Moulding/forming Processes Flashcards
Injection Moulding
Step-by-Step
-Moulds clamped together
-plastic pellets are poured into hopper
-pellets are pushed through by archimedes screw whilst being melted
-once at end of screw, plastic goes through the nozzle and into the mould
-plastic then cools and hardens
-ejection pins then push out the product from the mould
Blow moulding
Step-by-Step
-Plastic is fed into a hopper
-heated plastic granules are injection moulded into a pre-formed shape
-air is then forced into the mould which gives the shape of the product
-cooled and then removed
Extrusion
Step-by-Step
-Raw materials + colourants put inot hopper which goes to the extruder
-Materials then enter the barrel and forced out by a rotating screw
-Material is passed through the extrudate and then cooled in shape
-The extruded component is then pulled out
Vacuum Forming
Step-by-Step
-Make the desired mould shape
-place mould into vacuum former
-Heater is positioned above the plastic sheet
-When plastic is at a jelly-like form, the shelf holding it is pushed down on the mould
-vacuum is then turned on to suck air out
-cooled down and air goes back in and the sheet is removed with the desired shape
Rotational moulding
Step-By-Step
-A hollow mould of desired shape is made
-mould then has colourants and thermoplastic put inside it
-mould then rotates “bi-axially” in an oven coating the interior walls
-the mould is then cooled and hardened
-the rotation is then stopped and the desired shape is taken out the mould
Thermoforming
Step-by-Step
-a sheet of thermoplastic is heated to jelly form
-the sheet is then vacuum formed over a core mould
-it is then pressed by the cavity mould
-it is then cooled and taken out of the mould
Blow Moulding
Step-by-Step
-Granules of plastic are fed into the hopper to be stored
-they are then heated and injection moulded into a shape that is ready for the mould
-air is then forced into the mould and pushes the plastic against interior walls of the mould
-The mould is then cooled and removed
