Primary Sourcing and conversion (AQA GCSE Design & Technology): Revision Note

The primary source of paper and board is trees, both softwoods and hardwoods

The trees are turned into wood pulp

This is then used to create different types and thicknesses of papers and boards

Workable forms of paper and board include:

• Cartridge paper

• Bleed-proof paper

• Grid paper

• Layout paper

• Tracing paper

• Corrugated card

• Duplex board

• Foil-lined board

• Foam core board

• Inkjet card

• Solid white board

The process of converting the raw material into paper and board stock forms is as follows:

1. Cut down trees, debark them, and remove their branches

2. Chip the tree trunk into wood chips, which are then allowed to dry

3. Cook the wood chips to turn them into pulp, a soft-textured substance containing cellulose fibres which, when dried, will give paper and card strength

4. Clean and bleach the pulp to remove any colour, making it white

5. Spray the pulp onto large rollers, which press and dry the pulp to form long, flat rolls of paper, which can be cut into common stock forms such as A4 and A3

The primary source of timber is trees, both softwoods and hardwoods

Workable forms of timbers include:

• Planks

• Boards

• Sheets

• Rods or dowels

• Sections

The process of converting the raw material into timber stock forms is as follows

1. Cut down trees, debark them, and remove their branches (the bark is often reused in playground floor covering).

2. Saw either plain or quarter the trunk/log of the tree into the desired size of plank or board.

3. Dry the sawn timber through a process called seasoning.

   1. This can be natural, where the timber is stacked outside under large sheets to dry by itself or artificial, where the timber is stacked and dried inside a large oven called a kiln.

4. Plane, recut and finish the timber to the desired size and quality.

   1. Planing involves removing material to make the planks or board square and flat.

The primary source of metals and alloys is metal ore

This is rock which is mined from underground and separated to separate the waste rock from the valuable metal

Workable forms of metals and alloys include:

• Sheets

• Rods

• Bars

• Tubes

The process of converting the raw material into metal and alloy stock forms is as follows

1. Ore containing metal is removed from the ground through mining.

2. The ore is heated in a process called smelting, which burns away wastage, causes the metal to turn into a liquid, and allows for the separation of the metal from the material not needed.

3. The molten metal is cast or poured as a liquid into a mould into ingots.

4. The ingots are reformed into stock forms of metals, including those listed (ingots look like bars of metal).

The primary source of polymers is crude oil, also known as a petrochemical

Workable forms of polymers include:

• Sheets

• Pellets/granules

• Rods

• Thin films

• Filament for 3D printing

The process of converting the raw material into polymer stock forms is as follows

1. Crude oil is extracted from underground through drilling.

2. The crude oil is refined through a process called fractional distillation.

3. Cracking then breaks the long molecules from the oil fractions into smaller ones, which are polymerised into useful polymers.

4. The polymers are formed into pellets, which are small beads which can be used by manufacturers to put into machines which can heat them up and form them into stock forms like sheets.

Primary sources of textiles include natural fibres, such as cotton, which is sourced from a cotton plant, or wool, which is sourced from sheep, or synthetic fibres, which are made from crude oil

Workable forms of textiles include:

• Fibres

• Yarns

• Fabrics

The process of converting natural fibres into textile stock forms is as follows

1. Fibres are sourced and gathered together in large quantities

2. The fibres are sorted and cleaned

3. The fibres are spun into yarns, which are then woven, knitted or sewn into fabrics