Materials

Question 1

Materials - notes

Answer 1

You need to know about certain materials “used in the manufacture of electronic product cases”

You need to know about their working properties:-

conductivity - how well does it conduct electricity or heat

strength - the ability to resist a force without breaking

ductility - the ability to be stretched, usually along it’s length

plasticity - the ability to permanently change it’s shape

hardness - the ability to resist wear and scratching

Question 2

Pine

Answer 2

Comes from the scots pine tree (ignore other sorts of pine )

A coniferous (evergreen with needles) tree grown across the world but extensively in northern europe in managed forests (new trees are planted as they cut down older ones)

Advantages

• Grows quickly and new trees are planted in easily accesible locations makes it a cheap wood to buy
• A common wood so easily accesible to buy

Disadvantages

• Can be ‘knotty’ where all the small braches grew from the trunk
• Trees are tall and thin so wide pieces are not available - but pieces can be stuck together to make bigger peices (see IKEA furniture)
• Usually needs painting, especially if being used outside

Question 3

MDF

Answer 3

MDF is Medium Density Fibreboard and is made by cutting up a tree and grinding it down to a fine powder before mixing it with glue and rolling it into wide. flat sheets.

Advantages

• Consistent quality and easy to work with
• Can be made in sheets that are widee than the original tree
• Usually cheaper than ‘tree wood’ as whole tree is used (not just the trunk)
• Good for the environment as usually made from managed forest of fas growing softwoods that absorb CO₂ from the atmosphere

Disadvantages

• When machined (saw or sander etc) it redaily turns back into fne air-borne dust that can be dangerous if regularly breathed in - suitable ventilation and extraction must be used
• Not considered attractive for work that will be visible - usually needs covering (veneering) in a thin piece of real wood or a hard wearing material (e.g. formica) or it can be painted

http://www.design-technology.org/mdf.htm

Question 4

Aluminium

Answer 4

Lightweight and non rusting metal (‘non-ferrous’) metal often used in drinks cans and in aircraft. Can be in many forms but for electronic product cases most likely to be in sheet form and bent to make the case but could be die cast or machined (with the waste being recycled)

Advantages

• Lightweight - useful if device needs to be portable
• Doesn’t need to be painted as it doesn’t rust (but can be if appearance is important)
• Very easy and successful to recycle

Disadvantages

• An expensive metal as processing the raw materials takes lots of energy
• Probably needs more specialist equipment beyond some workplaces - bending jigs etc

https://www.youtube.com/watch?v=pkFVcgp5OzU

https://www.youtube.com/watch?v=4zBYRyMlL5I

Question 5

Brass

Question 6

Mild steel

Question 7

Copper

Question 8

High Impact Polystyrene

Question 9

Acrylic