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49 Cards in this Set
- Front
- Back
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what is Bakelite is made from
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phenol formaldehyde
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describe the hardness and the brittleness of bakelite
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hard and brittle, brittleness removed by practising
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what kind of filler material is usually used for bakelite
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mica or wood flour
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where is bakelite widely used
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electrical mouldings and low stressed handles
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state three main groups of plastics
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1. Thermoplastics 2. Thermosetting 3. elastomers |
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what is the affect of acetone on Plexiglas
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white marks, but will not affect the strength
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List 9 thermoplastic material
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1. polyethylene 2. Polypropylene 3. polyvinylchloride (pvc.) 4. acrylics 5. nylon 6. polytetrafluoroethylene 7. polystrine 8. acetate 9. polycarbonate. |
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what is acetate used for
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tool handles and electrical goods
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what is used for polyethylene or polythene
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flexible tubing, cable insulation and packaging |
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what is polypropylene is used for
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high pressure piping
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how is the rigidity/flexibility of polyvinylchloride (PVC) is achieved
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by varying the amount of plasticiser used
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what is polystyrene used in its expanded (not the rigid form)
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shock resistant packaging, thermal insulation, and buoyancy
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what will a prolonged UV light do to an acrylic
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craze cracking
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what is achieved if an acrylic is stretched in both directions before shaping
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more strength and shutterproof
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what is a polycarbonate (compared to acrylic)
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similar uses as acrylics but, temperature-resistant, superior impact resistant and more expensive
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what family does nylon belong to
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polyimide
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state some of the properties of nylon
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tough, strong less friction
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state some of the popular uses for nylon
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pulley, handles, textiles, ropes, tyre reinforcement, light weight moulding
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what is the difference and the similarities between nylon and polytetrafluoroethylene
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similar appearance, denser and more expensice
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what characteristics gives the polytetrafluoroethylene its low friction property
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a wax like surface
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state the temperature capability of polytetrafluoroethylene
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up to 300 degree celcius
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what is polytetrafluoroethylene (in its tape form) used for
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as a thread sealant, (oxygen pipe threads) backing ring for hydraulic sealeant
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what better properties does thermosetting has over thermoplastics
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relatively high temperature endurance(250 degree celcius), stronger than thermoplastics |
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resins alone can form a plastic, but an additives are added, why
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to give more body, to enhance its properties such, fire retardant, smoke suppressant, to delay its natural curing
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state three inert fillers that is added to resins in order to give it more body
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mica, cotton, glass flock, fumed silica AKA Aerosil
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tell me something about fluoro-elastomers
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fluoro-elastomers AKA Viton, have high temperature resistant (250 degrees) they are resistant to solvents,
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tell me something about neoprene.
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its solvent resistant, it has good tensile properties and excellent elastic recovery, because of its elastic recovery property, it is used as a diaphram
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tell me something about ploy-sulphide rubber.
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its sealant, has a poor physical quality, exceptionally good resistant to fuels and oils, used sealing fuel tanks
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tell me something about silicon rubber
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it has good temperature range, meaning it tolerate a temperature as low as minus 80 degree Celsius and as high 200 degree celsius
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define fibreglass
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also known GFRP is plenty of glass fibres in resin
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what is difference in stiffness for GFRP, CFRP and AFRP
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CFRP is 6 times stiffer than GFRP and over 50% stronger
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at what temperature can GFRP CFRP can tolerate
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220 to 250 c
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what temperature can a carbon fibres in carbon matrix tolerate
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3000 c
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what would be the elongation to fracture of cfrp and gfrp
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why would you use a light alloy sheets to laminate a honey comb instead of a fibre cloth impregnated with resin
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where would you find all the necessary information of a backing ring
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how do you prevent a sealing ring from being extruded or squeezed out under the intense hydraulic pressure.
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what material would you use to prevent a seal being extruded out and why
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which direction should the concave of backing ring face (either U-ring or a V-ring)
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at what pressures would you use a U-ring
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if a sharp object strikes a thermosetting, it shatters like a glass, what is the reason
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list five types of damage that a fibre re-enforced structure can suffer
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crack, delamination, blister, debonding and holes.
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what could cause a delamination
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what do blisters often indicate
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what could cause a hole in the fibre re-enforced structure
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what is a roving
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how many types of bi-directional cloth are there, and what are they
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plain, which is one under, one over. Twill weave, which is over one, under two |
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what is the rigidity difference between the plain and twill weave.
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