Product Design Flashcards
give me 5 polymers and there uses?
PET (plastic bottles) PVC (Windows) HDPE (Toys) Thermosets (mixed chemicals together, epoxy resin+aroldite) LDPE (plastic wallets)
name 6 properties?
tensile stiff tough durable ductile bending
name 5 non ferrous metals?
zinc gold aluminium platinum copper
name 3 ferrous metals?
cast iron
steel (mild or medium carbon)
what stock forms can you get metals in?
sheets ingots rods tubing bars
what is a ferrous metal?
a metal that contains iron
what are 4 manufacturing boards?
MDF
plywood
hardwood
chipboard
give me 3 properties about hard woods?
expensive tighter grains thicker, so harder to get in longer pieces. only come to the size of the tree slow growing
what happens within spinning?
there is two clamps on either side that holds the machine together, they use a stock form sheet of metal which Is spun around the mandrel which is turned by a specific roller which is an a forming tool, which pushed the sheet metal around the mould. it creates hollow products; like bowls and cups.
what happens within deep drawing?
the “punch” is pushed onto the blank and the metal goes around the mould, a bit like punching. the mould pushes the metal to create a hollow can for like cans or tubing. wall thickness becomes less that a 1/3.
what is punching and piercing metals?
punching is removing the specific moulded metal, it punches through the metal (holes created)
piercing is piercing holes through metals, it penetrates the metal.
what is blanking?
blanking is keep the moulded shape, the specific mould is placed and punched out the object.
explain the process of blow moulding?
the plastic pellets are put into the hopper, where they are vertically put onto the turning Archimedean screw which is turned by the gearbox. The polymers start going along the screw until they get to the heaters where they are softened to get extruded vertically down the extruder into the mould, by passing the parison. They enter the specific mould where hot air is blown up into the mould so that the polymers can make its shape. it’s then cooled down by removing ejector pins and removed any flash.
what is compression moulding?
is where the mould is heated up and also uses forces to create the product. the top mould halve punches onto the “preformed slugs” where they are melted and made into the shape of the bottom mould half.
what’s press forming?
press forming is where the die (top mould) used force to punch the “blank” into the bolster’s specific shape.
What is an alloy?
A mixture of metals to use a variety of their different properties
PET is a type of plastic, but what characteristics does it have and what is it used for?
good chemical resistance, it can be used within clothing for protection and also electrical plugs.
What properties does LDPE have and what is it used for?
it has good chemical resistance and also low density (lightweight) it’s used for toys and carrier bags.
what does HDPE stand for?
high density polyethylene
What properties does HDPE have and what is it used for?
it has good stiffness, high density and good chemical resistance. it’s used for crates and buckets
name 3 types of thermosets?
epoxy resins, urea formaldehyde and polyester resins
Name 2 advantages of blow moulding?
once set up, blow moulding is a quick process so can be made in mass production and also non circular shapes can be produced.
name 3 advantages of rotation moulding?
one-piece moulding can be produced.
a large range of sizes are available.
cheaper moulds allow lower production runs.
what is extrusion?
is the process used where products with a continuous cross section are required.
name 1 advantage and 1 disadvantage or extrusion?
they are generally low costing and only requires one simple die.
it’s main disadvantage it can only produce continuous cross sectional shapes.
what are the properties of aluminium?
good corrosion resistance, good surface finish, lightweight, its a relatively soft metal therefore can be bent into any shape and also it has good strength.
what are the properties of Carbon fibre?
lightweight, its a composite material therefore has uses of both properties, strength, high stiffness and used for like F1 cars.
what is a smart material?
is where the properties of a certain material can change due to a specific stimulus. e.g. thermo chromic- used for testing temperature of babies food bottle.
describe the 4 processes of steam bending?
- the veneers of wood are stuck together by resin.
- then they are CNC routered into it’s specific shape.
- it’s then steam bent in the machine and wood becomes softened.
- it’s the put into a specific mould and dries Into that shape.
what are the properties of polypropylene?
food safe, good impact resistance, good chemical resistance and light weight. used for most polymer based products and also medical equipment.
how would you finish wood?
varnish, painting, waxing, removing dust (sanding) and also natural barriers such as oils.
how would you finish metals?
deburring, electroplating, powder coating, filing and painting e.g. spray painting.
what are the two ways of cutting wood?
quarter sawing- where you cut to the size you want.
slab sawing- cutting to the size of the tree.
what are the properties of plywood?
layers are each at a 90’ angle, therefore strong as it’s all equal, it has on the outer face an odd number of layers, therefore the grain would be exactly the same on both sides, it’s made from veneers of wood stuck together by resin, and also it can come in many sizes as its man made
what attacks each wood?
hardwood- “death wood beetle” which lays it’s eggs In the wood and they crawl out, leaving holes.
softwood- “woodworm” which eats through the wood.
what defects can wood have?
warping- is where the wood becomes damp and dried again, it caused the wood to curl at the ends.
bowing- same process but the wood becomes like a U shape.
knots- where branches have began to come out of the wood, it reduces the woods strength.
give 2 positives about timber (wood)?
its sustainable as we can grow more
they are renewable.
what is the thermoset “Ureaformaldhyde. used for and it’s properties?
used for plug sockets- as it’s a good insulator and good stiffness.
what is foam board used for?
making models, as its cheap, recyclable and also easily to mould into shapes.
what is biodegradable?
e.g. plastic bags, the polymers break down due to natural barriers.
..its environmentally friendly
.. saves cost in landfills
.. however, If someone wanted to use them in the future and went to get it, it would have been in pieces. (not long lasting)
what is a memory shape alloy?
where a metal remembers it’s specific original shape due to the design of it, e.g. bending glasses back to shape.
what is the material used for smart materials? and why It is used?
thermo chromic- pigments, sheets etc.
its used because its a visual indicator.
advantages and disadvantages of rotational moulding?
start up costs are expensive, moulds are expensive, can create many sized containers and also makes one piece products.
adv/ disadvantages of injection moulding?
makes complex 3D shapes, moulds are expensive, mass produced quickly and also initial start up costs are high.
what is meant by CNC?
where a computer controls equipment such as machinery and tools. it is controlled by numeric data. e.g. CNC router.
what is a screw called?
archimedean.
describe the process of vacuum forming?
there are clamps on either side, and the plastic is placed on top of the mould, where it is softened and compressed air is pulled from the mould so that the plastic takes the shape of the mould. (comes fro, the vents). a draft angle of 3/5’ is on the mould, so that the plastic can be easily removed.
what are the properties of PVC?
used for window frames, it has good stiffness, good chemical resistance and lightweight.