Design and Technology GCSE AQA

Define Strength

the ability of a material to withstand a force without breaking or bending.

Define Elasticity

The ability of a material to bend or flex when subjected to a force and then return to its original shape.

Define Hardness

A measure of how easily a mineral can be scratched

Define Toughness

Mechanical property of a material that indicates the ability of the material to handle overloading before it fractures.

Define Brittleness

The tendency to crack or break; the opposite of elasticity

Define Durability

the ability to withstand wear, pressure, or damage.

Define stability

Resistance to withstand changes in shape or size over time.

What is wood like in relation to Stability?

Unstable - tends to warp and twist with changes in humidity.

What are the main the Client needs?
'ACCESS FM'

A - Aesthetics
C - Customer (Who?)
C - Cost
E - Environment (will it help the environment?)
S - Size
S - Shape

F - Function
M - Material

Why are man made boards made?

-They are the most economical method of using wood.
-They allow much bigger sheets to be produces than what can be cut from a tree.
-They are stable and are free from knots and splits.

Name 5 man-made wood

- Block Board
- Hardboard
- Medium density fibreboard
- Plywood
- Chipboard

Define welding

Pieces of metal are melted along the joints fusing the two sheets together as they cool.

What are the two main types of welding?

- Electric Arc (MIG)
- Gas (Oxy-acetylene)

What are bolts?

Similar to machine screws but with shaped heads that can be tightened with spanners

What are pop rivets?

Enable you to complete the joint when only having access to one side of the work. They are usually used for joining thin sheets together.

What is a Plastic weld?

A multi-purpose plastic adhesive that joins most types of plastics

What plastics must you not use a plastic weld on?

Foamed plastics

Name three devices that as well as joining metals can be used for joining plastics.

- Nuts
- Bolts
- Rivets

What is Tenasol 12?

It is good for acrylic, Its quick and easy but if split could mark the work and is not very strong.

Name 2 advantages of CAD

- Quicker than by hand
- More accurate than my hand

List 4 disadvantages of CAD

- Expensive to set up
- excess plastic from trial runs
- Need trained staff
- Software problems could occur

Define hard woods

Grows very slowly, Strong and relatively expensive, aesthetically pleasing

List 5 hard woods (Oh My! Thick Ass Booty!)

- Oak
- Mahogany
- Teak
- Ash
- Birch

Define Soft Wood

Grows quickly ,Widely available, Cheaper and used in furniture and papermaking

Name 2 soft woods

- Pine
- Spruce

What is a ferrous metal?

A metal that contains iron

What is a non-ferrous metal?

a metal that does not contain iron

List 3 factors of ALUMINUMN

Light weight, easy to machine, does not corrode easily

List 3 factors of MILD STEEL

Strong, Can we welded, rusts unless protected

List 3 factors of COPPER

Malleable, Excellent electrical conductor, Ductile

List 2 factors of PEWTER

Low melting point, can be cast into detailed shapes

List 4 Metals

- Mild Steel
- Aluminumn
- Pewter
- Copper

What is a thermoplastic?

A polymer that once heated can be formed into a variety of shapes using different forming techniques. once cooled the shape is held but they can be continuously reheated and shaped.

What is a thermosetting plastic?

These can't be altered by heat once they are made. Used where melting plastics would be dangerous. Eg, Plug Sockets

How is polystyrene made and what can it be used for?

Its vacuum formed - yoghurt pots etc...

How is Nylon made and what can it be used for?

Injection moulded -Washers, nuts and bolts

How is Polypropylene made and what can it be used for?

Injection moulded - Bottle tops

How is Acrylic made and what can it be used for?

Hand / CAM cut - sales display and CD racks

How is ABS made and what can it be used for?

Injection moulded - Cur bumpers

How is PVC made and what can it be used for?

Extruded - Drain pipes and packaging

How is PET made and what can it be used for?

Blow moulded - bottles

How is HDPE made and what can it be used for?

Injection moulded - buckets and wheelbarrows

How is LDPE made and what can it be used for?

Blow moulded - shampoo and hair gel packs

What is melamine used for?

Plastic coating for chipboard kitchen worktops

What is Polyester resin used for?

Casting, pouring into a mould mixed with glass fibres to make fibreglass

What is urea formaldehyde used for and how is it made?

it is compression moulded and is used for Electrical components eg, plugs, fuse boxes, light switches