Resistant Materials

Types of wood.

• Soft woods;
• - Scots pine ( Straight gained, light in colour, easy to work with, inexpensive.)
• - Parona pine ( hard, straight grained, almost know free, fairly strong, durable, very expensive.)
• - Yew ( Rich red- brown colour with small knots, very durable.)
• SOFTWOODS ARE FAST GROWING, WHICH MAKES THEM SOFT.
• Hard woods;
• - Beech ( Straight grained, fine texture, hard but easy to work with.)
• - Oak ( Very strong wood, open grained, hard but easy to work with.)
• HARD WOODS ARE SLOW GROWING, WHICH TENDS TO MAKE THEM STRONGER THAN SOFT WOODS.
• Manufactured boards;
• - Hardboard
• -MDF

Biscuit joint.

• Biscuit joints is a quick and easy method of joining boards.
• -At tight angles.
• - Side by side to make wider boards.
• - Slots are made in the board using an electric powered cutter.
• - The 'Biscuit' joints are elliptical pieces of timber and glued and dried and compressed.

Thermosetting and thermoplastics.

• Thermosetting plastics are heated and moulded to shape. If heated again they cannot soften as the polymer chain are interlined. Eg Polythene and PVC.
• Thermoplastics will soften when they are heated, and can be shaped when hot. The plastics will harden when it is cooled but cannot be shaped if heated again. Eg Ured formaldehyde.

Raw materials.

• All raw materials and processes used to make products and materials, have an impact on the environment.
• Harm can occur when materials are mined, filled, extracted from oils or grown.
• Designers have responsibly to make sure no one is harmed.
• Many manufacturing processes involve heat, gases given off in the process can harm the atmosphere. (GLOBAL WARMING.)

Finite resources.

• (SOME RAW MATERIALS CANT BE REPLACED, KNOW AS REFINE RESOURSES.)
• Coal - Used to generate electricity and smelt metal ores.
• Oil- Used to generate electricity and smelt metal ores.
• Metal ores - The raw materials are made into metals.
• TO AVOID USEING ALL OUR FINITE RESOURCES WE SHOULD;
• - Recycle materials.
• - Re-use products, such as water bottles that can be taken apart and used again.

Ethical employers:

• Many companies have ethical employers who ensure that their workers get fair wages and have safe industrial injures such as:
• - Deafness.
• - Lung problems.

6 R's.

• Reduce - The amount of materials used.
• Recycle - The materials used by melting or re-processing.
• Re-use - By designing and recouring materials form 'end and life' products.
• Repair - Products rather than replacing.
• Refuse- To accept unethical or wasteful designs.
• Re- think our attitude to environmental impact.
• 

Types of metals.

• Ferrous metals consist of iron, carbon and other elements. Wroldght iron, mid steel. tool steel, stainless steel and cast iron.. Prone to rusting and CAN be picked with a magnet.
• Non ferrous metals don't contain iron, they are not attracted by a magnet and not rust when exposed by moisture. E.g. copper, aluminium and tin and zinc.
• Alloys are examples of combined materials. Alloys are metals that contain two or more elements. E.g. Brass and pewter.
• The elements can be metal or non metal.
• Alloys are chosen for a purpose because of their properties, e.g. their low melting points, resistance or weight

CAD/CAM.

• CAD = COMPUTER AIDED DESIGN.
• - All about using computers to help design a products.
• CAM = COMPUTER AIDED MANUFACTURE.
• - Refers to any part if the manufacturing processes that controlled by a computer system.

Joints.

• TEMPORARY=
• - Tapping and threading.
• - Nutt's, bolts and washes.
• - Screws.
• - Knock down fittings.
• PERMANENT=
• - Nails.
• - Halving joint.
• - Butt joint.
• - Rebate joint.
• - Housing joint.
• - Mortise and tenon joint dowel joint.
• - Soft soldering
• - Bronzing
• - Welding.

Industrials processes.

• - Sand casting.
• - Drilling.
• - Turning (Wood and metal.)
• - Vacuum forming.
• - Extrusion (Plastic and metal.)
• - Wood laminating.