Please enable JavaScript.
Coggle requires JavaScript to display documents.
PLASTICS (Formation techniques (Vacuum forming (Then use a heater to heat…
PLASTICS
Types
Natural
Obtained from - raw vegetable matenals
Example: Latex
Synthetic
Made from - compounds extracted from
petroleum, natural gas and carbon
Polimerysation
Transformation of these raw materials and compounds into plastics
Manufacturing process
To reduce production costs, and to develop certain characteristics - we add matenals like
Natural rubber is obtained from latex. flbreglass, textile fibres, paper, silica and sascduct
Increase flexibility and to
strengthen the polymers - we incorporate chemrcal additives
To give colour to
the plastics - we add pigments
Properties of plastics
Depend on
Their composition
Mechanical (malleabillity, ductility, mechanical resistence), acoustic (acoustic insulation), electrical (electrical insulation), thermal (thermal insulation), low density, impermeability
Their type
Strength, elasticity, rigidity and flexibtflty
Ecological properties
Mechanical recycling
Agglutination
Material is compacted and then incorporated
into other matenals
Extrusion
Melt the matenal, and then tt's extruded into long
filaments
Pelletising
Filaments are then reduced to granules that we call pellets
Floating
Wash the plastics and then dry them by centrtfugal
force
Separation and crushing
Separate the plastics according to
type and then they' re crushed
Energetic recycling
Incinerate plastics and the energy that
is produced is used tn industry, for heating or producing electnctty
Chemical recycling
To make new
materials from the orinal components of plastic residues
Classification
Thermostable
Made from compounds dertved from petroleum
Formed by strongly-linked covering
chams runmng in different directions
When heated
They became soft and can be shaped
Elastomers
Made by vulcanisation
Mixing sulphur and rubber, and heating to 160ºC
Are hard, resistant and very elastic
Formed by chains linked laterally and then folded over
themselves
Thermoplastics
They're made up of weakly formed molecular chains
When we heat them
They became soft
The heating and cooling process
can be repeated many times
Formation techniques
Lamination
We can produce different finishes,depends on the outer coating applied by the
final cylinder
Vacuum forming
Then use a heater to heat the mould and soften the plastic
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
Put thermoplasttc into a mould
Leave the mould to cool, then remove the obiec
Extrusion
Apply pressure by means of a large, rotattng screw, whtch forces
the melted matenal out, through a nuzzle
Cool the shaped material slowly In a refngerated water bath until
lt's solid
Thermoplastic in granular form into a heated cylinder
Collect the pieces of plastic through a feeder system
Moulding
Blow
Hollow objects
Compression
Different types of containers,
Injection
Domestic utensils such as buckets and contatners
Joining plastics
Permanent joints
We don´t want to separate
Adhesives
Joining two surfaces permanently
Soldering
Joining thermoplastic is using heat and pressure
Temporary joints
We can join and then separate objects with mechanical fasteners
Double ended screw
Nut and bolt
Standart screw
Shaping and finishing techniques
Perforating
Drill bit
Trimming and filing
File and rasp
Cutting
Cutter, scissors, steel bit, fretsaw, jig saw, power press, hot meal theread trimmer