materials Flashcards
what are the 3 groups of metals
- ferrous
- non ferrous
- alloys
what are ferrous metals
metals found in rock haematite (earths crust)
- contain iron
- usually magnetic
- will rust
what are non ferrous metals
metals found in ores (earths crust)
- dont contain iron
- not magnetic
- won’t rust
- malleable
what is an alloy
mixture of 2 or more metals combined to improve mechanical/ physical property of original metal
types of non ferrous metals
- aluminium
- copper
- zinc
- tin
aluminium
- lightweight
- soft
- ductile + malleable
- used extensively in aircraft, canned drinks, bike frames
copper
- ductile + malleable
- thermal + electrical conductor
- easily soldered
- resistant to corrosion
- used extensively in plumbing for pipes and fittings
- used in manufacture of wire
zinc
- resistant to corrosion
- low melting point
- easily worked
- weak like a pure metal
- used as coating on steel to protect against corrosion
- used in die casting
tin
- resistant to corrosion
- has low melting point
- easily worked
- weak like pure metal
- used as coating on steel to protect from corrosion
- used as coating on food cans
- also used in soft solder
what are boards measured in
microns
- 1000 microns = 1mm
corrugated cardboard
appearance - natural brown board finished with 1 or 2 sides w bonded paper characteristics - lightweight, rigid - insulative - easily printed on - perpendicular to corrugation uses - packaging boxes and impact protection
duplex board
appearance - 2 layers of card bonded together - often white external layer characteristics - stiff, lightweight - coatings to improve functionality uses - given waxy coating and used for food/ drink containers
foil lined board
appearance
- white card coated in aluminium foil (1 side)
characteristics
- foil reflects heat, water and oil
- resistant coating enabled food/ liquid based products to be contained
uses
- takeaway container lids
foam core board
appearance - smooth board surface on each side - foam and inner corners have limited ranged of colours and thickness characteristics - 3 -10mm thick - lightweight, rigid in all directions - crease/ crack under pressure uses - architectural models - model making/ prototyping - mounting/ framing frames onto wall
ink jet card
appearance
- bright white card treated w smooth finish (matt and gloss)
characteristics
- treated to hold high quality photographic images
- ink dries onto surface to create deep colours
uses
- high quality photographic images
solid white board
appearance - high quality board - bright white - smooth finish on both sides characteristics - holds colour well easily cut or creased uses - greeting cards - packaging - hot foil stamping and embossing
manufactured boards
man made boards, come in large sizes, often flat and stable -manufactured into large boards by lamination or compression
advantages of natural timber
- available in large sheets (8ft x 4ft)
- stable, less likely to warp, twist, shrink or bow
- smooth, flat surface
- suited to CNC machining
types of manufacture boards
- MDF
- plywood
- chipboard
MDF
description - compressed fine wood fibres bonded with resin properties - relatively inexpensive - has flat smooth surface
plywood
description - wood veneers glued together with alternating grain properties - very strong - flat smooth surface
chipboard
description
- wood chips bonded together with resin
properties
- inexpensive construction material
what are hardwoods
come from deciduous trees and are generally hard and durable, more expensive and take longer to grow than softwoods
softwoods
come from coniferous trees that are relatively fast growing , more sustainable than hardwoods
what is timber
a natural and renewable product -
what are the 2 groups of natural timber
- softwoods
- hardwoods
types of hardwoods
- ash
- beech
- mahogany
- oak
- balsa
ash
properties - tough + flexible - wide grained - finishes well common uses - sports equipment - ladders
beech
properties - hard and strong - close grain - prone to warping and splitting common uses - furniture - kids toys - workshop tools + bench tops
mahogany
properties - strong and durable - available in wide planks - fairly easy to work out but can have interlocking grain common uses - good quality furniture - panelling - veneers
oak
properties - hard, tough, durable - open grain - can be finished to a high standard common uses - timber framed buildings - high quality furniture - flooring
balsa
properties - strong and durable - lightweight - easy to work with common uses - model making - floats and rafts
types of softwood
- larch
- pine
- spruce
larch
properties
- reddish colour
- tough but easy to work
- naturally resistant to rot
pine
properties - straight grained - light yellow colour - soft and easy to work - quite knotty common uses - interior joinery - furniture - window frames
spruce
properties - creamy white colour - easy to work with, small knots - lightweight, good resistant properties common uses - bedroom furniture - stringed musical instrument
standard components on wood
- used to assist in joining materials together, increase strength of structure, add functionality
- in timber, most components create a non-permanent joining methods meaning product can be taken apart without damage
types of standard components
- screws
- nails
- nuts
- bolts
- hinges
- knockdown fittings
advantages of standard components
- saves prep time
- fewer production steps
- less human effort and skill required
- less machinery/ equipment needed
- good quality
- saves money (all aspects)
- can be bought in bulk
- high quality consistency
blended and mixed fibres
fabrics containing more than 1 fibre
- blending achieved by spinning 2 or more fibres to make yarn
- will be produced based on required properties for purpose
why are fibres blended
- help reduce the cost of fabric
- make fabric stronger
- fabric is easier to care for
- enables fabrics to be more crease- resistant
- allows fabric to be heat-set
polyester/ cotton
- a popular blend used for clothes, bedsheets…
- different % of polyester and cotton depending on material being made
- dangerous when on fire, cotton burns easily and holds polyester in place, polyester melts and drips
burns at high temp and gives off black smoke
what does polyester do
helps to cancel out the shrinking, slow-drying and creasing of cotton
what does cotton do
makes fabric better at absorbing moisture and makes it more comfortable on skin
wool and nylon (polyamide)
- blended together to make socks, trousers, jackets and coats
what does the wool do in polyamide
makes fabric soft and warm
what does the nylon do in polyamide
- improves strength and resistance to abrasion
- makes fabric lighter in weight and helps prevent wool from shrinking when washed
lycra (elastane)
blended with many other fibres to give fabric stretch.
- very small amount needed to give lot of stretch
- makes fabric more crease resistant
