Lesson video

Hello, thank you for joining me for your Design and Technology lesson.

My name is Mrs. Conway and I will be guiding you through your learning today.

So our lesson outcome today is, I can describe where different materials come from and identify their common stock forms. And these are our key words.

We have source, raw material, process, and stock form.

I'll go through each one of these as we work through the lesson.

So first of all, we're going to look at sourcing and processing of materials.

Now, a source is where a material originally comes from.

For papers and boards, the source are trees, which are natural and also a renewable resource.

Paper was first invented in China, approximately 100 A.

D.

and was made from tree bark fibres mixed with water.

And the methods used to make paper in today's world are essentially the same, but the process is now highly automated.

Which of the following is a source of paper and boards? Is it A, a sawmill, B, the ground, C, a tree, or D, a timber merchant? You are looking for the source of the paper.

Pause the video here.

Just take a moment to think about your answer.

And the correct answer.

It was a tree.

Tree is the source of paper and boards.

So, paper and boards are a renewable resource, and this means that the source, so trees, can regrow naturally and be replaced over time through responsible forestry practises.

So, for example, the Forest Stewardship Council is an organisation that promotes responsible management of the world's forests.

The products that are sourced from responsibly managed forests carry the FSC logo, and you may have seen this previously, but you can see that's this there.

It's kind of looking like a little tree with a tick.

So, sustainable means that the resource can replenish itself so future generations can meet their needs.

So, if there is sustainable forestry, it means they are sustaining that source through carefully managed forests, such as replanting felled trees, paper and boards are a sustainable material.

However, if this is done unlawfully, there are certain practises that are done in this way, such as illegal logging, this then can become unsustainable.

Okay, quick check for understanding then.

Which of the following best describes sustainable timber? A, timber harvested from forests that are managed carefully, B, timber is cut down as quickly as possible to meet demand, C, timber that is imported from another country, and D, timber that is only used for making furniture and not construction.

Pause the video here just to take a moment to think about your answer.

And the correct answer was A.

So, timber harvested from forests that are managed carefully is a description of sustainable timber.

Now, different types of timber grow in various climates and also regions.

So, coniferous softwoods are common in northernmost Europe and also northwest USA.

Whereas tropical hardwoods mainly grow along the equator.

And some hardwoods grow in more temperate climates, as well as some softwood species.

So for example, in our country.

Transporting timber from far locations can contribute to carbon emissions.

So, we do have to consider that when we're considering the sustainability of an actual material choice.

So, making 1,000 kilogrammes of A4 white paper requires 24 mature trees.

Recycled paper was created to reduce the environmental impact of the paper making process.

And using recycled paper means that fewer trees are needed to make the same amount of paper.

Now, paper and boards are manufactured in two main categories.

You have paper, which is measured in GSM, grammes per square metre, and also boards, which are card and cardboards, and these are measured in millimetres.

Have a little look at the examples.

Can you identify any examples of each of either paper and boards from each of this collection? See which ones you can kind of work out are which.

Okay, so we have thin card used for the birthday card there.

We also have thick card, which has got laser engraving on it.

We have cardboard, as well as paper, and then we have foam board.

So, different examples of paper and board there.

Okay, so let's have a little look at this table then.

First of all, we have paper.

Now, paper is usually between 80 to 170 GSM weight.

Remember, that is grammes per square metre.

The typical working properties of that is that it is flexible, lightweight, and the physical properties mean that it's available in a range of colours and finishes.

Typical products would include things such as newspapers, magazines, bus tickets, receipts, toilet paper.

Can you think of any others in there as well? You've then got corrugated cardboard.

Now, this is three millimetres thick and upwards, and there's usually two layers of card with fluted sheet in between it.

This is strong, lightweight, and good impact resistance, so this is really useful for things such as packaging.

So, you've got things such as pizza boxes and packaging, for example, products.

Again, can you think of any other examples of when this is used? And here's an image of it, so you will recognise this.

It's got that fluted bit in the middle and it's kind of sandwiched between those kind of thick layers or the two layers of card at either side.

Then you've got foam board.

Foam board is five millimetres thick and upwards, and this is a polystyrene foam sandwiched between two pieces of thin card.

So, it's similar to corrugated cardboard in the fact that there is an internal layer that's sandwiched between two outer layers, but this is polystyrene foam sandwiched between this thin card.

This is really lightweight, but also quite rigid, and it's quite often used for things such as modelling and also point of sale displays.

There's the example of what that looks like.

Okay, quick check for understanding on those, then.

Can you identify corrugated cardboard from the images below? You've got A, B, or C.

Pause the video here.

Just take a moment to think about your answer.

And the correct answer was B.

So, that's your example of corrugated cardboard there.

You've got the fluted bit in the middle sandwiched between two layers of card.

A raw material is a natural material in its original state.

And timber is a raw material.

It's sourced from trees.

To make paper, timber is debarked and chipped into small pieces and this starts the pulping process to become usable paper.

The pulping process can either be mechanical or chemical.

So, let's look at mechanical pulping.

Now, mechanical pulping uses large tanks known as pulpers.

Raw timber chippings are soaked in water and then pulverised with rotor blades, making pulp.

Then, it is sprayed onto mesh and pressed through rollers into paper.

Chemical pulping, however, now this uses chemicals to break down timber pieces, making the pulp.

These are then blended with other fibres like cotton and linen to improve the quality.

Then, bleaching agents, dyes and fillers are added.

Then, it's washed to remove contaminants and formed in paper machine and coatings are added.

Okay, so if we have a little look then if we're taking a tree into paper, so, we have the trees, then the debarking, then the chipper, the pulpers, and the paper making rollers.

If however, we are going to be doing a recycling and we're taking the paper to make paper, we collect the paper, we de-ink it, we use cleaning chambers and then we use pulpers.

So, different processes depending on what our original source is or what we are working from.

Quick check for understanding, then.

The paper making pulping process can either be something or something.

What are the two different types that we've just looked at? Okay, pause the video here to take a moment to think about your answer.

And the answers, then, were either mechanical or chemical.

Well done if you got both of those right.

Mow, paper can be processed further into making cardboard.

And methods for making cardboard are sandwiching and pasting multiple layers of paper together to make thicker paper.

So, we can get thick white card or cardboard.

We're kind of sandwiching them.

Or we're pressing layers of wet pulp together into thicker layers.

Both methods can produce various thicknesses of card.

Now, corrugated cardboard is made by passing paper through a corrugation machine.

The middle layer is made by pressing paper into its required thickness, and then crimping it to achieve that kind of wavy shape that we can see in the middle of those two layers there.

The two outer layers of paper are glued either side of the wavy middle layer, and it's then cut into large pieces, or blanks, for use.

And they do come in quite large pieces.

The double-walled cardboard has an additional wavy and outer layer added.

It's over to you guys to have a go at a task, now.

I'd like you first to explain the difference between a raw material and a processed material using paper and boards as an example.

I'd then like you to use diagrams and annotation to explain the mechanical pulping process of producing paper into a usable form.

And then I'd like you to explain how to process paper into cardboard or corrugated cardboard.

And again, you may support your explanation with diagrams. Pause the video here to have a go at these three tasks, and good luck.

Right, let's have a look at each one of these tasks, then.

The first thing I asked you to do was to explain the difference between a raw material and a processed material using paper and boards as an example.

So, let's look at an example answer.

A raw material is a natural material in its original state.

Timber in the form of a felled tree is a raw material.

When it is debarked and chipped into small pieces, and goes through either the mechanical or chemical pulping process, it becomes a processed paper or board material suitable for use in products.

Okay, just compare your answer to this one, and see if you've got all of the key points there.

The second task I asked you to do was then to use diagrams and annotation to explain the mechanical pulping process of producing paper into a usable form.

Okay, and let's just have a look at an example answer for you to compare yours to.

So, here we have got this diagram showing how we make paper from trees, but also paper to paper.

So, hopefully you've got all of the key pieces on there.

So, if we're doing tree to paper, you should have included that we collected it from the trees, we then did debarking, then went through to a chipper, then the pulpers, and then the paper making rollers.

And if we're doing paper to paper, we would've had the paper collection, the de-inking, the cleaning chambers, and then the pulpers, before going through to the paper making rollers again.

And lastly, I asked you to explain how to process paper into cardboard or corrugated cardboard and you may support your explanation with diagrams. Okay, let's look at an example answer.

So, after paper has been made using the pulping process, corrugated cardboard is made by passing paper through a corrugation machine.

And the middle layer is made by pressing paper into its required thickness, then crimping it to achieve the wavy shape.

The two outer layers of paper are glued either side of the wavy middle layer.

And it is then cut into large pieces, or blanks, for use.

The double-walled cardboard has an additional wavy and outer layer added, which makes it more rigid, increasing its protection properties.

Have a little look at your answer compared to that and just make sure you've got all the key points there.

Okay, next we're going to look at material stock forms. A stock form is a standard shape and size in which a material is supplied.

And standardising means that the shape and size of the material are made to specific dimensions.

Stock forms allow designers and manufacturers to know which form a material is available in.

And this information is required when you're designing a product and also planning for its manufacture.

It's quite important information to make sure that your product is going to be able to be manufactured with the materials you intend to use.

Now, papers and boards are measured in grammes per square metre.

As I mentioned earlier, this is also known as GSM.

Anything under 200 GSM is considered a type of paper.

So, under 200 GSM is paper.

Anything over 200 GSM is considered a type of board, so, card or cardboard.

Okay, quick check for understanding on that then.

What are papers and boards measured in? A, GPI, B, PSM, or C, GSM? Pause the video here just to take a moment to think about your answer.

That's right, the correct answer was GSM, grammes per square metre.

Well done if you got that right.

Now, paper and boards stock forms are available in standard sized sheets, and these range from A10, which is about the size of a postage stamp that you put on a letter, through to 4A0.

So, that's larger than a king size bed.

Okay, so these are all the different sizes.

So you can see that A10, the length in millimetres is 37 millimetres and the width is 26 millimetres.

If we can compared that to 4A0, you then have the length being 2,378 millimetres and the width 1,682.

So, there's a large variation of the different stock sizes, but there is still some limitations in there.

Now, for papers and boards, each stock form is twice the size of the one before.

So, for example, A3 is twice the size of A4.

And this is a really simple diagram to hopefully show that a little bit clearer.

You can see that each time, it is double the size.

So, if you put two A4 sheets together, you would get the size of A3.

Now, paper and boards stock forms also include rolls.

So, these are large continuous lengths of paper or board, and they're used for things such as printing presses, packaging machines, tissue, toilet, or kitchen paper.

Also, ply, and ply refers to how many layers, or plies, are bonded together for strength or absorbency.

Single-ply is one layer, two-ply is two, and so on.

And these are typically used for things such as tissue paper, corrugated and laminated board.

This is a roll of newspaper, as an example.

And this is an example of three-ply toilet paper.

Your toilet paper is probably the most common thing that you are used to and consider as ply.

It's usually advertised on the packaging of how many ply it is, and the more ply it is, the more considered luxurious toilet paper it is and usually the more expensive it is.

Now, there are many benefits to materials being available in a range of stock forms, such as the handling.

When it's available in stock forms, it's easier to store and also to transport, or to organise the storage and transport of it.

Also, the cost.

The bulk production of the standard sizes does lower the cost and the lowering of the cost means that can be passed on to the manufacturer and the designer and eventually also the consumer.

Also, waste, because you know what size you're going to be getting and it's organised, you only need to buy what is needed, which will minimise waste.

And also, it helps with efficiency.

The consistent sizes are easier to work with if you always know what sizes are coming.

You can plan accordingly.

Okay, quick check for understanding on that, then.

What is one main benefit of using materials in standard stock forms? You have, it ensures all products made from the material will have identical properties, it eliminates the need for quality control, it makes material selection and processing more efficient and cost-effective, or it allows for completely custom sizing.

Pause the video here just to take a moment to think about your answer.

And the correct answer was C.

So, one of the main benefits of using materials in these standard stock forms is that it makes material selection and processing more efficient and also more cost-effective.

Now, sometimes you will need to work out how many pieces of a product can be cut from a length of paper or board.

You also will need to calculate total costs based on length or volume used and also estimate waste leftover after cutting.

So, for example, a piece of A1 corrugated cardboard is 840 millimetres long and 594 millimetres wide.

You need pieces that are 200 millimetres long and 200 millimetres wide.

So, how many full pieces can you actually cut? To work this out, you're going to take the length, the 840, and divide that by 200.

That's going to be 4.

2 pieces, which we wouldn't be able to get five pieces out of it, we need to round down, which would be four pieces.

We'd also take the width, the 594, divided by 200, and that would equal 2.

97.

Again, we'd need to round down, as we wouldn't be able to add more material on.

Even though it's high, we will need to round down, and that would mean two pieces.

So in total, that means you can cut four times two pieces, which will equal eight pieces in total.

Remember, this is with rounding down.

Now obviously sometimes in maths you're told to round up if it's over halfway over the next point.

But when we're talking about material, we'd need to round down as you wouldn't be able to have extra material there.

So, just like in the previous example, there are often occasions when you have to round down.

And as I've explained this is because any leftover material, called an offcut, is too short, and can't be used to make another full length.

Now, in the previous example, the calculations were rounded down to four and two.

So, this is what we had.

We had our length, the 840 divided by 200, which was 4.

2 pieces.

Now, that's 4 pieces with a 40 millimetre offcut.

The width, we ended up with 2 pieces with 194 millimetre offcut.

Now, in total, 8 pieces would be constructed, and that would leave an offcut of corrugated card that is 194 millimetres by 40 millimetres.

Now, you may have to calculate the total cost based on the length or volume of paper or board used.

If each piece costs £2.

50, what is the cost of 8 pieces? So, in this case, 8 pieces are £2.

50, which is 8 times 2.

50, and that equals £20.

Over to you now to have a go at some of these workings out.

You're cutting 800 millimetre pieces from a 3,000 millimetre length.

How many full pieces can you cut? Is it A, 3, B, 3.

75, C, 4, or D, 2? Pause the video here to have a go at working this out and good luck.

And the correct answer, it was 3.

You divide and then check if there's enough for another full piece.

So, in this case we divided 3,000 by 800, which is 3.

75, but of course there's not enough for another full piece, so we would need to round down to three full pieces.

Well done if you got that right.

Okay, it's gonna be over to you now to have a go at another task.

First thing I'd like you to do is describe what a stock form is.

Give one example of a stock form and explain how it might be used in a product.

I'd then like you to explain two reasons why paper and boards are manufactured and sold in standard sizes.

And also I'd like you to calculate this.

You have a large sheet of corrugated cardboard measuring 2,440 millimetres by 1,220 millimetres.

You need rectangular panels that are 750 millimetres by 500 millimetres for a project.

How many full panels can you cut from one sheet? Okay, pause the video here to have a go at these tasks, and good luck.

Right, let's go through the answers, then.

The first thing I asked you to do was to describe what a stock form is and give one example of a stock form and explain how it might be used in a product.

So, let's have a look at an example answer.

A stock form is a standard shape and size in which a material is commonly supplied.

An example of a paper and board stock form is a sheet.

Now, these come in sizes ranging from A10, which is the size of a postage stamp, up to A40, which is larger than a king-size bed.

They're also measured in grammes per square metre, or GSM.

And sheets can be used for many types of packaging.

Using stock forms makes it easier and faster to manufacture products.

Have a little look at your answer and just compare it to that one and see if you've got all the key points that you needed to include there.

The second task I asked you to do then was to explain two reasons why paper and board are manufactured and sold in standard sizes.

So, again, let's look at an example answer.

Standard sizes allow manufacturers and designers to plan products more efficiently because the dimensions are predictable.

And this reduces time spent measuring or adjusting materials to non-standard lengths.

Using standard sizes helps reduce material waste because products and components can be designed to fit these dimensions, leading to more efficient use of materials and lower production costs.

Again, just compare your answer to this one and see if you've got all the key points in there.

And the last thing I asked you to do then, you have a large sheet of corrugated cardboard sheet measuring 2,440 millimetres by 1,220 millimetres.

You need rectangular panels that are 750 millimetres by 500 millimetres for a project.

And I asked you to work out how many full panels can you cut from one sheet? So the first thing you should have done is taken the length, which was 2,440, divided by 750, which calculated out as 3.

25.

And as that's not enough to make a full-sized panel, we needed to round down to 3.

Step two, then, we should have then looked at the width, which was 1,220.

We divide that by 600 and that comes out at 2.

03.

And again that.

03 isn't enough to make a full-sized piece, so we're gonna round down to 2 panels.

So, then we have our total, which is the 3 panels length times the 2 panels width, which is 6 full panels.

Well done if you've got all of that right and the working out right, as well.

So, let's summarise today's lesson.

Today, we've been looking at sources and stock forms of papers and boards.

Now, raw materials need to be sourced and processed into a usable form.

And materials are available in a range of stock forms, which influences material selection and also production methods.

Stock forms and standard sizes help reduce material waste as products and components can be designed to fit these dimensions.

And rounding down is necessary for calculations because small offcuts can't be used as full pieces.

Well done for all of your hard work today and also all of the calculating of the math side of things, as well.

Thank you so much for joining me for the lesson and I will see you soon.