1.3 Enchancements Flashcards
What are the 10 polymer enchancements
Antioxidants, Antistatic, UV light stabilisers, Biodegradable plasticisers, Fillers, Flame retardant, Lubricant, Pigment, Plasticisers, Thermal antioxidants
What polymer enhancement is “reduce the deterioration of a polymer from exposure to oxygen in the air which can lead to brittleness, surface cracks and discolouration”
Antioxidants
What polymer enhancement is “reduce the build-up of static charge by improving electrical conductivity slightly which attracts moisture from the surroundings and helps prevent the build-up of dust and dirt on plastic parts with electrical internals.”
Anti statics
What polymer enhancement is “help prevent polymer molecular chains from breaking due to sunlight (UV energy). UV attack causes fading of colours or yellowing, brittleness and surface cracks”
UV light stabilisers
What polymer enhancement is “are used to speed up degradation times e.g. oxy-degradable additives added to carrier bags to ensure the bag disintegrates”
Biodegradable plasticisers
What polymer enhancement is “reduce the amount of polymer required (saving money) and some minerals e.g. chalk can increase the thermal conductivity of a polymer meaning it will heat up and cool down more quickly; which gives shorter mould cycle times (faster production rates)”
Fillers
What are the 3 wood preservatives types
Copper based, pigmented preservatives via pressure treatment, Cellulose based
What polymer enhancement is “are used to make plastics softer and more flexible e.g. PVC vs uPVC. Also useful in polymer production as they help to decrease the viscosity (aiding flow) and lower the polymer’s softening and melting temperatures”
plasticisers
What polymer enhancement is “reduce the likelihood of combustion or the spread of fire”
flame retardants
What polymer enhancement is “reduce the viscosity of molten polymer material to help it flow more easily and fill intricate mould cavities. They save energy/money compared to raising the temperature of molten polymer to reduce viscosity”
lubricant
What polymer enhancement is “are coloured particles that are mixed into a molten polymer to add colour”
pigment
What polymer enhancement is “help prevent a polymer oxidising or discolouration due to excessive heat when being processed”
thermal antioxidants
How does cellulose based wood enhancements enhance the wood
harder wood
What are the 3 SCLs (Structural composite lumbers)
Glulam, LVL (Laminated veneer lumber) , OSB (Oriented strand board)
What are the 4 adv of SCL’s
Greater stability, Defect free, Great length, greater strength than concrete
How does copper based wood enhancements enhance the wood
better fungicidal properties
What are combined with SCLs to enhance them via flame retardance and moisture resistance
a resin
What happens inside the metal as it is work hardened (Cold worked)
Crystals distort and move
What are the 4 metal enhancement processes
Work hardening, Annealing, Case hardening, Frame hardening and tempering
What type of steel is case hardening used on and why
low/mild carbon steel as it doesn’t contain enough carbon to be hardened and tempered
What is the outcome of work hardening (cold working)
Improved strength and hardness however can lead to more brittle
What happens inside the metal as it is annealed
crystals regrow or rearrange themselves
What is the process of annealing a metal
heating the metal and slowly leaving it to cool
What is the adv of case hardening metal
provide the steel with a harder shell and tougher core
What is the process of case hardening
Heating the steel in a container of carbon powder at a high enough temperature so carbon can diffuse onto the steel surface. The hot metal is then quenched in water to seal the surface
What are the benefits of annealing a metal
reduced brittleness
What are the adv of flame hardening and tempering
Develops the optimum combination of hardness, strength and toughness
What type of steel is flame hardening and tempering used on
med/high carbon steels
What is the process of flame hardening and tempering
Heating until red for some time and then quenched in a solution (Water or oil). The metal is then tempered where the metal is heated to a specific temperature and then lowered to a temperature for some time then quenched
