Chapter Five - Materials Flashcards
(25 cards)
Measurement of Paper
Grams per Square metre
How is paper made?
1 - Made from wood fibres called cellulose
2 - Chemicals used to break down fibres
3 - Chemicals added to give paper its colour or bleach it.
What is virgin fibre paper?
Paper made from entirely “new” wood pulp.
How is recycled paper made?
1 - Soaking waste paper to separate its fibres back into pulp
2 - Refined to remove unwanted contaminants
Why is paper laminated?
1 - Improve the strength and resistance to bending, creasing or ripping
2 - Improve the appearance and lifespan
What weight is paper classified as a board?
170 gsm upwards
What is a hardwood?
Timber that comes from a deciduous tree.
What is a softwood?
Timber that comes from a coniferous (ever-green) tree.
How is plywood made?
Layers of wood glued together
What are ferrous metals?
Those that contain iron
Where can non-ferrous metals be used?
Electronic devices and wiring
How do you prevent aluminium from oxidising?
Add a finish
What are thermoforming polymers?
Polymers that can be softened by heating, shaped and set over and over again.
What are thermosetting polymers
They cannot be reheated and reformed, they are the opposite to thermoforming.
What is a polymer?
Smaller units which are bonded together.
What is a fibre?
A long, thing stranded material like a hair.
Why are fibres blended together?
1 - To improve quality
2 - To improve appearance
3 - To improve functionality
What is copier paper used for?
1 - Printing or photocopying
What is cartridge paper used for?
1 - Drawing
How much is a micron
1/1000th of a mm
How are plywood, chipboard and MDF made
1 - All are glued with resin
2 - MDF - Wood Fibres
Plywood - Veneer
Chipboard - Chips of wood
3 Ferrous Metals
Cast iron
High-carbon steel
Low-carbon steel
Properties of the 3 Ferrous metals
Cast Iron - brittle if thin, can be cast in mould, strong compression strength
High-carbon Steel - brittle, less malleable, good electrical
Low-carbon Steel- easy to form, good electrical, good thermal
3 Non-Ferrous metals
Aluminium
Copper
Silver
