate yarns, making it unpatterned
- It's hardwearing, strong and holds shape well. Smooth finish so good to print on
- Cheapest and is used for lots of fabrics, especially cotton based ones
Twill Weave
- Creates diagonal pattern on the surface of the fabric. E.g. weft yarn goes over 2 yarns & under 1. Repeats but next yran along
- Stronger & drapes better than plain weave. Used in denim,
Satin Weave
- Weft over 4 or more under 1
- long weft yarns (floats) on surface catch light & make shiny fabrics e.g satin
- Floats can snag, so is delicate and doesn't resist abbrasion
Fabric Construction- Non-Woven
They don't fray and can be cut in any direction which means little waste
Dont stretch and aren't very strong
Bonded Fabrics:
- Webs of fibres held together by glue, stitches, needle-punching or heat.
- Used for interfacing, artificial leathers and disposible cloths.
Felted Fabrics:
- Older way
- Felt is made by combining pressure moisture and heat to interlock a mat of wool fibres.
- Can be used for carpet underlay, craft materials, hats, jewellary and snooker table coverings.
Fabric Construction- Knitted
Made by interlocking one ore more yarns together using loops,
Loops trap air making good insulators and stretch more than woven fabrics.
Weft Knitted Fabrics:
- Yarns run across fabric making loops underneath.
- They stretch &lose shape easily and if yarn breaks it unravels. (More likely to ladder).
- Can be made by hand or machine.
- Used for jumpers, socks and t-shirts.
Warp Knitted Fabrics:
- Yarns run up fabric, in loops which interlock vertically.
- Stretchy but still keep their shape and hard to unravel. (Less likelt to ladder).
- Made by machines- machines are expensive.
- Used for tights swimwear, fleeces and some bed sheets.
Fibres and Fabrics-Natural
Cotton- (Smooth appearance)
- Strong, hardwearing,absorbant,comfortable, cool, easy to wash & dye, no allergies, cheap
- Creases easily, highly flammable, poor elasticity, shrinks in wash, dries slowly.
- Makes denhim,corduroy, calico for jeans, t-shirts, blouses and soft furnishings.
Wool (Soft or Coarse)
- Warm, absorbant, good elasticity, low flammability, crease resistant, available in lots of weights
- Shrink when washed, dries slowly, itchy, fairly expensive.
- Makes Harris tweed, jersy,garbardie for suits, jumpers, coats, dresses and carpets
Linen (Natural look)
- Strong, hardwearing, absorbant, comfortable, cool. Creases badly high flamability, poor drape, expensive,
- In trousers, summer suits, dresses, furnishings.
Silk (Very smooth, glossy)
- Smooth, absorbant, good drape, low flammability, comfortable. Creases, hard wash, weak when wet, expensive.
- In Organza, chiffon, satin for lingerie, underwear, dresses, shirts and ties.
Fibres and Fabrics-Regenerated
Viscose:
- Smooth, light glossy appearance
- Absorbant, soft, comfortable, easily washable, good drape, fairly cheap.
- High flammabilty, not very hardwearing, poor elasticity.
- Made for Rayon in Lingerie, underwear, dresses, suits, linings and soft furnishings.
Acetate:
- Smooth and glossy appearance
- Soft, comfortable to wear, easily washable, good drape, resists biological damage, cheap.
- High flammibility, not very hard wearing, poor elasticity, not very absorbant.
- For linings and soft furnishings.
Fibres and Fabrics- Synthetic
Polyester (Smooth can have alot of different finishes).
- Strong, hardwearing, low flammibility, elastic, cheap, no creases, dries quick,resist bio damage
- Not absorbant, no biodegradeable damaged by strong acids, melts as burns
- In dacron for sports wear, bed sheets, curtains, cushings, passing, table cloths.
Elastane (Soft)
- Extremely elastic, strong, hard-wearing, lightweight, keeps shape, resists bio/sun damage.
- Not absorbant, high flammability, not biodegradeable.
- In Lycra for sports/swim wear, underwear, combined with other fibres to add stretch
Polyamide (Can be made with lots of different finishes).
- Strong, hardwearing, warm, good elasticity, crease resistant, cheap, biological resistant.
- Not very absorbant, damaged by sunlight and melts as burns.
- In Nylon in sportswear, furnishings, carpets tight and socks.
Acrylic (Similar to wool)
- Strong (except wet), soft, warm, good elasticity, lightweight, no shrink, cheap.
- Not absorbant, high flammibility, affected by static pilling.
- In fake fur, knitted clothes, furnishings.
Combining Fibres in Fabrics
Done for: Apperance, practical qualities, working qualities and cost.
Blending:
When 2 or more different fibres are combined to produce a yarn. Blended before spining. Yarns then knitted or woven to make fabric.
An example is poly-cotton which is stronger and ore hard-wearing and is less absorbant (dries quicker), resists creating and doesn't shrink easily. But is highly flammable.
Mixing:
A fabric made up of two or more different yarn. For exampl one yarn could be the weft the other could be the warp. This ca create patterned fabric.
An example is elastane mixed with cotton to create a stretchier fabric. It remains strong, fits snugly, comfortable to move in, crease resistant, dyed easily.
Modern Fabrics
Kevlar: Made chemically into a very strong polymer. Fabric woven to create a fabric that is very strong and resistant to abbrasion. Uses- bullet proof vest and motor cyclist clothing.
Nomex: Is fire resistant and used for fire fighters clothing & racing drivers overalls.
Tencel: Regenerated fibre, combines best properties of natural and synthetic, given many textures. Make many products. Can be made enviromentally friendly, using sustainable wood pulp.
Fastskin: Developed by Speedo. Mimicks shark skin, reduces drag, makes you go faster.
More 'green' fibres developed from natural sources- e.g. bamboo and hemp
Laminated Fabrics: Two or more layers stuck together providing strength, protection or warmth. Gortex: mebrane w. tiny pores allowing sweat out but no water in. Breathable and waterproof.
Microfibres: Thin fibres, 100x thinner than human hair. Usually synthetic eg polyester & polyamide. Versitile. Water repellant and breathable. Can be expensive,blended with cotton, linen & silk to reduce cost. Soft,comfortable, last well, drape well. Underwear, sports, hoisery
Smart Fabrics & Materials
Smart materials designed to react automatically to changes in the surroundings.
Micro-encapsulation: tiny droplet of chemical embedded in microfibre fabric to give different properties. Perfumes, insect repellant, vitamins, odur neutralisers, eg socks/ lingerie
Conductives: conductive fibres/coatings for more comfort to wear. Include, heart rate and blood pressure moniters. Electronic switches for MP3 or phone, electric heater.
Thermochromic: changes colour depending on temp. Lasts for 5-10 washes. Microencapsulation
Photochromic: changes colour due to light conditions. Microencapsulation
Nanomaterials: made from carbon or synthetic polymers. Thin, light but very strong. It involves tinkering with substances on a really small scale. Nanoparticles often behave differently to different to regular particles. Can be used for finishes as very thin.
Choosing Fabrics
The product must fit its purpose for the job it is meant to do.
You have to choose a fabric with the right properties:
Warmth
After Care
Durability
Appearance
Wearibility and Comfort
Safety and Flammability
Stain Resistance
Fabric Maintenance
Care Symbols
Dyeing
Natural Dyes: made from natural sources such as beetroot & flowers. Not consistant colour
Chemical dyes: Bright colours, easier &cheaper to make, always same colour. Some are toxic and harmful to people and enviroment.
Best fabrics are absorbant (natural) and one suitable colour (bleached if not), fixed with mordant to fix colour. Makes colour fast.
Batch dying is comercial. Lots of fabric in 1 go w. uniform colour. Can respond quickly to trends.
Tie Dye: every piece will be unique, equiptment cheap, easy. Outcome unpredictable, can't exactly repeat pattern. Can't create detail, time consuming for large areas.
Batik: More precise of adding patterns than tie dye, patterns can be more detailled, every product will be unique. It's time consuming, hot wax is difficult to control and tricky to iron wax out.
Printing
Printing is applying ink, dye or paint to fabric in patterns. Materials with tight weave are best as they have a smooth surface.
Block Printing (hand): can print differnet colours w. same block, use several blocks creates more complicated design, easy to repeat, use blocks lots. Making blocks long time, no fine detail.
Flat-Bed Screening (hand): creates intricate patterns easily repeated, good for large areas, easy for many colours using many screens, quick. Making screens takes long time, each colour applied seperately.
Commercially can be done with machines (screen &squeegee) same pattern long lengths of fabric.
Commercial Flat-Bed Screen Printing and Rotary Screen Printing
- Inctricate patterns can be repeaded accurately, much quicker and more can get done at once, rotary fastest. Can be computer controlled (CAD)
- Setting up is expensive, screen making is expensive (unless CAM/CAD)
Decoration and Enhancement
Applique: Zig zag stitch. Different types- normal, padded, layered, reverse
- Strengthens base, shapes repeatedly accurate, can use scraps, adds colour and texture can use be autmatic with CAM machines
- It adds extra thickness and requires extra material.
Quilting/Wadding:
- Can create 3D effect and warmth.
- Requires alot of material and is time consuming.
Embroidary:
- can do intricate patterns, adds texture & pattern, hand embroidary unique, quick by machine.
- easily damaged & hard to care fo, time consuming & expensive by hand and not identical (h)
Beads and Sequins: Add texture and colour and reflect light in interesting ways.
Fabric Finishes
Can be used to change appearance of fabric (sheen & colour), texture (smoothness/softness), wearing properties (crease/stain resistant) and after care characteristics (anti-shrinking).
Chemically Applied:
- Flame retardence
- Water resistance
- Stain resistance
- Shrink resistant
- Crease resistant
- Thermochromic dyes
Mechanically Applied:
- Fabric brushing
- Calendering (smoother/shinier)
- Pre-Shrinkage (pre-shrunk to reduce shrinking)
Fastenings
Zips:
- secure, quick &simple to attatch, lay flat, hardwearing, can match ot contrast, washable
- can snag, don't add interest, difficult to replace.
Toggles and Buttons
- easy to attach and replace, can match or contrast, decoration
- can fall off (chocking hazard), not very strong, can be damaged in wash
Velcro/Hooks and Loops:
- safe and soft, can be machine washed, hard wearing
- hooks collect fibres and become sticky, not very decorative
Press Studs (or Poppers)
Components
- Threads- different colours, textures and thickness
- Trimminings- lace, ribbon, braid, beads and sequins
- Interfacing- strength, support and stability
- Labels- show care instructions, fibre content, safety information and size
- Motifs- small fabric badges, show team or club or for decoration.
- Electronics- LEDs, heaters, solar panels or batteries
- Sensors- measure heart rate and blood pressure
- Washable electronic switches- control MP3 and phone
- Wadding that responds to temperature
- Conductive fibres
Environmental Issues
- Pollution & use of resources- textile production lots of energy and non-renewable fabrics.
- Disposal of waste materials- Fctories generate waste on landfill sites and take long to decomp
- Transport pollution- materials transported around the world.
- Disposal of toxic chemicals- used in dyeing & printing, escape into enviroment eg water
- Cotton farming- fertilisers pollute rivers and harm wildlife. Pesticides kill other things
- Fashion Trends- produce cheap low quality that you throw away when out of trend
- Ethical Concerns- poorer countries less safety, worse conditions, child labour, toxic chemicals, using animals for material (cruelty)
Solutions:
- Use renewable energy sources, biofibres (natural) and efficient processes. Biodegradable like cotton and Tencel. Fabrics can also be grown organically without artifical fertilisers.
- Reuse waste products, respin fibres, recycle old clothes, reduce waste (reduce packageing)
- Get raw materials from local suppliers and make nearby
- Use organic fabrics- eg cotton
- Remove chemicals before water leaves factory, use non-toxic dyes and unbleached fabrics
- Apply fair trade- fair price and conditions, use artificial animal skins
Consumer Rights and Safety
Trades Descriptions Act:
Any claim about product must be true. No false information or price reductions
Sale and Supply of Goods Act 1979:
Protects consumers. Goods must fit description, good quality and fit for purpose.
General Product Safety Regulations 2005:
Manufacturers responsible for the safety of their products, putting warnings on label. Lion Mark made by member of British Toy and Hobby Assciation- strict guidelines. CE mark product meets essencial safety standards allowing to be sold throughout Europe
Furniture and furnishings must meet fire regulations. Mainly sofas and soft furnishings eg cushains
You need to pick suitable fabrics and components to make the product safe.
Manufacturing Safely
Health and Safety at Work Act means employers are legally responsible for h&s of employees.
- Must provide safety equiptment & training, maintain machines, safety policies, first aid
- Providing safety guards and protective equiptment
Must complete a risk assesment - Identifying the potentail hazards at each stage of production and the proecautionswhich need to be taken to miminise risks.
4 main risks:
- Equiptment:
- Sewing machines- guards, dust extracters, emergency stop
- Sharp objects- non-slip mats, safety rulers, care, thimble, stored safely
- Materials & Chemicals- ventelation, protective clothing, stored safely
- Protective clothing- chain mail gloves, rubber gloves, goggles, hair net/tie up, ear protection
- Working practices- clear walkways, enough light, training, breaks, machinary checked regulary
Tools and Equiptment
Use the right tools for the job:
- Marking and measuring- measuring tapes, tailors chalk, pattern marker.
- Cutting- Scissors (paper, dressmaking, embroidary, pinking), craft knife, unpicker
- Sewing- pins, needles
- Pressing- dry or steam irons
Sewing machines speed up sewing and produce neat, high quality finish and are lockstitch machines.
Overlockers can sew seams and finishe edges at the same time.
Use computerised embroidary to add embroidery.
Construction Techniques
Plain seam- the easiest to do can be open or closed (look neat and quite strong)
French seam- encloses seam edges ( strong but not bulky)
Flat felled seam- strong and durable (on jeans)
Overlock seam- quick to do (strong and quick and good for stretchy materials)
Edge finishes:
- Pinking shears for wovens that don't fray much
- Overlocked
- Rolled hem - folded twice
Darts- create a better fit so closer to body
Tucks and Pleats- pressed/stitched, controls fullness
Gathers- gives shape
ICT and Industrial Equiptment
CAD and CAM is used in industry. Examples of CAM machines are:
- cutting machine
- sewing machines
- embroidary and knitting machines
- fabric printers
- plotters/cutters
- pressing machines
Advantages:
- Design development- quickly &cheaply modelled &compared, easy to change, can be sent across the world, arrange pattern pieces effectively
- Manufacture- speeds up production, more accurate, moniter quality, higher quality, cuts labour costs, safer, control stock levels, reduce manufacturing costs, identical, efficient.
Disadvantages:
Initial cost, workers need training, viruses, and power cuts.
Production Processes
One-off production- making a single unique product. eg. catwalk clothing or custom wedding dress
Batch production- the production method used to make a specific number of identical products. eg a winter dress for highstreet store.
Mass production- the production method used to produce a large number of identical products using a production line (one part each) and a sub assembly (one part eg pocket) This speeds up the process. eg white school blouses.
Mass produced is cheapest, One-off most expensive. Produces lots quickly and bulk buys. CAD/M
JIT (Just In Time)- getting materials & components delivered in small amounts when needed, saves cost on storage, and less money tied up in stock, and can change order quickly so no waste when trends change. Although if not delivered on time or faulty not much you do if something is wrong, production stops.
Quality Assurance and Control
Quality assurance: the system that is set up to make sure that high quality products are produced.
Quality control: the checks that are carried out on materials & products before, during and after production to make sure standards are being met.
Ouality control checks happen at 3 critical points:
- raw materials
- prototype
- production samples
Tolerance: the margin of error allowed for a measurement of part of a product. Usually given as upper and lower limit.
If a products not right, problem is relayed back to factory (feedback). Happens straight away so can be fixed quickly. Feedback modifys manufacturing process, feedback loop.
Quality conrol ensures: lower costs as less waste, less time wasted fewer products returned. Get good reputation.
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