Edexcel – Product Design: Graphics Other Materials Edexcel – Product Design: Graphics

Other Materials Composites Modern materials and products materials made from two or more constituent materials with significantly different physical or chemical properties Modern materials and products Smart Materials have properties that react to changes in their environment

Composites Carbon fibre Glass reinforced plastics (GRP) Medium density fibreboard (MDF)

Composites Carbon fiber Sports equipment Excellent strength to weight ratio Very expensive, only available in black, hard to recycle high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance, low thermal expansion,

Carbon Fiber Production The carbon atoms are bonded together in crystals Atoms are aligned parallel to the long axis of the fiber This gives the fiber high strength-to-volume ratio (making it strong for its size). Several thousand carbon fibers are bundled together to form a tow Can be used by itself or woven into a fabric.

Carbon Fiber Advantages Excellent strength to weight ratio Better tensile strength than steel alloys Can be formed into complex and aerodynamic one piece structures Disadvantages Very expensive Only available in black Highly specialised manufacturing required Cannot be easily repaired as structure loses integrity Cannot be easily recycled

Composites Glass reinforced plastics (GRP) Vehicle bodies Excellent strength to weight ratio Expensive, high quality mould needed GRP, sometimes called glass fibre. is stranded glass that is set in a polyester resin . The glass fibres are approximately 50 mm long and are bonded together in a flexible mat. The polyester resin is in liquid form. A catalyst, or hardener, is added to the res in to start a c hemica l reaction and make the resin set. A colour pigmen t is also normally added. The glass fibres proVide strength , while the resin bonds the fibres and prov ides, in the gel-coat, a smooth surface finish.

GRP How it’s made: Highly polished mould Mould covered with release agent First layer is gel coat (coloured polyester or epoxy resin) Polyester resin and catalyst/hardener is mixed to ensure resin ‘sets’ Chop strand mat/glass fibres or woven wordings used Layers of polyester resin and chopped woven & layered on mould air rolled out of polyester resin, CSM layers Can be hand rolled or use resin/CSM spray gun Edges need to be trimmed after lay up Mould is removed leaving shell structure

GRP Moulds

GRP

GRP Advantages Excellent strength to weight ratio Resistance to corrosion Water resistant Ideal for external shell structures Wide range of colours (pigments added to resin) Can be repaired easily Disadvantages Expensive material Specialised manufacturing process required High quality mould needed

Composites Medium density fibreboard (MDF) Flat pack furniture Consistent in all directions Heavier, dulls blades quicker

MDF Advantages Less expensive than natural timbers Available in large sheet sizes and range of thicknesses No grain (so no tendancy to split) Consistent strength in all directions Disadvantages Heavier (resins are heavy) Requires appropriate finishes to seal surface fibres Swells and breaks when waterlogged Warps or expands if not sealed Duls blades quickly Contains urea-formaldehyde which causes eye and lung irritation when cutting and sanding

Modern materials and products Liquid crystal displays (LCDs) Phosphorescent pigments Electroluminescent (E.L.) lighting

Modern materials and products Liquid crystal displays (LCDs) Digital watches and TV’s Goes dark when a voltage applied In TV’s has RGB layers

LCD Displays Benefits Slim/lightweight/suitable for portable devices Quick response to data input Range of colours on display Can be used to display photos/ moving images/web/email Low power so very little battery use Clear to see/high resolution

Modern materials and products Phosphorescent pigments “Glow in the dark” Absorb energy from light and stores it during the day Releases slowly at night

Modern materials and products Electroluminescent (E.L.) lighting Used for LCD backlighting and advertisements Converts electrical energy into light Waterproof and highly visible

E.L. Lighting How it works: Coverts electrical energy into light Power is applied across electrodes Organic phosphor sandwiched between the electrode conductors When electrical charge is applied phosphor crystals are charged Phosphor crystals emit radiation which is seen as light (different organic compounds emit different colour light/green/yellow) Features Extremely low current/very high voltage Low energy consumption Can be ‘packaged’ in variety of panels/wires/strips for different applications

Smart Materials Thermochromic liquid crystals/film Piezoelectric crystals Smart ink Radio frequency identification (RFID)

Smart Materials Thermochromic liquid crystals/film Reacts to temperature E.g. Forehead thermometers The conductive ink is screen printed onto film (or other material) – on the back On top is a layer of normal ink (if needed) There is then a thermochomic layer, which is black when cool

Smart Materials Piezoelectric crystals Converts movement into electricity and back Used in inkjet printers to push out ink Convert kinetic energy (movement energy) into a voltage Expands and contracts when electric current is applied

Smart Materials Smart ink Also known as electronic ink (or e-ink) Kindle Displays only use energy when the display is refreshed

Smart Ink (e-ink) How it works: Top transparent electrode, bottom electrode Clear fluid Negatively charged black pigment/beads Positively charged white pigment/beads Labels for +/- charges on bottom electrode

Smart Materials Radio frequency identification (RFID) A method of identification Uses tags to store and track data Used in libraries, factories etc Benefits / uses: Replaces need for regular stock management/inventory control Reduces labour costs due to ability of self-scanning Reduces theft/allows link to store security Allows for easier stock/product identification Reduces re-stocking/JIT stocking of products Allows product tracking Allows for sales analysis/track how many are being sold

RFID: Features Radio waves/wireless system to transmit/ store data. A method of identification using tags. Transmission is two way. The transmitter sends a signal. The transponder receives the signal. The transponder transmits a response signal. Transmitter then receives the signal. Transmitter also known as the reader. Transponder known as tag. Tag is attached to the product. Transmitter identifies position of the tag / product.

RFID Disadvantages of RFID Potential loss of privacy (1) Passive (receive only) and active (transmit and receive) tags can be inbuilt into labels and products (1) Auto price checking (1) Stock levels can be measured automatically/Auto reordering when low (1) Don’t have to scan products so reduces queue time when purchasing goods (1) Anti theft properties/alarm trigger as products tags can hold unique info (1) Marketing information can be made available/tracking product sales (1) Simple to install in products for tracking (1) Not easy to replicate information held (1) Do not require direct line of sight to work (1) Range can be greater distance (1) Disadvantages of RFID Potential loss of privacy (1) Big brother is watching you scenario (1) Interference can hinder reception/affected by certain materials (1) Range can be short: Passive (1) Reliability still not known as RFID is relatively new (1) Could be used by non-emergency services/ non-official services to monitor (1) Adds cost (1)

Task On the computer on the student dropbox: Fill out the sheet Subjects and Departments / Design Technology / Graphics / Year 12 Open the topic you are given Fill out the sheet Write a brief description for each material Find images of example products Advantages and disadvantages of each material Composites Modern materials and products Smart Materials