Natural Woods

Wood is fiberous with fibres running along the length of the trunk.

55% of the tree is cellulose

28% Lignin resin

Timber is a natural fibre reinforced polymer

Proccessing Timber

1) Harvesting - cutting down

2) Coversion - cutting the trunk & branches into boards. Slab or quarter sawn

3) Seasoning - reducing moisture content of the timber

4) Board Preparation - Sawing to size

Quarter Sawn Timber

Used for hardwoods.

A lot of waste, very stable, less liable to warp and twist. Has little shrinkage because of short annual rings.

Slab Sawn Timber

Timber shrinks most along the annual ring. The longer the annual rings, the more shrinkage.

Die Casting

This involves forcing molten metal under high pressure into steel moulds. This is used to produce non-ferrous metal parts. The process produces very precise parts, smooth surfaces and then sections.
Die casting commonly uses alloys of zinc & aluminium.
A typical Die set last 500,000 shots. First the mould is sprayed with luricant and closed. This helps control temperature. Molten metal is then injected into the die under high pressure. This ensures precision and a smooth surface. Pressure is then maintained until the casting is solid. This is kept as short as possible by water cooling.

Sand Casting

Sand casting involves placing a mould and 'ramming-up' moist a mixture of moist sand and sodium silicate into a core box over that mould. The sand mix takes about 10-30 mins to harden. The mould and casting can then be removed and metal can be poured into the cast. This is then left to cool and harden. Weight are placed on top of the cast to ensure that they are firmly pressed together. The mould can then be removed and the cast placed into a 'shake out' machine where it falls through a grate and is re-processed. Any remaining sand on the mould is removed by shot blasting.
The mould is sometimes heat treated to improve strength. This involves heating castings in an oven then rapidly cooling them in water. The product can then be sent to casting.

Types Of Metals

Metals are classified as Ferrous & Non Ferrous. These can then be separated into Alloys & Non Alloys.

Ferrous Metals

Metals that contain Iron & Carbon.

Mild Steel

Strong and cheap but rusts easily and can't be hardened or tempered.

Used on car bodies, screws, nuts & bolts.

High Carbon Steel

Harder than mild steel and can be hardened and easily tempered. Difficult to work and rusts.

Used on drills, files, chisels and saws.

Cast Iron

Hard, however brittle under impact.

Used on machine parts, brake disks and engines.

Non Ferrous Metals

Aluminium

Lightweight and corrosion resistant. Expensive and not nearly as strong as steel.

Used on aeroplanes, cars and ladders.

Brass

Quite strong, corrosion resistant, malleable, ductile and looks good.

Used on door furniture and electrical parts.

Copper

Relatively soft, malleable and ductile and very good conductor of electricty.

Used on wires and piping.

Ferrous Alloys

- Stainless Steel

- High Speed Steel

- Die (tool) Steel

Non Ferrous Alloys

- Brass

- Bronze

- Duralumin

Where does metal come from?

All metals except gold are processed. Metals are found in ores.

- Iron is converted from its ore by heating. Iron is rarely used without being combined with carbon, to give you steel.

- Steel is a mixture of iron and carbon. The amount of carbon determines strength.

- Carbon is an element found in a range of materials. Natural materials i.e. Coal & diamond are purely carbon. Adding carbon can increase strength but makes mthe material brittle.

Melting Points

Aluminium - 660 Degrees C

Copper - 1083 Degrees C

Gold - 1063 Degrees C

Lead - 330 Degrees C

Notes - 1/10/09

Natural Timbers

Lumber - When a tree has been felled
Timber - Processed material
Wood - Material

Hardwoods

. Come from deciduous tress
. Deciduous trees loose leaves in autumn
. Oak is an indigenous tree (grows in England)
. Slow growing
. Examples: Ash, Oak, Beech, Teek, Walnut

Softwoods

. From coniferous trees (needles & cones)
. Fast growing
. Cheaper to buy because of shorter growing time (more can be cut down in the same time as hardwoods)
. Examples: Larch, Spruce, Scots Pine, Douglas Fir



A trees age can be worked out by counting the annual/growth rings in its trunk. Each ring represents a summer/winter. The winter rings are darker because of bark that grows to protect the tree from cold, causing less light to reach the trunk.

The FSC are an organization that make sure the wood that is imported is from a sustainable source, meaning that more trees are planted in the old trees place.

Organic Design

I Should Never Have Purchased...

A few years ago I bought a Samsung MP3 player. I purchased this product because it had a very appealing, curved and smooth design. However, when I started to use the product I realised that the MP3 player was very slow and hard to use. Firstly, I noticed that you had to press the buttons on a certain angle to get them to work which was very annoying. Also it took ages to access all my songs. The font style was also quite hard to understand and the songs were not organised by artist name or album, but by file name which was very impractical. The volume buttons were also very badly made and felt as if they were going to fall off every time you pressed them. The maximum volume was also very quiet which was very poor. As if that wasn’t enough that was wrong with the sound quality, the headphones that came with the product were very bad quality and I had to buy my own pair to use with the player. I could have easily pay half the price for an MP3 player with the same memory and it is likely to have worked better but because of the cost a was drawn to the product, thinking that a high price would guarantee quality. I should have looked at some reviews of this product as I feel it was a waste of money. I had to replace the player within a few months which goes to show you should do some research on an expensive product before buying.