Lesson video

Hi there, everybody, my name is Mr. Booth, welcome to your Design and Technology lesson for today, it's wonderful that you could join me.

We have a fantastic lesson today where we are gonna be looking at modern materials and their properties, we're also gonna look at lots of products that utilize these fantastic materials.

This is part of the Materials Testing unit.

Let's have a look at our outcome.

Today's outcome: "I can describe the properties and uses of modern materials." Let's have a look at some of our keywords.

Well, first of all, we need to know what a modern material actually is.

And a great definition for a modern material: they are continually being developed through the invention of new or improved processes.

And every single year, we sometimes see new materials being developed, which gives designers lots of exciting opportunities.

Now when we're talking about modern materials, we need to consider their properties, and we can break our properties down into two types.

The first is working property: the way in which a material responds to an external force or certain environment, these can also be referred to as mechanical properties.

And when I say "force," I mean it could be a pull force, a twist, or a squashing force.

And when I say "environment," it could, of course, mean heat, or being left out in the rain.

We then have physical properties: the characteristics of a material such as appearance and features, just like your characteristics, such as your hair color or your eye color.

And then we have one of the modern materials we're gonna be looking at, these are composites.

And this is about combining the properties of two or more materials without being mixed at a chemical level.

That actually means that if you look closely under a microscope or even a magnifying glass, you should still be able to see the two different materials that have been combined to improve that material's properties.

We have two learning cycles for today, the first is all about modern materials, and then we're gonna focus on composites.

So let's have a look at some modern materials.

So, first of all, I'm gonna ask you a question.

What do all these people have in common? So we have an astronaut, we have a firefighter, and we have a motorcycle racer.

I want you to have a think about this.

Pause the video, and come back to me when you've got your answer.

So what do you think? What do they all have in common? Well, they all need protective clothing.

And as well as that, they're likely to experience high or low temperatures.

So think about the astronaut, if they are in the bright sunshine in outer space, one of the harshest environments that we know about, it's gonna be extremely hot, but also in the shade, it can be extremely cold.

Firefighters, it's part of their job to go into burning buildings, so they are going to experience high temperatures.

And motorcycle racers, obviously, they need to be protected, but also they can, if they crash, experience fire, which can be very scary.

So all of these protective clothing, all of this protective clothing requires modern materials to function properly.

Now modern materials are those that are continually being developed through the invention of new or improved processes.

Modern materials are designed to overcome the limitations of traditional materials by offering enhanced properties that help solve specific problems. For example, firefighters used to wear leather, believe it or not, and now, of course, they wear a modern material.

Now, of course, we need to look at our properties.

So the working properties, the way in which a material responds to an external force or certain environments, also referred to as mechanical properties.

And an example of this is toughness.

And then the physical properties, the characteristics of a material, such as appearance or its features.

So we need to keep these two types of properties in consideration when we're talking about our materials.

Quick check for understanding.

What defines modern materials? Is it a, have been used for centuries without change, is it b, are only made from natural resources, c, they cannot be altered or improved, or, d, continually developed through new or improved processes? Pause the video now have a go at this, and come back to me when you've completed it.

It is, of course, d, continually developed through new or improved processes.

Well done.

So we're now gonna start looking at some modern materials.

And what I want you to do is every time I introduce one to you, I want you to think about if you've heard of these before and what kind of products utilize these materials.

So the first one is Nomex.

So I want you to pause the video now, maybe have a chat with the person next to you.

Have you heard of Nomex? What products might this material be utilized in? Pause the video now.

So what did you think of? Well, what I'm gonna do is give you a clue.

I'm gonna give you a property, and, in this case, I'm giving you a working property, so it's heat and flame resistant.

So, once again, pause the video, have a little think about what products Nomex might be utilized in.

Let's have a look at some examples.

Well, for example, it's used in protective clothing, and this is, of course, what we talked about at the beginning.

So astronauts, firefighters, and also motorcycle races, they all have Nomex weaved within to their protective clothing.

Now let's have a look at what Nomex looks like underneath a micro magnifying glass.

So it's got a strong honeycomb structure, and that forms strong, stable bonds that do not easily break down when heated.

It also doesn't transfer heat from the surface to the user's skin, so that protects them from those extreme temperatures, a fantastic material.

So that's Nomex.

The next one is Teflon.

So, once again, I want you to have a think about, have you ever heard of Teflon? What products do we utilize Teflon in? Pause the video now, have a chat to the person next to you and come back to me when you think you've got some examples.

Well, once again, I'm gonna give you a clue.

So a working property of Teflon is that it repels liquid.

So it's got a very, very low absorbency.

Can you think of any products now.

Again, pause the video, come back to me when you thought of something.

So did you think of any? Well, we've got some examples here.

Non-stick frying pans, they have a coating of Teflon on them so your food doesn't stick when you cook it.

But we also have Teflon school trousers.

And the reason we want our school uniforms to be made of Teflon is because it repels water so well.

And, obviously, the non-stick frying pans as well, you'll find they're much easier to clean, but also you're not gonna get horrible messes if you're cooking your scrambled eggs.

Now many modern materials use what we call a weave.

So let's have a closer look at what we mean by a weave.

Well, we have vertical warp yarns and horizontal weft yarns, and they produce a woven fabric with interlacing patterns that determine the fabric's texture, it's strength, and also its flexibility.

And you can get lots of different types of weave, but here, you can see a nice example of how the warp and the weft interlock to produce a weave.

So our next modern material is Kevlar.

So, once again, can you think of any products that utilize Kevlar in their construction? Have a chat with the person next to you, pause the video now, and come back to me when you think you've got something.

So let's give you another clue.

The working properties; lightweight and high impact strength.

So, again, have another think, chat to the person next to you, come back to me when you think you've got some products.

So what did you think of? Well, a great example of this is, of course, bulletproof and stabproof vests, but also we have cut-resistant gloves, and tree surgeons often wear these.

In fact, I think they have to wear them for health and safety rules, because they're using chainsaws, which can be very dangerous, especially around your hands.

Now let's once again look and get our magnifying glass out and think about why does Kevlar protect users from bullets? Well, bullets move at a very high speed, they also have sharp, pointy ends, they're pretty horrendous things, the bullets, but the weave takes the impact of the bullet.

Now, if you're wearing a bulletproof vest and you get shot with a bullet, hopefully, that never ever happens, it will still really hurt.

And, in fact, lots of people that it happens to, they still break ribs, but the bullet can't break through the vest, which means it doesn't go into the person, and it, of course, saves their life.

What a wonderful material.

Quick check for understanding.

Which product is an example of the modern material Teflon? Is it a, is it b, or is it c? Pause the video now, have a go at this, and come back to me when you've got your answer.

It is, of course, b.

You can see there, it is the school uniform trousers that has Teflon in it so it repels water.

Well done.

So we now have PLA, this is polylactic acid, and it's a biodegradable thermopolymer.

So, once again, can you think of any products that might utilize this modern material? Pause the video now have a chat to the person next to you, come back to me when you think you've got some products.

So I'm gonna give you another clue; it has a low melting point.

So that might help in what the products are gonna do.

So pause the video now, have a go at this, and come back to me when you've got some product examples.

Well, PLA, you might have seen that in your 3D printers, because it's the filament that is used.

It's also sometimes used in compostable bags, and also disposable cups.

And the reason for that is because it's a natural material made of corn starch or sugarcane, which means it will break down under certain conditions.

So that's why it's great for single-use items, but also for 3D printing as well.

The fact it's got a low melting point means we can safely use it within our classrooms in our 3D printers.

And the next we have is Fastskin.

Now I'm not gonna ask you for a product for this 'cause it's pretty obvious.

Now this mimics the skin of a shark giving a streamlining effect underwater and reducing drag or resistance underwater.

Now the working properties: it reduces drag and it's very lightweight.

And examples for this are competitive swimwear, and there you can see the fabric.

Now, users that wear this, they actually swim faster, they actually swim faster, they go faster underwater, they are more hydrodynamic, that's what we call it when we're talking about going faster underwater, aerodynamics is in air, hydrodynamics is underwater.

And as you can see, designers actually looked at the skin of a shark in order to make this fabric.

So it's fantastic, these are knitted fibers that mimic the skin of a shark.

Isn't that amazing? Quick check for understanding.

Fastskin: it mimics the skin of a shark by giving what effect underwater and reduces what? And your choices are; aerodynamic, friction, streamlining, and drag.

Pause the video now, fill in the blanks, and come back to me when you've done that.

So the blanks that you should have filled in were, of course, streamlining and drag.

Well done.

So we're now onto your first task.

What I would like you to do is match the modern material to the example product.

You have Nomex, Teflon, Kevlar, Fastskin, and PLA.

And the example products you have are competitive swimwear, a non-stick saucepan, bulletproof vests, a firefighter's clothing, a biodegradable shopping bags.

Pause the video now have a go at this, and come back to me when you've completed it.

So how did you get on? Well, the competitive swimwear is, of course, the Fastskin, we have the non-stick saucepan that utilizes Teflon, bulletproof jackets are made of Kevlar, firefighters clothing is Nomex, and the biodegradable shopping bags are often made of PLA.

Well done.

Next part of this task, I would like you to design a simple product that uses at least one modern material.

I want you to draw a simple quick sketch of your product, I want you to annotate your sketch to explain which materials you chose, and why their properties make them suitable for your design.

Pause the video now, have a go at this task, and come back to me when you've completed it.

So how did you get on? Well, I designed a drinks bottle.

I made it out of PLA, because it's lightweight, which makes it easy to carry around, it's also relatively cheap.

The other thing as well is I could actually 3D print it, allowing for customization, as we have done with this one, by adding a child's name or some kind of defining feature.

And after use, PLA is a natural material, so it will obviously biodegrade under certain conditions, reducing environmental impact of polymers.

Well done.

So we're now onto our second learning cycle, which is all about composites.

So, first of all, we need to know what a composite is.

Well, many composites are also examples of modern materials.

Composite materials, they combine the properties of two or more materials, but without being mixed at the chemical level.

If you think about an alloy, so a metal, if you picked up an alloy and looked at it, you wouldn't be able to tell which other metals or elements are used within its structure.

You would have to get down to the chemical level to be able to understand that.

With composites, even with a microscope or even a magnifying glass, you can usually tell which materials have been used in its construction.

Now this, of course, improves the working and/or the physical properties of the material, that's why we make them.

Now, frequently, composites improve the strength of a material and make them more lightweight.

So that is a very common improvement that we see and we call that strength to weight ratio.

Quick check for understanding.

What defines a composite? We have, a, made from a single material that is chemically altered, b, created by chemically bonding two materials together, c, combine the properties of two or more materials without mixing at a chemical level, or, d, have no distinct properties and act as a single material.

Pause the video now, have a go at this, and come back to me when you have your answer.

It is of course c, combine the properties of two or more materials without mixing at a chemical level.

Well done.

So, once again, what I'm gonna do is I'm gonna give you the name of the material in this case composites, and I want you to try and think of any products that might be made of this material.

So the first is glass reinforced plastic.

This is glass fibers, fiber strands that are set in resin, so have a chat with the person next to you.

Do you know any products that are manufactured out of glass reinforced plastic? <v ->Pause the video now and have a think.

</v> So, of course, the working property, let's give you a clue, all the properties of a polymer, but with a higher strength to weight ratio, because we are including that resin in there as well.

So any ideas, pause the video now and see if you can come up with any ideas.

Well, what we've got is we've got blind poles, that's one example, we've got lots of roofing uses glass-reinforced plastics, and also boats as well.

And that's, again, because of that high strength to weight ratio, you might have come up with some other examples.

And, actually, if we take our magnifying glass once again and we look at our material, we can see we've got glass fiber strands that are set in resin.

Now Izzy is asking a great question here.

"Why does glass reinforced plastic have such good strength to weight ratio?" Well, all the glass fibers fall in different directions, giving strength in many directions rather than one.

The glass fibers are then set in a resin and we can demonstrate this using spaghetti.

So here you go, all the spaghetti is nice and aligned, the fibers are all in one direction, we don't have that much strength.

But if we pour them into the mold and put them in multiple directions, you can see there's much more strength.

Imagine then we pour over a resin to set those, we've got a really strong material that is also lightweight.

Great question, Izzy.

Next material: carbon fiber reinforced polymer.

Sometimes it's shortened to just carbon fiber, but the actual name is carbon fiber reinforced polymer.

So once again, have a chat with the person next to you, see if you can come up with any products that are made from this material.

Pause the video now.

So did you think of any? Well, let's give you a working property.

High strength to weight ratio due to the weave of carbon fibers set in resin.

I'll also give you another clue; it's usually with high-end products.

Pause the video now, see if you can think of any other products that use carbon fiber reinforced polymer.

So did you think of any? Well, you've got helmets, high-end bike parts, car parts, and sporting equipment, even things like Formula One cars are made of carbon fiber reinforced polymer.

And, of course, there we have the weave of carbon fiber, we've got our magnifying glass out again, and you can see it's woven in a very special way, and you can change that weave, and that will alter the performance of your product.

Resin is also used to set it, and that gives it its high strength to weight ratio.

Now we have laminates.

Now laminates are made up of layers.

When the layers are different materials, they are called a composite.

So, once again, can you think of any products that might use laminates? Pause the video now have a chat with the person next to you and come back to me when you've maybe got an answer.

So, of course, what we've got is we've got things like shelves and worktops.

And the physical properties, well, they're attractive appearance, and they're often at a affordable price, such as shelving and worktops, as you can see there.

But we also have waterproof jackets.

So that's because of working properties, durability and water resistance, and that's why we use them for waterproof jackets.

Let's have a closer look at how that works.

So if you are wearing a waterproof jacket, you still want the jacket to breathe, you don't wanna get too hot and sweaty under there, but you don't wanna get soaking wet from the rain.

So they've got lots of layers of special materials, which obviously allows sweat to escape, but keeps the water out.

Very clever indeed.

Quick check for understanding.

Which modern materials including composites commonly use a weave? We've got carbon fiber reinforced polymers, glass reinforced plastic, we've got Fastskin, and we've got Kevlar.

Pause the video now, have a go at this, and come back to me when you've got your answer.

It is, of course, carbon fiber and Kevlar, they use a weave.

Now, modern materials, including composites, provide exciting opportunities for designers and users, but they come with both advantages and disadvantages.

So let's have a look at some of these.

The advantages.

High strength ratio, we've said that a lot during this lesson, they are often resistant to corrosion and environmental damage, and they have customizable properties for specific applications.

So, for example, carbon fiber, I might make a fishing rod, or I might make a Formula One car.

They both have to carry out two very different functions, but it's the same material.

But they're disadvantages.

They're expensive to produce, they're often very difficult to recycle due to the mixing, the layering of the composites of the materials, you've got your fibers, but you've also got your resins, and they often require specialized manufacturing techniques.

And, again, that adds to the complexity and also the cost of these products.

I certainly can't afford to buy a Formula One car.

We can also create our own composite.

Now this is a nice little test, it's a composite, 'cause we're gonna make it out of two materials, and it gives us a chance to actually test physically the properties of these.

So what we're gonna do is make a small woven piece of material using plain weave, and we're just gonna use strips of paper.

Then we're gonna make a second one the same size using the same weaving method, but, for this one, we're gonna cover it in tape.

Now the tape represents the resin that holds the composite together, and the paper represents the fibers, and, in this case, we could pretend that they are carbon fibers.

What we then do is we could test both samples by applying load and force, just as we would in the real world.

We can bend them, we can pull them, we can twist them, and we can compare their properties very easily.

So we're now onto task B.

What I want you to do is create your own paper and tape composite, one with tape and one without.

I then want you to test the differences in strength, flexibility, durability, and recyclability between the plain material and the composite version.

I then want you to discuss the following questions when you are testing.

Strength: how much force can each sample take before it starts to fail? Flexibility: which sample bends more easily without breaking? And durability: which sample shows signs of damage first when twisted, pulled or bent? Which sample would last longer if used repeatedly? And then finally, recyclability and also material use: which sample could be recycled more easily? Pause the video now, have a go at these tasks, and come back to me when you've completed.

So how did you go on? Well, I'm sure your samples look just like this, and I'm sure you made them brilliantly.

And then your discussions.

Well, let's look at what Izzy said.

"When I tested the two samples, I noticed that the paper covered with tape was stronger and more resistant to breaking than the plain paper.

It was less flexible, but it could be bent a little without tearing.

The tape sample appeared to be more durable and would last longer if used repeatedly.

However, it would be harder to recycle because of that tape.

The plain paper was easy to bend and recycle, but it was weaker and tore more easily.

Overall, adding the resin," which, of course, was the tape in this case, "Made the woven material stronger and more durable, much like real composite materials." Fantastic, and I'm sure your answer was similar.

So that brings us to the end of today's lesson.

Let's have a quick summary.

Modern materials are continually being developed through the invention of new or improved processes.

Modern materials have improved working and/or physical properties.

Examples of modern materials include Nomex, Teflon, Fastskin, PLA, Kevlar, and, of course, composites.

Composite materials combine the properties of two or more materials.

Examples of composite materials include glass reinforced polymers and carbon fiber reinforced polymers, and, of course, laminates.

Modern materials including composites, provide exciting opportunities for designers and users that have both advantages and, of course, disadvantages.

You've been absolutely brilliant today, I look forward to seeing you all next time.

Goodbye.