1 Materials and components

1 Materials and components

1. Paper and board; paper and board are produced from hard and softwoods however other materials can be used such as cotton, straw and hemp. wood is made from cellulose fibres that are bounded together by a material called lignin. in order to produce paper, these fibres must be separted.

   • Mechanical pulp; the logs of coniferous trees are saturated with water and de-barked. the wood is ground down which softens, the lignin and the mechanised forces separate the fibres to form groundwood pulp. the resulting pulp can be used for low grade paper such as newspaper. ADVANTAGES; investment costs for mechanical pulp mills are relatively low in comparsion to other ones. well suited for bulk grades of paper (newspapers). DISADVANTGES; Lower strength characteristics than softwood chemical pulps. paper can yellow when exposed to light.
   • Chemical pulp; after de-barking the hard and softwoods logs are cut into 2cm chips along the grain. the left over pulp is stored and treated with acid or alkali. the amount of fibres produced are lower but the fibres are strong . ADVANTAGES; higher quality wood pulp produced with longer stronger fibres. waste lignin from the process can be burnt as a fuel. DISADVANTAGES; no chemical pulp is produced in the uk therefore it must be imported.
     • Carbon fibre is a carbon composite made up of caron fibres and polyer resin matrix. its used for high performance structural in aircraft f1 racing and sports equipment. it 4 or more times stronger then the best steel alloys. it has a excellent strength to weight ratio, better than steel alloys. however the lows are its expensive, only comes in black, cannot be recycled.
   • waste pulp; recylced paper and board are used for waste pulp used for lower grades of paper. pulp are often mixed with virgin fibres to produce better quality papers. ADVANTAGES; makes use of recycled papers which is a sustainable resource. DISADVANTAGES; does not save any more energy in processing.
   • Properties of paper and board; the correct choice of paper must satisfy the design requirements of the client brief (colour, surface finish, size and weight. the demands of the printig process and the economic considerations (scale of production)
   • metals; ferrous metals; steel and has other substances eg carbon steels. non ferrous metals; contain no iron (alumimuim and tin). alloys; are formed by mixing to or more metals such as steel alloy or aluminium alloy.
     • Metals in commerical packaging; metal are used in a wide range of ways and these are the advantages; added security, containes can be made in a range of shapes, containers can be embossed.
     • Aluminium; is a strong but lightweight metal. it is a non ferrous metal so it does not rust. its a pure metal and is a naturally occurring element. Aluminium has good strenght and lightness and has a excellent strenth to weight ration. copper has good strength and is hard and tough. these also have a good casting ability. TIN is a tin oxide. it most important propertie is the ease with which it alloys or mixes a range of other metals. STEEL; is used the food packaging. its produced for the iron ore which is mimed so it takes alot of energy. Carbon steel has good strength and rigidity and is excellent resistance to rust. chromium has a high quality finish, is 100% recyable however steel is expensive and is hard to machine.
   • Polymers are a thermoplastic which once heated can be formed in range of shapes using different forming techinques such as blow moulding. they can be heated, softened, shaped and cooled many times. they are lightweight and verstaile, strong, tough, rigid, durable, recycable, and inexpensive. Polymers can be used is packaging as they can be identified by an coding system which is mouled into the base of the package. they enables polymers to be easily indetified.
     • the main disadvantge of the widespread use of polymer is how sustainble it is as oil is the raw material of syntheric poymyers and this consumers a lot energy. also polyemers also degrade very slowly which is a problem for landfills. so RECYCLING is the answer to this problem however recylcing has its own problem of collection and sorting.
   • Styrofoam is a blue or pink extruded polystyrene foam. its an excellent modelling material. it has a great rigidity, easily cut, high compressive strength. it comes in range of thickneses and can be painted with acrylic paint which gives a high quality finish. this can be achinved by layers of plaster, sanding and using spray paints. however its has disadvantges such as its weak and surface breaks very easliy and the surface can be also become dented.
   • Acylic; is the common name for polymethyl. it comes in sheets but can also be found in tubes and tods and does not require a surface finish. its used on range of ways such as graphic work to architectural display or point of sales displays. it also withstands extreme weather conditions and is durable. its also used on illuminated signage. the main disadvantges is its brittleness and its low scrath resistance. it lows cracks very easily therefore create care must be taken.
   • hardwoods; are produced from broad leaved trees whose seeds are enclosed such as oak, ash and elm. hardwoods grow in warm countries such as africa and are usally strong and tough. because of there age and location they are expensive and are only used for high quality products. the only excepetion is balse wood.
   • Softwoods; are made from needle like leaves such as pine whitewood. they grow more quickly than (30 years) so they can be replanted and forested which means they are cheaper to buy. softwoods are easy to work with and are lightweight they are also sustiable for modelling materials however like all woods they have a grain that makes them hard to shape when modelling.
   • composites are two or more materials and are bonded. the resulting material is improved mechanical, fuctional therefore giving a excellent strenght to weight ratio.
   • glass reinforced plastic are a composite made up of polyester of resin reinfoceced by fine fibres of glass and then plastic. these two materials becomes something that is compressive and tensile strength. it rivides a lightweight rigid structure. used for wind turbine, has a excellet strength to weight ratio, water resitant, wide rnage of colours can be added to the pigment. however the lows are its expesive and a high quality mould is needed.
   • Medium density fibreboard is made from wood waste. its used for plat pack furniture, moulds and forming processes. it comes in large sheets and thicknesses, the lows are it swells and breaks when waterlogged and is heavy as resins are heavy.
   • phospgorescent pigments often known as afterglow materials. they absorb energy or charge in daytime and can even store the charge. they are used in paints and inks and safety signage.
   • electroluminescent lighting converts electrical energy into light. it has a extremly low power consumpution which makes it ideal for use of backlight for LCD displays. its also used in posters and display which need a high impact.
   • Smart materials; are new or improved technologies. they respond to differences in temperature or light and change in some way as a result. they are called smart because they sense the condistions in their enviroment and respond to the conditions.

2. Manufacturing paper using the fourdrinier process. the fourdrinier transforms wood pulp into a final paper. the wet ends starts with the wood pulp diluted to 99% water and 1% fibre to form a slurry. the press section uses a system of nip presses or rollers that wrings out the majoirty of excess water from the pulp and stretches it out into a rough paper. the dryer section dries the paper using a series of steam-heated rollers by removing the moisture (ironing clothes). the calendar section; comprieses a series of rollers through which the paper is fed into. the paper is than put into a web and stored.

3. Paper weight and size; paper is defined in weight at gsm with 80 gsm being the weigh of a average copier paper. Layout paper; 50 gsm, thin translucent paper with a smooth surface, applications; outline sketches of proposed page layouts. translucent property allows tracing. cost is relatively expensive. TRACING PAPER; 60-90gm, thin tranparent paper with a smooth surface. pale grey in appearance. some as layout paper. it also allows tracing and its heavier weight can be quite expensive. COPIER PAPER; 80 gsm, lightweight grade of quality paper and is used for B/W photocoping and printing from inkjet and laser printers. smooth finish, its looks bright white and comes in alot of colours. inexpensive when brought in bulk. CARTRIDGE PAPER; 120-150 gsm, creamy white paper and is used for good general purpose drawing paper. its more expensive than copier paper.

   • Commercial printing papers; BOND PAPER; high quality durbale writing paper which often has watermarks; used for letter heads and electronic printers, its widely used for graphic work. its inexpensive when brought in bulk. COASTED PAPER; 70-300 gsm; used for wide range of high quality jobs. Relatively expensive.
   • Commercial card and board; RECYCLED CARD, 220gsm, card from waste pulp and is eenvironmentally friendly. lower quality than cards and is inexpensive. MOUNTING CARD; 1000-1500 gsm, thick board with white back. used for mounting work for presentations, very high quality and strong and is expensive.
   • liquid crystal displays; are organic carbon bases compounds that exhibit both liquid and solid crystal characteristics. when the cell has high voltage in which the lights falls, it goes dark. this is caused by molecular rearrangement within LCD.

4. Cartonboards; are used in retail packaging industry. the advantages if using cartonboard are total graphic coverage and excellent protection. FOLDING BOXBOARD; used for food packaging and all carton applications. its also had a excellent printing surface and is relatively inexpensive. SOLID WHITE BARD; packaging for frozen foods (ice cream) its very strong and rigid however is expensive. FOIL LINED BOARD; pre-packed packages; very strong visual impact. is expennsive.

5. thermochromic liquid crystals are used in products such as forehead thermometers, battery test panels. in a forehead thermomter a layer of conductive ink is screen printed on to the reverse of the thermometer strip. by put on the forehead the themochromic ink turns transucent reavling the body temprature.

6. smart ink; also know as electroic ink or electroic paper is a display techinolgy designed to mimic the appearnace of odinary ink paper. its being developed for applications such as electroic books and momory effect that requires no power to mainain an image.

7. radio frequency identifiation; is method of identifaction that used tags stuck of products to store. the method is used to track pallets of products from the manufacture and retailer. its also used in library for books so they can identify the book and lender which prevents fraud and theft. RFID is based around the transimission and recaption of RF signals between the transimitter (reader) and the reansponder (tag). active transponders are battery powered and can be read over greater range (tens of meters) and are used of cars and shipping contianes. passive trannsponders take the paower they need however the strength falls and are used in pallet tracking or secuity syetems in libraries.