Section 2 Flashcards
What do fibres come in?
Short length (staple fibres) and long lengths (filaments)
Can filaments be cut into stable fibres?
Yes
How is yarn produced?
Stable fibres are spun to produced yarn and tend to be hairier, also filaments can be spun as they are and the yarn is more smooth
Where do natural fibres come from?
Natural sources eg cotton, silkworms, sheep
What length to natural fibres come in?
Staple fires apart from silk they come in filament fibres
What happens after the natural fibres are harvested?
They’re cleaned, straightened before there spun
What do natural fibres come from?
Natural sources
Are natural fibres biodegradable and sustainable?
Yes
What are advantages about natural fibres?
There absorbent and strong
What are disadvantages about natural fibres?
Poor resistance to biological damage eg mound and moths
What are regenerated fibres?
Are made of natural materials that are chemically treated to produce fibres.
Are all regenerated fibres the same?
No different fibres are made by using different chemicals
Give an example of a regenerated fibre.
Viscose fibres are made by dissolving cellulose in sodium hydroxide solutions. This liquid is forced through tiny holes, and hardened to form filament fibres. These filaments are stretched into a yarn which is around onto spools, or chopped into staple lengths
Are regenerated fibres sustainable?
The fibres have a renewable origin but many are made using synthetic chemicals, which make them less sustainable than natural fibres. However, some regenerated fibres like ten cel are produced so that almost all of the chemicals used can be recycled, and the fibres are recyclable and biodegradable
What properties do regenerated fibres have?
They have similar properties to natural fibres, but can be given different properties by using different chemicals
What are synthetic fibres?
Man made fibres
What are synthetic fibres made of?
They’re made from polymers, long chains of molecules. These molecules come mainly from coal and oil
How are synthetic fibres made?
The polymers are melted or dissolved in solution. This liquid is then forced through tiny holes and hardened to form filament fibres
How are synthetic fibres turned into yarn?
The filaments are stretched into yarn which is wound onto spools, or chopped into staple lengths
What are synthetic fibres properties?
They can be given different properties. In general, they’re resistant to biological damage, and can be changed by heating to form different shapes and textures. However they’re not very absorbent , so can be hard to dye
Are synthetic fibres sustainable?
They are made from non-renewable sources, they’re less sustainable than other types of fibres
What are fabrics made of?
Yarn or fibres which are stuck together
What are 3 weaves?
Plain, twill and satin
What are fabrics made of?
Yarn
What are woven fabrics?
Different woven fabrics are made by interlacing two sets of yarn - the weft, which travels from right to left, and the wrap, which travels up and down the weave
What is a plain weave?
The simplest weave - the went yarn passes over and under alternate warp yarns, making it unpatterned
What are the properties of a plain weave?
It’s hard wearing, strong and holds it shape well. It also has a smooth finish (making it good for printing)
What weave is the cheapest and used to make loads of fabrics, especially cotton based ones?
Pain weave
What is a twill weave?
A twill weave creates a diagonal pattern on the surface of the fabric. Eg the weft yarn goes over two yarns and under one. The next weft yarn repeats this, but one warp yarn further along
What are the properties of a twill weave?
It’s stronger and drapes better than a plain weave
What is a twill weave used for?
Denim
What’s a satin weave?
The weft yarn goes over four or more warp threads and under one
Why is a satin weave shiny?
The long weft yarns on the surface (called floats) catch the light, so satin weave makes shiny fabrics like satin
What’s bad about a satin weave?
The floats can snag, so the fabric is quite delicate and doesn’t resist abrasion
What are non woven fibres?
Non woven fabrics are layers of fibres held together by bonding or felting
What are the advantages of non weave?
They don’t fray, and can be cut in any direction, which means there’s little waste when laying out patterns
What are disadvantages of non woven fibres?
They don’t stretch and aren’t very strong
What are bonded fabrics?
These are webs fibres held together by glue, stitches needle punches or heat
What are bonded fabrics used for?
They’re used for interfacing, artificial leathers and disposable cloths
What are felted fabrics?
Felting is an older way of making non-woven fabric. Felt is made by combing pressure, moisture and hearts interlock a mat of wool fibres
What are felted fabrics used for?
Carpet, underlay, craft material, hats, jewellery and snooker table coverings
How are knitted fabrics made?
Knitted fabrics are made by interlocking one or more yarn together using loops
What are advantages about knitted fabrics?
These loops tarp air, making knitted fabrics good insulators. They also stretch more than woven fabrics
What is a weft knitted fabric?
The yarn runs across the fabric, making interlocking loops with the row of yarn beneath
What are properties about weft knitted fabrics?
These fabrics stretch and can lose their shape easily, also if the yarn breaks it can unravel and make a ladder
What are weft knitted used for?
Jumpers, socks and t-shirts
How are weft knitted fabrics produced?
Hand or machine
How is a warp knitted fabrics made?
The yarns run up the fabric, in loops, which interlock vertically
What are the properties of warp knitted fabrics?
They’re stretchy but still keep their shape. These fabrics are hard to unravel and are less likely to ladder
What are made out of warp knitted fabrics?
Tights, swimwear, fleeces and some bed sheets
How are warp knitted made?
They’re made by machine and the machines can be expensive
How do you find how a fabric is made?
1) Pick it apart to see how it’s constructed
2) if the yarns run straight, it’s woven, to work out which type of weave it is, count how many warp yarns the weft yarns cross before they go underneath one
3) if the yarns loop around each other in a repeated pattern, it’s knitted, weft knitted fabrics will have a simpler pattern than warp knitted ones
4) if there are no yarns, just fibres, it’s no woven.
What is embroidery?
Embroidery is decorative stitching it can be done by hand or machine . Different types of thread give different textures and finishes. CAM embroidery machines can be used to automatically produce designs
What are advantages of embroidery?
1) can do very intricate designs
2) adds texture as well as colour
3) hand embroidery fives unique results
4) quick to do by machine - can be done automatically using cam and cad
What is the disadvantages of embroidery?
1) can be easily damaged so it’s more difficult to care for
2) very time consuming and expensive if done by hand
3) hand embroidered products won’t be identical
How do beads a sequins add decoration?
They add colour and textiles
They also reflect light
You can buy sequin material
What is quilting?
Quilting used wadding between two layers of fabric which are them stitched together in straight lines or in a pattern