Y10 DT Distance Learning

Theory- Summer Term 1This work can either be completed on paper or using computer software of your

choice. BUT IT WILL BE COLLECTED IN SEPTEMBER.

This work contains 13 tasks that should be completed over the next 5 weeks- the first

task (processing metals) is quite long and is the equivalent of 3 lessons worth of work.

The remaining 12 tasks are stand alone lessons each.

You should also complete 1 hour of independent revision alongside this work. For this,

you should use you ‘Pocket Poster’ book- either the hard copy or digital copy.

The overview of the 5 weeks of work is as follows:

Week commencing Lesson 1 Lesson 2 Lesson 3

20/4/2020 Processing metals Processing metals Processing metals

27/4/2020 Ergonomics Quality control CAD/CAM

4/5/2020 Biodegradable

polymers

Processing woods Manufacturing

woods

11/5/2020 Adhesives Finishing wood Materials

properties

18/5/2020 Product analysis

exam question

Product analysis /

disassembly

Product analysis

exam question

Lessons 1, 2 and 3- Processing

metals

Processing metalsProcessing metals

Redistribution

Processes where materials are

reshaped without loss of material

Wasting processes

Generally all those

processes where

material is cut away

Addition

Processes where

materials are joined

together

Sawing and

filling

Drilling and

milling

Grinding and

sanding

Blanking and

piercing

Bolts and

screws

Adhesives

Welding,

brazing and

soldering

Casting Forging SinteringForming

Sand casting

Die casting

Gravity die casting

Low pressure

die casting

High pressure

die casting

Press forming

Embossing and

coining

Cold forging

Hot forging

Drop forging

Hot pressing

Metals can be processed in a variety of ways. You need to know about casting- which is a redistributing process, highlighted with the red box beside.

Processing metals- RedistributionLike polymers, metals can be heated to known melting temperatures. When molten,

the liquid metal can then be poured (or forced under pressure) into a mould. Mould

can be created from sand, alloy steel or ceramics, depending on the metals being

cast.

Sand casting

Sand is used for the mould. Sand contains oils that act as binders to help it hold its

shape while the hot metal is being cast into it.

Step 1: a ‘pattern is made’. This could be made from a range of materials such as

woods, metals or plastics. Patterns can be split for more complex shapes.

Step 2: Each half of the pattern s placed on a baseboard. A mould box half is placed

over it.

Step 3: green sand is ‘tamped’ around the pattern forcing it into contact with the

pattern. This is followed by packing sand.

Step 4: The pattern is removed from the mould half. The runner and the riser gates

are then cut into the top half of the sand mould.

Step 5: the mould halves are fitted together with location pins, ensuring correct

alignment.

Step 6: molten metal is poured into the running gate. The rise is used to indicate

when the mould is full. De-gassing tablets may be necessary to reduce the risk of

porous casting.

Step 7: Once metal has solidified, the sand mould is broken open leaving the product

with runner and riser gates attached. These will be removed either by using a hand

saw or by some other means, depending on the material being cast.

Advantages:

• Complex 3D

shapes can be

produced.

• Cores can be

used to produce

hollow sections

• Its appropriate

for small runs

• Automated

processes are

suitable for

longer

production runs.

Disadvantages:

• Due to the poor

surface finish,

some machining

will be

necessary.

• It’s not as

accurate as die

or investment

casting

• It has a low rate

of output and is

therefore

suitable only for

small production

runs.

Casting

Sand casting for

Ferrari engines

https://www.youtube.com/watch?v=K8SYhISGxN4

https://www.youtube.com/watch?v=9g_JfhjcBAU

Engine block casting

https://www.youtube.co

m/watch?v=yXVLbzI3xTE

Die casting

Die casting is the term used

for the processes of casting

metals with a low melting

point into alloy steel dies (or

moulds). It is known as a

permanent mould process, and

the molten metal either enters

the mould under the action of

gravity or it is forced into the

mould under pressure.

The alloys cast in this way are

generally zinc, aluminium and

magnesium based alloys. Their

low melting temperatures

make them particularly useful

for large scale production.

The processes involved in die

casting vary due to the amount

of pressure/ force applied to

the molten metal as it enters

the mould.

In general, the higher the

force applied, the quicker the

process and the finer the

detail being produced.

Advantages of die casting over

sand casting:

Finish: the surface finish of a

die cast product is superior to

that of sand casting; it’s a

smooth as the finish of the die

surface.

Accuracy: the shape of the die

determines the shape of the

product, therefore the

accuracy of size and detail are

as required.

Quality of the material: die

cast products tend to be better

from the material’s point of

view due to the effects on the

material structure of rapid

cooling.

Scale of production: rapid

cooling of the components (1

sec per cycle) makes high

pressure die casting suitable

for large scale production; this

is necessary to cover the cost

of dies and for the

manufacturer to make profit.

Energy: alloys with a low

melting point require less heat

to melt, resulting in lower

energy costs.

Casting

Die cast shell housing

https://www.

youtube.com/

watch?v=Pj_

mjjUQad8

https://www.

youtube.com/

watch?v=_A6

KG010u3o

Gravity die casting

Molten metal is poured into the

dies through runners., in a similar

way to that of sand casting. The

process uses force of gravity to

ensure the molten metal reaches

all parts of the metal mould.

The dies are made from alloy

steel and are split to allow for

removal of the completed

product.

Gas rings around the outside of

the die keep the mould heated,

ensuring even cooling of the cast

metal

Fluxes are also used to prevent

oxidation of the metal as it is

being cast.

Gravity is the only force applied

to the molten metal as it enters

the die and makes contact with

all parts of the die. Therefore,

products manufactured in this

way tend to be large with simple

shapes . Examples include car

wheels.

Casting https://www.yout

ube.com/watch?v

=xxPLYjqOx9k

Pressure die casting

Die cast processes can also use high or low

pressures to force the molten metal into

the die. The additional pressure is required

to ensure that the molten metal reaches all

parts of the more intricate dies.

High pressure die casting uses a hydraulic

ram to force the material into the die.

In this process molten metal is poured into

a cylinder, either from a crucible of from a

ladle. The hydraulic ram then forces the

molten metal into the closed dies.

The dies are water cooled, resulting in

rapid cooling of the product. As the dies

open, ejector pins push the product out of

the die.

In hot chamber high pressure die casting

process the molten metal is also forced

into the dies by the use of a hydraulic ram

but, in this case, the ram is fed directly

from the reservoir of molten metal

Typical products of high pressure die

casting include small, highly detailed

components. Examples include components

for lock mechanisms for uPVC sliding doors

Casting

Hot chamber

high pressure

die casting:

https://www.

youtube.com

/watch?v=bzS

SfBgkWfc

Industrial die casting

A development of hot chamber die

casting is the multi-slide die casting

process. Traditional die casting processes

use just two halves of a die to form the

shape, making it difficult to produce

components with very complex 3D

shapes.

By using 4 (or more) slides, complex 3D

shapes can be achieved. Each of the

components of the die is secured to one

of the slides and contains either a cavity

(external) or core (internal) shape which,

when closed together with the other

dies, will form the correct shape for the

product.

Each of the slides moved independently

of the other for opening and closing; this

is controlled by a computer and operated

by pneumatics. Mechanical locking

mechanisms hold the dies together while

the material is being injected. ]

Multi-slide die casting is used for the

rapid manufacture of small zinc and

magnesium components. Products include

door locks and sensor casings for cars and

the internal components of domestic

electrical sockets.

CastingFully Integrated Manufacturing -Four-slide die

https://www.you

tube.com/watch?

v=0WOaKcJVPiw

Investment casting

Used for the production of casting materials

with a high melting point, it is a very old

process.

Step 1: A wax pattern is produced to a high

degree of accuracy.

Step 2: This is then coated in a high

temperature ceramic material, by dipping the

wax pattern into the ceramic slip. When a

sufficient thickness of ceramic is achieved, it is

left to dry.

Step 3: Once dry, it can be fired in a kiln. This

will of course cause the wax pattern to melt

(hence alternative term for this process ‘lost

wax casting’) leaving the cavity to be cast

into.

Step 4: When the ceramic mould has cooled,

the molten metal is poured in. This is generally

done using gravity to help fill the mould.

Step 5: When the cast has cooled , the ceramic

mould is broken open thereby destroying it and

leaving only the cast product.

Example products made form investment

casting include turbine blades for jet engines,

tools and dies.

Casting

Advantages:

• Good finishes can be obtained along with a fair degree

of accuracy.

• Complicated shapes that cannot be produced by other

casting processes can be made.

• There is no spilt line showing on the product.

Disadvantages:

• The cost is very high

• The size of components is limited by weight.

https://www.youtube.com/watch?v=tyrXq_u1OH0

https://www.youtube.com/watch?v=UrUsaGussfc

Low temperature casting (pewter)

Pewter is composed of 96 percent tin and 4 percent

copper although there are many variations. It is a

soft metal and can be shaped easily by hand tools

and machine tools. Due to its low melting point

(approximately 230 degrees centigrade) it is

suitable for casting. It is a bright material, which

makes it popular for the manufacture of

‘silverware’ such as tankards, candlesticks and

even jewellery.

Because pewter is malleable, it can be cut with a

hacksaw easily. When preparing to cast pewter

small pieces of approximately 60mm in length are

cut. This size will fit comfortably in the ‘bowl’ of a

casting ladle, ready for casting

Before casting can take place a mould must be

made. Moulds can be made from a range of

materials including MDF, steel or silica sand. In

schools and colleges, MDF is an ideal material and

moulds made from this material can be reused a

small number of times. The mould have two parts

and they are held together with wire or small

cramps

The pattern/cavity can be cut in the MDF using

hand tools or for accurate results a CNC machine

can be used.

Casting

https://www.

youtube.com

/watch?v=2j4

zJWMPgNw

Processing metals- Casting

You need to know about 7 metal casting processes:

1. Sand casting

2. Die casting

3. Gravity die casting

4. Pressure die casting

5. Industrial casting

6. Investment casting

7. Pewter casting

1. Read all the information and watch the video links on casting

2. Summarise each process and provide examples of what products can be manufactured in

this way- this could be done on paper or using computer software available to you. Hints:

3. Do not just copy information- use bullet points / identify key points

4. Key point include:

1. Each stage of the process

2. Advantages and disadvantages

3. Examples of use

This work should be the equivalent of 3 lessons- make sure the quality and quantity of

work reflects this.

Lesson 4- Ergonomics

Ergonomics

Ergonomics concerns the interaction between the human body

and products, systems or environments. Product designers are

particular concerned with making products that are easy to use.

Ergonomists are designers specialising in ergonomics. They may

design:

Products: they may conduct trials with users to check the

usability of a product such as the operation of a games

controller, a steam iron, computer mouse etc.

Systems: the layout of a restaurant kitchen or a

manufacturing product cell / area, in order to make them

more efficient and reduce strain injury risk.

Environments: the interior of a car or aircraft, to ensure

comfort of the user and an efficient interface between the

control systems and the driver or pilot.

How do ergonomists influence design?

Ergonomics is a critical factor n the success of a product. There are many

factors that can influence ergonomics, 4 of these include:

Colour- power switches, waring lights on dashboard, function keys on a

mobile phone etc. The type of colour used and how it performs in

different levels of light are important factors to consider.

Lighting- the correct level of illumination can be a very important

ergonomic factor. Visual displays need to be bright enough to be seen

in full sunlight but perhaps adjustable for night time use, so as not to

strain the eyes. Many electrical products have day time and night time

settings.

Sound- Audible instructions and warnings are common in products such

as sat navs, in-car safety systems, air craft controls, lifts, self-service

tills and many other areas. Sound level and clarity of sound under

different conditions such as engine noise are very important factors to

consider. Noise such as background sounds from machinery can affect

ergonomics. High levels of noise can be uncomfortable and can have

serious health implications.

Comfort- These factors might include shaping a product to fit part of

the body, such as a chair seat. Sometimes products can be

uncomfortable to use is the user has to stretch or move awkwardly to

reach something i.e. a poorly designed kitchen. Comfort can also be

affected by temperature i.e. too hot or too cold in car interior or

computer room. Noise level and vibrations are also factors that could

affect machine operators.

Anthropometric Data

Anthropometric involves using body sizes to improve the

ergonomics in products, systems or environments. For

example, designers of item such as personal stereos would look

at data for hand sizes in order to ensure that the product can

be comfortably held, and that the controls are positioned to

allow easy operation with finger tips.

Anthropometrical data taken form the measurements of

hundreds of volunteers in normal recorded as percentiles. The

average size is known as the 50% percentile. Most design

activity is for the body sizes between the 5th and 95th

percentile which would take in the majority of the population.

TASK: Ergonomics and Anthropometric Data

1. Summarise the 3 areas ergonomists specialise in

2. Give an overview of the 4 of the factors that can influence ergonomics.

3. Pick a product of your choice (I.e. Game controller) and explain how ergonomics has been

considered in it’s design. Try to also give an explanation and use of ‘anthropometric data’ in

your work. For example, you could compare the two products below:

Task 3- Quality Control

Quality Control

Quality control ensures products are manufactured to a high standard.

Checks should be made at every stand of the manufacturing process.

This involves testing materials, products or components to check

they’ve made to a high enough standard and they meet the

manufacturing specification. E.g. Musical greetings cards might be

tested to make sure all the images are printed clearly, the edges are cut

accurately, the card is folded in the right place, the text is straight, it

plays the right tune etc.

Usually, one sample of the materials, components or products are

testing, as it would take too much time to check them all.

Tolerance

Its important that the dimensions of components are accurate. If they

aren’t, the parts won’t fit together properly when the product is

assembled.

Just how accurate they need to be is specified by the tolerance. This is

the margin of error that is considered acceptable.

The tolerance is normally given as an upper (+) and a lower (-) limit for

the measurement. For example, a 20mm measurement with a tolerance

of 0.5+ has a lower limit of 19.5mm and an upper limit of 20.5mm.

Tolerances should be included on working drawings (in the manufacturing

specification) to show the limits within which the product should be

manufactured.

Components must be within the tolerance to pass through any size

checks in quality control.

Quality Control Tests

Go/ No Go Fixtures check dimensions are within tolerance

Go/no go fixtures are limit gauges- they check to see

whether the size of a part is within its tolerance.

They're usually doubled-ended- one end is machined to

the lower limit and the other end to the upper limit of

tolerance.

These checks don’t take very long and are much

quicker than measuring the actual dimensions of a

component.

Registration Marks check printing plates are aligned

A colour registration mark normally appears a cross

shape- it is used by manufacturers to check the quality

of colour printing onto paper and board.

They’re use to make sure the printing plates are

aligned in the right position

Prints should be checked against the Original

To check repeating prints (such as stripes and

chequers) are being printed correctly onto fabric,

manufacturers will often compare prints to an original

sample print. This can be done well by eye.

Its much quicker and easier to do this than try to

measure the dimensions of each part of the repeating

pattern one at a time.

Achieving consistency during manufacture

Depth stops

Depth stops are long rods that are clamped close to the

drill bit of some drills.

They allow you to drill a hole to an exact depth in

whatever material you’re drilling. Once this depth has

been reached, the depth stop will come into contact with

the material and will prevent you from drilling any deeper.

The drill depth can be adjusted by clamping the depth stop

in a different place.

Along with the width of the drill bit, this allows you to

carefully control the dimensions of the hole.

Laser cutters need to be programmed correctly

To cut a material accurately, a laser cutter needs to be

programmed with the right information. This includes:

The dimensions of the component to be cut- so it

knows exactly where t cut.

The correct power settings and feed rate (the speed

that the laser moves over and cuts the material).

These values depend on the type of material to be cut

and its thickness.

If programmed correctly, the laser can cut to a tiny

tolerance (with high accuracy and precision), so the

component should end up as you want it.

Task- Quality control

1. Explain the importance of quality control in the manufacturing industry (what is it and why is it

used?).

2. Using a specific product, explain the term ‘tolerance’ and why it is used when manufacturing

products.

3. Explain 3 specific examples of quality controls used during the manufacturing process.

4. Investigate how consistency can be maintained during the process of manufacturing:

1. A hand-made product in the workshop (when drilling)

2. A laser-cut product using CAD/CAM (what should be checked before machining?)

Task 4- Cad/CAM

CAD/CAM

CAD stands for Computer Aided Design/ Computer

Aided Manufacture. CAD related to the designing and

CAM relates to the actually machining/ making.

Examples of CAD include:

2D Design

ProDesktop

SolidWorks

Inventor

Or any software that aids the designing process.

Examples of CAM include:

Laser cutting- Can only cut / engrave patterns on

2D material (usually).

Routing- CNC Boxford Router- uses drill bit to

remove material on ‘soft’ materials i.e. wood,

plastic, aluminium

Milling- uses drill bit to remove material from

metal and is usually more accurate / precise than

routing

Turning- CNC lathe to machine work as it is turned

Plotter cutting / vinyl cutting- drawing on or

cutting large sheets of paper / card / vinyl. The

blade can be removed and replaced with a ‘pen’.

Advantages Disadvantages

Easy to modify / change designs- Can

save multiple files and modify them in

different ways

High start up costs- high spec

computers and actual CAM machine

Can produce very accurate

components with consistent quality

Workers / operators have to be skilled,

therefore expensive to employ

Can run for long periods of time Repairs can be expensive

Designs can be sent via e-mail to

anywhere in the world for

modifications and manufacturing

If not ‘backed up’, designs can be

easily lost if there is a computer

malfunction

Do not need to pay hourly rate (other

than operators)

Complex designs can be potentially

easy to ‘steal’ (copy)

Can produce realistic 3D rendered on-

screen models which can save time

money / on ‘manual modelling’.

Ethical issues surrounding CAD/CAM

replacing a workforce.

Can also produce scaled models

quickly (rapid prototyping) to evaluate

and modify design ideas.

Possible reduction in skilled

tradespeople i.e. carpenters.

Human error can be catastrophic. I.e.

one incorrect measurement on a CAD

file could render a huge production

worthless.

CAD/CAM

There are many advantages and disadvantages of CAD/CAM. You need to be aware of these…

Task- CAD/CAM

1. Explain what is

meant by the term

CAD/CAM and

provide examples.

2. Describe 2

different

examples of Cad

3. Describe 5

different

examples of CAM

4. What are the

advantages and

disadvantages of

CAD/CAM? Try to

provide examples

in your answer to

explain them.

Task 5- Biodegradable

polymers

Biodegradable polymers

Most polymers are produced from finite, non-renewable resources such as crude oil, which do not break down easily

or quickly. Discarded polymers are a major cause of pollution and kill marine and bird life, as well as environmental

scarring due to land fill.

Bio-polymers are examples of plastics that have been developed to slow down / prevent this pollution.

Bio-polymers can be split into two groups:

Natural bio-polymers: made from natural materials such as starch and cellulose

Synthetic bio-polymers: made from renewable resources but chemically engineering to break down more

quickly.

There are 3 main types of biodegradable polymers:

Oxy-degradable polymer- plastic bags

Photodegradable polymer- plastic cutlery

Hydro-degradable polymer- washing capsules

However, there are implications with the use of biodegradable polymers. Many produce methane when they

decompose- this contributing to global warming. Some can take high temperatures to decompose and may leave

behind toxic residue. Traditional agricultural land could be lost to ‘grow polymers’, making food more

expensive.

Task

1. What are Bio-polymers? And what are the two main groups of bio polymers?

2. Explain the 3 main types of biodegradable polymers (include examples)

3. Explain the implications of the use of biodegradable polymers

4. Use the internet (if available) to investigate 3 different biodegradable polymers. The investigation should

include information, advantages, disadvantages and examples of use.

Task 6- Processing woods

Woods

Wood is a natural material which is grown all over the world and has been used for building

work, furniture and decorative items for thousands of years.

Prior to use, wood is converted (sawn into useable pieces) and then seasoned (removing

excess moisture, 80-90%). There are two main forms of seasoning:

Air seasoning – traditional, in expensive method where wood is stacked under a shelter

to protect from rain. Air circulates between the planks to slowly remove the excess

moisture. Air seasoned wood is used for outdoor wooden products because it is

seasoned to the same moisture content and its surroundings and therefore the wood

will be less prone to defects.

Kiln seasoning- more expensive but controlled method which is very quick and can take

just a few weeks. Indoor products such as furniture will use kiln-seasoned wood

because it has been seasoned to meet the indoor conditions and will have low moisture

content than air-dried wood.

Classification of woods:

Hardwoods:- Oak, Mahogany

Softwoods:- Pine, spruce, cedar

Manufactured boards:- Plywood, Chipboard, MDF

Dust and sap from wood can be hazardous and form a health risk to workers. The toxicity

of a wood depends on the species and the employer must provide PPE and have expose

limits to protect workers.

Stock forms is the term used to describe ‘how’ wood is available i.e. Rough sawn, planed

square edge and planed all round are 3 different options when selecting timber.

Natural wood is only available at the maximum width of the tree but manufactured boards

can be produced in huge sheets, if required. Some wood is made into moulding such as

skirting boards or wooden trims.

Task- Wood

1. What is the definition of wood?

2. What percentage of water is removed during the seasoning process?

3. Describe air seasoning

4. Describe kiln dry seasoning

5. What are the three classifications of wood? Name some specific

examples.

6. What are stock forms?

7. What is an advantage of manufactured wood when compared to natural

wood (timber)

Task 7- Manufacturing woods

Woods

Manufacturing processes associated with wood can be group into addition, wasting and forming processes. You

need to be able to identify which processes are used with specific products, and recognise how the production

method changes with different scales of production.

Addition

Traditional wood joints. You need to now about 8 types of joints: Butt, dowel, mitre, comb, dovetail,

mortise and tenon, housing and half lap joint.

Knock-down fittings. These are used to manufacture flat-pack furniture. You need to know about 3

fittings: Modesty blocks, barrel and bolt and cam-lock connector.

Wood screws: Wood screws have a coarser pitch (fewer thread per inch) compared to screws used for

sheet metal. Often, part of the screw- known as the shank- does not have a thread. This makes is easier

for screwing two pieces of timber together where the thread is only needed at the bottom. Bolts can also

be used to join wood.

Wasting processes

Turning. This involves machining wood on a lathe. The wood is rotated and tools applied to remove

material.

Routing. Routers can be used to machine timber to make slots and holes. They can be CNC or manual.

Milling. Similar to routing, but milling machines run at tool slow a speed for machining timber accurately,

but useful for small size, basic jobs such as rough prototypes. Can be operated manually or CNC.

Forming

Lamination. This is the process of bonding materials together. Veneers (thin slices of natural timber) or

thin manufactured boards can be glued together and bent over a former.

Steam bending. Heat and steam enables strips of timber to be made pliable so that they can be shaped

over a former. Quicker than laminating- no glue drying time, also less wasteful as laminating usually

requires trimming to final size.

Manufacturing wood

1. What are the three processes associated with manufacturing wood?

2. Explain 3 ‘Addition’ methods. Try to include examples of products that

have been manufactured using these methods (use the internet to help

you, if available).

3. Explain 3 ‘wasting’ methods. Try to include examples of products that

have been manufactured using these methods (use the internet to help

you, if available).

4. Explain 2 ‘forming’ methods. Try to include examples of products that

have been manufactured using these methods (use the internet to help

you, if available).

Task 8- Adhesives

Woods- Adhesives, jigs and fixtures (page 80-82)

Adhesives

Adhesives are substances used to stick materials together.

PVA – Commonly used to bond wood-base materials together. Water based and

white in colour. Not usually waterproof. Typically used to bond wooden joints for

indoor furniture / products in the home.

Contact adhesives – Used for large areas such as sheet material. Can be used to

join the same or different materials together i.e. wood sheet / metal sheet /

polymer sheet. Sets in 10 minutes, used for bonding MF sheet to chipboard for

kitchen worktop.

UV hardening – a clear liquid which ‘cures’ to form a bond when exposed to UV

light. Contains a photo initiator, which means that as it absorbs the UV light

wavelength, it begins to cure and set to a solid bond. Used to join metal, glass

and polymers. Often used in workshop projects made form polymers such as

lighting. Any excess adhesive can wiped away prior to being exposed to UV light.

Solvent cement - Tensol is an example of this- it is an acrylic cement. Works by

softening the surface of the polymers to be joined , allowing them to fuse

together. Used in plumbing to bond non-pressure pipes made from ABS or PVC.

Also used in schools for joint acrylic parts of project work.

Jigs and Fixtures

A fixture is something that holds work in a given position while a manufacturing

process takes place. A jig both holds the work and guides a tool. Used to ensure that

parts or components can be made repeatedly and accurately. They can also speed up

manufacture. Mitre blocks are an example- used to cut 45 degree angles.

Sanding jigs – Used to hols and guide timber as it is sanded in disk or belt sanders.

Routing jigs – Can be used with routers to help shape wood accurately and

consistently.

Task- Adhesives, jigs and

fixtures.

1. Explain 4 wood adhesives and

include examples of where

they are used. You could

answer this / present the

information in a table.

2. Explain the use and

application of Jigs and

Fixtures.

3. Give an example of a product

that has been manufactured

with the use of a jog or

fixture.

Task 9 - Finishing wood

Finishes

Purpose of finishing wood is:

Prevent the wood from absorbing moisture

Protect against decay

Protect against insect attack

Enhance the appearance of the final product

Natural wood can degrade in the following ways:

Altering wetness and dryness means that moisture is

absorbed into the wood. Although the surface may

dry out, moisture remains below the surface. This

wet rot leads to breaking down of the wood fibres

and a fungus can spread throughout the wood. This

converts wood into a soft, crumbly state.

Insects can also lay eggs in the cracks in the wood

and the hatched larvae eat into the wood creating

tunnels.

Before applying a finish, good surface prep is essential.

They should be planed or sanded with glass paper.

Sanding should be done in direction of the grain to

avoid scratching the surface. When using glass paper,

start with the roughest (most coarse) progressing to

finer grades.

You need to know about 6 different finishes for wood.

Polyurethane varnish and acrylic

varnish

Available in gloss. satin and matt. Clear

or coloured. Several thin coats should

be used with sanding down with fine

glass paper between coats. Provides

hard, tough, heatproof, waterproof

finish. Clear finish allows the grain of

the wood to be seen through the finish

Water-based paints

Available in gloss, satin, matt and

metallic effects. Applied with rush,

roller or spray. Treat knots with

knotting before applying paint to

prevent resin oozing out and spoiling

the finish. It can then be primed and

then an undercoat applied prior to

paint finish. Provides protection and

colour. Indoor and outdoor use.

Stains

Available in many different colours and

types such as mahogany and walnut.

Apply with brush, roller or spray.

Surfaces should be grease-free prior to

application. Water or spirit based. Used

to colour inexpensive wood to make it

look like more expensive timber. No

specific protective qualities.

Wax

Available I clear and coloured waxes.

Apply with brush and then buff clean

once dry. High provide a high gloss

finish. Was increases surface hardness

and toughness. Clear finish allows grin

of wood to be seen through wax.

Pressure treating

Wood is placed in a pressure vessel

containing solution consisting of copper

sulphate and other preserving salts or

preservatives. Vacuum and pressure are

controlled to force perseveration deep

into fibres of the wood and then the

wood is steam dried. Protects wood for

50 from rot, insects, fungal attack and

weathering. Used for decking and

cladding.

Danish oil

Available in clear and coloured tints.

Rub the oil into the wood with a cloth

in direction of grain. Not a very

hardwearing finish but regular

application and additional coats build

up a matt, water-resistant finish.

Task- Finishing wood

1. State 4 purposes for finishing wood.

2. Explain 2 ways that natural wood can decay.

3. Why is surface preparation essential prior to finishing?

4. Present information of the 6 different types of finishes. This work could be a visual piece of

work, such as a poster, or simple power point slides of research. Your work should include

information about each finish, examples of where it is used and images / sketches to support

the information.

Task 10- properties of

materials

Material properties and classification

There are two principle categories of material properties: Mechanical and

physical.

Mechanical properties are associated with how a material reacts to an

external force

Physical properties are associated with the actual make-up or structure of

the material

Mechanical properties of materials:

Compressive strength-ability to withstand being crushed.

Tensile strength- ability to resist stretching

Bending strength- ability to resist forces that bend the material

Shear strength- ability to resist sliding forces on a parallel plane

Torsional strength hardness- ability to withstand twisting forces

Hardness- ability to resist abrasive wear such as scratching

Toughness- ability to absorb impact force without fracture.

Plasticity- ability to be permanently deformed (shaped), and retai8n the

deformed shape

Ductility- ability to be drawn out under tension, reducing the cross sectional

area without cracking.

Malleability- ability to withstand deformation by compression without

cracking.

Elasticity- ability to be deformed and then return to the original shape when

the force is removed.

Physical properties of materials:

Electrical properties.

Electrical conductor- allows flow of electricity

Electrical insulator- does not allow the flow of electricity through the

material

Thermal properties

Thermal conductor- allows the transfer of heat energy through the

material. High thermal conductivity allows transfer of heat to occur

quickly across the material.

Thermal insulator- prevents the transfer of heat through the material

Thermal expansion- the increase in material volume to a heat input

Optical properties

Opaque- prevents light from travelled through

Translucent- allows light through but diffuses the light so that objects

appear blurred. Frosted glass is an example.

Transparent- allows light to pass through easily which means you can see

clearly through the material.

Density- the mass of the material in and standard volume of space.

Fusibility- ability of the material to be fused or converted from a solid to a

liquid or molten state, usually by heat. Good fusibility is an essential property

for a metal being cast.

Magnetism- the natural force between objects that causes the material to

attract iron or steels.

Corrosion / degradation resistance- ability of the material to withstand

environmental attach and decay.

Task

1. Define the 2 principle categories of

material properties.

2. List the mechanical properties of a

material- give examples.

3. List the physical properties of a material-

give examples.

4. Above is a stainless steel sink. Give three

physical and three mechanical properties

of the metal used for the kitchen sink. In

each case, state why the property is

suitable for this product.

Task 11- Product Analysis

exam question

Product analysis- outdoor products- Plastic V Hardwoods.

Compare the two types of chairs below, one plastic, one wooden. Evaluate their suitability for long term

use in an outdoor environment [10 marks].

Task

1. Use your revision guide (‘Pocket Posters’- the book you also have access to a digital version of) to

plan content for an answer to the above question. If you have left the book at school, use the

internet to help you with this (where available). You should spend a maximum of 30 minutes

planning this.

1. Think about how you will evaluate their suitability for long term outdoor use. Consider

advantages and disadvantages of each, and remember to draw conclusions.

2. You should consider materials, sources of materials, finishes, use and recyclability (and more)

in your answer

2. Once planned, write / type the answer in essay form. You should spend 20 minutes maximum writing

this.

WARNING- ANSWERS / THINGS TO MENTION ARE ON THE NEXT SLIDE. ONLY LOOK AT THEM ONCE YOU

HAVE COMPLETED THIS TASK. THIS IS SO YOU CAN CHECK YOUR ANSWERS.

Product analysis- outdoor products- Plastic V Hardwoods.

Compare the two types of chairs below. Evaluate their suitability for long term use in an outdoor

environment [10 marks].

Polymer chair Hardwood chair

Manufactured by one piece redistribution Contain oils which prevent decay

Self-finish material, requiring no additional processing

which may peel or chip

Polyurethane waterproof varnish

UV stabilisers can be added to prevent colour

degradation and increased brittleness.

Microporous finish can be added

Colour all through the plastic- makes scratches less

obvious

Finish has to be reapplied on a regular basis.

Not affected by frost, moisture, fungal or insect attack-

non porous

Timber could be pressure treated with chemical preservatives,

increasing longevity

Light weight material, easier to store / move Wood preservatives can have a combined stain or colour to

improve aesthetics

Susceptible to insect attack.

Task 12- Product Analysis task

using mnemonics - free choice of

product

Being able to analyse and evaluate existing products in detail is key- for both the NEA and

the exam.

1. Choose a product of your choice to analyse- this could be a football boot/ toaster/

remote control/ anything.

2. Produce a detailed analysis of the product using the Mnemonics on the following slide.

Try to address each Mnemonic bullet point in detail- this will pay dividends in the

exam.

If you are unsure of a Mnemonic on the list, use the internet to read around /

research it.

If possible, disassemble / take apart to aid your analysis / include photos

Suggest possible modifications / changes that could be made to improve the

product

3. Prepare a presentation for the analysis:

Use paper or any software to produce the presentation i.e. PPT/ Publisher/ Adobe

InDesign

Presentation / layout of your work should be suitable for hand outs-

comprehensive, yet easy to follow

Product Analysis / Disassembly

Task 13 – Product Analysis

exam question

Philippe Starck

French designer who has famously worked on kitchenware for Alessi. (Alessi is a

housewares and kitchen utensil company in Italy, producing everyday items from plastic

and metal, created by famous designers).

Some of his designs can be regarded as postmodern sculptural pieces, focussing on

aesthetics before function.

However, his work in architecture and interior design is aimed at ‘democratic design’ for

the population rather than the elite.

Starck challenges perceptions and aims to enhance the experience of the user through

playful and thought-provoking design.

His desire to experiment with modern materials and manufacturing processes make him a

highly influential designer.

Very high centre of gravity and becomes

unstable during juicing.

The head of the juicer is large

enough for a lemon, but when

juicing an orange, much of the

fruit is missed due to the small

diameter.

The tripod legs exit the body of the

juicer at an angle to prevent juice

running down the legs. This also

widens the base of the juicer to

increase stability and allow a glass to

be place under the juicer.

The form of the product is striking and lends itself

to being displayed in a kitchen, rather than stored in

a drawer as with most juicers.

Juicy Salif- Designed by Starck for Alessi in 1990

Cast aluminium with

polished finish.

TASK

Look at the polypropylene juicer below:

1. Use the internet (where available) to Plan

and write an answer to following

question:

“For each lemon juicer, compare the

materials used and their suitability.” [10

marks].