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PLASTICS - Coggle Diagram
PLASTICS
PROPERTIS
The propertres of plastrcs depend on their type and on their comosition. Strength, elasticity, rigidity and flexibtflty are charactenstics of many plastics, although they vary from one type to another
JOINING PLASTICS
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PERMANENT JOINTS
We use this type of joint when we don't want to separate or dismantle
the pieces. We can use adhesives or soldering
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CLASIFICATION
TERMOSTABLE PLASTICS
These plastics are made from compounds dertved from petroleu. They are formed by strongly-linked chains running in different directions
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THERMOPLASTICS
We manufacture thermoplastics from compounds acquired from petroleum. They' re made up of weakly formed molecular chains.
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ELASTOMERS
Made by vulcanisationi mixing sulphur and rubber, and heating to 160'C They are hard, resistant and very elastic — stretching easily under
force They' re formed by chains linked laterally and then folded over
themselves, like a ball of wool or starting
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FORMATION TECHNIQUES
EXTRUSION
- We put thermoplastic, in granular form, Into a previously heated cylinder
- We apply pressure by means of a large, rotattng screw, whtch forces
the melted matenal out, through a nuzzle
- We cool the shaped material slowly In a refngerated water bath until
lt's solid
- Finally, we collect the pieces of plastic through a feeder system.
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LAMINATION
Thermoplastic produced by the extrusion method ls passed through a
senes of hot cylinders to produce sheets of varying titckness. With this technique, we can produce different finishes, for example,
glossy, matt or textured. This depends on the outer coating applied by the
final cylinder.
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VACUUM FORMIG
- We put thermoplasttc into a mould
- We then use a heater to heat the mould and soften the plastic.
- We extract the air below the sheet so that the plastic ts pulled against
the instde walls of the shaped mould, and the desired form ts created
- We leave the mould to cool, then remove the obiect
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MOULDING
blow moulding
- We put a tubular-shaped piece of plastic into a hollow mould which has the same shape as the oblect that we want to make
- We close the mould and blow pressurised air into it, so that the plastic adheres to the sides of the mould and takes its shape
- When the object is cold, we remove it from the mould.
compression
- We put thermostable plastic which can be in granular form, into the base of a cavity mould.
- The outer part of the cavity
mould, shaped the same, is closed to compress the matenal inside We then heat it and t
becomes soft and mafleabie
- The plastic adapts to the shape of the cavity between the two parts of
the mould
- We extract the oblect when the plastic has cooled and solidified
injection
- We tniect melted thermoplastic into a mould
- When the material has cooled and solidified,
we extract tt from the mould
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