There are two types of metals: ferrous (contains iron) and non- ferrous (without iron)
Iron and stainless steel
aluminum, gold, silver, copper,brass
(brass is an alloy as is stainless steel)
Stock forms of metals include: bar, rod, sheet, tube, u shaped channel
Metals are coated via:
Painting - weatherproof finish, plastic coating, plating - electroylsis barrier, lacquering - transparent coating
Woods are either hardwood or softwood:
HARDWOOD: grown in warmer climates & take a long time to grow therefore they are expensive e.g. mahogany, oak and ash
SOFTWOOD: grown in colder climates & quick to grow (they are usually evergreen) therefore are cheap e.g. scots pine and parana pine
woodstain - enhance apperance
oil - can protect wood to outdoors
thermoplastics and thermosetting polymers
Thermoplastics are easy to shape and mould and are recycleable e.g. acrylic, acetate and PVC
Thermosettings can't be remoulded (are rigid) and are non recycleable e.g. epoxy resin, urea formaldihyde and glass reinforced plastic
plastics are made from crude oil and are joined via polymerisation, crude oil is finite so it will run out eventually.
stock forms: rod, sheet, tube, rolls. granules and foam
plastics don't need finishes as they are very resistant to erosion but to smoothen edges wet and dry paper can be used or in mass production a buffer machine
card and paper
paper is grown via the cutting down of trees, being made into wood chips, added to chemicals to make pulp and washed and bleached and rolled to make paper.
types of paper:
cartridge paper, grid paper, tracing paper, layout paper
types of card:
corrugated cardboard made up of fluted inner core and two surrounding layers, duplex board, solid white board
laminating paper means to add another layer of material for example paper cups are coated with polethene to make them waterproof.
Lithography -water and ink are added and the image is pressed on via a printing plate and a roller
offset lithography - paper doesnt come into contact with printing plate, image is transferred via a rubber roller
flexography -printson flexible printing plates made from rubber
gravure - holes are filled with ink and pressed against the plate
blow moulding - air is blown in largening the plastic shape
injection moulding - plastic granules are heated and moulded into a specific shape
press moulding - former is pushed onto the 'fermale mould' and with heat it liquifys forming the permenant shape
die casting- melting material into a mould
embossing - textured roller presses onto material to impress the image
new materials and smart materials
new materials have useful properties e.g. cornstarch polymers instead of plastic as cornstarch is renewable and better for the environment.
smart materials react to surrounding environment for example thermochromic materials which change colour according to their hotness.
nanomaterials have useful properties e.g. self cleaning glass and odour free socks
intergrated electronics are built in circuits, they are made in with a design. they usually have quatum tunneling compsotites which become more electronically charged the more squashed it becomes.