Please enable JavaScript.
Coggle requires JavaScript to display documents.
Polymers - Coggle Diagram
Polymers
Moulding and joining
Injection moulding
-
Plastic granules are inputted via a hopper into the screw chamber where the plastics melt through the motion of the screw in tandem with external heaters
Then the melted plastic is then pushed into the injection chamber where it is pushed under pressure into the pre made mould
-
Extrusion
-
Instead of being pushed into a mould to produce a single product, it produces long continuous strips of the moulding exactly the same shape as the exit hole e.g plastic covered wires
-
Polymer can be welded
Using high temperatures, polymers can be welded together - the process melts the edges of the joint so that they flow together
Solvents can also be used to weld polymers by chemically 'melting' the polymers to join them together
-
Uses
example: Polymer seating
-
-
Tough, flexible and strong so can withstand people sitting down on them over and over again
-
When looking at what a material is good at, look at the material and it's properties to see what it use suitable to be used for
-
Polymers properties
-
Thermosetting plastics
Epoxy resin (ER)
Rigid, durable, corrosion resistant - used in circuit boards
Urea formaldehyde (UF)
Electrical insulator, hard - used in plug sockets
-
Phenol formaldehyde (PF)
Hard, heat resistant easily moulded into bottle caps
Polyester resin (PR)
Hard, stiff, cheap and good electrical insulator. Added to glass to form GRP used in kayaks
Thermoforming plastics
Acrylic
Hard, stiff, shiny, used for helmet visors
-
PET
Polyester that is light, strong and tough used for fibres for clothes
-
Polyvinyl chloride
Cheap, durable, brittle - used in blister packs, vinyl records
Polypropylene
tough, flexible - used in plastic chairs
-
Finishes
Polymers are self finishing so they don't need protective surface finishes as they're resistant to corrosion and decay
However, plastics can be decorated to improve aesthetics e.g decorative vinyl decals or designs printed directly onto the plastics
