Hello, my name's Mrs. Taylor and thank you for joining me today.

Our lesson today is in the Unit Principles of materials and manufacturing.

And it is called Materials in design.

The Outcome.

I can identify different materials and categorise them.

And we have four keywords today.

Aesthetics, physical properties, mechanical properties, and strength.

And in today's lesson we have four learning cycles, categorising materials using aesthetics, categorising materials using material groups, categorising materials using properties, and then the final learning cycle, how designers make material choices.

We begin with categorising materials using aesthetics.

In designing technology, we design and manufacture products.

In order to do this, we need to select the most appropriate materials.

Materials can be selected for different reasons such as appearance, cost, function, and availability.

Here we have a check.

When manufacturing products, why do we consider different materials? Is it A, to select the strongest.

B, to select the most appropriate for the product's function.

Or C, to select the cheapest.

Pause the video and have a go.

Well done.

Let's have a look.

That's right, it's B.

To select the most appropriate for the product's function.

We can categorise materials in different ways.

One way is to use aesthetics.

Aesthetics is concern with appearance and can be defined as an appreciation of visual beauty or how it looks.

Aesthetics considers colour, shape, and texture.

Texture is how something feels.

Examples include smooth, rough, fuzzy, or slimy.

Here we have a check.

What is aesthetics concerned with? A, size.

B, appearance.

Or C, visual beauty.

Pause the video.

Well done.

Let's have a look.

That's right.

It's B and C.

Appearance and visual beauty.

Here we have a picture of some material samples.

You may have some as well.

Materials can be categorised.

This means to group them.

If we are considering aesthetics, we could group by colour.

For example, we can group together all the red materials.

Now we have a task.

Task A, part one, group the materials using aesthetics.

This could be colour, shape, or texture.

And part two, explain how you decided upon the groups.

Pause the video.

Fantastic.

Let's have a look at some of the answers you may have come up with.

Sam and Jacob explain how they grouped the materials considering aesthetics.

Sam says, "I put the materials into colour groups because they were so many different colours.

Silver, brown cream, and then the bright primary colours, red, yellow, and blue." Jacob says, "I thought about the colour groups, but decided to use texture and put all the shiny materials in one group, and the ones that feel rougher in another." Well done.

We now move on to the second learning cycle.

Categorising materials using material groups.

There are many different materials we can use when designing and making.

These include metals, papers and boards.

Polymers, you may know them as plastics.

Textiles, you may know them as fabrics.

Or timbers, you may be more familiar with the term wood.

Here are some paper-based products.

A, is an egg box.

B, is a promotional display stand.

And C, is a greetings card.

Why do you think paper and board is suitable for these? Paper is suitable for the egg box as the pulp can be formed into curved shapes when wet.

When dried, it is rigid enough to hold the eggs whilst transporting.

Board is suitable for the promotional display stand as it can be printed on.

It is also rigid enough to stand upright.

Paper is suitable for the greetings card as it is lightweight to post.

It can also be enhanced with foil and embossing.

Here we have a check.

Which of these are paper based products? A, a garden chair.

B, a magazine.

C, a concert ticket.

Or D, a computer mouse.

Pause the video.

Let's have a look.

That's right.

B, a magazine, and C, a concert ticket.

Here are some textile products.

A flag, a T-shirt, and a backpack.

Why do you think textiles are suitable for these? Perhaps, you thought because they need to be flexible and these products can all move.

Here we have another check.

Which of these could be textile based products? A, curtains.

B, a backpack.

C, a laundry basket.

Or D, a saucepan.

Pause the video.

Let's have a look.

That's right.

Three of those could be correct.

It could be curtains, backpack or the laundry basket.

Now we have Task B.

Group the materials using material groups.

Describe the similarities and differences of the materials in one of the groups you have created.

Pause the video.

Amazing.

Let's have a look at some of the answers you may have come up with.

Your answers could include polymers, sheet acrylic, corrugated polypropylene, and sheet polypropylene.

Or textiles, polymer fleece, denim and felt.

Or timbers and boards, birch plywood, pine, which is a soft wood, or medium density fiberboard, often known as MDF.

Part two.

Sam describes some similarities and differences of the materials in the papers and boards group.

Sam says that the similarities are, "All the paper and board examples I have are flat sheet materials." And the differences.

"They are all different colours.

Some are only coloured on one side.

This is shiny and must be a different layer to the grey card beneath it." Jacob also describes some similarities and differences but for the material group metals.

He says the similarities, "The metal examples I have are flat sheet material.

They are all shiny and smooth." The differences are, "They are different colours, silver and golden.

Some are heavier than others and feel stronger." Well done.

The third learning cycle today is categorising materials using properties.

Materials have different properties.

These are sometimes called characteristics.

There are two types of material properties, physical properties and mechanical properties.

Physical properties are characteristics which a material has all the time and can usually be measured.

For example, density or conductivity are physical properties.

Mechanical properties are characteristics which are evident when the material is being worked or used.

For example, strength or elasticity are mechanical properties.

Sometimes these are called working properties.

Here we have a check.

True or false.

Physical properties of materials are those which are always there.

Pause a video.

Let's look.

That's right.

It's true.

They don't have to be used, manipulated, or worked to show these physical properties.

Physical properties.

Density is how solid a material is.

Polystyrene is less dense than stainless steel.

We can see a picture of a polystyrene cup on the left and a stainless steel cup on the right.

Here is a check.

What is density? A, how heavy a material is.

B, how thicker material is.

Or C, how solid a material is.

Pause the video.

Well done.

Let's look.

That's right.

It's C how solid A material is.

Physical properties.

Electrical conductivity describes how well a material allows electricity to pass through.

Copper is very good at conducting electricity, but PVC is not, which makes it an electrical insulator.

Here we have a picture showing PVC covered copper electric cables.

The inside, the copper is very good at conducting electricity, but PVC is not so it insulates.

Here we have another check.

Electrical conductivity is, A, how well a material stores electricity.

B, how well a material allows electricity to pass through.

Or C, how quickly electricity flows.

Pause the video.

Let's have a look.

That's right, it's B.

How well a material allows electricity to pass through.

Mechanical properties.

Strength is the ability to withstand forces.

There are different types of strength depending on the forces acting upon the material.

We can see five examples in these diagrams. Compression forces act to squash a material or product.

Tension forces act to stretch a material or product.

Sheer forces act to cut a structure in two.

Torsion forces act to twist a material or product.

And bending forces act to bend a material or product.

Here we have a check.

Which of these are examples of material strength? A, compression.

B, tension.

C, fusibility, or D density? Pause the video and have a go.

Well done.

Let's check.

That's right, it's A and B.

Compression and tension.

Well done.

Mechanical properties.

Elasticity is the ability to be stretched and then returned to the original shape.

Lycra in clothes is very elastic but paper is not.

Here we can see an image on the left with denim clothing, which contains lycra, this means it is stretchy.

And an image on the right, which are some newspapers and paper is not stretchy.

Here we have a check.

Elasticity is, A, the ability to move many times.

B, the ability to be flexible over time.

C, the ability to be stretched and then returned to the original shape.

Or D, the ability to be stretched.

Pause the video.

Have a go.

Fantastic.

Let's have a look.

That's right, it's C, the ability to be stretched and then returned to its original shape.

Well done.

Here we have Task C.

There are three parts to this task.

One, choose a material property.

For example, density, conductivity, compressive strength or elasticity.

And then rank the materials using the chosen property.

And the third part is to explain how you made your decisions.

Pause the video and have a go.

Well done.

Let's have a look at some of the answers you may have come up with.

Sam explains his choices.

"I chose compressive strength.

I rank the steel as the strongest when forces press trying to squash it together.

The pine and the MDF will be less strong than the steel but more than the calico.

I think the calico textile will be the least strong under compression." Jacob also explains his choices.

"I chose electrical conductivity.

The rank order for this is all the metals will be good conductors and the timbers, polymers, and textiles will not be good conductors.

Some metallic textiles can conduct electricity, but not as well as metals but the timbers and polymers are electrical insulators." Well done.

We now move to the fourth learning cycle for today.

How designers make material choices.

Designers compile all the information that a product must have or do.

This is called a specification.

The information must be justified, which means explained.

Here is an example of a specification for a child's backpack.

The specification states that it must be strong and soft.

And the justification, so it feels comfortable when wearing it.

The specification also states that it must be flexible and fold.

And the justification, so when not in use it can be folded for storage.

The specification states it must be waterproof.

And the justification for this, so the contents does not get damaged when walking in the rain.

Task D.

Part one.

Consider this specification for a child's backpack.

Which material group would you choose to manufacture the backpack from? And part two is to explain your answer.

Pause the video and have a go.

Fantastic.

Let's have a look at some answers you may have come up with.

Sam explains his answer.

"I chose textiles.

They are soft and comfortable.

They are also flexible and can fold up or roll up small.

Not all textiles are waterproof, but some are so I would choose one that is." Jacob also explains his answer.

"I thought about how flexible paper is, but that wouldn't be strong enough to hold the items like books.

Also, paper isn't waterproof.

Some polymers are flexible but not very soft or comfortable, although they are waterproof.

In the end, I also chose textiles as they are the best combination of soft, flexible, and waterproof." Well done.

Here we have a summary of today's learning.

Designers consider the specification requirements when selecting materials.

Designers can choose materials for products using aesthetics such as colour, shape, or texture.

Designers can also choose from material groups such as metals, paper and boards, polymers, textiles, or timbers.

Another way designers may choose is by considering the material properties such as compressive strength or conductivity.

Designers may have to compromise on one aspect of the specification to choose the best fit material.

Thank you for joining me today and really well done.