Design and Technology

• There are 2 types of energy sources - renewable and non-renewable.
• Non-renewable energy sources cannot be replaced once they have been used up, including fossil fuels like coal, oil, and gas.
• Renewable energy come from a natural supply that is continuously replaced.
• Non-renewable energy sources often need to be extracted from the earth and sometimes processed, which can give off pollution and be very damaging.
• Wind power

  • They are unsightly
  • Expensive to install
  • Can affect wildlife (mainly birds)
• Solar energy

  • Expensive to set up
  • Dependent on weather conditions
  • Can be space-consuming
  • Storing solar energy can be expensive
• Tidal energy

  • Expensive to set up
  • Can damage ecological coastlines
  • Can harm marine life
  • Generates power for 10 hours per day
  • It is 80% efficient
• Geothermal Energy

  • Uses ‘hot-spots’ where molten rock close to the earths crust generates hot water
  • Involves drilling into the earths surface to reach deeper geothermal resources
  • Very high-cost resource
  • Risks triggering earthquakes
• The UK government has made a commitment for the UK to be net zero emissions by 2050.
• There are many ways in which society is encouraged to reduce waste and recycle more, because:

  • 90% of waste is dumped or burned, mostly in low income countries
  • lots of poorly managed waste contaminates the world’s oceans
  • waste causes clogging of drains, flooding, the spread of disease and harm to wildlife.
• Carbon fibre

  • High stiffness
  • High tensile strength
  • Low weight
  • Hight temperature tolerance
  • High chemical resistance
  • Low thermal expansion
  • Resistant to corrosion
• Metals

  • Ferrous metals contain iron
  • Non-ferrous metals do not contain iron
  • Alloys are combinations of base metal with other metals or non-metals
  • Metals are sourced from ores, which are naturally sourced and will run out
• Annealing – heating then slowly cooling the metal to remove stress, make softer and refine structure.
• Normalising – heating and then cooling the metal at room temperature, reducing hardness and increasing ductility.
• Case hardening – This hardens an alloy’s surface by adding carbon, heating and quenching.
• Tempering – applied to steel and cast iron, increasing toughness and reducing hardness and brittleness. Tempering involves heating to a high temperature and air-cooling.
• Hardening – heating and then cooling the metal rapidly by submerging into a liquid or oil.
• Natural and manufactured timber

  • Natural timber is grown on trees!
  • Manufactured timbers are man-made.
  • Timbers are categorised into hardwoods and softwoods.
• Polymers

  • Polymers that can be heated and shaped repeatedly are called thermoplastics/ thermoforming.
  • Thermosetting polymers (or thermosets) can only be heated and shaped once.

  Some polymers are natural, some are synthetic.
• Papers and boards

  • Paper is made from wood pulp.
  • Paper is fully recyclable, reducing the need for wood fibres from trees.
• Aesthetics

  • Aesthetic properties are how a material or components looks.
  • This includes shape, colour, texture, form, reflection, gloss, style etc.
• Function

  • Functional properties refer to how a material or component works for the intended use.
  • Function includes performance, efficiency, reliability and operation.
• Global manufacture

  • This is when parts of products are made in different locations.
  • The benefits include cheaper labour and investing in poorer countries’ economies.
  • However, this can result in child exploitation and unfair conditions!

  Fair Trade tries to ensure that everyone benefits.
• Biodiversity and deforestation

  • We must avoid damage to natural habitats and source materials sustainably.
  • The Six Rs help!
  • FSC and managed forests supply sustainable timbers.
  • Select recycled materials over virgin materials.
  • Protect wildlife and natural eco systems.
• Cost of a prototype

  Making a prototype involves more costs than just materials:

  • Energy costs to power machinery
  • Labour costs – prototypes can be one off, hand-made items
  • CAD/CAM CNC are very expensive
  • Intellectual property to protect that brilliant invention.
• One off production - single products made as prototypes or concepts, or bespoke custom-made items are manufactured.
• Batch production – products made in limited numbers at any one time, although this may be repeated.
• Mass production – identical products made in large volume, normally thousands, with some use of automated machinery to achieve accuracy, efficiency and identical outcomes.
• Continuous flow production – identical products constantly being produced 24 hours per day, 7 days per week without stopping. There will be heavily automated production lines in use for speed, accuracy and quality control purposes.
• Jigs – a jig is a device used to hold or secure material and guide cutting or drilling tools to ensure accuracy and repeatability.
• Pattern – a pattern is a shape attached to the surface of the material to help to shape it.
• Template – a template is a tool for marking out a shape repeatedly, so it is exactly the same each time.
• Blow moulding – used for forming bottles, a soft plastic tube is inflated to fill a cavity.
• Vacuum forming – a sheet of HIPS or acrylic is heated and then pulled over a mould or former by extracting air using a vacuum.
• Press moulding – polymer sheets are heated, placed over the mould and pressed down onto the mould to take the shape.
• Compression moulding – a polymer is placed into a heated mould cavity, the mould is then closed with a plug and compressed with a hydraulic press.
• Pre-press printing – creates a print layout, a digital pre-press machine then transforms electronic files onto paper.
• On-press printing – a plate is covered in ink before paper is pressed against the plate then released.
• Die cutting – metal cutters stamp out the desired shape from the material - like cookie cutters!
• UV varnishing – parts of a graphic design can be finished with ultraviolet varnish to create a vivid, luxurious or tactile finish.