Fichas
Casting and Moulding
Fichas del conjunto (10)
- 1explain press moulding?some thermosetting plastic powder e.g. melamine formaldehyde is put into a female mould
A former male mould is pressed onto it and pushes the plastic into the mould
very high temps and pressures liquefy the powder and the plastic is set into a permanent shape - 2draw a simple labelled diagram for blow moulding
- 3explain vacuum forminga sheet of thermoplastic (e.g. polypropylene or HIPS) is heated until it goes soft
a mould (often made from MDF) is then put onto the vacuum bed. The bed is then lifted close to the heated plastic
the air is sucked out from under the plastic creating a vacuum, the air pressure from outside the mould then forces the plastic onto the mould - 4explain blow moulding, what is this process often used to make?a tube of soften plastic is inserted into a solid mould
air is then injected which forces the plastic to expand to the shape of the mould
the mould is then opened to remove the product
> bottles and containers - 5explain die castingused to mould metals and thermoplastics
the material is melted and poured into a mould (the die) which is the shape of the product
some plastic resins can be cold-poured into moulds (without heated) they harden or set through a chemical reaction - 6draw a simple diagram for press moulding
- 7explain injection mouldingthe molten material is forced into a closed mould under pressure
moulds are often made from tool steel so they're quite expensive
the plastic is often melted using built-in heaters
this is an industrial process which is usually automatic and continuous - 8draw diagram for injection moulding
- 9explain extrusion what is it used for?very similar to injection moulding however it produces long continuous strips of the moulding exactly the same shape as the exit hole,,, plastic covered wire and plastic and aluminium edgings
- 10what is the difference between injection moulding and extrusion?injecting moulding means being put into a mould to set whereas extrusion creates continuous strips the same cross section of the die
extrusion allows you to choose two dimensions and length, moulding allows 3D designs
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- GCSE (SECTION TWO) RM Fichas sobre Casting and Moulding , creado por Lily Pritchard el 23/04/2016.
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- Lily Pritchard
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