1. Project-2 PLASTICS
Álvaro Díaz Hernando
Beatriz de la Varga Puente
Noelia Martin Ruiz
Adrián Muñoz Benavente
2. the 1st and the 2nd step of the
process of obtaining plastics:
O 1st Sourcing of raw materials
O -Raw materials can be of mineral, plant, or
animal origin. The following are some
important examples:
O Plant origin
O Animal origin
O Mineral origin
3. O • Plant origin:
O -Latex is a liquid which is obtained from certain
tropical trees. Rubbers and gums are made with
this.
O Animal origin:
O -Casein is a protein found in milk which is used to
make galalith and lanital.
O • Mineral origin:
O -Petroleum, coal, and other fossil fuels are the origin
of a long industrial process.
4. O 2nd Synthesis of monomers.
O -This stage is especially important in plastics
derived from petroleum and other fossil
fuels.
O -It consists of extracting the monomers from
the raw material through chemical
reactions. These monomers will be used
to make plastic substances.
5. Methods
O Thermocompression:
O The plastic passes into a hot mold. It is is compressed. When
the plastic cools and hardens, the mold is opened and the
piece is removed.
O Thermosetting plastic products is made with with
thermocompression
6. O Extrusion molding:
O -The plastic passes into a heat pipe. The melted
plastic is pushed through an opening which
shapes it. Then goes on to a cooling chamber and
when it is cool, it is cut to measure.
O Pipes are made with this method
7. O Blow molding:
O The plastic is preformed with another method. Then it
is put in a mold.When the plastic has cooled and
hardened, the mold is opened and the piece is
removed.
O Containers for liquids are made with this method
8. 3rd and the 4th steps of the
process of obtaining plastics:
O Synthesis of the basic polymer:
It consist of a chemical reaction, in which, by pressure, heat…
it transforms, from one molecule(monomers) to many
molecules(polymer) by a series of bonds that joins one to the other.
O Incorporation of additives:
They are elements that modify polymers giving them an
specific characteristic such ass flexibility or colour
9. methods of shaping and finishing
plastics
O Foam molding :
O It is use to make insulations, such a thermal or acoustic.
O The plastic that is use in this technique, contains foaming
elements, obtained through a process in which this ones are
transported to a mold that it´s heated at a temperature in which
it creates an spongy mass
10. O Vacuum forming:
O It is used to make glasses, boxes…
O A plastic layer is placed on a mold with tubes trough which
air flows. The mold is heated until the plastic gets more
sof t and a vacuum is formed between the mold and the
plastic. Afterwards, It is again compressed to the mold, so it
finally obtains the shape.
O Injection molding:
O It is used to make objects with difficult shapes, such as: parts for
vehicles
11. PROPERTIES OF PLASTICS
O Physical properties.
O Mechanical properties.
O Chemical properties.
O Biological properties
12. Physical Properties
O Electrical Conductivity: Yes, but very low.
O Thermal Conductivity: Yes, but very low.
O
13. O Density: Mass / volume. Low density in plastics.
O Expansion: High coefficient of expansion, except reinforced
plastics.
O Melting Point: It is normally lower to 200ºC.
O Fusibility: Different temperature for each plastic. (Specific
Heat Capacity)
14. Mechanical Properties
O Types of Stress: Reaction depends on the intensity, size,
material, type of stress.
O Traction: 2 opposing forces that pull on it. Increase
length.
O Compression: 2 opposing forces that push on it.
Decrease length.
O Bending: Forces try to bend it.
O Shearing: Try to cut the piece. 2 forces acting at near
points.
O Torsion: 2 forces try to twist it around an axis.
O
15. O Elasticity: Deform plastics, but it comes back to
the original form.
O Plasticity: With high temperature, can shape very
well plastics.
O Malleability: Permanently deformed under the
stress of compression.
16. O Ductility: Permanently deformed under the stress
of traction.
O Resistance: Plastics are not resistant
O Hardness: Plastics have a wide range of
hardness.
O Weldability: Plastics weld (join) very well.
17. Chemical Properties
O Permeability: Most plastics are
impermeable.
O Solubility: Only some plastics are soluble.
O Combustibility: Plastics burn easily (Very
polluting)
18. Biological Properties
O Recyclability: Plastics are very recyclable.
O Toxicity: Most of the plastics are toxic. When
heated, or joined with food.
O Biodegradability: Biodegradability in plastics
happens in very long periods.
19. O Plastic materials are classified in three
groups:
O A. Thermosetting,
O B. Thermoplastics,
O C. Elastomers.
20. Thermosetting
O They are derived from petroleum in a solid state
O They are better suited to high-temperature
applications
21. Thermoplastic
O They are excellent insulators, both electrical and thermal.
O -they can withstand temperature extremes of up to 600 F.
O - Can become liquid when heated and return to the solid state
when cooled.
22. Elastomer
O Has viscoelasticity
O Very weak inter-molecular forces
O High capacity of deformation
