Autumn 2020 Flashcards
What type of trees are softwood?
coniferous
What are features of coniferous trees?
- They grow in cooler climates
- They are softer and easier to work with
- They grow tall and straight which makes it easier to cut long planks of wood
- They have a looser grain structure
- They are evergreens so they grow all year round and do not lose their needles
- They are often used as building materials
- They grow faster and are therefore cheaper
What are 4 examples of a Coniferous tree?
- Larch
- Pine
- Spruce
- Redwood
What type of trees are hardwood?
most are Deciduous, however some are coniferous
What are features of a deciduous tree?
- They have a harder wood
- They generally grow in temperate climates
- They are broad-leaved trees and the seeds are enclosed in the fruit that the tree produces
- They are slower growing trees and therefore more expensive
- They have a tighter grain
Where are evergreen hardwood trees found?
in tropical and subtropical countries
What are 5 examples of deciduous trees?
- Ash
- Beech
- Mahogany
- Oak
- Balsa
What does FSC stand for?
FSC stands for the “Forest Stewardship Council”
What do FSC do?
FSC is an international organisation dedicated to responsible management of forests around teh world, they manage forests to preserve biological diversity and sustainable forestry. Their work is important as it guarantees biodiversity and for forests to survive for years to come. They do this by cutting down only a few trees in a certain area then letting the forest regrow in that area, rather than clearing large areas of forest
What are 6 types of manufactured boards?
- Chipboard
- Laminated Chipboard
- Plywood
- Fibreboard
- Medium Density Fibreboard
- Particle Board
Why would MDF be used to make a living room table or a kitchen cupboard door?
MDF is relatively cheap to produce and the board is smooth, making it aesthetically pleasing. They can also be faced with a veneer to make it look even nicer
Why would chipboard be used to make boarding for a loft area?
Chipboard is extremely cheap to produce and is fairly durable meaning that it can stay in a loft without having to be replaced often
Why would chipboard be used to make a kitchen work top?
Chipboard is extremely cheap to produce and is fairly durable. It can be laminated/given a plastic finish making it look aesthetically pleasing and is more durable
What composition is Aluminium?
Pure Metal
What are the properties of Aluminium?
- Greyish-White
- Soft
- conductive to heat and electricity
- it is corrosion resistant.
- Lightweight
- Malleable and Ductile
What are the uses of Aluminium?
Aircraft, boats, window frames, saucepans, packaging and insulation, pistons and cranks
What composition is Low Carbon Steel (Mild Steel)
Alloy - Ferrous Metal
What are the properties of Low Carbon Steel (Mild Steel)
- Mild Steel is a ferrous metal
- It is malleable, ductile
- conductor of heat and electricity,
- not resistant to corrosion.
- It has an intermediate weight
What are the uses of Low Carbon Steel (Mild Steel)
General structure work, girders, nuts, bolts, screws, non-cutting tools and car bodies
What composition is High Carbon Steel (Tool Steel)
Alloy - Ferrous Metal
What are the properties of High Carbon Steel (Tool Steel)
- Tool steel is a ferrous metal .
- It is not as malleable or ductile as mild steel and is
- very hard and strong although the strength decreases if it contains more than 0.9% carbon.
- Its hardness and strength can be improved by heat treatment.
- It is a conductor of both heat and electricity,
- resistant to wear and has an intermediate weight
- High melting point
What are the uses of High Carbon Steel (Tool Steel)
Hand tools, chisels, screwdrivers and punches
What composition is Zinc
Pure Metal
What are the properties of Zinc
- Zinc is a pure metal
- Low melting point
- It is resistant to corrosion
- a conductor of bot electricity and heat.
- It is brittle and crystalline at room temperature however when heated it becomes malleable and ductile.
- It has an intermediate weight,
- is soft and is quite weak
What are the uses of Zinc
Galvanised Steel buckets, tanks and dustbins and rust proof paints
What composition is Copper
Pure metal
What are the properties of Copper
- Copper is a pure metal
- It is malleable and ductile and is the
- 3rd best metal for conducting heat and electricity.
- It is resistant to both corrosion and wear.
- It has an intermediate weight,
- it is soft but also tough
- Welds easily
What are the uses of Copper
Electrical wire, printed circuit board, central heating pipes, boxes, bowls and rivets
What composition is Cast Iron
Alloy - Ferrous Metal
What are the properties of Cast Iron
- Cast Iron is a ferrous metal
- It is not malleable and has to be cast.
- rusts easily
- can conduct both heat and electricity.
- It is strong and hard
- intermediate weight
What are the uses of Cast Iron
Cylinder Blocks, Piston rings, car brake drums, vices, manhole covers, fire grates and machine tools
What composition is Stainless Steel
Alloy - Ferrous Metal
What are the properties of Stainless Steel
- Stainless Steel is a ferrous metal
- it is malleable and ductile.
- It is resistant to wear, corrosion, and rust
- It is hard and strong
- intermediate weight.
- Unlike other ferrous metals it contains chromium so stainless steel does not rust
What are the uses of Stainless Steel
Sink units, kitchenware, pipes, and aircraft
What composition is Brass
Alloy
What are the properties of Brass
- Brass is an alloy
- It is malleable and ductile
- resistant to both corrosion and wear.
- It is a conductor of heat and electricity.
- It has an intermediate weight
- intermediate strength
What are the uses of Brass
Castings, boat fittings, ornaments, wood screws, and cartridge cases
What are 4 types of metal finishes?
- Paint
- Plastic Coating
- Galvanising
- Electroplating
Describe the process of Paint
Paint is sprayed through a high pressure hose from a paint supply or painted onto the necessary components by someone wearing PPE. This could also be done by a robotic machine where it is given set instructions to spray certain areas of the components and certain areas not to
What are the advantages/disadvantages of paint?
Advantages: It is a relatively cheap and easy way to finish metals
Disadvantages: It can wear away and needs maintaining relatively often. When applied parts can be missed, leaving areas exposed
Describe the process of Plastic Coating
A piece of metal is heated up to around 250°C, once hot, it is then dipped into a polythene in powder form. The plastic is applied with a negative charge as the item being dipped is positively charged
What are the advantages/disadvantages of Plastic Coating
Advantages: Plastic powder coating is very durable and will not have to be reapplied
Disadvantages: Large start up costs, limited range of suitable materials
Describe the process of Galvanising
The 98% zinc bath is heated to 839*C .Steel components are dipped into the hot, molten zinc. The zinc provides a uniform protection all over the steel
What are the advantages/disadvantages of Galvanising
Advantages: It protects the steel from corrosion and is extremely durable. Once galvanised the component basically maintenance free and is aesthetically pleasing whilst protecting the component from even the harshest conditions. It provides a uniform protection all over the component, You can further finish it with plastic coating or paint
Describe the process of Electroplating
Electroplating involves passing an electric current through a solution called an electrolyte. When the electricity flows through the circuit they make, the electrolyte splits up and some of the metal atoms it contains are deposited in a thin layer on top of one of the electrodes—it becomes electroplated.
What are the advantages/disadvantages of Electroplating
Advantages: It is very aesthetically pleasing
Disadvantages: it does not protect the metal, it is only for aesthetics
Where do most polymers originate from?
crude oil
What are bioplastics made from?
Plant oils
What are polymers more commonly known as?
plastics
What are the 3 types of polymers?
Thermoforming Polymers
Thermosetting Polymers
Bioplastics
What are thermoforming polymers?
Thermoforming polymers are plastics that can be re-heated and therefore shaped in various ways. They become mouldable after reheating as they do not undergo significant chemical change. The bond between molecules become weaker and weaker when reheated, allowing reshaping. These types of plastics can be recycled
What are thermosetting polymers?
Thermosetting polymers are plastics that once “set” cannot be reheated to soften, shape and mould. The molecules of these plastics are cross linked in 3 dimensions and this is why they cannot be reshaped or recycled. The bond between the molecules is very strong
What are the pros and cons of thermoforming polymers?
Pros:
- Highly recyclable
- Aesthetically-superior finishes
- High-impact resistance
- Remoulding/reshaping capabilities
- Chemical resistant
- Eco-friendly manufacturing
Cons:
- Generally more expensive than thermoset
- Can melt if heated
What are the pros and cons of thermosetting polymers?
Pros:
- More resistant to high temperatures than thermoformed
- Highly flexible design
- Thick to thin wall capabilities
- Excellent Aesthetic appearance
- High level of dimensional stability
- Cost-effective
Cons:
- Cannot be recycled
- More difficult to surface finish
- Cannot be remoulded or reshaped
What is the molecular structure of thermoforming Polymers?
layers of molecules on top of each other, each with bonds to 2 other molecules
What is the molecular structure of thermosetting polymers?
lattice of molecules cross linked, each with bonds to 4 other molecules
What is an example use of Acrylic (PMMA)?
A car indicator cover
What are the properties of Acrylic (PMMA)?
- Quite hard and brittle
- Resistant to weathering
- Scratches easily
- Excellent optical properties
What is an example use of High Impact Polystyrene (HIPS)?
a yogurt pot
What are the properties of High Impact Polystyrene (HIPS)?
- Flexible
- Good impact resistance
- Lightweight