9. energy types and types of moulding

Question 1

How does a thermal power station work?

Answer 1

1. it burns fuel such as coal, oil or gas, in a furnace to produce heat - chemical to heat energy
2. this heat is used to change water into steam in the boiler
3. this steam drives the turbine - heat to kinetic energy
4. this drives the generator to produce electricity - kinetic to electrical energy

Question 2

What is biomass energy?

Answer 2

energy gained from burning wood or other organic matter. burning biomass releases carbon emissions, but has been classed as a renewable energy source in the EU and Un legal frameworks, because plant stocks can be replaced with new growth

Question 3

How is nuclear energy generated?

Answer 3

• nuclear fuel undergoes a controlled chain reaction in the reactor to produce heat - nuclear to heat energy
• heat is used to change water into steam in the boiler
• the steam drives the turbine (heat to kinetic energy)
• this drives the generator to produce electricity - kinetic to electrical energy

Question 4

How is hydroelectricity generated?

Answer 4

• in a hydroelectric power station water is stored behind a dam in a reservoir. this water has gravitational potential energy
• the water runs down pipes (potential to kinetic energy)
• the turbine is connected to a generator to produce electricity (kinetic to electrical energy)

Question 5

What are the 2 different types of batteries?

Answer 5

• alkaline batteries
• rechargeable batteries

Question 6

What are alkaline batteries?

Answer 6

they are the most common type of domestic batteries, they are disposable but contain chemicals that are bad for the environment

Question 7

What are rechargeable batteries?

Answer 7

batteries that are better for the environment and more economical in the long run (high initial purchase price). their lifespan decreases with every charge

Question 8

What are the steps for vacuum forming?

Answer 8

1. Mould is made from MDF or expanded polystyrene
2. The mould is placed in the bottom of the vacuum former
3. The sheet of plastic is placed above the mould and clamped in place
4. The electric element (heater) is turned on and begins to warm the plastic sheet
5. The thermoplastic becomes flexible as it is heated. The mould is moved up to the plastic using the handle
6. The pump is turned on and the air is removed from under the plastic, sucking the plastic over the mould

Question 9

What are the types of manufacturing processes for plastics?

Answer 9

• Vacuum forming
• Injection moulding
• Blow moulding

Question 10

What are the steps for blow moulding?

Answer 10

1. parison ready
2. Mould closes over parison
3. Parison inflated to fill mould. Extruder forming new parison
4. Bottle removed and trimmed

Question 11

What are the steps for injection moulding?

Answer 11

1. Clamping
2. Injection can begin after the two plates of the mould are clamped together
3. Dwelling - the melted plastic fills the entire mould
4. Cooling
5. Mold opening
6. Ejection