This document discusses the process of plastics production from four student perspectives. Student 1 describes the sourcing of raw materials from plants, animals, and minerals, and the initial modification process. Student 2 then discusses the synthesis of monomers, addition of additives, and various shaping techniques like injection molding. Student 3 outlines some physical properties of plastics like electrical conductivity and thermal expansion. Finally, Student 4 categorizes plastics into thermosets, thermoplastics and elastomers and their characteristics and applications.

1. PROJECT 2:
PLASTICS
Martín Mora
Sarai de la Rosa
Adrián Utrera
Paula Monzón

2. Student 1
1st Sourcing of raw materials
 Raw materials can come from: minerals, plants, or animals.
 They are extracted from nature.
 Then they are modified so they obtain plastic properties.
Examples:
-Plant origin
 Rubbers and gums are made from latex, a liquid extracted from tropical
trees.
 Rayon and cellophane are made from cotton and wood cellulose.
 Varnishes are made from the oil of oily seeds.

3. Rubbers from Cellophane from Varnishes from
latex wood cellulose
oily seeds

4. -Animal origin
 For making shellac it is used the resin secretion from an insect called lac.
 Galalith and lanital are made from one protein called casein found in milk.
lac bug galalith

5. -Mineral origin
 The basic substances, called monomers are extracted from fossil
fuels.
2nd Synthesis of monomers
 In this process, the basic substances are extracted from raw materials throw
chemical reactions.
 Then they are transformed into plastic substances.
 Is carried out in petrochemical industries.

6. Shaping and finishing
This process is when the plastic substance are manufactured and
transformed into products.
Thermocompression
 For making thermosetting plastic products.
 The process:
The plastic is pass trough a hot mold then is compresd and when it has the
mold shape and has cold down it is pulled out.
Extrusion molding
 The plastic is introduced in a heat pipe then the hot screw moves the plastic
foreward.
 Then the melted plastic is shaped.
 Finally is cooled down and cut in measured pieces.

7. Blow molding
 The plastic is form with a different method.
 Then is introduced in a closed mold with pressurized air which makes the plastic to the
walls.
 Finally when its called down is removed.
Thermocompression Extrusion molding Blow molding

8. Student 2
3rd Synthesis of basic polymers
 Plastics are made up of different components.
 The quantities vary according to the kind of plastic we want to obtain.
 Then, chemical ractions (polymerization,polycondensation and polyaddition occur).
 This chemical processes change the properties and the shape of the components.

9. 4th Incorporation of additives
 Chemical products that give several properties to the polymers
 Dyes: change the color of the polymers
 Plastizers: make the surface of the material brighter
 Antistatic agents: take dust away by reducing the static electricity charge

10. Additives
 Fireproof agents: make the polymers resist fire
 UV stabilizers: make the polymers resist UV radiation and atmospheric phenomena
 Fillers, reinforcements, and lubricants: made better mechanical processes and make easier
the manufacturing process
 Mold release agents: made easier the extraction of the polymer from a mold
 Antioxidants: prevent the oxygen to cause chemical reactions
-UV stabilizers action

11. Elastomers Thermoplastics Thermosetting

12. Shaping and finishing
 Injection molding: Is the process in which a polymer is injected ,in a liquid state,
inside a mold
 Foam molding: process that concerns some gases and its usually used to create
softpolymers

13. Shaping and finishing
 Vacuum forming: you place a plastic sheet in a mold with some channels, it is heated so that a
vacuum which will compress the sheet so that it take the shape
 Calandering: in this process we have to pass the polymer between the hot rollers and it will be
compressed by them

14. Student 3
Physical Properties of Plastics
 electrical conductivity:
- is an electrical phenomenon.
- where a material contains particles with electric charge.
-Has a high capacity of insulation

15.  Thermal conductivity:
- is the property of a material to conduct heat.
-In SI units, thermal conductivity is measured in watts per meter kelvin.
 Density:
-It was discovered by Arquimedes.
-High thermal and chemical resistance.
-Low density polymer.

16.  Thermal Expansion
-When an object is heated or cooled, its length change by an amount
proportional to the original length and the change in temperature.
 Melting point
It depends of what the plastic its made of :
-If it is made of LDPE its melting point will be at the temperature of 150 Cº.
-And it is made of HLPE its melting point will be 135 Cº.

17. Mechanical Properties of Plastics
Types of stress
-Traction: two opposites forces that pull the plastic to the sides.
-Compression: Two opposites forces that pull the plastic to the centre.
-Shearing: its the deformation of a plastic in two different directions
.
-Torsion: Bend a plastic without breaking it.
-Plasticity: it’s a capacity of plastics to undergo a deformation in a
compressed form.
-Elasticity: Its how much flexibility have an object.
-Malleability: When you can deform a plastic althought its cold.

18. -Ductility: Is an ability of a hard material.
-Resistance: It’s the ability os supporting an stress without breaking.
-Hardness: resistance without scratching.
-Weldability: Ability of joining with other materials when the material heats.
Chemical properties
-Permeability(NO) Ability of passing throught a solid without changing its
structure.
-Solubility: (NO) : ability of mixing with homogeneous mixtures.
-Combustibility (YES) : ability of burning.

19. Biological Properties
-Recyclability (YES) : ability of changing into an useful material
-Toxicity (YES) : When materials are affected by toxic products.
-Biodegradability (NO) : it’s the effect that causes the descomposition of the
environment

20. Student 4
Plastic materials classification
 Thermosetting: -properties: fragile, difficulty of processing.
-characteristics: Light weight, high flexibility.
-applications: handle of frying pan, car body.
 Thermoplastics: -properties: deform with heat, recycleable.
-characteristics: very fragile, very rigid.
-applications: bottles, polyethylene.
 Elastomers: -properties: can’t melt, insoluble.
-characteristics: low density, resistance.
-applications: silicones, rubbers……

21. Bibliography
http://wemaketechnology3eso.wikispaces.com/file/view/Materials+-+plastics.pdf
http://en.wikipedia.org/wiki/Plastic
http://www.ensinger-online.com/en/materials/basics-of-plastics/plastics-classification/
http://plc.cwru.edu/tutorial/enhanced/files/polymers/synth/synth.htm