processes techniques t3

• What is the types of heat treatment?


  Hardening, tempering, quenching, annealing, normalising
• What is hardening?


  Process of making metal hard by heating and quickly cooling it in oil/water so it becomes very hard, but brittleness increase as steel is likely to break under pressure
• What is work hardening?


  Occurs when a non ferrous metal is cold worked( bent over time) which increases strength and hardness
• What is annealing?


  Through the application of heat when a metal is too difficult to work with it is annealed to relieve hardness and increase ductility which can change the physical and chemical properties of the metal
• What is quenching?


  A fast cooling process which seals the surface of a carburised metal whilst not affecting the properties of the inner core. Water or oil is often used.
• What is tempering?


  After quenching, steel becomes hard and brittle, so can be easily broken
• What is case hardening?


  Case hardening or surface hardening is the process of hardening the surface of a metal deeper underneath to remain soft, so forming a thin layer of harder metal at the surface, to be tough and durable
• What is normalising?


  Type of heat treatment that relieves stress on steel thus improves the ductility and toughness in steels that may harden after cold working
• What is a printing gravure?


  A simple technique used to apply printed matter from one cylinder to another, high accuracy, less set up stages , high costs as used in more high volume orders
• What are the parts involved in printing gravure?


  Ink bath, doctor blade, gravure cyclinder, impression cyclinder, substrate
• What is flexography?


  Form printing process which utilises a flexible relief plate, which ink is applied to various surfaces by means of flexible rubber, drys quickly, safe as comes constantly into contact with foods
• What is involved in flexography?


  Ink bath, water based ink, fountain cyclinder, doctor blade, flexible plate, plate cyclinder, impression cyclinder, substrate, anilox cyclinder
• What is screen printing?


  Transferring an image by forcing ink through a stencil (opening), very labour intensive, vivid colours, unpredictable blends
• What is offset lithography?


  A form of lithography in which ink is transferred to an intermediate printing surface before being transferred to the print medium, surface does not come into direct contact with the plate, CYMK
• What is sand casting?


  Sand casting, also known as sand moulded casting, characterised by using sand as the mould material
• what is resin?


  is quick and effective, used to cast directly from objects using a mould
• What is vacuum forming?


  Process of heating up the thermo plastics sheets, held in place by toggle clamps and vacuum pump sucks it over a 3D mould onto the platen, the wall thickness is very thin, always has rounded edges
• What is blow moulding?


  Blow moulding is mainly used for producing a variety of hollow containers such as bottles PP, PET, nylon, plastic billet heated up and blown inside then gradually inflated to form a 3D shape
• What is injection moulding?


  process of which heats up thermoplastic to inject it at high pressure into a 2 or more part mould, highly accurate, mass produced
• What is extrusion?


  Extrusion is used for both plastic and metal and heats the material up to force it through a sectional mould so it forms a cross section eg used for sheets and films, tubing and pipes
• What is involved in extrusion moulding?


  Feed hopper, plastic pellets, turning screw, barrel, heaters, shaping die, molten plastic, extrudate
• What is involved in injection moulding?


  Hopper, plastic granules, heater, reciprocating screw, barrel, nozzle, mold cavity, mold, moveable platen
• What is involved in vacuum forming?


  heater, thermoplastic, toggle clamp, mould, platen, vacuum pump
• What is rotational moulding?


  Rotational moulding is a technique used to produce large scale hollow objects, thermoplastic is loaded, heated up then rotated which attracts positive charge then a water jet is used to calm it down, cost effective, low cooling costs eg bin, chair
• What is lamination?


  Can be used with most materials to overall aesthetic or strength creating MULTIPILE layers eg chipboard