unit 2 - plastics activities
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ACTIVITY 2
ACTIVITY 1
1Plastics are all around us today and help to make our personal lives cleaner,
easier, safer, more convenient and more enjoyable.
introducing
The use of plastics is increasing all thetime as they replace materials such asmetal, wood, paper, ceramics and glassin a wide variety of uses. There arealso new roles which only plasticscan fulfil.
The motor car is a good example ofa product in which plastics are nowextensively used. Over the last 20 years,the use of plastics in cars has increasedby 114 per cent and it is estimated thatwithout plastics today’s cars would beat least 200kg heavier. Weight savingsachieved through the use of plasticshave enabled parts, such as the chassisand drive shaft, to be made lighter. It isestimated that over the average life-span of a car of 150 000km, thislightweighting has contributed to areduction in fuel consumption ofaround 750 litres. In turn, this reducesoil consumption by approximately12 million tonnes and CO2 by
30 million tonnes per annum inWestern Europe.
But what are plastics? Why arethey so useful and so widespread?Why do they behave as they do?What is their chemical structure?
Many materials we use every dayare made of polymers. These are large,long molecules constructed of smaller,shorter molecules called monomers.
Polymers can be natural or synthetic. Natural polymers are common in
animals and plants. Much living tissueis based on polymers - for example,proteins in animals and carbohydratesin plants. A lot of our food is basedon polymers - for example, fibre, grainand meat. Plants and animals alsoproduce non-living materials based onpolymers. These are usually produced
Think of at least three objects which, a few
years ago, would have been made
of other materials and which are
now commonly made of plastics.
For each object you listed, see if there are
any obvious advantages of the plastic over the
other material. Give reasons why you believe
plastics are now used.
This picture shows a typical
modern car. Which parts are made
of plastics materials? What
advantages do you think plastics
have over metal? Think of
safety
economy
style
colour
cost
It is estimated that a 1000kg
car, containing 100kg of plastics,
would use 4% less fuel than a car
made of more traditional
materials. If a car uses 2000 litres
of fuel each year, costing 70p per
litre, how much money is
saved through the use
of plastics?
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2
This diagram shows the structure of a
monomer and a polymer
monomer
polymer
ACTIVITY 3
http://www.apme.org
as fibres and then have to beprocessed to produce materials suchas threads and fabrics.
Synthetic polymers are mademainly from petroleum. This isprocessed in an oil refinery toproduce basic chemicals known asmonomers. The monomers are thenturned into polymers. Some polymersare turned into a solid plasticsmaterial, and others into textilefibres. Some can be turned intoeither, depending on how they areprocessed.
As we enter the 21st century it isclear that plastics are now an integralpart of our lives. From the packagedproducts we purchase, the transportwe use and the buildings we live andwork in, to the sports equipment weuse and the advanced medicaltechnology employed to keep us fitand healthy, plastics have becomeindispensable.
Plastics products were first madein 1862 from plant materials.Cellulose fibres in the form of cottonwool were treated with nitric acid toform cellulose nitrate (‘Celluloid’),which was used to make objects suchas ornaments, knife handles, boxes,cuffs, collars and film for movies.
In 1909 a new source of rawmaterials was found - coal tar. Thisprovided the ‘Bakelite’ plastics, usedfor electrical insulation and the cases
for cameras, early radios and evenjewellery.
In the early years of this century,chemists began to understand thereactions which they were observing,thus accelerating the search for newtypes of material. In the 1930s themanufacture of plastics from chemicalsproduced from petroleum began, andpolystyrene, acrylic polymers, andpolyvinyl chloride were produced,although their use grew only slowly.
Nylon was discovered in 1928, andentered production in the late 1930s. Itwas produced as long filaments whichcould be spun and woven or knitted.The production and manufacture ofother plastics materials - low densitypolyethylene, polyurethane, polyvinylchloride (PVC), PTFE, polyesters,
Look at these pictures of
objects made from synthetic
polymers. Try to decide
whether the polymer is a solid
plastic material or a fibre.
Whether a plastic is a solid material orwhether it is a thread-like fibre dependsonly on how it has been produced. Fromnow on, the word plastics will be used todescribe all such materials.
The history of plastics
silicones, epoxy resins - grew during the1940s. Polycarbonates were added inthe 1950s. High density polyethelene(HDPE) and polypropylene were addedin the 1960s.
The1970s saw the arrival of the‘third generation’, high-tech,performance plastics which built onprevious developments. These includednew polyamides and polyacetals.Innovation continued throughout the80s and 90s, with new polymers beingcreated to meet specific designchallenges. For instance, recentadvances in catalyst technologies haveallowed even better control of apolymer’s molecular structure andprovide improved physical properties.For example, a new generation ofmetallocene catalysts allow muchstronger polyethylene films to be madewhich are tougher and moretransparent while using even less rawmaterials.
Today, more than 700 types ofplastic are produced which fall into18 main polymer families. Readilyavailable, versatile and economic tomanufacture, plastics are used toproduce both hi-tech and everydayobjects. A regular consumer surveyshows that the most positive attitudestowards plastics are in connection withinnovative, hi-tech applications.
ACTIVITY 4
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20101870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
Describe the shape of this graph.
Why do you think the graph changes shape so
much during the 1950’s?
What happened in the early 1970’s to make
the graph change direction so sharply?
Extend the graph to the year 2010. What does
this suggest the level of production will be?
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The growth in the production ofplastics across the world (tonnes m)
These fractions are still complexmixtures of compounds and nochemical changes have yet takenplace. They need to be chemicallyaltered to make them into moreuseful products with different meltingand boiling points and differentchemical properties. There are twotypes of process:
Cracking breaks large molecules intosmaller ones which are more useful –and therefore of greater value. Forexample, very high boiling pointfractions are cracked to produce
2The raw material for plastics is crude oil, a complex mixture of thousands of
compounds. To become useful, it must be processed. Around 4% of the
world’s production is turned into plastics.
the raw
Cracking
ACTIVITY 1
Because the compounds in crude oilhave different masses, and thereforeboil at different temperatures, it ispossible to separate them by a processknown as fractional distillation.
The mixture is separated intofractions, not into individualcompounds. Fractions contain amixture of compounds whose boilingtemperatures are similar.
The diagram on page 2 shows thefractional distillation process. It ismainly the naphtha and gas oilfractions which are used for furtherprocessing to make products suchas plastics.
Heating,electrical &
energy42%
Transport45%
All other 5%
Other petrochemicals 4%
Plastics 4%
Most compounds in crude oil are hydrocarbon molecules –
they contain carbon and hydrogen atoms only. These
diagrams show a few of the compounds which are found in
crude oil. Diagram (a) shows ethylene.
Draw the formula of each of these compounds in the
following form
CH2=CH2 This is the structural formula of ethylene
And then write the formula in this form
C2H4 This is the molecular formula of ethylene
The mass of a molecule depends on the number of carbon
and hydrogen atoms in it. A carbon atom has a mass of
12 units; a hydrogen atom has a mass of 1 unit. In the
example shown below, the mass of an ethane molecule,
C2H6, is [2x12] + [6x1] = 30 units
Work out the mass of the molecules shown here (a-g).
If the boiling point of the compound increases as its
mass rises, arrange the compounds in order of increasing
boiling point.
A range of
molecules showing
different ways in
which chemical
bonds are formed
between atoms.
represents a carbon atom
represents a hydrogen atom
represents a chemical bond
a
c
d
f
g
e
b
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Monomers
reactive compounds
small number of carbon atoms in amolecule
usually a gas or a liquid
relatively cheap compounds toproduce
of little use as they are
Polymers
unreactive compounds
very large number of carbon atomsin a chain
always a solid
nearly always more valuable to sell
very useful once they have beenprocessed
Polymer chains have very different properties to monomers
ACTIVITY 2
http://www.apme.org
gasoline and gas oil fractions. Today,most cracking uses catalysts, but someheat treatment still occurs.
Reforming changes the internalstructure of molecules to producedifferent compounds with a greaterusefulness – and therefore highervalue. By altering conditions – such astemperature, pressure and the catalyst– the cracking and reformingtechniques can now be controlled toproduce exactly the blend ofcompounds which will be most usefulat a particular time.
Naphtha is cracked by mixing itwith steam and heating it to 800°C.It is cooled rapidly to 400°C, causingchemical changes. The mixture of C6
to C10 compounds is converted to asmall number of C2, C3 and C4
compounds which contain carbon-carbon double bonds, C=C.
The simple compounds are oftenknown as ‘basic chemicals’ – many ofthese are shown on this card inActivity 1.
All the basic chemicals are smallmolecules containing between two andseven carbon atoms. It is thesemolecules which are the ‘monomers’from which the ‘polymers’ are thenmade.
The small monomer molecules arereacted together to form a polymerrather like paper clips to form a chain.In order to make the monomers reactand join up together, small amountsof special catalysts are added to thepolymerisation reactor.
Polymer manufacturing hasbecome increasingly sophisticated inrecent years, as researchers havedeveloped new compounds to meetthe needs of specific designchallenges. For example a new familyof catalysts known as metallocenesgive greater control over howmonomers join up in a more ordelyfashion. This can make the resultingplastic much stronger and transparent.
One of the simplest synthetic polymers is polyethylene.
This is made from ethylene.
The structure of Part of the structure
ethylene is: of polyethylene is:
List the structural differences between
the two molecules.
The monomers react by the end of one
molecule bonding to the end of another. In this
way chains are formed. This is rather like
paper clips being linked together. Draw your
own picture of how this chain formation
takes place.
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2
Reforming
H
H
H H H H H H
C C C CCC
H H H H H
C
H
CCH
H
H
H
This diagram shows the fractional distillation process. It is
mainly the naphtha and gas oil fractions which are used
for further processing to make chemicals such as plastics.
fractionising
column
crude
oil
heater
gasoline
naphtha
kerosine
gas oil
40°C
110°C
180°C
260°C
340°C
refinery gases
long residue
3Eight of the most important polymers are produced from only three basic
chemicals which come from naphtha.
polymersand
polymerisation to form polybutadiene which is a synthetic rubber
Ethylene C2H4
Propylene C3H6
Butadiene C4H6
polymerisation to form high density polyethylene (HDPE), low density polyethylene (LDPE) or linear low densitypolyethylene (LLDPE)
reaction with chlorine to form chloroethene polymerisation to form polyvinyl chloride (PVC)
reaction with benzene to form styrene polymerisation to form polystyrene (PS)
reaction with oxygen to form ethene oxide further reaction and polymerisation to form polyethyleneterephthalate (PET)
polymerisation to form polypropylene (PP)
reaction with oxygen to form propylene oxide further reaction and polymerisation to form polyurethanes (PU)
Ethylene and propylene can be polymerized together to make a rubber which can also help make polypropene even tougher
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ACTIVITY 1
The table to the right shows the
total sales of the major plastics by
Western European manufacturers
from 1992 to 1998 (figures show
thousands of tonnes sold).
Describe how sales have
changed for each of the plastics.
Summarise in one sentence
how sales of plastics generally
have changed over the period.
Suggest reasons for the
changes you have reported.
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3
LDPE
4698
4544
4920
4727
’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98 ’92 ’94 ’96 ’98
LLDPE
899 1281
1429
1692
PVC
4829 5401
5251
5370
PP
4432 4982
5782
6834
HDPE
3107 3
718
3861
4195
PET
433
630
604 965
PS
1779
1749 2146
2194
ACTIVITY 2
Imagine that you are a small part of a thermoplastic polymer. You are part
of a lump of plastic material which is waiting to be processed into a cup.
You have strong chemical bonds along the polymer chain to parts of the
molecule next to you; you also have some weak bonds across to parts of the
polymer which are positioned near to you. The weak bonds keep the plastic
material solid and rigid.
As part of the manufacturing process, the plastic material is warmed to
make it soft and pliable; then squeezed in a press into a new shape; then
allowed to cool and solidify into the new shape.
Describe what happens to your part of the polymer as this processing
takes place.
Use words, a diagram, or a cartoon to do this.
It is clear from this that the chemicalbonding in a polymer and the shape ofthe polymer will affect its properties.
Although there are many different examples of plastics, they fall into two distinct categories:
These are called thermoplastic polymers because theykeep their plastic properties
These polymer molecules consist of long chains whichhave only weak bonds between the chains
The bonds between the chains are so weak that they canbe broken when the plastic is heated
The chains can then move around to form a differentshape
The weak bonds reform when it is cooled and thethermoplastic material keeps its new shape
These are called thermosetting polymers because onceset into a shape, that shape cannot be altered
These polymer molecules consist of long chains whichhave many strong chemical bonds between the chains
The bonds between the chains are so strong that theycannot be broken when the plastic is heated
This means that the thermosetting material alwayskeeps its shape
Those which soften on heating and then harden again on cooling
Those which never soften once they have been moulded
The bonding process. When thermoplastic polymers are heated they become flexible. There are no cross-links and themolecules can slide over each other. Thermosetting polymers do not soften when heated because molecules are cross-linked together and remain rigid
Most plastics made from thebasic chemicals that come
from naphtha are thermoplastic
Examples are polyethylene(HDPE, LDPE and LLDPE),
polypropylene (PP), polystyrene (PS),polyethylene terephthalate (PET), andpolyvinyl chloride (PVC)
Common examples ofthermosetting plastics are
polymers based on formaldehyde(Bakelite was the earliest example)
Examples aremelamine/formaldehyde
(MF), urea/formaldehyde (UF),phenol/formaldehyde (PF) and
polyurethane (PU)
Epoxy glues are alsothermosetting plastics
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The polymer is made from onemonomer e.g. A-A produces
In addition reaction, chains areformed from one small molecule. Themonomer always contains a carbon-carbon double bond.
Most thermoplastic plasticsmade from naphtha are
addition polymers. e.g. polyethylene,polypropylene, polystyrene.
High density polyethylene HDPE Dustbins Bottles Pipes
Low density polyethylene LDPE Bags and sacks Bin liners Squeezable detergent bottles
Polypropylene PP Margarine tubs and Garden furniture, Telephonesfood wrappings crates, suitcases Car bumpers
Polystyrene PS Food containers Computers Video and audio cassettes
Polyvinyl Chloride PVC Blood bags Credit cards Window frames and pipes
Polyethylene Terephthalate PET Fizzy drinks bottles Oven-proof trays Anorak and duvet filling
Polyurethane Upholstery Sports shoe soles Roller skate wheels
Acrylics (e.g. Perspex) Sink and bathtubs & tap tops Protective glasses Car light covers
Polycarbonates CDs Car headlights Firemen’s helmets
Plastic Uses
This table shows the main plastics and gives examples of some of their uses.
ACTIVITY 3
Write down the molecular formula of each of the
compounds shown above, in this form:
CxHyNz and CxHyOz
The first step in the polymerisation is the two monomers
reacting together to form a dimer. In this reaction a
molecule of water H2O is produced from the H of one of the
NH2 groups and the OH of one of the COOH groups.
Draw a diagram of this dimer.
Write down the formula
of each of these compounds
in this form:
CxHyOzNw
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There are two ways of producing polymer chains:
Addition reactionsCondensation
reactions
The polymer is made from twomonomers e.g. A-A and B-B produce
In condensation reactions, chains areformed from two small molecules.During the reaction a small moleculesuch as water is formed and removed(condensed out). All thermosettingpolymers are condensation polymers,for example, formaldehyde-basedplastics and epoxides.
Some thermoplastic polymers arecondensation polymers. Examples areNylon and polyethylene terephthalate(PET).
Nylon belongs to a class of polymerscalled polyamides. Nylons are producedby condensation polymerisation. Twomonomers which can produce Nylon are:AA A A AA AA
CC
AA A B BBBA
H H H H H H HH
NC C C CCCN
H H H H H H H H
H
O
OO
H H H H
C C C CCC
H H H H
O
H
6 Extrusion andextrusion coating
The materials are heated, compressed,and extruded through a die of thedesired shape. Materials can also becoated with soft polymerand then passedbetween rollers togive an even coating(coatings on foodand drink containers).
Heated polymer is fed betweentwo rollers which squeezes itinto a thin sheet (flooring,tiles, panelling, sheeting).
4 Rotational moulding
Plastics powder or paste is heatedinside a closed mould which isrotated until the walls ofthe mould are coveredwith an even layerof polymer (large,hollow items suchas litter bins, fueltanks, drums).
http://www.apme.org
ACTIVITY 4
Find out more about the uses of plastics. Suggest two properties which PET has which the other plastics do not have.
What special properties do you think that polypropene has, if it is used as a wrapping for food such as biscuits and crisps?
Look at the uses of the two forms of polyethylene. From your knowledge of the different things which the two plastics are
made into, list the main differences in their properties.
Think about these objects which are all made from polyethylene:
➔ toys ➔ pipes ➔ film ➔ wrapcoatings for cardboard containers ➔ petrol tanks in cars ➔ electrical cable ➔ coatings
Which is likely to be made from the high density form, and which from the low density form? Why?
Consider PVC window frames. Suggest reasons why PVC compares favourably with other materials used for window frames.
Try and find out why PVC is used rather than other traditional materials.
Design an investigation to test the effectiveness of the plastic used to wrap biscuits. Begin with a clear statement of what
you wish to test. Now design a simple method of investigation.
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The plastic is first heated, thenthe soft polymer is
forced underpressure into acool, closed mould(containers, lids,footwear, crates,
gear wheels).
1 Injection moulding
2 Compression moulding
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The polymer is placed in a mould andpressure applied to make the plastic
take up the shape of the mould(electrical plugs and sockets).
The warm, soft polymer is blowninto the shape of a mould by
compressed air or steam (bottles,containers).
Soft polymer is forced into atube-shape. This is blown upwith air and either heat sealed orslit (bags, film).
7 Calendering
The family of materials which formplastics has a wide variety of differentproperties. Some resist high pressureand extremes of temperature, someresist air and moisture. There aredifferent forms of the same basicplastics type which can be stiff orflexible and so suitable for particularapplications.
Plastics’ properties can also betailored by the use of additives (seecard 4).
Polymers are converted intoplastics products inseven main ways.These are listedhere. A briefdescription of thedifferent methodsis given and a listof typical products.
3 Blow moulding
Blow film extrusion
4
ACTIVITY 1
Today, plastics provide an environmentally sound and cost-effective
solution for many design challenges.
the propertiesof
Plastics do not usually conduct electricity. Think of as many different
ways in which this property is used in the home or at work.
A lot of the plastics used to package foods are transparent. How might
this increase food safety?
Plastics are widely used in hospitals. Look at this picture. What are the
particular advantages of using plastics in this way? Think of the advantages
that cheapness of production brings.
Plastics are likely to be safer than glass because they do not break, and
safer than steel because they do not rust and are less likely to have jagged
edges. Can you think of objects made from plastics which might pose a
hazard to people or animals if not disposed of sensibly?
Some plastics can withstand very high temperatures, why might this be
useful?
Some plastics are waterproof and resistant to attack by chemicals.
Think of ways in which these properties are useful to us.
Industries, especially the hi-tech onessuch as aerospace, medicine,computing and communications, relyon new plastics materials for progressin engineering and design. Plastics areoften superior to any other materialsin these fields. Many newdevelopments would not in fact bepossible without them.Think about the clothes we wear, thehouses we live in and how we travel.What about the toys we play with,the televisions we watch, thecomputers we use and CDs we listento? Whether we’re shopping in asupermarket, having major surgery ormerely brushing our teeth, plastics arean integral part of everything we do.
Why are plastics so widely used in allour lives? It is because they are:
➔ safe and hygienic
➔ tough and durable
➔ lightweight, cost-effective andconvenient
➔ good insulators
➔ flexible and adaptable
➔ capable of re-use
➔ supportive of innovation
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Safe and hygienic
ACTIVITY 2
1 Around 30-50% of food
produced in developing countries
is wasted before it reaches the
consumer, whereas in western
Europe this figure is only 2-3%.
Modern plastics packaging plays a
part in this. What other factors
might be responsible for this wide
difference?
Look around at home in the
kitchen or bathroom – or in a
supermarket. Find as many
different ways as you can in which
plastics add to the safe use of
other things.
By weight, plastics account for
about 50% of the packaging of
food sold in supermarkets, yet
only 17% of packaging waste by
weight is plastics. Look at these
pictures and think of the food you
buy yourselves. Make a list of
different types of packaging for
food. Think in particular of
examples of how shape is used as a
means of protection.
Expanded polystyrene is an
alternative to corrugated
cardboard as a protective
packaging material. Design an
investigation to compare the
effectiveness of the protection
offered by the two materials
against penetration by a sharp
object such as a screwdriver. You
will need to think of the quantity
of each material used to provide a
fair comparison. Discuss your
ideas before you begin the
investigation.
Bubble-wrap is widely used to
protect delicate objects such as
crockery. Just how effective is it?
How much protection can it give
to an egg? Design an investigation
which compares the amount of
protection given to the shell of a
hard-boiled egg as the amount of
bubble-wrap used changes. Begin
by thinking of ways in which you
can carry out the investigation.
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Tough and durable
cost-effective and
ACTIVITY 3
Suggest why using bottles
made from plastics on jet aircraft
can save up to £6000 per year on
the cost of running an aircraft.
What else might you need to
know about the plastic bottles
before you could say whether the
real saving was £6000? Explain
how it might be more or less
than this figure.
When faced with a choice of
using plastic or paper bags which
do you choose? Why? What does
it depend on? Make a list of the
advantages of both paper and
plastic bags for holding fruit and
vegetables.
Compare the masses of
plastic and paper bags which are
used to carry fruit and
vegetables. First of all decide
how you will ensure that your
test is a fair one.
Looking at your results,
discuss what the impact would
be on the mass of packaging used
if we had to use paper bags all
the time.
Compare a soft drink carried
in a plastic, glass, metal, and
card container. Measure the
masses of the total package and
the masses of the liquids they
contain. Make a chart showing
the percentage of the total mass
which is taken up by the
packaging material.
Compare a one-litre drink
packed in glass and one packed
in plastics. Make a list of the
differences in the use of energy
as it moves:
from the factory towarehouse to storage in theshop
from storage in the shop tothe shelves
from shelves to checkout tohome and storage
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Now do the same but compare
metal and card drinks packaging
with plastics. Are these likely to
be similar to glass or plastics?
Why?
Compare the four materials
again. Think of other advantages
and disadvantages of each one.
Now summarise the
advantages and disadvantages of
using plastics as containers.
Think of energy savings, the
amount of raw materials needed,
other environmental issues such
as pollution and waste, and the
impact on our lives.
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Lightweight, convenient
Plastics are widely used in cups,
mugs and beakers, at home and in
vending machines. You know that
various plastics materials conduct
heat to different extents. Design an
investigation to see how the
material used affects the rate at
which heat is lost from a cup containing hot water. Try to use expanded
polystyrene, a thin-walled plastic cup and a paper cup. You will need the
cups, a thermometer and a clock or watch that records seconds. Discuss
ways in which you will make this a fair comparison.
Plastics are normally poor conductors of electricity. Look around your
home and make a list of ways in which plastics are used in objects with
an electrical power supply. Looking back in time, would some of these
objects previously have been made of other materials? See if you can
identify the material which plastics have replaced.
ACTIVITY 4
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The properties of everyday plasticsare different from those of the basicpolymers. A wide range of additivesis used to give plastics the requiredproperties. They are ‘designer’materials – we are able to createexactly what we want from the rawmaterials.
The additives used include:
➔ Pigments incorporated intoplastics to add colour.
➔ Impact modifiers to ensure thatplastics don’t crack or break whenthey are knocked or bumped.
➔ Anti-static agents to reduce theamount of dust and dirt whichadheres to the plastic due tostatic electricity.
➔ UV absorbers protecting againstdecomposition by ultra-violetlight.
➔ Flame retardants reducing theflammability.
➔ Mineral fillers increasing rigidityand improving the properties ofelectrical insulation. Inertmaterials such as talc, chalk andclay are used.
➔ Blowing agents which breakdown at high temperatures(above 200°C) to release gasessuch as nitrogen or carbondioxide. When this happens insidea plastic in a mould, a foam isproduced.
➔ Anti-oxidants used widelyprolonging plastics’ life bypreventing reaction withoxygen and breakdown of thepolymer chain.
Flexible andadaptable
Good
insulators
The versatility of plastics. Theplastic wrapping is used to store andsafeguard this frozen meal. The plasticwrapping is removed and the meal canbe quickly reheated in a microwaveoven using the plastic container andcan then be eaten on the plastic plate.
http://www.apme.org
ACTIVITY 5
Today, everyone is more aware of theneed to act more responsibly to protectour world for the future – a drivetowards sustainable development. Thismeans acting in a way which does notlimit the range of economic, social andenvironmental options available tofuture generations.
Ensuring we use our valuableresources wisely is an importantconsideration for all of us. Re-use isone way of achieving this. But first wehave to make sure we use as littlenatural resources in production anduse as possible.
Plastics make the most of valuableresources by using the minimumamount of raw materials and energyduring manufacture and processing.
Plastics only consume a smallfraction - 4 per cent - of the world’soil. Today, plastics are lighter, yetstronger and more adaptable than everbefore, thanks to continuingtechnological innovation. This meansthat product for product,proportionally less of the world’s oiland energy resources are being usedwith lower overall impact on theenvironment.
Look at what happens to
plastics which come into the
home. How many are used
again – and what for?
How many are disposed of –
and how? Which are re-used
and which are thrown away?
Why is this?
Throughout their history, plastics haveenabled designers to innovate, toimprove existing products and tocreate new ones that improve ourquality of life and minimiseenvironmental impact.
In every aspect of our lives wehave benefited from theseinnovations. For example, theenhanced performance of the sportsequipment made with plastics hasallowed athletes to set themselvesever more challenging records tobreak. In medicine, plastics not onlyprovide an alternative to traditionalmaterials for garments and productsimproving hygiene and safety, butthey have enabled ground breakingdevelopments in micro-surgery.
Plastics packaging hassignificantly improved theconvenience of buying food for oneperson with microwavable packagingfor ready meals. And the shelf life ofpackaged fresh food has beenlengthened with oxygen-scavenging
films. Refill pouches for detergentshave significantly reduced thepackaging to product ratio found onsupermarket shelves.
They’ve contributed to increasedcomfort, safety and energy efficiencyof many forms of transport, from carsand bikes to planes and trains.Providing a lightweight alternative toconventional materials, they conservenatural resources in manufacture,contribute to reduced fuelconsumption and ultimately limitenvironmental impact. Plastics havealso played a crucial role inthe development of electriccar technology andinnovations such asairbags in cars and theaerodynamic noseconeof high-speed trainslike the Eurostar.
Communicationshas been completely transformed byplastics. With mobile phones, palm-top computers, the internet anddigital technology, we can accessinformation more easily and contactpeople while on the move. Internetusage is forecast to continue growingat more than 300 per cent a year.Although polymer optical fibres havebeen available for 30 years, theirusage has increased exponentially inline with the demand for cost-effective global communications.
If anything, the pace ofinnovation is increasing. Designers inevery industry are experimentingwith plastics’ capabilities. Where thepolymer doesn’t yet exist to meet thedesigner’s needs, researchers aredeveloping new types of plastics.Plastics batteries, light-emittingpolymers and roll-up computerscreens may sound like fantasy, butthey could be in the shops in thenear future.
1
Innovation
supporters
Capable of
re-use
5Everyone is increasingly aware that we need to act more
responsibly to protect our world for future generations.
Many industries and governmentsexplain their commitment as “actingin a way which does not limit therange of environmental, social andeconomic choices available to ourgrandchildren”. This mission is knownas ‘sustainable development’.
Everyone has a key role to play.Plastics and the plastics industry playtheir part in contributing tosustainable development in thefollowing ways:
➔ Environmental protection:
constantly seeking ways to helpsave resources such as oil, otherfossil fuels, water and even food.The industry aims to do morewith less.
➔ Economic development: the plasticsindustry adds value to societythrough the employment and thewealth it creates – over one millionworkers in Europe.
➔ Social progress: plastics play acrucial role in innovativetechnologies and products thatprovide higher standards of living,healthcare and education for anever-growing world population.
This card explores how plastics cancontribute to environmentalprotection to help us all achieve theambition of a more sustainablelifestyle. You may want to look atcards 4, 6 and 7 to help with some ofthe activities.
The environmental group Greenpeaceoften asks the question “why are weusing these materials in the first place
Doing more with less
protecting our world for future
and are they necessary?” This is agood starting point.
All products are made from rawmaterials. Most plastics are producedfrom crude oil, which is a limited andvaluable resource. However, very littleof total oil production is used for thispurpose – only 4 per cent for allplastics products. Although theproduction and use of plastics havegrown steadily, the amount of oil usedhas grown less quickly. This is becausecontinuing innovation means plasticsare lighter, yet stronger and moreadaptable.
This opens up a huge range of usesfor plastics yet at the same timemeans that, product for product,proportionally less of the world’s oiland energy resources are being used,with lower overall impact on theenvironment.
Describe three examples of efforts people are making now to live
more sustainable lives than, say, in the 60s and 70s, e.g. using less
energy than before, or using resources more efficiently. What benefits do
these efforts bring?
1
Assessing environmentalimpact
Everything we use, whether made ofwood, glass, plastics, paper or metal,has an impact on the environment.This includes finding raw materials,making and using products anddisposing of them at end-of-life.
Heating,electrical &
energy42%
Transport45%
All other 5%
Other petrochemicals 4%
Plastics 4%
ACTIVITY 1
Environmental impacts includecontribution to global warming,depletion of finite natural resourcesand waste. Without taking all of thesefactors into account, through properstudies, it is impossible to make soundenvironmental decisions. Such studiesinvolve looking at each part of the ‘lifecycle’ of a product, as shown above.While the European wastemanagement industry is working hardto meet the challenges of therecovery targets set by the EU (seecard 6), it is important to keep inmind the ultimate goal – the efficientuse of resources to meet the needs offuture generations. In some instances,new plastics products andtechnologies, that reduce the amountof raw materials used and the impactduring use, may make it moredifficult, and therefore lesseconomically or environmentally
beneficial, to collect and sort theplastics at end-of-life.
For example, lightweight film usesless raw materials than traditional
packaging options and is lighter totransport meaning less fuel isconsumed and fewer emissionsproduced. However, at end-of-life,plastics film is often contaminatedand difficult to separate from thehousehold waste making it difficultto recycle mechanically. Using lifecycle analysis it is possible todetermine the overall environmentalimpact of a product, from productionto disposal.
ACTIVITY 2
Think of a plastics item you might find in your home or classroom. Using
the flow diagram as a frame, consider the environmental impact of this item
throughout its life cycle.
Use these ideas to draw your own flow diagram. Begin by making a rough
sketch and then compare notes with others in your group. Then see if there
are any points you want to add to your sketch before making your final
diagram. You might find it helpful to add artwork of some kind.
Make sure it is clearly labelled with the following key words:
➔ raw materials ➔ energy ➔ manufacture
➔ product distribution ➔ consumer use ➔ re-use
➔ disposal ➔ combustion with energy recovery
➔ recycling ➔ chemical treatment ➔ landfill
1
Savings throughout thelife cycle
raw materials
acquisition
manufacturing,
processing and
formulation
distribution and
transportation
use/re-use/
maintenance
recycling
waste management
Reducing the amount of rawmaterial used in the first place
New polymers and new technologieshave greatly reduced the amount ofraw materials needed to pack aproduct. For example, by printinginformation directly onto the plasticswrapper of its bread, one supermarkethas reduced the need for extra labelsand packaging materials by 23 percent per package.
Using less fuel, creating feweremissions during use
Reducing the amount of material usedin a product has a direct impact onthe weight of loads. For example,reducing the amount of packaging for
outputs
watereffluents
airborneemissions
solid wastes
products
power and heat
inputs
energy
raw materials
a product – whether large or small –means you transport more productand less package each time you fill atruck or load a train. This reducesemissions, fuel usage and costs.Granular detergents are now beingsold in plastics pouches which use 90per cent less packaging thanequivalent containers.
Improvements in design andtechnology used in cars havedramatically reduced fuelconsumption. Between 1974 and1988, fuel consumption dropped byan average of 14 per cent for 18 carmodels in Europe. Plastics contributedto at least half the saving throughlighter weight and improvedaerodynamics because of theirmouldability.
Minimising impact and maximisingrecovery at end of life
Often we look at waste when wethink about saving resources. But animportant question should be askedbefore we think about waste andwhether it should be recycled orthrown away. Can we prevent it frombecoming waste in the first place?Either by reducing the amount ofmaterial used to make it or extendingits life by re-using the product.
Making transport work harderDifferent modes of transport havedifferent environmentalconsequences. For instance, ifeveryone travelled to school by bus,rather than in individual cars, therewould be less fuel used and feweremissions. This may not always be apractical solution but we should all beencouraging such systems.
Plastics have made a greatcontribution to energy efficiency intransport because they are light andreduce the weight of vehicles. Thiscan be achieved by a simple designsolution i.e. choosing plastics insteadof a heavier material, and bytechnological advances.
For example plastics have madepossible the largest one-piececomponent in the world – a railwaycarriage. This is manufactured inSwitzerland and has four majorbenefits:
➔ the carriages are quicker to make;
➔ they are 25 per cent lighter thantraditional carriages;
➔ they need less raw materials anduse less energy to manufacture.
➔ Their low mass means less energyis needed to pull them, there is lesswear on the machinery, the wheelsand the rails and the plasticsmaterial will not rust.
Looking further into the future, itis predicted that ultra light-weightvehicles will be made from plastics,including parts of the engine,transmission and axles. This couldmean a 500kg car with greatlyincreased fuel efficiency that weighsless than its passengers and luggagewhile retaining its safety features.
Sustainable development
ACTIVITY 3
and how we can make a contribution in our
day-to-day lives
For example, a large chain ofsupermarkets encouraged customersto bring the company’s plastics bagsback to their stores and use them
again. The incentive was a smallrefund for every bag re-
used. As a result, theyreduced their use ofnew bags by 60million in one yearand saved 1000
tonnes of plastics. ACTIVITY 4
Look at the different
means of transport which
students in your class use
to travel to school. List
some parts of those vehicles
which are made of plastics,
e.g. car seat, bicycle
mudguard. For each one,
what alternative material
could be used, e.g. leather,
metal. Can you describe any
advantages or disadvantages
of using plastics in terms of
function, environmental
impact or cost?
1
Find an example of an
object that can be made from
less raw material today than
in the past. Does the object
function better, worse or the
same?
Do you think there are
energy savings from using
less raw materials to make
it? What are they?
1
http://www.apme.org
➔ Emergency housing: today, morepeople live in cities than the totalnumber of humans alive 100 yearsago. At the same time, with theworld’s population growing fasterthan at any time in history, theprovision of shelter is becomingeven more critical. Advances inplastics engineering and design areallowing the development of low-cost ‘system-built housing’ that canbe constructed simply and quicklyin any climate and can even meetthe demands of earthquake zones.
What do you think is meant by an ‘intelligent polymer’? Describe an
imaginary intelligent polymer and what uses it would have.
What functional and
environmental benefit might
there be to ‘system-built
housing’ compared with
conventional building methods?
Think of the features of a
housing construction site, e.g.
bricks, wooden beams, window
frames, glass.
ACTIVITY 5
1
Creating sustainable buildingsThere are many examples of buildingmaterials and fittings where plasticsmaterials are replacing traditionalones because of their benefits ofstrength, durability, lightness,insulation, low cost, lowenvironmental impact, non-corrosionand aesthetic appeal. These includewindow frames, pipes and insulation.
Plastics contribute to sustainablebuildings in a number of ways:
➔ Energy efficiency: is a key concernin modern buildings, and plasticscan provide huge benefits. Innorthern European countries,almost one quarter of total energyconsumption is used for domesticheating. Plastics’ insulatingproperties means that this can andis being reduced considerably.Research shows that 50kg ofplastics foam used to insulate ahouse saves 3,700 litres of heatingfuel over 25 years – equivalent to150 litres a year. It is estimatedthat since the energy crisis of the1970s, the use of such foam inconstruction has saved theequivalent of more than five billiongallons of oil.
➔ Environmental impact: in southernEurope, more and more homes arebeing fitted with solar heatingsystems which turn the sun’senergy into heat. Plastics are avital component of the solar heatingequipment.
As well as helping to warmbuildings, plastics can also helpkeep them cool. Two ‘intelligent’polymers are now being developedto provide shade and preventoverheating in buildings. Thematerials are transparent at roomtemperature but become milkywhen exposed to bright sunlight.They reflect the light and preventthe building overheating. They willprovide alternatives to blinds andthe need for air conditioning.
➔ Space exploration is providing theinspiration for some of thesedevelopments. For example, one ofthe concepts considered for livingquarters on the International SpaceStation is a lightweight, inflatablehabitation module. Based on thedesign of a space suit, the module isa multi-layer, puncture-resistantconstruction to house four to sixastronauts.
6Despite reduction and re-use, there will always be waste to deal with,
whatever materials we use.
deal ing with
As the demand for plastics grows, thechallenge is to find ways to ensuremaximum recovery to avoid the lossof a valuable resource at the end of aplastics product’s or package’s usefullife. The best way to do this is to useall the available recovery techniquesto optimise the balance betweenenvironmental gain and cost. Thereare three main options to manageplastics waste:
The process of mechanical recycling isencouraged where it makesenvironmental and economic sense.For example, this is often the casewhen large amounts of the same typeof plastics waste can be easily collected,such as distribution and agriculturalfilms, car battery cases, soft drinksbottles and other containers.
Recycling
The five stages in the recycling ofplastics are:
1 disposal by the user
2 collection by a local authority orcompany
3 sorting into single types ofplastics
4 cleaning to remove labels, dirtand content residues
5 re-processing into granules orflakes which can then be formedinto new products
Throughout the European Union,material recycling targets have beenset for some sectors and opportunitiesto increase plastics recycling are being
explored. For packaging, for example,research forecasts that there is thepotential to increase the amount ofmechanically recycled packagingplastics to a European average of 15per cent in 2006, compared to 11 percent in 1995. There are alsoopportunities for increases in areassuch as agriculture, automotive andproduct distribution. However, thereare barriers where the waste is hard tocollect or where different componentsin integrated, complex products, mustbe separated (for example computersand electronic equipment).
Different thermoplastics do notmix well when heated together andthe strength of the recyclate isreduced. While mixed plastics can berecycled into products such as fenceposts it is much better to recycle thesame type of plastics together.
Recovery Options
Municiple Solid Waste
(MSW)The incineration of
plastics waste alongwith other materials in
MSW can safely andcleanly generate heat
and/or power.
Mechanicalrecycling
Material reprocessingof waste plastics byphysical means intoplastics products.
Feedstockrecycling
Material reprocessing ofwaste plastics by
chemical means intobasic chemicals,
monomers for plasticsor hydrocarbon
feedstock.
High calorificalternative fuelWhen separated fromother waste, the high
energy content ofplastics make them anexcellent substitute forfossil fuels in energy-
intensive processes, forexample in cement
production.
Landfill – A disposal route for residues not recoverable
Energy recovery
Plastics are made from oil –this gives them a calorificvalue equal to or greater
than coal. This energyvalue can be recovered
via combustion.
Material recycling
Reprocessing in a productionprocess of waste plastics forthe original purpose or forother purposes excludingdirect energy recovery.
ACTIVITY 1electrostatic separation. Thiscan be used with plastics that
take different electrical charges – forexample, PET and PVC
selective dissolution. Organicsolvents are used to dissolve
one or more polymer types that canthen be filtered, isolated andre-solidified
It is important to try to separate different plastics early in the recycling process.
Why is waste separated into different plastics always likely to be more
valuable and more useful than waste which remains mixed?
Why are dark plastics separated from clear plastics - even though they are
made from the same material?
Have a look at home at the plastics packaging materials in the kitchen or
bathroom. Look for the code number stamped on the bottom or inside of a
container. Make a table showing which plastics are used for which purposes.
Make a careful note of where two different plastics are used in the same
item e.g. for a lid and a container. Why are different types selected?
1
2
3
4 ACTIVITY 2
The density of
polypropene is 0.91 g/cm3.
The density of polystyrene is
1.05 g/cm3. What density
would a liquid need to be to
make sure that the
polypropene floated and the
polystyrene sank?
PET has a density of
1.35 g/cm3. What density
would a liquid need to be if it
was to separate PET from
polystyrene?
Ease of separation of
plastics materials is now
being taken into account at
the design stage. What
recommendations about
design rules would you make?
Think about densities, colour,
inks and labels.
Recycling makes a lot of
sense, but only if demand for
recycled materials matches
the supply. If demand is much
less than the supply, what
will happen to…
➔ the price paid for therecycled material
➔ the amount of recycledmaterial in storage
➔ the costs of the process
➔ the profitability of theprocess?
If there is a large
difference between supply
and demand, the amount of
waste being collected will
have to be reduced. What
effect might this have on
public opinion and on the
wisdom of recycling?
1
2
3
4
5
The common plastics have been givena code number which you will find onmuch of today’s packaging. Thiscoding system can now be used tohelp identify plastics when separatedby hand. In several Europeancountries, including Germany andFrance, a labelling system called the‘green dot’ is used to indicate thatmoney has been paid to nationalrecycling systems.
To further help in recycling end-of-life products, manufacturers arebeing encouraged to take recyclinginto account at the design stage. Thiscould, for instance, involve making alabel more easily removeable from a
package by using water-soluble glue.Recycled plastics are often used in
completely different applications. Forexample, fizzy drinks bottles are mainlyrecycled into fibres.
Apart from hand-sorting, threeother methods for separation are used:
analysis of the elements inthe plastic. PVC is easy to
spot because of the chlorine atom inthe molecule. Automatic systems exist,for example to identify and sortdifferent types of plastics bottles
separation by density. Theplastics are cut into
flakes and mixed with a liquid sothat some float and some sink,or can be spun in centrifuges
PET (polyethylene
terephthalate)
HDPE (high density
polyethylene)
LDPE (low density
polyethylene)
V (vinyl)*
*PVC
PP (polypropylene) PS (polystyrene) Other (including
multi-layer)
Re-use and recycling are not the onlywaste management options. Plasticswaste has a high calorific value,equivalent to coal or oil, which can besafely and cleanly released throughcombustion to generate heat and/orpower.
There are three main types ofplants to recover energy from plasticswaste: combustion with householdwaste in a municipal incinerator or thecombustion of plastics as a fuel, usuallyin combination with traditional fossilfuels in a manufacturing process or apower generation plant. Pre-sortedmixed plastics packaging waste forexample, has been used effectively as asubstitute for coal in energy-intensiveprocesses such as cement manufacture.In mixed waste incineration, the 8%plastics content produces 30% of theheat energy released.
One concern often associatedwith combustion is the level of dioxinemissions. A very small number ofthese are toxic although their degree
There are four main methods offeedstock recycling:
Pyrolysis
Plastics waste is heated in avacuum producing a mixture ofgaseous and liquid hydrocarbonsnot unlike petroleum.
Hydrogenation
Plastics waste is heated withhydrogen. This ‘cracks’ thepolymers into a liquid hydrocarbon.
Gasification
Plastics waste is heated in airproducing a mixture of carbonmonoxide and hydrogen gases.This is used to produce new rawmaterials such as methanol.
Chemolysis
Certain plastics can be chemicallytreated and turned back into theraw materials for making the sameplastics.
ACTIVITY 3
Summarize these processes in a flow diagram. Make sure that you
distinguish between the different stages, and between the usefulness of the
four end-products.
What other factors do we need to take into account before we can know
whether processes such as these are actually of benefit? Think of the costs
involved.
1
2
of toxicity varies greatly.Dioxins are formed where carbon,
oxygen, hydrogen, chlorine and heatare present and they are an unwantedby-product in a variety of combustionand manufacturing processes. Theycan also occur in nature in forestfires, volcanoes and compost heaps.
Dioxin emissions from wastecombustion have been closelymonitored and much researchundertaken to reduce such emissionsto meet the most stringent safetyrequirements. Well operatedincinerators in fact destroy dioxins.European legislation means that by2005 all municipal and clinical wastecombustion will contribute just 11gper year (or 0.3%) to overall dioxinemissions.
Already across Europe over2.6 million tonnes of plastics waste isburnt each year replacing fossil fuelsto produce useful heat and/or power.This takes place in well-managedincineration plants or cement workswhere emissions are carefullymonitored and limited.
There is an obvious need inrecycling to balance supply anddemand. There is no point incollecting material for recycling if therecycled material cannot be producedand marketed in an environmentallyand economically acceptable way.There is also a need to consider otherways of treating waste.
What should we do?
➔ Recycle plastics as materials?
➔ Recycle them as feedstock
chemicals?
➔ Release the energy they contain
through combustion?
Feedstock recycling
Energy from waste
The potential of new recyclingtechnologies such as feedstockrecycling is being investigated by theplastics industry.
Feedstock recycling, which ismainly used for mixed plastics wasteis currently only practised in Germanybut possible investment in othercountries is being considered. There isstill much to be learnt about thepotential for these technologies ifthey are to offer the opportunity toincrease recycling in the future.
Collection and sorting
Treatment of the plastics wastee.g. grinding
Feedstock recycling into basic rawmaterials
Closed-loop recycling back to theoriginal plastics or as feedstock for
new petrochemical products
15000
12500
10000
7500
5000
2500
kcal
1kg lignite 1kg diesel oil 1kg plastics
This diagram shows the heat energycontent of 1kg of lignite, diesel oil andplastics.
The answer is probably to do all three,and to decide on the best combinationof options. The option chosen dependson the specific circumstances. Forexample: What sector is the wastefrom? How is it collected? Whatsorting, separation technology isavailable? Is there a demand forrecyclate, feedstock or alternativefuel? Studies can be done which assessthe environmental impact of therecovery or disposal option chosen. Infact, such studies can be carried outover the whole life-cycle of theplastics product and this sort ofanalysis can help with choosing thebest material at the design stage.
Degradable plastics have beenproduced which can be broken downeither by light or bacteria, but theyare not yet widely used. Such plastics,however, are not an easy solution towaste management because they cantake many years to degradecompletely and can represent the lossof a valuable resource that could beotherwise recovered for a second life.However, they do have certain
Degradability
ACTIVITY 5
1/ Draw up a table of
advantages and
disadvantages of
➔ recycling of waste
➔ energy recovery fromwaste through burning
Think of transport costs,
emissions, effect on other
resources, land use.
Legislation now strictly
controls the design and
operation of landfill areas.
1
http://www.apme.org
ACTIVITY 4
1/ Look at the following information & produce a poster which summarises it.
2.6 tonnes of domestic waste has the energy value of 1 tonne of coal.A 10% increase in the amount of waste combusted would save over1 million tonnes of coal.
Sweden already recovers energy from 33% of its plastics in domesticwaste, providing a significant proportion of its total district heatingneeds. In Denmark, 56% of plastics in domestic waste is recovered forenergy. In Switzerland the figure is 55%.
If European waste was incinerated and the heat energy recovered, it couldprovide 5% of our domestic electricity needs and halve coal imports.
This table shows what happens to plastics waste across Europe
Amounts (’000 tonnes) 1994 1995 1996 1997
total plastics waste 17505 16871 17454mechanically recycled 1057 1222 1440feedstock recycled 51 99 251 334energy recovered 2348 2698 2496 2575total plastics recovered 4019 4067 4349% waste recovered 20% 25% 24%
1
2
Complete the table by calculating the data missing from the empty boxes.
applications in medicine (e.g.degradable stitches and other bio-products) and agriculture (e.g. film forimproving the growth of crops).
In parts of Europe where waste cannotbe burnt to release energy, it is stilldisposed of in landfill sites. Landfill is awaste of resources. The plastics industryis committed to optimising thecombination of recovery options todivert as much waste as possible fromlandfill.
In the past, landfill sites have oftenbeen located in disused quarries or claypits. Filling these large holes in theground with solid waste has been agood way of removing landscape eye-sores and restoring land.
Landfill sites contain organicmaterial – usually more than 50 percent of the total mass of waste.Because of this they behave likegigantic compost heaps with paper,food and natural fibres slowly breakingdown through bacterial activity.Modern sites can contain many millionsof tonnes of material, with thousandsof tonnes being added each day.
Landfill
Landfill sites create two by-products – a liquid and a gas. Theliquid is rather like concentratedsewage and must be contained withinthe site to avoid its seeping into thewater supply. To prevent this, the siteis usually lined with clay or plastics.The gas is a mixture of carbon dioxideand methane (which can be explosiveif not properly controlled) and bothcontribute to global warming. Thereare a number of sites where this gas isnow collected and used for thegeneration of electricity or heat.
Today, it is recognised that landfillis not a viable long-term wastemanagement option. To encouragemanufacturers to design products thatmaximise the use of resourcesthroughout the life-cycle and to makerecovery options more attractive, thefinancial cost of landfill is beingincreased.
This card has shown something ofthe three main options for dealingwith plastics.
➔ Recycling
➔ Combustion with energy recovery
➔ Disposal
All of these are used to varyingdegrees across Europe today. There arechanges from time to time as to whichprocess is the most attractive. Forexample, changing oil prices on theworld market can affect the value ofrecovered plastics materials and hencethe incentive to recycle.
7Individuals, communities, corporations – we all contribute to the large
amounts of waste that need to be taken care of.
deal ing with
On average each of us throws outthese items each year:
As discussed in card 4, plastics areoften used for packaging becausethey are resilient, light, clean and costeffective. Therefore, household wastecontains plastics as well as othermaterials. In card 6 we looked at someof the ways in which we can dealwith plastics waste.
Increasingly, efforts are beingmade to manage this waste in orderto reduce its impact on theenvironment and maximise theamount of waste given a second life.
Once collected, waste can be re-used, recycled or recovered asenergy. As a last resort it shouldbe buried in landfill sites forsafe disposal. However,when we throw thingsaway irresponsibly theyhave no chance ofentering a sensible waste
management andrecovery system andinstead, they become
litter. Litter typically consists of
packaging items thrown awaywithout regard to the surroundings.It ends up in public spaces causingserious social, and environmentalconsequences, as well as being awaste of resources.
In an ideal world, litter would notexist because people would behavewith care for their environment.
One of the most important stepstowards solving the litter problem ismaking sure that everyone knowsthat it is people who create litter,and not the companies which makethe products.
Sadly, wherever you are youwill find litter – in citycentres, the countryside,on the coast and at sea.Although it’s hard tobelieve, even MountEverest in theHimalayas has a litterproblem!
A survey of European cities foundthat the top five items of litter werecigarette butts and matchsticks,pieces of paper, sweet wrappers andbits of plastics.
To find out whether our attitudetowards littering is improving orgetting worse, litter in theenvironment is measured.
Identifying litter
of vegetable wasteand food scraps
70kg
66 plasticbottles
130newspapers ormagazines
290metalcans
110 glassbottles
ACTIVITY 1
One way of measuring litter is with alitter index such as the one below.Using a five-point scale, litter found ona 50-metre length of road, footpath,beach or parkland is measured.
Nearly all of us can remember anincident when our behaviour createdlitter. The way we act in differentenvironments determines the type oflitter produced and where it isfound.
For example, litter found onbeaches comes from a number ofsources. Holiday-makers picnickingon the beach bring a large number ofdisposable items such newspapers,packaged food and drinks andcigarettes. When these items aretaken home after use or put in a bin,
no litter is created, butfrequently people don’t
dispose of themresponsibly. Sometimes
this is becausethere are not
enoughbins, but
often it isjust carelessness.
But not all coastal litter is createdby irresponsible individuals at thelocation in question. Evenuninhabited islands are littered withmaterials washed ashore by oceancurrents that do not recognisenational boundaries. This litter cancome from other beaches or by the
(source: Tidy Britain Group)
As a class, identify at least ten different 50-metre strips of land near your
school or where you live. Identify, list and classify all the items of litter.
For example bottles, bags, cigarette butts.
Which items are most commonly found?
Which could be dangerous to people or wildlife? Explain why.
Which would be difficult or costly to remove?
Which could be recycled or used again?
Using the Litter Index below, what grade A-D would you give to the areathat you surveyed?
Based on the Tidy Britain Litter Index, towns and cities can be assessed as awhole. If ten sites were surveyed and each scored A (or 5), then the townwould score 50/50 or 100%, but if each site scored only D (or 1) then itscleanliness index would be 10/50 or 20%.
Use the grades that the class calculated for the ten sites to calculate anoverall cleanliness index for your neighbourhood.
Although you are probably moreaware of the litter in your local areathan elsewhere, when you visit otherplaces you cannot escape the litterproblem. In fact, litter in holidayspots and at sea attracts the mostattention. Is this because we expectto enjoy the seaside or naturalscenery where we choose to spendour holidays and forget that ouractions create the same impactwherever we are?
Grade A Rating 5/5
Completely free of allitems of litter
Grade A- Rating 4/5
Appears free of litter but oncareful inspection has 5 or less
small items of litter
Grade B Rating 3/5
Small items of litter present,like bits of paper and milk
bottle tops
Grade C Rating 2/5
Clearly noticeable build-up of litter: cigarette butts, paper,
cans and packets
Grade D Rating 1/5
Lots of clearly visible litter and large items like
household goods
▲▲▲▲▲
Coastwatch Europe collects dataabout coastal litter and pollution.A recent survey of some 10,000 sitesfound over 60 items of packaginglitter at each location. These includedcans, cartons, bags and bottles as wellas cigarette butts, matches andnewspapers. Pollutants – includingsewage, oil and tar – were also seen.
of litter
Causes and consequences
ACTIVITY 2
casual but illegal dumping at sea ofitems including food packaging andbottles.
While some litter will rot overtime, much of it remains unless it iscollected and removed. Apart fromthe fact that it is unpleasant tolook at and spoils our environment,
it can also:
injure peopleFor example, rustingcans and broken glasscan lie hidden in thesand or in the grass
and cause nastyinjuries when people
tread on them.
be a health hazardInsects, rats and micefrequently congregatearound discarded foodwrappers andsanitary products,potentially leadingto the spread ofdisease.
kill or injure wildlifeFor example, a harmless plastic bagdisposed of carelessly could look likean edible jellyfish to a sea turtle, but ifeaten it may kill. Damaged fishing netscut loose by fishermen can be a deathtrap for dolphins who becomeentangled and drown.
cost money to clean upFor example, according to the Local
Government Financial StatisticsUnit of the Department of
Environment, Transport andthe Regions, street cleaningin England and Wales costslocal authorities almost
£340 million a year.Throughout Europe, campaigns havebeen run to raise people’s awareness oflitter. In the UK, the Tidy Britain Group,which uses programmes of action andeducation to fight litter andlittering, is the recognisednational agency. On amore local scale, schemesrange from theannual enlisting ofvolunteers fromschools, sportsclubs and localorganisationsto help clearlitter on aparticularday, to more formal partnerships. Forexample, in Devon, the Tamar EstuariesManagement Plan brings togetherlocal municipal and harbourauthorities, water companies andresidents. They work together to ensurethat adequate facilities for litterdisposal are in place, collection servicesarranged and that the public is keptinformed.
ACTIVITY 3
Find out what schemes operate
in your country, who is involved
and how they work.
solve the problem of litter?What can be done to
Everyone is responsible for theproblem. If anyone breaks the litter orwaste disposal laws then localauthorities can take action. Thishappens all over Europe. Localauthorities also encourage individualsto take pride in their area, providedisposal facilities and organise littercollection. Clearly, it is much cheaperto manage waste disposed ofresponsibly, than to collect it as litterfrom the streets, countryside and sea.
Think about the type of waste found in different places:
rural, urban and coastal.
Who is responsible for the litter in each environment?
Do you think the amount of litter has increased in recent years?
Consider each environment in turn, what measures could be taken toreduce litter?
Identify what litter might be biodegradable, do you think biodegradabilityis the answer to protect our environment or would it encourage people tolitter more?
Consider the consequences of the types of litter foundin each environment.
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What can you doACTIVITY 4
Who would you needto involve?
Which organisations/authorities would beable to help oradvise?
Which organisationswould you need toconsult?
Can you say that you have never addedto the problem? When did you last dropa sweet or crisp wrapper, a piece ofchewing gum or drinks can somewhereother than in a waste bin?
Now you have learnt a bit moreabout the consequences of youractions, would you stop and thinkbefore contributing to the litter
problem?
While it is important that cleaningup litter is organised, it is only part ofa solution. We all have a role to playso that one day litter will no longerbe a problem.
As a class, discuss the litter problems in your local area.
Think about the causes and the consequences. Choose ONE
aspect of the litter problem and draw up a plan to tackle it.
For example, this could be organising a litter
awareness campaign in your school, or getting the
local authorities to place more bins in a specific
location.
Make sure your plan answers these points:
How could the planbe carried out?
How would you tellpeople about it andget them to takepart?
How would you checkits progress?
How and when wouldyou measure itssuccess or failure?
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to help?
8
We live on a blue planet, where two-thirds of the surface is covered with
water, but most of the water on Earth is too salty to be useful for
anything but sailing on.
for l i fe
Only 3.5 per cent of the planet’s totalsurface water is fresh, and most of thatis frozen in the ice caps. A mere 0.01per cent – one drop in every bucketful– is in a form suitable for direct humanuse: in streams, rivers, lakes andgroundwater aquifers.
Between 1950 and 1990, globalwater demand tripled – and it is stillrising. If current trends persist, thedemand for water could exceed theavailable supply within 30 years. Theresimply won’t be enough falling fromthe sky to satisfy our needs.
to solveA problem But we need more water now. TheUN has declared water a human right,which means that everyone shouldhave access to sufficient, affordable,accessible and safe water supplies andsanitation services. Unfortunately, onebillion people live without access toadequate drinking water, and over twobillion people lack basic sanitation.
Every day, 10,000 children die fromcholera and other waterborne diseases.Eighty per cent of all diseases and one-third of all deaths in developing nationsare caused by contaminated water.Bilharzia, typhoid, salmonella, E coli,hepatitis, parasitic worms – all theseare potential killers. They can be foundin the rivers and streams that many ofthe world’s poor depend on for their
water supplies.There are many needs that
must be met by clean water.Farmers need water for their crops.
Families need water for cooking andwashing. In parts of Africa, women andchildren may spend three hours a daywalking to a water source, thenqueuing for a chance to fill a pot.
Water is also a problem in Europe.In an average year, over 3000 cubicmetres of water are available for everyEuropean Union inhabitant. Around 20per cent of the available water isactually used, but there are stillshortages in some areas. For example,in southern European countries,periodic droughts are a majorenvironmental, social and economicproblem. In other countries, ageingwater supply systems lead to crackedpipes and subsequent water leakage.
The problem of water shortageslooks set to get worse due to theimpact of climate change. Mostscientists agree that globaltemperatures will rise by the end of thecentury by between 1.4°C and 5.8°C.There are likely to be more floods andstorms but also more droughts andheat waves, affecting crop yields, watersupplies and health.
We have to learn to use the waterwe have more carefully, in a moreefficient way. The world is becomingincreasingly aware of the need to actmore responsibly to extend our help tothose in need and at the same time, toprotect our world for futuregenerations; what is now known as“sustainable development”. This is aterm used to describe acting in a waythat does not limit the economic, social
ACTIVITY 1
How much water do you
think you use on average per
day? Think about what purposes
you use water for and list some
ways in which you could be
more efficient in your use of
water.
Identify three European
countries that you think would
be likely to suffer water
shortages in summer.
Can you discover the name
of one European country that
uses desalinated sea water for
nearly half its drinking water?
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22008 UK Water AW 04-03-2003 10:21 Pagina 2
and environment options available tous now and in the future. Efforts topromote sustainable developmentreceived a boost at the World Summiton Sustainable Development held inJohannesburg, South Africa, in 2002,where world leaders met to discuss theprotection of the environment and howto tackle the causes of povertythroughout the planet. Scarcity andmisuse of fresh water were highlightedas two of the most serious threats tosustainable development. As a result ofthe Summit, all heads of governmentsagreed to aim to halve the number ofpeople without access to clean water orproper sanitation by 2015.
Water can be ‘delivered’ toconsumers in different ways. Whateverthe solution, the aim is to makeavailable adequate quantities of watersafe for human consumption.
Plastics play a vital role inpreserving and distributing watereconomically and reliably to a growingworld population. In many areas of theworld where water is scarce,conservation and irrigation systemshelp retain water and distribute it –either for domestic or industrial use,or for growing crops. Plastics are afavoured material in many of theseapplications due to their cost-effectiveness, ease of transport andassembly, flexibility and durability.
‘All people, whatever their stage ofdevelopment and social andeconomic condition, have the right tohave access to drinking water inquantities and of a quality equal totheir basic needs.’Source: UN Conference at Mar del Plata, 1977
ACTIVITY 2
Where would it be best to source water for piping? Further upstream?
From a deep water pool? From a spring above the village? Explain why.
Contaminated water may contain bacteria, viruses and parasites. For
each type of contamination, give an example and explain how someone
would be made ill by the micro-organism in the water.
The Guinea Worm is a parasite. Explain what a parasite is. Which of the
following are parasites and which are not?
house fly, fleas, rats, dandruff, tapeworm, salmonella
Would filtering water protect against bacteria and viruses? Explain why.
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Preserving and distributingclean water
In much of the world, polluted water,improper waste disposal, and poorwater management cause serious publichealth problems. Such water-relateddiseases as malaria, cholera, typhoid,and schistosomiasis harm or kill millionsof people every year. In an ideal world,the solution would be to prevent thewater supplies becoming polluted inthe first place. But sewage treatment toclean the water source is expensive andeven European rivers aren’t drinkingwater quality… yet!
There are other ways of accessingclean water. In remote mountain areas,such as Nepal, there is often plenty ofwater. But poor hygiene and a lack ofsanitation may leave the village streamor river badly polluted. One solution isto pipe in clean water from furtherupstream, relying on gravity flow.Plastic piping is ideal for this situation.It is light, flexible, easy to carry, yetstrong once it is in place.
life
Use of abstracted water(ie taken from rivers,reservoirs, canals etc) inEurope: 18% – public water supply30% – agriculture (mainlyirrigation)14% – industry, excludingcooling water38% – power (hydropower,cooling water) and non-defined uses
In lowland areas, the problems areoften more difficult. There are morepeople competing for the same water,which is often dirty and unsafe. Oneanswer is to drill down to the water-bearing aquifer below the surface.Using hand pumps and plastics pipes, avillage can often find clean water, butthe drilling operation can be expensiveand, if too much water is extracted, theaquifer itself can become contaminated.
Plastics also help purify water andremove disease-causing bacteria andparasites. A simple nylon filter hasalmost eradicated Guinea WormDisease which cripples victims, leavingthem unable to work, attend school,care for children or harvest crops.
The worm enters through thedigestive system, but then makes itsway to anywhere in the body, boringclose to the skin surface. When aninfected person steps into water, theworm releases millions of larvae. Peoplewho drink the water become infected –and the cycle starts all over again.
The answer is to filter the parasitesout of the water. In the past, this hasbeen done with muslin cloth, but thespecial nylon monofilament cloth iseasier to disinfect and cheaper tosupply. Filtering has successfullyreduced the cases of infection by95 per cent.
WaterAid was able to help7 million people gain accessto clean water in thedeveloping world, thanks, inpart, to plastic piping.
Water for
22008 UK Water AW 04-03-2003 10:21 Pagina 3
Preventing water lossthrough conservation and
irrigationWater lossIn most countries, leakage in waterdistribution networks is still too high.
Previously, where traditionalmaterials were used in the constructionof piping infrastructure, cracks andleaks would occur in the piping systemsover time. In some Europeancountries, old pipes resultin losses of up to30 per cent andthe cost ofleakage isestimated at over9 billion euros / year in clean waterwasted alone.
Although rarely seen, plastics pipesunder our streets and in our homesplay a critical role in delivering cleanwater for drinking and other needs. InEurope today, modern housing oftenuses high-strength plastic piping todeliver gas and water.
Plastics pipes have a long life-time, are flexible and mouldablewhich means that they are lessvulnerable to damage and easy tomanufacture and assemble. They areextremely strong, which means theycan be used in the most demandingof conditions, crucial to ensure thatthey can distribute water in townsand cities. Plastics are also light andprovide cost-effective solutions –qualities that also make the materialideal for widespread use, including inthe developing world.
IrrigationAgriculture requires water, and rainfalldoesn’t always occur when farmers needit. Add that to the fact that muchfarming is in countries with low orunreliable rainfall, making irrigation vital.
Irrigation systems exist to divertwater to crop, from a river, a dam or aborehole. The first irrigation probablytook place on the River Nile thousandsof years ago, using a simple bucket andlever mechanism called a shadouf.
Water forliving
ACTIVITY 3
Plastics are flexible and
mouldable. Explain why this is
an advantage for pipes that
carry water. Give an example of
a material with poor elasticity.
Give an example of a
European crop that relies on
irrigation.
Evapotranspiration
describes water loss from the
ground and through vegetation.
How do plants and trees lose
water and at what point in the
year is loss through evapotrans-
piration likely to be highest?
Some farmers use strips of
plastic as a mulch – spread over
the surface of the soil around
the growing plants. Why do you
think this is?
Try to explain why so few
buildings are constructed with
water conservation in mind.
What would it take to change
this situation?
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Today, agriculture is the largestconsumer of water, worldwide.Between 70 and 80 per cent of thewater withdrawn globally is used toirrigate fields. Traditional methods ofirrigation are, however, enormouslywasteful. It is estimated that only
40 per cent or so of all irrigation watergets to where it is needed.
One answer is drip-irrigation(sometimes called trickle irrigation).This works by applying water slowlythrough plastic piping directly onto thesoil. Traditional sprinklers throw hugeamounts of water into the air and ontoplants, where much is lost toevaporation. In contrast, micro-irrigation emitters apply water slowly,close to the soil and roots of plants.This is estimated to result in a 70 percent saving in water.
Drip irrigation is being used inCalifornia, Israel, Spain and SouthAfrica – all places where water isexpensive and in short supply. In thedeveloping world, a cheaper solutionusing buckets and surface pipes canproduce similar results.
In fact, pipes as old as 75 years havebeen dug up – still in excellent condition.Plastic sheeting can also be used toreduce water losses from the soil. InChina, farmers are using plastics to linethe furrows in which rice is planted.
22008 UK Water AW 04-03-2003 10:21 Pagina 4
Solutions to the provision of cleanwater continue to evolve and plasticshave their part to play.
For example, future developmentsinclude a solar still which has beendesigned by a company as a way ofproducing pure water, using the simpleprinciples of evaporation andcondensation.
The pack is placed over a watersource – even floating on top of it ifrequired – and a wick allows water to
www.apme.org
ACTIVITY 4
Try making your own
solar still. Dig a hole about
50 cms deep and a metre
wide. Place a plastic bowl in
the middle and cover the
whole thing with a thick
plastic sheet. Put a small
weight in the middle of the
sheet. Leave during a warm
day and cold night. See how
much water has collected in
the bowl the next morning.
Think about water use in
the modern home. How could
designers reduce family
water consumption? Make a
list of water conservation
measures – consider reducing
waste, recycling, rain water
capture.
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The sheeting lasts for five years andprevents water waste in a desert areabetween Mongolia and the BadainJaran desert. The plastic-lined furrowsalso work to hold nutrients in the soil,giving the farmers a double benefit.
Farmers have used plastic sheetingto build temporary greenhouses foryears, but now the technology hasgone a step further with a purpose-built controlled environment whereevery plant has just the right amountof light, water and food, and unwantedflies and bugs are kept firmly outside.
Technology and plastics providesolutions to water losses in agriculture.
soak into the porous base. Sunlightheats the inside of the plastic tent andthe water evaporates, leaving behind itsimpurities as it does so.
On contact with the plastic walls,the moist air condenses and pure waterruns down, to be collected in a channel.The makers claim that the inventioncould provide more than a litre ofwater a day. But scientists areconsidering farms of solar stills, capableof producing enough water for afamily, or even a village.
Advanced plastics-basedtechnologies used in space explorationcould also be the key to improving thedistribution of fresh water supplies.
Plastics used in the life support systemsin space exploration help provideastronauts with the cleanest air andpurest water possible, and bettersanitation than ever previouslyexperienced.
Only a thousand or so litres of waterare carried into orbit because of weightand the amount of fuel that would beconsumed in order to take this water
into space. Space travel requires theability to reuse and recycle the existingsupply of water. As a result, highlyadvanced personal water purificationsystems have been developed for use byastronauts, based largely on a plasticsfilter system. These allow recovery of85–95 per cent of the waste water andurine. The water is then turned to steam,and, following additional stages ofchemical, heat and mechanicaltreatment, it is returned pure enough todrink some 8–9 hours later.
This technology is now beingdeveloped by organisations who hopeto make large scale water purificationsystems for countries that need it.
Solutions to our water problems doexist – the challenge is to make thesolution available to the people inneed. To date, plastics have helpedprovide millions of people with accessto clean water, and will continue toplay a vital role in the future.
“Innovative materials such asplastics have often providedthe solution to the problemsand challenges encounteredin space missions. Now thesame technologies are helpingto meet the challenges weface on Earth”, says PierreBrisson, Head of ESA'sTechnology TransferProgramme
One of the responses to the problem of poor water supply andhygiene has been the growth of bottled water in recent years. Thispresents a challenge in terms of packaging – how do you combinesafety, hygiene, convenience and ease of transport? Bottled drinksare frequently packaged in plastics because they are:
� lightweight yet strong (hence more energyefficient to transport) and safer than glass
� shatterproof
� able to withstand high pressures withoutshattering
� pure and do not affect the taste of theproducts they protect
� recyclable
solutionsInnovative
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