Sustainability

Challenge 1: Let’s do Lunch- Activity Sheets

Print the activities here

Your Task

Every day we throw stuff away. A lot of what you are likely to discard as rubbish on a school day probably started life as food and drink packaging in your lunch box.

Your task is to design a piece of sustainable food packaging that not only keeps your food of choice fresh, but also helps to protect the world’s resources.

To carry out this task you will need to work in a small team and to have access to a lunch box. Your teacher will show you an example lunch box, or you might be able to use your own if you have one.

1. What’s inside?

Take a look at the contents of the lunchbox and fill in the table below.

Write a brief description of the items in your lunch box	Describe the packaging/container that the item is in	Do you think this packaging is made using renewable (R) or non-renewable (N-R) resources?	Do you think this packaging could be...
			...reduced?	...re-used?	...recycled?
		R or N-R
		R or N-R
		R or N-R
		R or N-R
		R or N-R

2. Why is it made from that?

Whenever we use materials to make something we have to make sure that the properties of the materials we are using match with what we want the finished product to do.

For example, if you have a fizzy drink the chances are that it will be in a bottle made from a plastic called polyethylene terephthalate (PET). In the table below you will find some of the properties of PET and some of the functions of a drinks bottle. Draw arrows on the table to link the properties of PET which best match with the functions of the bottle. The first one has been done for you as an example.

 

Material Property	Link	Function of Bottle
Waterproof		To be impermeable to liquids
Tough/strong		To look attractive
Flexible		To be strong enough to contain any excess pressure produced by fizzy drinks or heating of liquid inside the bottle
Lightweight		To be able to contain hot liquids if necessary
Easily moulded		To be recyclable
Thermoplastic		To be practical to carry around (i.e. not too heavy or brittle etc)
Melting point of 260°C		To maintain its shape
Impact resistant

If you have time, try to create similar tables for the other packaging used in your lunch box. Here is some information which might help.

Cling film

• Usually made from polyvinyl chloride (PVC) but now increasingly made from low density polyethylene (LDPE)
• PVC and LDPE are thermoplastic polymers
• PVC and LDPE are flexible and transparent
• PVC is slightly stretchier than LDPE
• PVC melts at 212°C
• LDPE melts at 120°C
• PVC and LDPE are both poor thermal and electrical conductors
• PVC has better barrier properties than LDPE so substances are less able to diffuse through it if it is used for long term storage
• LDPE is cheaper to produce than PVC
• PVC and LDPE are both flammable

Aluminium foil

• Usually about 0.02mm thick
• Tears easily
• Flexible
• Melts at 660°C
• Good thermal conductivity (237 Wm −1K −1)
• Low electrical resistance (26.50 x 10 -9 Ωm)

Paper

• Made from cellulose fibres obtained mainly from wood pulp
• Tears easily in thin sheets
• Flexible
• Ignition temperature of about 450°C
• Fully recyclable and biodegradable
• Poor barrier properties - substances will pass easily through paper
• Poor thermal and electrical conductivity

Aluminised Mylar – the metallic looking plastic that cereal bars etc are sometimes wrapped in

• Consists of a thin film of PET with an aluminium coating
• Much less permeable to gases than PET alone
• Flexible
• High tensile strength
• Can be laminated with an additional coating of polyethylene to improve puncture resistance
• Should not be confused with the shiny material used for helium balloons – this is metallised nylon.

3. Sustainable Lunches

If something is sustainable it should be able to carry on into the future without causing negative effects on the environment. Sustainability is becoming increasingly important in everything we do.

Take a look at the table you filled in back in section 1 of this sheet. Your task now is to give each of the pieces of packaging in the lunchbox a sustainability rating. One way of doing this is to look at how many ticks an item has in the ...reduced, ...re-used, ...recycled columns.

• NO tick in the reduced column gets one point as this means the packaging is minimal, but we may still need to use new resources to make these items.
• A tick in the re-used column gets two points as this means we can re-use that particular item but doesn’t necessarily mean the new resources won’t be used to create more of these items.
• A tick in the recycled column gets three points as this means we can carry on using the same material indefinitely without using further new resources

Now look at the renewable or non-renewable column

• For renewable score 3 extra points
• For non-renewable subtract 1 point

Put your results in the table below

Write a brief description of the packaging item	Sustainability Score

This method of scoring is very approximate. If you think you have a better method try it out – but you must be able to explain how it works.

4. Let’s Do Lunch

Now it’s your turn. Working in your team can you design a piece of packaging with a better sustainability rating than the ones you have just investigated?

First of all decide which piece of packaging you are going to redesign – write it in the box below

Now think about the function of that packaging. In the left hand side of the table below, write down all the different things that the packaging has to do. Remember to think about the marketing side of things as well as practical things like keeping food fresh and clean. People are going to have to want to buy the item!

In the right hand side of the table write down all the properties that the packaging material has in order to do the things your packaging will need to do.

What the packaging has to do	Properties the packaging material will need

Now look for links between the points you have written in the left hand column and the points you have written in the right hand column. Join them up with arrows as you did for the table in section 1.

Can you think of a material that will do all these things?

You may have to decide on a set of priorities and you may also have to accept that no one material can do everything you want it to do.

Once you have decided on a particular material write it in the box below. If you have time, you may want to use the internet to research the properties of different materials to help with your choice.

Now give this material a sustainability score in the same way as you did in section 3.

Packaging Material	Is this packaging is made using renewable (R) or non-renewable (N-R) resources?	Do you think this packaging could be...
		...reduced?	...re-used?	...recycled?
	R or N-R

Does your new material beat the sustainability score of the original material?

Yes / No

Does your material have any disadvantages when you compare it against the new material? If it does, write them in the box below.

 If you have time you can draw a sketch of your new packaging and possibly create a prototype for testing.

Related links

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