Core content Flashcards
What is a design breif?
This is a statement thats explains what you will design and make to meet the design context, and will meet the needs of the intended user.
What is a design specification?
This is a list of detailed points that will be constantly referred to when developing your designs and making your prototype. They include quantitative and qualitative points to which the design ideas and finished prototype can be compared to.
What is a rational design?
The logical way to solving decision problems.
What is an intuitive design?
The decision making done mentally, without calculations, systems and methods supported.
What are advantages of renewable energy (non-finite) ?
- it will never run out
- renewable energy facilities usually require less maintenance
- little to no CO2 emissions or other chemical pollutants
What are disadvantages of renewable energy (non-finite) ?
- it can be difficult to generate the large quantities of electricity
- renewable energy often relies on the weather
- it cannot be stored and used later
- it’s more expensive than fossil fuels
Wind energy
turbines driven by blades that catch the wind
Hydro energy
Dams are built to trap water. Stored water is released to turn turbines and generate power
Solar PV energy
Photovoltaic cells convert the sun’s energy directly into electricity
Wave energy
Kinetic energy from the waves forces air up a cylinder to turn the turbine and generate power
Tidal barrage energy
As the tide comes in and goes out, the water movement turns turbines which generate power
Geothermal energy
Natural heat from the earth heats up water to produce steam. The steam spins a turbine and generates electricity.
Biomass energy
Organic matter such as wood and dried up vegetation are burned to heat water and produce steam. The steam turns the generator to produce power
How can a manufacturer reduce their product miles and CO2 emissions?
- they can get rid of the middle man and deliver products straight from them to the consumer
- they can reduce the amount of waste produced
- they can increase the amount of recycled material used
What does product miles mean?
It is the total lifetime distance that a product is transported fro its place of production to the place of use by the consumer
What is built-in obsolescence?
Planned obsolescence is when a product is deliberately designed to have a specific life span. This is usually a shortened life span.
Why are some products designed with built-in obsolescence?
To encourage consumers to purchase the upgraded and new version of the product, increasing demand
Why is built-in obsolescence bad?
- It’s bad for the environment as more products are being thrown out
- more natural resources are being used which means they can run out
What is job production?
Manufacturers produce one product at a time as ordered by the customer
Advantages of job production
- high quality product
- motivated and highly skilled workers
- custom products can be customised
Disadvantages of job production
- production is slow
- high labour costs
- material can be expensive
What is batch production?
Groups of the same product are produced as a batch
Advantages of batch production
- workers can specialise
- production can take place as the previous ‘batch’ starts to run out
Disadvantages of batch production
- requires careful coordination to avoid shortages
- money is tied up in stock
- completed products need to be stored
What is flow production?
Continuous manufacturing of standardised products, usually on a production line
Advantages of flow production
- can exploit economies of scale
- capital intensive
Disadvantages of flow production
- customisation is difficult
- capital equipment can be expensive to purchase
What is ergonomics?
it considers how the product will be interacted with and how the design will assist the ease of use for the client
What is anthropometric data?
its the use of scientific measurements of the human body in the design and construction of a product
Kinetic energy store
The energy of a moving object.
Potential energy store
The energy stored in an object
Thermal energy store
The energy contained within a system that is responsible for its temperature
Electrical energy store
The power an atom’s charged particles have to cause an action or move an object.
Chemical energy store
Energy stored in the bonds of atoms and molecules.
What is an electrical system?
An electronic system is a series of parts or components that control a task or activity
What is a subsystem?
Subsystems or subtasks are events or tasks that happen within a system
What is an open loop system?
An open loop systems doesn’t make
decisions based on feedback
What is a closed loop system?
A closed loop system uses feedback to make a decision
What does CAD stand for?
computer aided design
What does CAM stand for?
computer aided manufacture
What are the advantages of CAD?
- CAD speeds up the product design and development process
- designers can easily work collaboratively
- it is easy to modify
What are the disadvantages of CAD?
- initial set up costs can be high
- software can lag
- the designers need to learn how to use it (training costs)
Hardness
the ability to resist abrasive wear such as scratching or indentation
Ductility
the ability to be stretched without cracking
Toughness
the ability to absorb impact force without fracture
Elasticity
the ability to be deformed then return to its original shape when the force is removed
Compressive strength
the ability to withstand being crushed or shortened
Tensile strength
the ability to withstand stretching or pulling forces
Shear strength
the ability to resist sliding forces on a parallel plane
Torsional strength
the ability to withstand twisting forces
Plasticity
the ability to be permanently deformed
Malleability
the ability to withstand deformation by compression without cracking
Electrical conductor
it allows the flow of electrical current through the material
Corrosion resistance
the ability of the material to withstand environmental attack and decay
What is non-destructive testing?
it is testing that is usually carried out on products such as large castings where there is a likelihood of an internal defect which wouldn’t de detected by other methods
What are examples of non-destructive testing?
- ultrasonic testing
- x-ray testing
- electrical and thermal conductivity
What is destructive testing?
Destructive testing aims to deform or destroy a material to analyze its point of failure.
What are examples of destructive testing?
- corrosion testing
- fracture testing
- aggressive environmental testing
- fatigue testing
- residual strength
- tensile testing
What are disadvantages of destructive testing?
- there is a waste of material
- can be expensive
- time consuming
What is a ferrous metal?
a metal containing mostly iron and carbon, they are magnetic and will rust
What is a non-ferrous metal?
a metal that doesn’t contain iron, they don’t rust and aren’t magnetic
Examples of a ferrous metal
- cast iron
- low carbon steel
- medium carbon steel
Examples of a non-ferrous metal
- aluminium
- copper
- zinc
What is an alloy?
a metal made of two or more metals, or combining two or more elements, one of which must be metal
Examples of alloys
Ferrous alloys: stainless steel, die steel
Non-ferrous alloys: bronze, brass
What is a hardwood?
a dense wood from a broad-leafed tree, that grows pretty slow and in warm climates
What is a softwood?
a wood from a coniferous tree, that grows pretty fast and in colder climates
What is a manufactured board?
a man-mad wooden composite material
What are examples of hardwoods?
- oak
- ash
- mahogany
- beech
What are examples of softwoods?
- pine
- spruce
- cedar
- larch
What are examples of manufactured boards?
- Plywood
- MDF
- Flexiply
- Chipboard
What is a thermoplastic?
a material which can be repeatedly reheated and reshaped, allowing it to be recycled after its initial use. They have a long linear chain held by van der Walls forces
What is a thermosetting plastic?
a material which cannot be heated and reshaped after it sets. This is because when its heated it undergoes a chemical change where the molecules form rigid cross links
What is an elastomer?
a material which at room temperature can be deformed under pressure and then upon release it’ll return to its original shape
Examples of a thermoplastic
- low density polyethylene (LDPE)
- high density polyethylene (HDPE)
- nylon
- HIPS
Examples of thermosetting plastics
- Bakelite
- epoxy resin
- Urea formaldehyde (UF)
- Melamine formaldehyde (MF)
Examples of elastomers
- natural rubber
- silicon
Papers and boards
papers and boards can be described as compliant materials, meaning that they can be scored, folded and cut with basic tools
What is a composite?
a material composed of two or more different materials, resulting in a material with enhanced properties
Smart materials
a material whose physical properties change in response to an input or change in the environment
Examples of smart materials
- shape memory alloys
- thermochromatic pigment
- photochromic pigment
Modern material
a material developed through the invention of new or improved process
Examples of modern materials
- kevlar
- precious metal clay
- high density modelling foam
Describe air seasoning
it involves stacking the wood under a shelter, protected from rain. Air circulates between the planks slowly to remove excess moisture. The wood can be used for outdoors products because it is seasoned to same moisture content as its surroundings and this makes it less prone to defects
Describe Kiln
it is more expensive than air seasoning but it controlled and faster. The planks are stacked onto trolleys and placed in the kiln where the temp and humidity is controlled. Initially the kiln atmosphere is very steamy but it’ll gradually become hotter and drier. The wood is better for indoor conditions and will have a lower moisture content than air-dried wood.
Advantages of using a hardwood
- very durable
- low maintenance
- higher fire resistance
Disadvantages of using hardwood
- more expensive
- hard to work with due to the dense grain
- forests take longer to replenish
Advantages of using a softwood
- easy to work with
- more sustainable as it grows faster
- they are cheaper
Disadvantages of using a softwood
- lower density so less durable
- doesn’t last as long as hardwoods
- poor fire resistance unless its treated
Advantages of using a manufactured board
- it’s cheaper
- it comes in many sizes and thicknesses
- it can be easier to work with
Disadvantages of using a manufactured board
- easy to damage
- they don’t have the same natural grain finishing
- they may not be able to carry a lot of weight
What are different metal finishing methods?
- cellulose and acrylic paints
- electroplating
- dip coating
- galvanising
- powder coating
Explain cellulose and acrylic paints (metal finishing)
paints provide colour and sometimes texture to metals, they also provide a barrier against corrosion. The surface should be cleaned and degreased prior to primer and paint application. After the primer undercoats in a similar colour should be applied then the top coats. They can be applied by brush or spray. Paints are usually used on low-cost materials such as steel.
Explain electroplating (metal finishing)
this involves using a metal to coat a usually cheaper base metal, to provide a protective layer and give a greater aesthetic appeal. The product and donor are placed in a container with electrolyte solution. A direct current is applied, the product attracts. the donor metal and the product is electroplated.
Explain dip coating (metal finishing)
Polymer dip coating is where the metal is heated then dipped into a tank of fine polymer powder. The retained heat melts the polymer over the product.
Explain galvanising (metal finishing)
it involves dipping steel into molten zinc, similar to dip coating
Explain powder coating (metal finishing)
the product to be coated is initially negatively charged and a positively charged thermoset polymer resin is sprayed on. Then the product is baked to melt the powder over the product to give an even coating that is much more hardwearing than painting.
What are different timber finishing methods?
- acrylic varnish
- water based paints
- stains
- wax
- pressure treating
- oil
Explain varnish (timber finishing)
it is available in many colours and finishes like gloss, satin and matt. Thin layers should be painted on. After a layer dries it should be sanded down before the next layer is painted on to ensure the wood will have a smooth finish. It provides a hard and waterproof finish.
Explain water based paints (timber finishing)
it is available in different finishes and is applied with a brush, roller or spary. paint makes the wood more aesthetically pleasing and can add some protection
Explain stains (timber finishing)
it is available in many colours and is applied with a brush, roller or spray. It can enhance the colour of the grain but it doesn’t add any protection
Explain wax (timber finishing)
it is available in clear and coloured waxes and should be applied with a brush or cloth. It increases the surfacse strength and toughness
Explain pressure treating (timber finishing)
wood is placed in a pressure vessel containing a solution consisting of preservatives and then vacuum and pressure force the solution deep into the fibers of the wood. This helps protect the wood for a long time
Explain oil (timber finishing)
it is available in colours and tints and is rubbed onto the wood with a cloth. Depending on the type of oil it can add protection, but it should be regularly applied so it can last a longer time
Explain Die cutting and creasing (paper and board forming processes)
Die cutters are used to cut paper or card ‘nets’ or ‘developments’. Die cutters use a plywood ‘substrate’ board into which steel cutting dies and creasing rules are inserted. The stock material is placed under the board, and a press pushes the board into the stock material
Explain bending (paper and board forming processes)
The stamped out net is placed in a folding table. Some die cutting presses might be equipped with moving parts that help to bend to fold parts of a net automatically
Explain laser cutting (paper and board forming processes)
Laser cutters are prefect for prototype construction or small-scale production because it can be used to cut, engrave and carve. A design is made on a software then it is sent to the laser cutter.
Explain vacuum forming (polymer processes)
The mould is placed on the bed of the machine, which is called the platen. The platen is lowered to the bottom of the machine.
Polymer sheet is clamped over the mould and a heater is pulled over the polymer sheet.
When the polymer has softened, the platen is raised into the polymer and the heat is removed.
The vacuum pump is switched pn, which sucks the polymer onto the mould.
Once the polymer has cooled and returned to a solidified state, the platen is lowered and vacuum switched off.
The mould is removed from the moulding. Excess polymer is then trimmed off.
Explain thermoforming (polymer processes)
Thermoforming is a very similar process to vacuum forming, except there is an additional mould that is pressed onto the surface of the polymer sheet at the same times as the vacuum is applied, sucking the polymer down to the mould below. The two moulds trap the softened polymer in between them, giving extra detail to the moulding.
Explain injection moulding (polymer processes)
Thermoplastic granules are poured into the hopper.
A screw thread is rotated by a motor. This pulls the granules through the chamber and past electric heaters.
The heaters melt the polymer.
When a sufficient charge of polymer has melted and formed at the end of the screw, a hydraulic ram forces the screw thread forward. This injects the polymer into the mould.
The mould is water cooled, which enables the motel polymer to harden quickly.
The mould is opened and any extra polymer is trimmed off the moulding.
Explain blow moulding (polymer processes)
The polymer is fed into the hopper.
A screw pulls the polymer through a heated section, melting the polymer.
The melted polymer is extruded as a tube, which is called parison.
The mould slides close around the parison and air is injected into the mould, forcing the polymer to the sides.
The polymer is allowed to cool for a few seconds, the mould opens and the finished bottle is ejected.
Explain soldering (metal processes)
The metal is cleaned and degreased.
The joint area is wired up or clamped.
The metal is heated up to the melting point of the solder.
The solder is added to the metal. The solder will flow along the joint using capillary action.
The metal is cleaned to remove any flux residue.
