What are the properties of hardwood?
- Tighter grain
- Usually hard
- Expensive
- Takes longer to grow than softwood
- Loses leaves in winter
- Grows in temperate climate
What are the properties of softwood?
- Looser grain
- Cheaper in comparison to hardwood
- Softer than hardwood
- Evergreen (doesn’t lose leaves in winter)
- Grows in cooler climates
- Often used in building materials
What woods are hardwoods?
- Oak
- Beech
- Ash
- Balsa
- Mahogany
What woods are softwoods?
- Larch
- Pine
- Spruce
- Redwood
What are the ferrous metals?
- Cast Iron
- Low Carbon Steel
- High Carbon Steel
What are properties of ferrous metals?
- Contains iron which makes it magnetic
- The lower the carbon content, the more malleable it is
- Prone to rust
- Hard
What are the names of non-ferrous metals?
- Copper
- Aluminium
- Zinc
What are the properties of non-ferrous metals?
- Non-magnetic (No iron content)
- Malleable
- Resistance to corrosion
What are the names of the alloys?
- Brass
- Stainless steel
- High speed steel
Are alloys ferrous or non-ferrous?
They can be either, depending on if they contain iron or not.
How are polymers (plastics) made?
Most polymers are made from crude oil. After refining, chemical reactions produce a large number of identical molecules called monomers which are then combined together to form long strands called polymers.
What are bioplastics?
Bioplastics are polymers made from renewable materials (e.g. plant oils)
What are the properties of polymers?
• Can be produced in any colour
• Self finishing
• Shaped - can be formed into unusual shapes
• Formed - can be formed a number of ways
• Cost - reasonable
• Versatile working properties
What are the properties of thermoforming polymers?
• They can be reheated and shaped in various ways
• Highly recyclable
• Aesthetically-superior finishes
• High-impact resistance
• Remoulding/reshaping capabilities
• Chemical resistant
• Eco-friendly manufacturing
• Generally more expensive than thermosetting polymers
What are the names of the thermoforming polymers?
• High-impact polystyrene (HIPS)
• High-density polythene (HDPE)
• Polyvinyl chloride (PVC)
• Polypropylene (PP)
• Acrylic (PMMA)
• Polyethylene Terephthate (PET)
What are the properties of thermosetting polymers?
• More resistant to high temperatures than thermoplastics
• Highly flexible design
• Thick to thin wall capabilities
• Excellent aesthetic appearance
• High levels of dimensional stability
• Cost-effective
• Cannot be recycled
• More difficult to surface finish
• Cannot be remoulded or reshaped
What are the names of the thermosetting polymers?
• Urea Formaldehyde (UF)
• Polyester resin
• Epoxy resin
• Melamine Formaldehyde (MF)
• Phenol Formaldehyde (PF)
What are the names of the polymer additives?
• Plasticisers - Soft and flexible (often PVC)
• Pigments - changes colour
• Stabilisers - withstand UV light damage
• Fillers - increase the bulk, improve its impact resistance
What are the names of the manufactured boards?
• MDF (Medium Density Fibreboard)
• Plywood
• Chipboard
What is a veneer?
A thin layer of real wood that often covers a type of manufactured board. Can be used to improve appearance or properties
How are the types of timbers priced?
Hardwoods are usually the most expensive, due to taking the longest to grow. Softwoods are usually cheaper than hardwoods, due to taking less time to grow. The cheapest type of timber are manufactured boards, due to often being made with waste wood.
How are polymers priced?
Generally, thermoplastics/thermoforming plastics are the most expensive, due to being able to be reshaped after being heated up, while thermosetting plastics are not able to be reshaped.
What is a smart material?
A material that reacts to an external stimuli by changing their characteristics and/or properties.
