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  • Created on: 10-01-13 19:29

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Product Design Revision:
There are 3 types of plastic:
Thermoplastics- can be reheated and reshaped as they have loose monomer chains, can be recycled
and coloured pigments can be added to make it more aesthetically pleasing.
Thermosets ­ undergo a chemical change so permanently rigid, cannot be reheated or reshaped as it
forms rigid cross links, e.g. spoons
Elastomers ­ can be distorted under pressure but will return to their original shape
The properties of plast6ics are:
Electrical and thermal insulators
Good strength to weight ratio
Good atmospheric and chemical corrosion resistance
They are lightweight
Fairly low melting points (thermoplastics)
They can be self-coloured, opaque, translucent or transparent
Common Working name Characteristics Common uses Manufacturing
name process
ABS High impact strength, giving good Kitchen products, mobile phone Injection
toughness and strength, scratch- cases, safety helmets, toys, car parts moulded
resistant, li9ghtweight durable
PC polycarbonate Good chemical resistance, expensive, Protective shields, safety hats and Injection
very tough, high melting point glasses, hairdryer bodies, telephones moulded
PP 5 Polypropylene Lightweight, food safe, good impact Food containers, medical Injection
and chemical resistance equipment, string and rope moulded
HIPS High impact Good impact resistance, good Toys and refrigerator linings Vacuumed
polystyrene strength and stiffness, lightweight formed
PMMA 7 acrylic Food safe, tough, hard, durable, Light units, illuminated signs, lenses Hand/CAM cut
easily machined for car lights
HDPE 2 High density Good stiffness, good chemical Crates, bottles, buckets, bowls Injection
polyethylene resistance moulded
LDPE 4 Low density Lightweight, low stiffness and Detergents bottles, toys, carrier bags Blow moulded
polyethylene rigidity, good chemical resistance
PET 1 Polyethylene Moderate chemical Clothing, blow moulded bottles for beer and Blow moulded
terephthalate resistance soft drinks, electrical sockets, video tapes,
insulation tapes
PS 6 polystyrene Lightweight, rigid, colourless, low Packaging, disposable cups, sound Vacuum formed
impact strength and heat insulation, yoghurt pots
PVC 3 Polyvinyl Good chemical and weathering Hose pipes, cable insulation, drain extruded
chloride resistance, hard, rigid, tough, pipes packaging
lightweight, can be coloured
Epoxy Good chemical and wear resistance . Adhesive for bonding wood to metal, plastic to
resins metal..
Polyester Good chemical and wear resistance Used for casting (pouring into a mould) mixed with
resin glass fibres to make fibreglass
Melamine Rigid, good strength and hardness, Plastic coating for Tableware,
formaldehy scratch-resistance, can be coloured. decorative laminates for work
de surfaces.
Elastomers: common ones are thermoplastic elastomer (TPE), thermoplastic rubber (TPR) and liquid silicon
rubber (LSR). Used for car bumpers and trims, and product grips (over mouldings)

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Joining plastics:
Plastic weld ­ a multipurpose adhesive that joins most plastics (not foamed plastic)
Tensol 12 ­ is good for acrylic, it is quick and easy to use, if spilt marks the work, not very strong
Rivets, nuts, bolts and machine screws can be used to join plastic
Fillers ­ used to reduce bulk of plastic so cheaper e.g. sawdust (increases strength and hardness)
Flame retardants ­ used to reduce risk of combustion, releases agents that stifle it.…read more

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produces very complex 3D shapes
Large numbers can be produced with consistent
Metal inerts can be included
Initial set up costs are high
Moulds are expensive
Blow moulding
A tube of softened plastic called a parison is extruded into a mould.
Blow moulding
1. A tube of heated and softened polymer, a parison, is extruded vertically downwards
2. The mould halves close, trapping the upper end of the partisan, sealing it.
3.…read more

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Mould halves loaded with thermoplastic powder and clamped together
2) The moulds are rotated whilst heated until it melts ensuring it covers all the mould
3) The mould is then cooled
4) The mould halves are separated and the product removed
Vacuum forming
This process uses a wooden mould or form. A sheet of thermoplastic is heated, then shaped by creating
a vacuum underneath it. Air pressure then forces the plastic over the
1. Plastic placed over mould.
2.…read more

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Press or compression moulding
A mould is made in two halves. Sheet plastic is placed between the
two halves, which are then heated and pressure applied, enabling
the plastics to assume the new shape.
Press moulding is used to make electrical fittings, handles, and
many other products. It can only be used with thermosetting plastics.
Extrusion moulding is used to produce long, but fairly thin products such as pipes or curtain tracks. Both plastics
and metal can be extruded.…read more

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They have equal strength in all directions unlike natural timbers.
E.g. man-made boards
material Image Common uses
Plywood Backs of furniture e.g. cabinets, bottom of drawers,
panelling ­ can be flexible for producing curved shapes.
It is very strong due to the grain of each ply is positioned
at ninety degrees to each other. The plies are glued
together with synthetic resin. Plywood is less likely to
warp or split, due to this construction.…read more

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Glass fibre:
This glass reinforced plastic ­ glass is spun to produce a fibre that is then coated to aid bonding to the
resin, it comes in a range of thicknesses
A mould is required, which can be made of woods, metals and polymers
"Laying up" is the process and inserts can be added
Can be used to manufacture vehicle bodies, sports equipment, canoes, boat hulls.…read more

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Pewter Low melting point, can be cast into detailed shapes.
Inert: does not react to liquids or oxygen so does not corrode.
Stock forms of metals are: sheet, tube, bar.
Sand Casting:
1- A pattern is made out of
wood or plastic, can be
complex shapes.
2- Each half of the pattern is
placed on a baseboard, and a
mould half box placed over it.
3- Green sand is `tamped'
around the pattern forcing
itinto contact, this is followed
by the backing sand.…read more

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Non-ferrous metals ­ doesn't contain iron, wont corrode, are not magnetic
o Alloy ­ a mixture of two or more metals e.g. brass, stainless steel
o Finishes ­ paint, dip in plastic, dip in zinc
Finishes ­ a surface coat applied to a material to protect and enhance its aesthetic properties.
Galvanising ­ is the process of plating mild steel with zinc to prevent rusting, e.g. steel fences.…read more

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Seasoning is the controlled drying of timber to increase its strength and stability, reduce moisture content
reduces the risk of the timber causing corrosion to the surrounding metal work. And it makes the timber less
prone to rot and decay.
Veneers: is a thin layer of wood that has been shaved off the trunk of a tree, usually hard woods because they
are more decorative and durable surface to inferior quality woods e.g.…read more



Oh my god thank you o_o This is perfect! Wish I'd looked here before xD


exactly wat i was looking for. thank you so much. 

Danni Bedster

Amazing! Thank you.


i think i love you


thank you soo much


i recommend this for anyone doing DT A-Level, its perfect. :D




This has made my revision so much easier... thank u :)




no one's commented for a while but... is this basically all you need for the exam? Regardless, this is a great help! :D

Matthew Nargol

Missing some vital content such as for the thermosets you havent listed the thermoset used for electrical fittings > Urea Formaldehyde. Its pretty vital that people know this as this is a common question. But very helpful notes apart from that so far, thanks!

Teddy Ng

Archemidial Screw in page two should be Archimedean screw as in mark scheme. I think


can you re-upload it or something? i can't see it x


A2 notes?


I can't access the file? Can you re-upload it please?


This is excellent! Really helps me for my revision.


Love this! How would you suggest I revise from these notes? 


i like crutons


they make me feel so much nicer inside

ruthie ainsworth

Thanks for this 

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