Material Considerations Flashcards
Define
gsm.
and state what it is used for.
grams per square meter
used to classify the weights of paper and card
Define
micron.
and state what it is used for.
one-thousandth of a millimetre
used to classify the thickness of paper and card
What weight classifies something as a
board?
(rather than a paper)
> 170gsm
What are some
common paper types?
(5 examples)
- layout paper
- copier paper
- cartridge paper
- bleed proof paper
- sugar paper
What is the weight of
card?
(s)
180-300gsm
What are some positives of
card?
(2)
- available in a wide range of colours, sizes and finishes
- easy to fold, cut and print on
What are some uses of
card?
(3)
- greeting cards
- paperback book covers
- simple modelling
What is the thickness of
cardboard?
> 300microns
What are some positives of
cardboard?
(3)
- available in many different sizes and surface finishes
- inexpensive
- can be cut, folded and printed on easily
What are some uses of
cardboard?
(3)
- packaging
- modelling
- templates for parts and pieces of products
What is
corrugated cardboard?
and what thickness is it?
a strong but lightweight type of card that is made from two layers of card with another, fluted sheet in between
thicknesses of 3000+ microns
double walled corrugated card is also available, this is twice as thick and gives extra strength and damage resistance
What are some positives of
corrugated cardboard?
(6)
- strong
- lightweight
- stiff
- difficult to bend or fold
- can absorb knocks and bumps
- good heat-insulating properties
What are some uses of
corrugated cardboard?
(2)
- packaging fragile or delicate items during transportation
- packaging for takeaway foods (e.g. pizza boxes)
What is
mounting board?
and what thickness is it?
a rigid type of card with a smooth surface
thickness around 1400 microns
it is most commonly used in white and black
What are some uses of
mounting board?
(2)
- picture framing
- architectural modelling
What is
foam board?
and what is its most common thickness?
A lightweight board that is made up of polystyrene foam sandwiches between two pieces of thin card or paper.
a thickness of 5000 microns is most common
What are some positives of
foam board?
(6)
- lightweight
- smooth
- available in a range of colours, sheet sizes and thicknesses
- rigid
- easy to cut
- can easily be folded
What are some uses of
foam board?
(2)
- modelling
- point-of-sale displays
What is
styrofoam?
A tradename for expanded polystyrene foam. It can be identified by its blue colour. It has a structure of uniformly small, closed cells.
What are some positives of
styrofoam?
(6)
- available in a wide range of sizes and thickness
- easy to cute, shape and sand to a smoth finish
- strong
- lightweight
- water-resistant
- good heat-insulation properties
What are some uses of
styrofoam?
(2)
- wall insulation in caravans, boats and lorries
- 3D model creation
What is
corriflute?
An extruded corrugated plastic sheet similar in structure and thickness to corrugated cardboard. It is made from a high-impact polypropylene resin.
What are some positives of
corriflute?
(5)
- available in a wide range of colours and sheet sizes
- rigid
- lightweight
- extremely waterproof
- easy to cut (but can be difficult to fold)
What are some uses of
corriflute?
- outside signs (e.g. estate agent’s signs)
- plastic containers
- packaging
- point-of-sale displays
- modelling purposes
Define
timber.
the general name given to wood materials once they have been processed into useable forms such as planks and strips
What are the
three main types of timber?
- softwoods
- hardwoods
- manufactured boards
What are
hardwoods?
wood that comes from broad-leaded, decidupus trees that lose their leaves over winter
these trees grow slowly and as a result the timber obtained from them tends to be dense, hard and heavy
What are some examples of
hardwoods?
(3)
- oak
- birch
- teak
What are some properties of
hardwoods?
(4) and what are they used for?
- dense
- hard
- heavy
- come in many different colours
generally used for high-quality items such as furniture
What are
softwoods?
wood that comes from conifers - evergreen trees that keep their needles all year round
these trees grow faster than hardwood trees and the wood is usually lighter in colour
What are some examples of
softwoods?
(3)
- pine
- cedar
- spruce
What are some properties of
hardwoods?
(2) and what are they used for?
- cheaper than hardwoods
- lighter in colour
usually used in the building industry for roof, wall and door frames
What are
manufactured boards?
sheets of timber made by gluing either wood fibres or wood layers together
What are some exmaples of
manufactured boards?
- MDF
- plywood
- blockboard
- chipboard
How is
metal made?
(2 steps)
- Metal ores are extracted from rocks in the Earth’s crust by mining.
- The metal ore is processed and refined to create a more useable material with improved properties.
What are the
two main categories or types of metal?
- ferrous metals (metals that contain iron)
- non-ferrous metals (metals that do not contain iron)
What are some properties of
ferrous metals?
(3)
- will corrode quickly (unless trated with a suitable surface coating)
- magnetic (generally)
- less expensive than non-ferrous metals (generally)
- available in a wide variety of shapes and sizes
What are some properties of
non-ferrous metals?
(3)
- more resistant to corrosion (than ferrous metals)
- significantly better electrical conductors (than ferrous metals)
- generally more expensive (than ferrous metals)
- available in a wide variety of shapes and sizes
What are some examples of
ferrous metals?
(5)
- mild steel
- carbon steel
- stainless steel
- cast iron
- wrought iron
What are some examples of
non-ferrous metals?
(3)
- aluminium
- copper
- tin
What are some
uses of metals?
mild steel?
aluminium?
stainless steel?
tin?
brass?
solder?
mild steel - building and engineering (e.g. steel girders)
aluminium - ladders
stainless steel - cutlery
tin - tin cans
brass - decorative products (e.g. door knockers)
solder - electrical connections on printed circuit boards
Define
alloy.
a metal made by combining two or more metals to give greater strength or resistance to corrosion
What are some examples of
alloys?
- brass
- bronze
- pewter
- lead/tin solder
What is a
polymer?
a very large, chain-like molecule made up of monomers
these can occur naturally or be manufactured
What are some examples of
naturally occurring polymers?
(4)
- silk
- wool
- hair
- animal horn
What are the two families of
manufactured polymers?
and what are they derived from?
- thermo polymers
- thermosetting polymers
they are derived from petroleum oil
Define
polymer memory.
the ability of thermo polymers to return to their original state after heating
What are
thermo polymers?
Polymers that soften when heated and can be moulded into shape. They harden again once they have been cooled.
This can be repeated many times, which means thermo polymers can be recycled.
What are some examples of
thermo polymers?
(9)
- PET
- HighDensityPolyEthylene
- PVC
- LowDensityPolyEthylene
- PolyStyrene
- PolyPropelene
- PolyEthylene
- acrylic
What are
thermosetting polymers?
Polymers that undergo a chemical change when heated to become hard. Once they have ‘set’ they cannot be reheated and remoulded and so they cannot be recycled.
What are some examples of
thermosetting polymers?
(3)
- silicone
- polyester resin
- epoxy resin
What are
fibres?
tiny hair-like structures that are spun (twisted) together to make yarns
these yarns are then woven or knitted together to create fabric
Where do
synthetic fibres come from?
(4ish)
a range of sources including:
- coal
- oil
- minerals
- other petrochemicals
What are some properties of
synthetic fibres?
(3ish)
- man-made
- (mostly) non-biodegradable
- not sustainable
they can be engineered to give them a range of useful properties including:
- flame resistance
- crease resistance
- stain resistance
Define
blending fibres.
mixing fibres of different origins together in order to improve the properties of the finished yarn
What are the properties of a
polyester cotton blend?
- strong
- breathable
- absorbent
- crease-resistant
- cheaper than not blended fabric
What are the
two different types of woven fabrics?
warp and weft
warp: yarn runs vertically
weft: yarn is woven horizontally un an under/over configuration (weft goes left)
What are some differences between
non-woven and woven fabrics?
and some uses of non-woven fabrics?
non-woven fabrics are less strong
they are used for decorative or disposable products
What are the
two types of non-woven fabrics?
- bonded
- felted
How are
bonded fabrics manufactured?
by applying pressure and heat or adhesives to bond the fibres together
these fabrics lose their strength and structure once wet so they are usually only suitable for one us
What are some uses of
bonded fabrics?
(5 examples)
- wet wipes
- tea bags
- surgical masks
- dressings
- nappies
How are
felted fabric produced?
by applying heat, moisture and friction to fibres, which matt together
the most commonly used fibres are wool and acrylic
What are some uses of
felt?
- the surface of pool and snooker tables
- cushioning
- insulating
What are
knitted fabrics?
fabrics that are made up of rows of interlocking loops, also known as stitches
(these come in weft and warp)
Define
modern material.
a material that is continually being developed through the invention of new or improved processes
What are some examples of
modern materials?
(6)
- polymorph
- teflon
- lenticular plastic sheet
- flexiply
- precious metal clay
- conductive polymers
Tell me about
polymorph.
- how does it come?
- how do you mould it?
- how do you remould it?
- comes in the form of polymer granules
- when heated to 60°C in warm water the granules melt and can be moulded into shape
- you can reheat it again using warm water or a hairdryer
What are some uses of
teflon?
(5)
- a non-stick coating on cookware
- paint
- fabrics
- carpets
- clothing
all to repel liquids
What is
lenticular plastic sheet?
A sheet that is smooth on one side whil the other side is made of small lenses.
These lenses transform 2D images into a variety of visual illusions
What is
flexiply?
a form of plywood that is extremely flexible and can quite easily be bent into various shapes
What is
precious metal clay?
and what is it used for?
a clay that is made from 99% silver or gold and 1% clay
this can be shaped at room temperature then heated in a kiln to produce jewellery
What are
conductive polymers?
plastic products that can conduct electricity
What are
smart materials?
materials that sense conditions in their environment and respond to these
What are some examples of
smart materials?
(6)
- shape-memory alloy
- shape-memory polymers
- thermochromic sheet
- thermochromic pigments
- photochromic materials
- self-healing materials
What is
shape-memory alloy?
and what is it used for?
a material that remembers its original shape when deformed and returns to it when heated
it can be used for glasses frames that return to their original shape after being bent
What are
shape-memory polymers?
polymers that can be ‘programmed’ to remember their original shape when heated
What is
thermochromic sheet?
and what is it used for?
a sheet that is printed with liquid crystal ‘ink’ that changes colour above 27°C
it is used in children’s toys, jewellery and temperature indicators
What are
thermochromic pigments?
and what are they used for?
Pigments that are often used on novelty mugs that reveal a design as hot water is poured into the mug.
They can also be added to polymers to create plastics that react to heat, such as colour-changing drink stirrers and** baby-feeding spoons** that warn you if food or drink is too hot.
What are
photochromic materials?
and what are they used for?
materials that react to light
glasses that darken in bright sunlight use photochromic lenses
What are
self-healing materials?
and what are they used for?
Materials that have the ability to detect and repair damage done to them.
The first of these were polymers that had internal adhesive and were used on products such as cutting mats. Self-healing materials can use embedded capsules that release adhesive when the material cracks. BioConcrete heals itself using bacteria that react with any water that gets into it and produce limestone to fill any micro-craks that appear.
What are
composite materials?
materials that are produced by bonding different materials to produce newe materials with improved properties
What are some examples of
composite materials?
- glass-reinforced plastic
- carbon fibre
- kevlar
- laminates
What is
glass-reinforced plastic?
and what is it used for?
Polyester resin reinforced with glass fibre strands. It has all the properties of a polymer but is much stronger.
it is used for large structural items such as boats and car bodies
What is
carbon fibre?
and what is it used for?
Polyester resin reinforced with carbon fibre strands. This makes the material even stronger and also lighter in weight.
it is used for protective helmets, high-end bicycles and hockey sticks
What is
kevlar?
and what is it used for?
Polyester resin reinforced with very strong polastic. It is even lighter and stronger than carbon fibre.
it is used for bulletproof vests
What are
laminates?
and what are they used for?
They are materials that are made up of layers. Since the layers are usually different materials, if a material is not strong or durable enough to survive by itself, you would combine it with one that is. For example, a waterproof jacket is made from layers that stop wind and rain getting in but allow moisture vapour out.
it is used for laminated glass and waterproof jackets
What are
technical textiles?
textiles that are engineered specifically for their performance properties, not for their aesthetic value
What are some examples of
technical textiles?
(4)
- nomex
- kevlar
- coolmax
- fastskin
What are the properties of
nomex?
and what is it used for?
(3)
it is heat and flame resistant
it is used for:
- protective clothing for racing drivers, firemen and astronauts
- oven gloves
- fire-resistant insulation in buildings
What are the properties of
kevlar?
and what is it used for?
(4)
it is resistant to abrasion and damge by sharp or pointed objects
it is used for:
- stab and bullet resistant vests for police and armed forces
- linings in motorcycle clothing and accessories
- car and motorcycle tyres
- protective gloves for butchers and fishmongers
What are the properties of
coolmax?
and what is it used for?
(4)
it wicks water away from your body and improves breathability
it is used for:
- bedding
- sportswear
- uniforms
- underwear
What are the properties of
fastskin?
and what is it used for?
(1)
it mimics the skin of a shark, giving a streamlining effect when underwater
it is used for competitive sportswear and swimwear
What are important
properties of materials
to consider? (18)
maybe we don’t memorise this one
- density
- strength
- hardness
- durability
- strength to weight ratio
- stiffness
- elasticity
- impact resistance
- plasticity
- ductility and malleability
- brittleness
- corrosive resistance to chemical and weather
- water resistance
- absorbency
- flammability
- electrical conductivity
- thermal conductivity
- magnetic properties
What is the
strength
of a material?
its ability to withstand forces that try to bend or break it
Because there are different forces that can be applied to a material, there are different kinds of strength, related to hoe well a material can resist these forces:
- compressive strength - compression forces
- tensile strength - tension forces
- yield strength - before it is permanently deformed in some way
- impact strength - sudden forces
What is the
hardness
of a material?
how resistant it is to pressure from cutting, scratching or wear
What is the
durability
of a material?
the ability of a material to withstand wear, pressure or damage
What is the
strength to weight ratio
of a material?
a measure of a material’s strength compared to its weight
What is the
stiffness
of a material?
its rigidity - its ability to resist being deformed when a force is applied to it
What is the
elasticity
of a material?
its ability to return to its original shape when forces are applied to it that will make it bend or flex out of shape
What is the
impact resistance
of a material?
the ability of a material to withstand a force or shock applied to it over a short period of time
What is the
plasticity
of a material?
the ability of a material to permanently change in shape when force is applied to it
What is the
ductility and malleability
of a material?
how easily it can be deformed or bent out of shape without snapping or breaking
What is the
brittleness
of a material?
how easily a material will snap or break when bent or impacted
this is the opposite of ductility and is affected by heat
What is the
corrosive resistance to chemicals and weather
of a material?
how susceptible a material is to degradation from elements such as oxygen, moisture and other chemicals
What is the
water resistance
of a material?
The ability of a material to resist the ingress of water. Materials that do not absorb moisture or water are called waterproof.
What is the
absorbency
of a material?
the ability of a material to absorb moisture
What is the
flammability
of a material?
the ability of a substance to burn or ignite, causing fire
What is the
electrical conductivity
of a material?
how easy it is for electricity to flow through a material
What is the
thermal conductivity
of a material?
The way heat can be transferred through a material. Materials with good thermal conductivity will allow heat to be transferred through them relatively easily.
What are the
magnetic properties
of a material?
A material with magnetic properties will emit forces that attract or repulse other materials. All materials have a certain amount of magnetism, but it is very low in most of them.
examples………
