Unit 3 Flashcards
What are paper and boards made out of
Natural cellulose fibres usually sourced from wood
Alternative sources of fibre to make paper
Bamboo, straw and sugarcane
Bleedproof paper
- smooth
- has a special coating to reduce absorbency
- lightweight
Cartridge paper
- thick, quality paper
- slight texture
- heavier paper (200gsm) more suitable for watercolour, acrylic
Grid paper
- printed squares or isometric grids
- graphs, diagrams, mathematical functions or scientific data
Layout paper
- lightweight
- smooth
- greater opacity than tracing paper
- accepts pencil and most other media well
Cardboard
- heavy duty paper
- lamination to other materials increases strength or an alternative surface
Corrugated cardboard
- made up of one or two outer flat layers and a corrugated layer
- delivery and packaging
- lightweight, strong
- smooth surface, easily printed on
- it can insulate (ridges)
Foil lined board
- stiff card, aluminium foil on one side
- cartons containing liquid are foil lined making it food safe
- waxy coating to make things liquid resistant
Duplex board
- exterior has wax coating to provide moisture barrier, glossy sheen
- smooth white surface good for offset printing
- weight of card ideal for folding, die cutting
- aesthetic
Foam board (foam core)
- sheet of polystyrene and outer layers of paper
- rigid, lightweight
- used for backing material for graphic signage
- outs cleanly with sharp blade, suitable for models and prototypes
Electrolysis
Used to extract metals such as aluminium
Smelting
- extracts common industrial metals such as iron
Ferrous metals
- iron and steel can rust
- contain iron
- may rust
- magnetic
Ductile metal example
- copper: highly ductile and can be drawn into long, thin wired
Malleable metal example
- foil: can be rolled or pressed into sheets
Hardness definition
- a materials ability to withstand abrasion
- cast iron, hard and brittle
Toughness definition
- requires strength and ductility
- how well a metal can absorb energy and not fracture without deforming
Tensile strength definition
- the amount of stretching a material can withstand before breaking
Steel properties
- ferrous metal
- high resistance to corrosion, staining and friction
- hard and tough
Low carbon steel
- tough
- ductile
- easily welded
High carbon steel
- v hard wearing, less ductile/ malleable
Cast iron
- hard
- easily cast into shapes, but brittle
Non ferrous metals
- don’t contain iron
- more expensive than ferrous metals
- lightweight
- good conductivity
- ductile, malleable
- resistant to corrosion
What does galvanising do
- adds protective coat of zinc to iron and steel to prevent rusting
What is copper most commonly used in
Electrical cabling
Name the non ferrous metals
- aluminium
- copper
- tin
- zinc
Tin properties
- soft ductile and malleable (tin can is made of steel and has tin coating, ‘tin plating’)
Alloys
- improved working properties and appearance
- brass and steel are common alloys
