unit 3

Question 1

how to make paper

Answer 1

tree chipped to small pieces and mixed w chemicals to make pulp
breaks down wood into cellulose fibres
bleached white
fed thru rollers

Question 2

types of paper

Answer 2

cartridge paper- sketching and ink
bleedproof paper
plotting paper
cardboard
tracing paper

Question 3

softwood

Answer 3

evergreen, coniferous, grow faster, readily available, the grain is wider, so less strong and more absorbant

Question 4

hardwood

Answer 4

deciduous, slower growth, good aesthetics, closer grain so more dense so less water absorbant, more expensive

Question 5

examples of softwood

Answer 5

pine, larch, spruce, cedar
balsa - open grain, sfot and light

Question 6

examples of hardwood

Answer 6

ash, beech, oak
mahogany - good durability, colour and aesthetics

Question 7

properties of metals

Answer 7

ductility - stretched?
toughness - absorb energy and not fracture
tensile strength
malleable
hardness
thermal and electrical conductivity

Question 8

thermoforming vs thermosetting

Answer 8

FORMING : liked as long chains, making them easy to reheat and remould
SETTING : interlinked in a net making them more rigid

Question 9

thermoformed plastic examples

Answer 9

polythene HDPE - milk crates, buckets
polythene LDPE - food packaging, carrier bags, shampoo bottles
polypropene PP - syringes, food containers
high impact polystyrene HIPS
casing on appliances
nylon - clothes
poly vinyl chloride PVC - pipes, shoe soles.

Question 10

thermoset plastics examples

Answer 10

epoxy resin - two part resin and hardener
phenol formaldehyde - pan handles
urea formaldehyde - plug sockets