Important flashcards
Properties of Glass reinforced plastic (GRP) (6)
- Lightweight
- Corrosion resistant
- Tough
- Hard
- Low thermal expansion
- Good compressive strength
Uses of Glass reinforced plastic (GRP) (5)
- Boat hulls
- Pond liners
- Kayak shells
- sports car bodies and parts
- Locomotive train cabs
Properties of CFRP (6)
- Lightweight
- Corrosion Resistant
- Tough
- Hard
- Good compressive strength
- Low thermal expansion
Uses of CFRP (5)
- Sports equipment such as bicycle frames and tennis racquets
- Fishing rods
- Racing Car bodies and parts
- Helmets
- Prosthetics
Properties of concrete (4)
- High compression strength
- Low tensile strength
- Few surface defects
- Easy to mould
- Can be situ or pre fabricated
- Very stable material
Uses of concrete (5)
- Pathways
- Beams
- Blocks
- Driveways
- House foundations
Vacuum forming:
- Polymer stock form
- Products
- Thermoplastic sheet up to 6mm thickness
- lightweight trays, box inserts and liners, takeaway coffee cups and yoghurt pots
Key features of vacuum forming (3)
- Moulds are relatively easy to make but need a draft angle, air holes and rounded corners
- Not cost effective for one-off manufacture
- Small-scale batch and mass production
Injection moulding:
- polymer stock form
- products
- Thermoplastic granules
- Electrical product casings (computers, TVs, vacuum cleaners, calculators
Key features of injection moulding (4)
- Complex 3D shapes can be easily made
- Fast industrial production method
- Used for large-scale mass or production
- High initial tooling cost
Blow moulding:
- polymer stock for
- products
- Thermoplastic tube ‘parison’
- Drink bottles, shampoo bottles, detergent bottles etc
Key features of blow moulding (3)
- Produces hollow thin-walled components
- High initial tooling cost
- Used for continuous production
Rotational moulding:
- polymer stock form
- products
- Thermoplastic powder or granules
- Traffic cones, kayaks, water tanks, kerosene tanks, children’s play equipment
Key features of rotational moulding (3)
- Seamless hollow components with a large wall thickness
- Mould continuously rotated through heating and cooling
- Large-scale batch of mass production
Compression moulding:
- polymer stock form
- Products
- Thermoset polymer charge ‘slug’
- Electrical light fittings, switches, plugs, picnic plates and cups
Key features of compression moulding (3)
- Uses a pre-weighed ‘slug’ of polymer
- Polymer removed from moulds
- Large-cale batch production
Press forming:
- stock form
- products
- Sheet
- Metal seats, car body panels, boxes and containers
Spinning:
- stock form
- products
- Sheet
- Body of stainless steel kettles, saucepans, metal light shades
Cupping and deep drawing:
- stock form
- products
- sheet (round blank)
- tube-like shapes such as fire extinguishers, aerosol cans, drink cans
Drop forging:
- stock form
- products
- Billet
- Spanner’s, pliers and screwdriver shafts
Wrought iron forging:
- stock form
- products
- Bar
- Decorative metalwork such as gate scrolls, decorative fencing
Key features of wrought iron forging (3)
- Uses wrought iron (carbon content less than 0.08%)
- Can be hand or hydraulic press process
- Suitable for one-off or small-batch production
Key features of press forming (3)
- Shapes sheet metal into 3D forms
- Often used in conjunction with robots for lifting sheet into place
- Suitable for mass production or large-scale batch production
Key features of spinning (2)
- Products May show parallel lines where the sheet has been forced onto the mandrel
- Suitable for small-scale batch production
Key features of cupping and deep drawing (4)
- Starts with a metal blank
- Metal is stretched into shape
- High initial tooling cost
- Used for large-scale mass or continuous production
Key features of drop forging (4)
- Used for products that need to be tough and hard
- Maintains the internal grain structure which retains the strength
- Hot metal billet shaped on an anvil or die and then pressed into shaped and cooled
- Suitable for mass production