Material categories and properties

Question 1

Physical properties vs working properties

Answer 1

• Physical: traits a material has before it is used
• Working: how a material behaves when it is manipulated

Question 2

List of physical properties

Answer 2

• Absorbency: the ability to soak up mositure, light or heat
• Density: how solid a material is
• Fusibility: the ability for a material to be heated and joined to another material when cooled
• Electrical conductivity: the ability to conduct electricity
• Thermal conductivity: the ability to conduct heat

Question 3

List of working properties

Answer 3

• Strength: the ability for a material to withstand compression
• Hardness: the ability for a material to withstand impact without damage
• Toughness: materials that are hard to break and can absorb shock
• Malleability: being able to bend or shape easily
• Ductility: materials that can easily be stretched
• Elasticity: the ability to be stretched and then return to its original shape

Question 4

Where do hardwoods come from?

Answer 4

• Come from deciduous trees (lose leaves during autumn)
• Take longer to grow, not easily sourced and espensive to buy

Question 5

Where do softwoods come from?

Answer 5

• Come from coniferous trees (don’t lose leaves)
• Faster growing, cheaper and considered sustainable

Question 6

Types of hardwoods and characteristics

Answer 6

• Ash: flexible and tough
• Beech: tough, durable and smooth to finish
• Mahogany: cuts and polishes nicely, used for high quality furniture
• Oak: tough and durable, polshes well
• Balsa: very soft and easy to form

Question 7

Types of softwood and characteristics

Answer 7

• Larch: durable and water resistant
• Pine: lightweight and easy to form
• Spruce: easy to form and takes stain colour well

Question 8

Thermoforming vs thermosetting polymer

Answer 8

• Thermoforming can be reformed when heated
• Thermosetting are brittle and can be only formed once

Question 9

Types of thermoforming polymers

Answer 9

• Acrylic (PPMA): hard, brittle, shiny
• HIPS (High Impact Polystyrene): rigid, cheap
• HDPE (High Density Polyethene): stiff, strong, lightweight
• PP (Polypropylene): easily coloured
• PVC (Polyvinyl Chloride): cheap, can be matte or gloss
• PET (Polyethylene Terephthalate): clear, smooth finish

Question 10

Types of thermosetting polymers

Answer 10

• Epoxy Resin (ER): resin and hardener are combined to give a strong adhesive
• Polyester Resin (PR): resing and hardener, sets clear and smooth