paper 2 revision Flashcards
what are the 4 types of commercial manufacture?
- one off manufacture
- batch manufacture
- mass manufacture
- continuous manufacture
what is one-off manufacture?
when a single product is produced by a highly specialised craftsman
what is batch manufacture?
a small batch of identical products produced by highly skilled workers (e.g. chairs)
what is mass manufacture?
a large amount of identical products are made, highly automated with low-skill workers. maybe injection moulded parts
what is continuous manufacture?
extremely high volume 24 hour manufacturing process, highly automated with low skill workers, high demand consumer products (e.g. plastic bottles)
advantages of computer aided manufacture (CAM)
- high volume high pace
- costs are low when high volumes are produced
- identical products
- high level of detail
- reduced waste
disadvantages of computer aided manufacture (CAM)
- everything stops if a machine breaks
- reduction in employment opertunities
impact of emerging technologies
- job availability for skilled workers
- less labour intensive jobs
- reduction in work related injuries
- economic impact on the local area
- unemployment in local area
advantages of manufacture in developing countries
- cheap material costs
- low cost labour
- increase profits
- skilled workforce (highly trained labour force)
- low running costs (e.g. electricity)
advantages of 3D printing
- high level of accuracy
- repeatable process
- no craft skills required
- one off parts quickly made
- no need for moulds
what is injection moulding?
- a manufacturing process that allows parts to be produced in a high volume
- it is most typically a mass manufacturing process
- used for complex shapes like toys, remote controls, buckets, toothpaste caps, etc.
what is the process of injection moulding?
- melt plastic pellets
- inject into a 2 piece mould
- wait until solidified
- remove the mould
what is rotational moulding?
rotational moulding is a plastic manufacturing process which is ideal for making large hollow products, such as kayaks
what is the process of rotational moulding?
- fill empty mould with material
- heat and rotate mould
- cool mould
- unload mould
what type of plastic is used to rotational mould?
Polypropylene (PP)
how is rotational moulding identified?
hollow plastic product with mould split lines
what is the process of vacuum forming?
- heat thin sheet of plastic to forming temperature
- stretch onto single-surface mould
- force against mould by vacuum
- eject product from mould
what plastic is needed to vacuum form?
thermoplastic, such as:
- polystyrene
- ABS
- acrylic
- polypropylene
what is vacuum forming typically used to make?
packaging
properties of vacuum forming
- easy to form with low forming temperature
- needs round edges to form so material doesn’t split
- high impact strength
- low levels of shrinkage when cooling
properties of laser cutting
- use acrylic
- can only print 2D flat parts
- drawn on CAD
- laser leaves a clean cut which doesn’t require a finish
what is die-casting?
it’s a metal manufacturing process which is much like injecting moulding but with metal
how can you tell if a product has been die casted?
solid metal product with intricate details or surface pattern and sprue marks it ejector pin marks
what is sand casting
a metal manufacturing process in which a 2 part mould is made from sand
disadvantages of sand casting
- labour intensive
- mould lines
- parts can be brittle
what materials are tools typically made from?
high carbon steel or tool steel
why must tools be made from strong materials?
they must:
- be able to withstand forces (pushing/twisting)
- be resistant to wearing out
- have a higher melting point than material of product being manufactured
what type of plastic is needed to injection mould?
thermoplastic, but only ABS or polypropylene (PP)
how can you know if a product has been injection moulded?
injection moulding can be identified by:
- mould split lines
- pin marks
- tapered edges
