Edexcel Resistant Materials

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Unit 2 Knowledge and Understanding of Resistant Materials• Technology 24

– Topic 1 Materials and components 25• Topic 1.1 Woods 25• Topic 1.2 Metals 26• Topic 1.3 Polymers 27• Topic 1.4 Composites 27• Topic 1.5 Modern and smart materials 28

– Topic 2 Tools and equipment 28• Topic 2.1 Marking out and measuring 28• Topic 2.2 Wasting 29

– Topic 3 Industrial and commercial processes 29• Topic 3.1 Scale of production 29• Topic 3.2 Materials processing and forming 30• Topic 3.3 Joining methods 30• Topic 3.4 Adhesives 31• Topic 3.5 Heat treatment 31• Topic 3.6 Finishing techniques 32• Topic 3.7 Manufacturing processes for batch production 32• Topic 3.8 Health and safety 32

• Topic 4 Analysing products 33• Topic 4.1 Specification criteria 33• Topic 4.2 Materials and components 33• Topic 4.3 Manufacturing processes 34

• Topic 5 Designing products 34• Topic 5.1 Specification criteria 34• Topic 5.2 Designing skills 35• Topic 5.3 Application of knowledge and understanding 35

• Topic 6 Technology 35• Topic 6.1 Information and communication technology (ICT) 35• Topic 6.2 Digital media and new technology 36• Topic 6.3 Computer-aided design/computer-aided manufacturing• (CAD/CAM) technology 36

• Topic 7: Sustainability 36• Topic 7.1 Minimising waste production 36• Topic 7.2 Renewable sources of energy 37• Topic 7.3 Climate change 37

• Topic 8 Ethical design and manufacture 37• Topic 8.1 Moral, social and cultural issues

Natural Woods

OakDescription•A very strong, light-brown wood•Open grained•Very hard, but quite easy to work with

Uses•High quality furniture•Beams used in buildings•Veneers

Description•Reddish-brown in colour•Easy to work with

Uses•Indoor furniture•Shop fittings•Bars•Veneers

Mahogany

Description•A straight- grained hardwood with a fine texture•Light in colour•Very hard but easy to work with•Can be steam bent

Uses•Furniture•Toys•Tool handlesBeech

Description•Open grained•Easy to work with•Pale cream colour, often stained black•Can be laminated (i.e. sliced into veneers which are glued together)

Uses•Tool handles•Sports equipment•Furniture•Ladders•Veneers

Ash

PineDescription•Pale-yellow coloured with dark lines and a fine, even texture.•Medium in weight•Stiff and stable•Inexpensive

Uses•Readily available for DIY work•Mainly used for constructional work and simple joinery•Furniture

Natural Woods

Medium density fibreboard (MDF)

Description•Has a smooth, even surface•Easily machined and painted•Available in water and fire-resistant form•Often veneered or painted to improve its appearance

Uses•Furniture and interior panelling

PlywoodDescription•A very strong board, constructed of layers of veneer or piles, which are glued together with the grains at 90° to each other•Interior and exterior grades available.

Uses•Furniture making•Boat building and exterior work

Description•Made from chips of wood glued together with urea formaldehyde (glue)•Usually veneered with an attractive hardwood or covered in plastic laminate

Uses•Kitchen and bedroom furniture•Shelving and general DIY WorkChipboard

Description•A very cheap particle board•Can have a laminated plastic surface

Uses•Kitchen unit and furniture back panelsHardboard

Man-Made Woods

AcrylicProperties:• Hard wearing • Will not shatter• Can be coloured• Bathtubs, School

Projects, Display signs

Polypropylene

Properties:•High Impact strength•Softens at 150°C•Can be Flexed many times without breaking•School chairs, Crates

Properties:•Light but strong•Widely available in sheets•Used for casings of electronic products

High Impact Polystyrene (HIPS)

Plastics

Polythene (LDPE)

Properties:• Weaker and softer

than HPDE.• Lightweight• Carrier Bags +

Squeezy Bottles

Polythene (HDPE)

Properties:•Stiff strong plastic•Used for pipes and bowls•Buckets

Properties:•Colourless plastic•Can be coloured•Door and cupboard handles, Electrical fittings

Urea formaldehyde

Plastics

AluminiumProperties:

•Light Weight•Light grey in colour•Can be polished to a mirror like appearance•Rust resistant

Mild Steel

Properties:•Heavy•Dark grey in colour•Rusts very quickly if exposed

Stainless Steel

Properties:•Heavy•Shiny appearance•Very resistant to wear / rust.

Metals

Cast IronProperties:•Re melted pig iron with some quantities of other metals•Strong in compression.•Brittle

CopperProperties:•Reddish brown metal.•Soft•Excellent conductor of heat and electricity

BrassProperties:•Yellow metal•Hard•Alloy

Metals

Composites – Carbon Fibre• Carbon Fibre is sometimes referred to as Carbon Fibre Reinforced Plastic is similar

to fibre glass. Carbon fibre is woven into a textile material and resin such as epoxy resin is applied and allowed to cure. The resulting material that is very strong as it has the best strength to weight ration of all construction materials. It is an improvement on glass fibre reinforced plastic, although much more expensive.

• Carbon Fibre Reinforced Polymers tend to be used in the manufacture of expensive sports cars, where strong and light materials are required. Expensive, competition bicycles and motorbikes tend to have CFRP frames, forks, handlebars to keep weight to a minimum and yet retain great strength. The aerospace industry has embraced the use of CFRP in the manufacture of planes.

Eurofighter has a large proportion of its airframe manufactured from Carbon Fibre Reinforced Plastic.

FIBREGLASS / GLASS REINFORCED PLASTIC (GRP)

• Fibreglass is an excellent example of a relatively modern composite material. In industry it is often referred to as Glass Reinforced Plastic (GRP).

GRP is composed of strands of glass. Each individual glass fibre is very fine with a small diameter, and they are woven to form a flexible fabric. The fabric is normally placed in a mould, for instance a mould for a canoe and polyester resin is added, followed by a catalyst. The process is repeated so that there are many layers of fibre glass and resin and allowed to dry/cure. The resulting material is strong and light. Glass Reinforced Plastic can be sanded for a smooth finish and painted.

• Glass reinforced plastic is lightweight and has good thermal insulation properties. It has a high strength to weight ratio, making it useful for the production of products such as water tanks, surfboards, canoes, small boat hulls and similar products.

Material Properties

Strength The ability of a material to stand up to forces being applied without it bending, breaking, shattering or deforming in any way.

Our technology technician (Ed) demonstrates the ‘strength’ of a material by performing a hand stand on a strong piece of timber (wood). It does not bend even under his weight. He has eaten pies and drunk a large amount of beer for twenty years and yet the strong material does not bend, flex or deform (change shape) in any way.

ElasticityThe ability of a material to absorb force and flex in different directions, returning to its original position.

Our technology technician demonstrates the ‘elasticity’ of a material by springing up and down on a piece of steel rod. Do not try this at home as an accident may result. Ed our technician is an expert at demonstrating this property as it is his hobby.

Material Properties 2

DuctilityThe ability of a material to change shape (deform) usually by stretching along its length.

Our technician stretches the lead above his head. As it stretches if deforms (changes shape).

Ed thinks he is a strong man, little does he realise that lead is a very soft metal and stretches very easily. He performs these tricks in local pubs in an attempt to pass himself off as a ‘hard man’.

MalleabilityThe ability of a material to be reshaped in all directions without cracking

Our technology technician demonstrates the ‘malleability’ of a material by heating a piece of mild steel until it is red hot. He then beats it with a large forging hammer to reshape it. Because of the high temperature it reaches while heating the steel becomes malleable, it can be reshaped permanently.

Ed often heats up steel, because he likes the colour and it matches his complexion after he has run up the stairs.

Material Properties 3

Hardness The ability of a material to resist scratching, wear and tear and indentation.

Our technology technician, dressed in a kilt, slides along the floor to see if it will scratch. It will be considered to hard wearing if it resists scratching.

Ed has been known to fall over. Not a sight for sore eyes.

ToughnessA characteristic of a material that does not break or shatter when receiving a blow or under a sudden shock.

Our technology technician demonstrates the ‘toughness’ of a material by hitting a piece or material to see if it will break or shatter.

Ed has been known to test authentic Chinese Ming Dynasty pottery with the same technique. This is why he is often arrested in Museums and has been banned from the local Antique dealers.

Shape memory alloys (SMA)SMA wire is sometimes called ‘Nitinol’, as it is a composed of nickel and titanium. On first site this special wire looks like ordinary wire and even has many of the same properties. It can be folded to form complex shapes quite easily and it conducts electricity. However, it is very expensive when compared to ordinary steel or even copper wire. However, it has properties that make it very special:

The wire has a memory - for example, if it is folded to form a shape and thenheated above 90 degrees (centigrade) it returns to its original shape.

Modern & Smart Materials 1

Photochromic paintPhotochromic paint darkens, as the light level increases. Some photochromic paints change colour. In fact, it is UV light (Sun Light) that causes the darkening of the ink, which means the ink works best in natural light. This special paint has two main applications; sunglasses and spectacles. However, it is also used in novelty items such as embroidery thread and toys, where colour change takes place according to light level. Nail lacquer / varnish is also available with photochromic technology.

Changing Lens Glasses / Transition LensesThe tint of a photochromic lens changes according to the intensity of natural light (UV light). Inside a building, the lenses remain clear but they darken when outside in sunlight. Spectacles with this type of lens are comfortable to wear, in all conditions. However, they are more expensive than spectacles with normal, clear lenses.

Modern & Smart Materials 2

Novelty Teddy Bear

The teddy bear seen opposite is an example of a novelty toy. The sunglasses and ribbon change colour when exposed to natural light (sun light). The ribbon on the bowler hat, also changes colour.

d30d3o™ Intelligent Shock Absorption™ is a patented, shock absorbing material, engineered with Intelligent Molecules. d3o™ is rate-sensitive meaning that when moved slowly, the molecules flow freely making it soft and flexible. At high speeds however like in an impact the molecules lock together making the material an excellent shock absorber. The whole process is repeatable, occurs instantly and returns to its original state as soon as the impact is over.

d3o™ is also extremely low profile and integrates seamlessly into garments, so neither style or function has to be compromised. These qualities make it perfect for any application where you need total freedom of movement and excellent shock absorption.

Modern & Smart Materials 3

Marking Out and Measuring 1Micrometer

Although the micrometer provides a very accurate measurement, it can be difficult to learn how to read it.

Centre PunchCentre punches are used to make an indent in the surface where holes are to be drilled in metal. They provide a starting point for the drill and stop it skidding over the surface.

TemplatesA template is used when a number of identical shapes or patterns need to be marked out. You can make a template from any thin material, such as plywood or aluminium, that is easy to draw around.

ScribersA scriber is used to scratch the surface of metal and plastic lightly.

Rules

Marking Out and Measuring 2SquaresThere are a number of squares:•Try square•Engineer’s square•Mitre square

Take great care when using any form of square for marking out orchecking, and ensure that it is being held firmly and tightly against thesurfaces or edges of the material.

Marking Out and Measuring 3Gauges There are three basic types of gauge:

•Marking gauge - is used for marking lines parallel to the face edge and side on wood

•Mortise gauge - It is used for marking two parallel lines where a mortise and tenon joint is to be cut. It has two pins; one pin is fixed and the other is adjustable.

•Cutting gauge - is used for cutting across the grain. It is used in the same way as a marking gauge

SawsSaws are used to cut material that is not neededaway from material which is.

Saw blades have alternate teeth bent out or ‘set’ inopposite directions.

When using a saw, youshould always cut to thewaste side of the markedline so that you leave a small amount for finishing by either sanding or filing.

Wasting Tools - Saws

PlanesPlanes are used to smooth wood flat and to reduce to size. A jack smoothing plane, which is used for finishing and planing end grain because it is easier to handle than a jack plane. A block plane is the smallest plane and is generally used for removing sharp edges and for putting a small bevel along an edge.

Wasting Tools - Planes

chiselsfilesdrillsabrading tools.

Wood ChiselsFour basic wood chisels are used in the school workshop:• the firmer chisel is a general-purpose chisel, which has a square• edge• a bevel-edge chisel has a bevelled blade that allows it to get into corners and is

especially useful for cutting dovetails• mortise chisels have much deeper blades and are used with a mallet for cutting

mortise joints• gouges have curved blades and are used for carving.

Wasting Tools - Chisels

filesdrillsabrading tools.

Metal ChiselsCold chisels can be used to cut sheet metal, either by shearing acrossit or by chopping down on it vertically. They have a hardened andtempered cutting edge while the other end is left soft to absorbthe impact from the hammer blows. Different profiles are available,allowing access to corners or for producing grooves in the workpiece

Wasting Tools – Abrading Tools

filesdrillsabrading tools.

Abrading toolsAbrading tools remove very small particles of waste, such as those produced by filing. Abrading tools include rasps, which are used on wood, and surforms. Surforms have replaceable blades. They are formed and operate a bit like a cheese grater.

Abrasive papers are also available for wood, metal and plastics. Glasspaper, sometimes called sandpaper, is used on wood.

Emery cloth is used on metals and plastics.

Any form of abrasive paper is best used wrapped around a cork block. This ensures that an even pressure is applied over the work.

Wasting Tools – Files

drillsabrading tools.

FilesTwo basic filing processes are used in the workshop:

Cross-filing - Cross-filing removes waste rapidly. You should use the whole length of the file with a downwards force. The file only cuts forwards. It should be lifted off at the end of the stroke and not dragged back across the workpiece.

Draw-filing -Draw-filing removes marks in the work left as a result of cross-filing. This method gives a much better surface finish, and a smoother file should always be used for draw-filing.

General work is carried out with a flat file. One of the long edges has teeth; the other is plain and is known as a safe edge. The safe edge prevents cutting into the face of a square corner. Files with different profiles are available for a range of applications. There are also other, more specialist forms of file

Wasting Tools – DrillsDrillsTwist drills, the most common type of drill used in school workshops, can create holes in most materials.There are many other forms of drill, each with its own specific use and application. The most common types used in school workshops are shown below.

One off production - This is when only one product is made at a particular time. This one off product could be a prototype a one off object or a hand made object. Prototypes are made to see if a product works before it goes into large scale production. One off production takes a long time and often means it is expensive. A classic product could be a mobile phone prototype, a one off specialist product, handmade items, etc.

Batch production - This is when a series of products which are all identical are made jointly in either large or small numbers. Once these have products have been made once more of the same products may be made using the same equipment. This equipment includes tools, moulds, machinery and labour. A classic product could be a chair, newspapers, books, electrical products, etc.

Mass production - Mass production involves the product going through many stages of a production line. There are workers and machines at certain stages along the line that are responsible for making certain parts of the product. This means the product is often made over days or even weeks depending how complicated it is. This product is often quite reasonably priced due to the large scale production techniques used. However if a problem occurs it will stop the whole line of production. A classic product could be a car.

Continuous production - This is where a product is continuously produced over a period of hours, days, weeks or even years. This kind of production means the product will often be quite reasonably priced. A classic product could be screws, bricks, food products, etc

Just in time production - Just in time production means just that. This involves the arrival of parts at just the exact time that they are required in the factory. This means that less storage space is needed at the factory, so saving space at the factory. If the flow of parts is stopped or is late the line will stop and this production technique could then become very costly.

Production Methods

Materials Processing & Forming – Sand CastingThere are six steps in this process:

1. Place a pattern in sand to create a mold.2. Incorporate the pattern and sand in a gating system.3. Remove the pattern.4. Fill the mold cavity with molten metal.5. Allow the metal to cool.6. Break away the sand mold and remove the casting.

Materials Processing & Forming – Drilling

Materials Processing & Forming – Turning

Blow moulding a shape is a common industrial process. The example shown below is of the production of a plastic bottle. The plastics normally used in this process are; polythene, PVC and polypropylene.

The process is similar to injection moulding and extrusion:

1. The plastic is fed in granular form into a 'hopper' that stores it. 2. A large thread is turned by a motor which feeds the granules through a heated section. 3. In this heated section the granules melt and become a liquid and the liquid is fed into a mould. 4. Air is forced into the mould which forces the plastic to the sides, giving the shape of the bottle.5. The mould is then cooled and is removed.

Materials Processing & Forming – Blow Moulding

Materials such as polystyrene, nylon, polypropylene and polythene can be used in a process called injection moulding. These are thermoplastics - this means when they are heated and then pressured in a mould they can be formed into different shapes.

The DVD Storage unit seen opposite has been made in one piece using this process

An animation of an injection moulding machine is shown below. The product being produced is the DVD / CD storage unit seen opposite.

Materials Processing & Forming – Injection Moulding

Materials Processing & Forming – Vacuum Forming

Vacuum forming is a technique that is used to shape a variety of plastics. In school it is used to form/shape thin plastic, usually plastics such as; polythene and perspex. Vacuum forming is used when an unusual shape like a ‘dish’ or a box-like shape is needed. Below you can see the stages involved in vacuum forming.

Below is an example of a vacuum formed toy. The simple 'lorry' mould has been placed in a vacuum former and a compressed polystyrene sheet has been placed above it. The polystyrene has been heated and then vacuum formed to the shape of the mould.

Many everyday items have been vacuum formed in this way. Look around your home - list some examples. as a guide - some food products are packaged in vacuum formed materials.

Materials Processing & Forming – Vacuum Forming

Materials such as polystyrene, nylon, polypropylene and polythene can be used in a process called extrusion. These are thermoplastics - this means when they are heated and then pressured in a mould they can be formed into different shapes and sections.

A machine used to extrude materials is very similar to the injection moulding machine. A motor turns a thread which feeds granules of plastic through a heater. The granules melt into a liquid which is forced through a die, forming a long 'tube like' shape. The extrusion is then cooled and forms a solid shape. The shape of the die determines the shape of the tube.

Materials Processing & Forming – Extrusion

• Topic 3.3 Joining methods• What students need to learn• Characteristics, recognition, preparation, processes, application and• advantages/disadvantages of using the following temporary and• permanent methods when joining materials and components:• Temporary

– tapping and threading– nuts, bolts and washers– screws– knock down fittings

• Permanent– nails– halving joint– butt joint– rebate joint– housing joint– mortise and tenon joint dowel joint– soft soldering– brazing– welding– rivets — snap and pop.

PVAUsed for:

Gluing Wood

Tensol Cement

Used for:

Gluing Plastic

Epoxy resin / Araldite

Used for:

Gluing Plastic / Wood / Metal /

Ceramic

Contact Adhesive

Used for:

Gluing Plastic / Wood / Metal /

Ceramic

• Topic 3.5 Heat treatment• What students need to learn• Characteristics, preparation, processes, application and

advantages/• disadvantages of using the following heat treatments

when altering the• properties of metals:• hardening and tempering• annealing• case hardening.

• Topic 3.6 Finishing techniques• What students need to learn• Processes, application and advantages/disadvantages of applying the• following finishes to improve the performance, quality and appearance

of• manufactured products:• varnish• wax polish• stain• paint• plastic dip-coating• electroplating.

• Topic 3.7 Manufacturing processes for batch production

• What students need to learn• Preparation, application and

advantages/disadvantages of the following• when manufacturing products and components:• jigs• patterns.

• Topic 3.8 Health and safety• What students need to learn• How to understand/describe safe working

practices.• How to identify workshop hazards and

precautions.

• Topic 4 Analysing products• Topic 4.1 Specification criteria• What students need to learn• When analysing a product, students should take into account the• following specification criteria:• form — Why is the product shaped/styled as it is?• function — What is the purpose of the product?• user requirements — What qualities make the product attractive to• potential users?• performance requirements — What are the technical considerations• that must be achieved within the product?• material and component requirements — How should materials and• components perform within the product?• scale of production and cost — How does the design allow for scale of• production and what are the considerations in determining cost?• sustainability — How does the design allow for environmental• considerations?

• Topic 4.2 Materials and components• What students need to learn• Students should identify the materials and/or components used

in the• manufacture of a product, including:• the properties and qualities of the materials and/or components• the advantages/disadvantages of the materials and/or

components• justification of the choice of materials and/or components.• Note: materials and components are those referenced in Topic 1.

• Topic 4.3 Manufacturing processes• What students need to learn• Students should identify the processes involved in

the manufacture of• products, including:• the stages of the manufacturing process• the advantages/disadvantages of the

manufacturing process• justification of the choice of manufacturing process.

• Topic 5 Designing products• Topic 5.1 Specification criteria• What students need to learn• When designing a product, students should take into account the• following specification criteria:• form — How should the product be shaped/styled?• function — What is the purpose of the product?• user requirements — What qualities would make the product attractive• to potential users?• performance requirements — What are the technical considerations• that must be achieved within the product?• material and component requirements — How should materials and• components perform within the product?• scale of production and cost — How will the design allow for scale of• production and what are the considerations in determining cost?• sustainability — How will the design allow for environmental• considerations?

• Topic 5.2 Designing skills• What students need to learn• When designing a product, students should be able

to respond creatively• to design briefs and specification criteria, including:• clear communication of design intentions using

notes and/or sketches• annotation which relates to the original

specification criteria.

• Topic 5.3 Application of knowledge and understanding• What students need to learn• When designing a product, students should be able to apply their• knowledge and understanding of a wide range of materials and/or• components and manufacturing processes to each design idea,

including:• the properties of materials and/or components• the advantages/disadvantages of materials and/or components and• manufacturing processes• justification of the choice of materials and/or components and• manufacturing processes.

Topic 6Information and Communication

Technology

Electronic communications between designers, manufacturers, retailers and consumers using email

Advantages:- Quick delivery and reply of messages- Convenient- Can contact a group of people at once- No limit on how short or how long the message should be (it would seem ridiculous to send a one line letter to someone in the post, but on email this is acceptable)- Can attach large documents and other files with a click of a button (and without using up resources like paper)- Doesn't use any paper (good for the environment)

Disadvantages:- Less social contact with people (social relationships won't be as well developed)- Messages may be misinterpreted easily- Can be easy to make a "typo" and say the wrong thing, or send the email to the wrong person- Access to a computer and the internet is necessary, and this may not be convenient for all people

• The use of bar-coded products that are scanned at the point of sale.

• The sale of the item can be registered with the shop, the distributors and the warehouses etc.

• These items can then be electronically re-ordered from the supplier.

Electronic Point of Sale in Retail (EPOS)

Internet Marketing•Display advertising: the use of web banners or banner ads placed on another companies website or blog to make people click on it to go to their own website

•Search engine marketing: a form of marketing that promotes websites by increasing their visibility in search engine result pages by paying or through the use of free search engine optimization techniques.

•Search engine optimization: the process of improving the visibility of a website or a web page in search engines for free.

•Social media marketing: Putting adverts on social media websites such as Facebook, Twitter and LinkedIn.

•Email marketing: directly messages to a group of people using e-mail.

Internet SalesAdvantages of Internet Sales• Cheap set-up and operational costs. You don't need to rent high street premises,

pay shop assistants or answer a lot of pre-sales queries.

• Reaching a global audience, thereby increasing sales opportunities.

• Competing with larger businesses by being able to open 24 hours a day, seven days a week.

• Less order processing costs - customer orders can automatically come straight into your orders database from the website.

• Improving your offerings using the data gathered by tracking customer purchases.

• Using your online shop as a catalogue for existing customers.

Video conferencing means using computers to provide a video-link between two or more people. Instead of just talking to someone by telephone, you are able to see them as well.

Advantages• Meetings can take place without

leaving the office.• Travel costs and the time taken to

travel can be reduced significantly.

• Meetings can be called instantly worldwide with little notice.

• People can still attend meetings even if they are physically unable to.

• Can easily show prototypes of products

Disadvantages• May not be as productive as a

discussion around a table.• Confidential documents may

need to be viewed and signed in person.

• There will always be times when you need to be able to meet face to face.

Video Conferencing

• Involves using computers to generate either 2D line drawings or 3D, photo-realistic, colour rendered drawings.

• Product Designers use CAD software to speed up the design process.

CAD – Computer Aided Design

• Allows designers the opportunity to see and manipulate their designs in photo-realistic, 3D environment.

• It is very useful when talking to clients who can visualise the products in place

• At Jaguar cars, designers and production engineers use VR systems to plan how production cells work. The layout of the work cells, the interaction of employees and operation together.

• They can also sequence an assembly operation in VR to ensure it works correctly.

• This makes HUGE cost savings for the company and helps to reduce the lead-time of the new models.

Virtual Reality Modelling (VR)

• The use of CNC machines that create 3D objects.

• Three dimensional CAD drawings can be downloaded to a machine that will make a prototype model of a design. There are many different Rapid Prototyping machines available. The common types are:

• Layered object modelling (LOM): this is similar to a plotter/cutter which would cut the design layer by layer in thin card of self adhesive film. The layers are then assembled like a 3D jigsaw.

• Fused deposition modelling (FDM): this is similar to a glue gun. A nozzle extrudes molten plastic and builds up the design layer by layer as it solidifies. Plastics such as ABS are often used.

• Stereo-lithographic modelling (SLM): this works by using a bath of liquid resin, which uses lasers to solidify the plastic in the shape of the design.

Rapid Prototyping

Rapid PrototypingSpeed

A model can be designed on the computer and With rapid prototyping, the same model parts can be made within hours.

Time to MarketThe faster a prototype is created, the quicker designers and engineers can check it for any problems and then get ready for full scale manufacture

Cost Savings/ReductionThere are no set up costs for tooling to make the model, just the initial cost of the machine which are now available for as little as 20 Grand. (This is not a lot or money for design companies.

The machine can be used over and over again to build a variety of different parts within their build size.

Rapid Prototyping Video

Laser CuttingADVANTAGES

· Quick production of prototypes (models)

· Can cut paper, card, acrylic, polypropylene sheet, textiles

· Quick & easy to set up

DISADVANTAGES

· Can’t cut plastics containing polystyrene (gives off dangerous fumes)

· Can’t be aligned with pre printed NETS

CNC – Computer Numerical ControlCNC Computer Numerical Control machines are widely used in manufacturing industry. Traditional machines such as vertical millers, centre lathes, shaping machines, routers etc.... operated by a trained engineer have, in many cases, been replaced by computer control machines.

Disadvantages1. CNC machines are more expensive than

manually operated machines.2. Less workers are required to operate CNC

machines compared to manually operated machines. Investment in CNC machines can lead to unemployment.

Advantages1. CNC machines can be used continuously 24 hours a day,

365 days a year 2. CNC machines are programmed with a design which can

then be manufactured hundreds or even thousands of times.

3. Less skilled/trained people can operate CNCs 4. CNC machines can be updated by improving the software 5. CNC machines can make products that cannot be made

by manual machines.6. Modern design software allows the designer to simulate

the manufacture of his/her idea. There is no need to make a prototype or a model. This saves time and money.

7. One person can supervise many CNC machines at a time.8. A CNC machine will manufacture each component as an

exact match.

• Topic 7 Sustainability• Topic 7.1 Minimising waste production• What students need to learn• Principles, application, advantages/disadvantages to society and the• environment of minimising waste production throughout the

product life• cycle using the following 4 Rs:• reduce materials and energy• reuse materials and products where applicable• recover energy from waste• recycle materials and products or use recycled materials.

• Topic 7.2 Renewable sources of energy• What students need to learn• The characteristics, applications and

advantages/disadvantages of using• the following renewable sources of energy:• wind energy using turbines and wind farms• solar energy using solar cells and photovoltaic cells• biomass converted into biofuels for transportation.

• Topic 7.3 Climate change• What students need to learn• The responsibilities of ‘developed’ countries in

minimising the impact of• industrialisation on global warming and

climate change including:• • reducing greenhouse gas emissions through

the Kyoto Protocol.

• Topic 8 Ethical design and manufacture• Topic 8.1 Moral, social and cultural issues• What students need to learn• The strategy, characteristics, applications and

advantages/disadvantages• of the following value issues when designing and manufacturing• products:• built-in obsolescence in new products for a ‘throwaway’ culture• offshore manufacture of mass-produced products in developing• countries by multinational companies• tolerance of different cultures to avoid offence.