Material categories and properties - polymers and textiles Flashcards
what are thermoforming polymers
polymers that can be heated and reshaped repeatedly, they are pliable and recyclable
examples of thermoforming plastics
Acrylic (PMMA)
High impact polystyrene (HIPS)
High density polythene (HDPE)
Polypropylene (PP)
Polyvinyl chloride (PVC)
Polyethylene terephthalate (PET)
properties and uses of acrylic
- hard
- brittle
- shiny
- available in wide range of colours
- scratches easily
- used in baths, car lights
properties and uses of high impact polystyrene HIPS
- rigid
- cheap
- available in lots of colours
- used for CD cases and yoghurt pots
properties and uses of High density polythene (HDPE)
- stiff
- strong
- lightweight
- flexible
- used for washing baskets, chairs
properties and uses of Polypropylene (PP
- easily coloured
- tough and flexible
- used for chairs and casings
properties and uses of Polyvinyl chloride (PVC)
- cheap
- brittle but durable
- used in blister packs and window frames
properties and uses of Polyethylene terephthalate (PET)
- light
- tough
- strong
- used for clothing and drink bottles
what are thermosetting polymers
polymers that do not change shape when heated
properties of thermosetting polymers
- brittle
- good insulators
- resistant to heat and chemicals
examples of thermosetting polymers
Epoxy resin (ER)
Melamine formaldehyde (MF)
Phenol formaldehyde (PF)
Polyester resin (PR)
Urea formaldehyde (UF)
properties and uses of epoxy resin
- rigid
- durable
- expensive
- strong
- used to bond materials and lamination
properties and uses of Melamine formaldehyde
- hard
- brittle
- printable surface
- used for picnic wear
properties and uses of Phenol formaldehyde
- rigid
- brittle
- Easily injection moulded
- good insulator
- used for snooker balls and bottle caps
properties of Polyester resin
- strong
- heat resistant
- good insulator
- used as waterproofing and for encapsulating items
properties of Urea formaldehyde
- heat resistant
- brittle
- hard
- easily injection moulded
- used for electrical fittings
what are natural fibres
fibres that come from plants or animals, they are renewable and biodegradeable
examples of natural fibres
- cotton
- wool
- silk
properties and uses of cotton
- takes dye well
- absorbent
- strong
- recyclable
- used in clothing
properties and uses of wool
- warm
- crease resistant
- can be thick or coarse
- used in clothing and carpets
properties and uses of silk
- soft
- shiny
- difficult to wash
- creases easily
- used in luxury clothing, underwear and bedding
what are synthetic fibres
fibres made from non renewable coal and oil refined into polymers, and do not degrade easily
examples of synthetic fibres
- polyester
- polyamide
- elastane
properties and uses of polyester
- strong
- versatile
- holds colour well
- washes well
- can be woven or knitted
properties and uses of polyamide (nylon)
- shiny
- water resistant
- hard wearing
- used for parachutes, sports clothing, sports equipment
properties and uses of elastane
- smooth
- stretchy
- Hardwearing
- quick drying but not biodegradable
- used in sportswear and swimsuits
what are blended fabrics
mixtures of fibres which combine properties
examples of blended fabrics and uses and properties of this fabric
polycotton
- easy to wash
- cheaper than cotton
- can be printed or dyed
what are woven fabrics
fabrics that use a warp and weft yarn on a loom to interlock fibres.
how to remember woven fabrics
woven in overlapping layers, (under one, over one)
properties of plain weave
- woven fabric
-Simple and cheap - strong
- available in different thicknesses
- when torn it rips in a straight line
what are non woven fabrics
webs of fibres that are glued, compressed or melted together
examples of non woven fabrics
- felted fabrics
- bonded fabrics
properties and uses of felted fabrics
- available in many thicknesses
- Formed with moisture, heat and pressure
- can be shaped as it has no elasticity or drape
- used for hat making
- Randomly matted fibres, often wool
properties and uses of bonded fabrics
- often have holes at the surface
- Does not fray as it has no grain
- not strong
properties of knitted fabrics
- made from a variety of fibres, not just wool
- Can be warp knitted (straight lines) or weft knitted (knitted upwards)
- Warm,
- stretchy
- strong, tend to unravel when a hole is made,
- used in clothing and sportswear
how to remember weft knitted
in loops like an oxbow river
how to remember warp knitted
looks like broken glasses
how is wool made
(MADE FROM A SHEEPS FLEECE)
- a sheep is sheared
- the wool is then cleared and scoured to remove dry grease and sweat
- the fibres are then combed using wire rollers (this is called carding)
how is cotton made
(MADE FROM THE SEED PODS OF THE COTTON PLANT)
- before harvesting, plants are treated with chemicals to make the leaves fall off
- fibres are cleaned to remove dirt
- seeds are removed
- carding
how is silk made
(FROM THE COCOON MADE BY SILK WORMS)
- the cocoon protects the worm whilst it turns into a moth
- the cocoon is one long piece of silk fibre which is stuck together with a hard gum called sericin
- the gum is softened by soaking in warm water, then the filament is unwound (this is called reeling)
what are regenerated fibres
fibres made from natural materials which are chemically which are chemically treated to make fibres
examples of regenerated fibres
a viscose fibres which are made by dissolving cellulose in sodium hydroxide. the liquid is forced through tiny holes and hardened to form filament fibres
