Project 2- Plastics By Ana Díaz Sánchez Ángela Oliva Jiménez María Osuna Galisteo Paula Porra García-Bravo

Explain the first and the second steps of the process of obtaining plastics:

•1st sourcing of raw materials;

• The process lasts more than 50 years.

• Before the manufacturing process, raw materials often are altered to be used in different processes.

• First, crude ore is processed to increase the concentration of metal, called beneficiation.

• Second, additional processes are used to produce the metal that is going to be fabricated.

STUDENT 1

• 2nd Synthesis of monomers:

• Monomers: structural repeated unit.

• Small subunits that ultimately link together to form larger molecules are called monomers.

·Explain the following methods of shaping and finishing plastics. Mention at least one object that could be made with each technique:

• Thermocompression: It needs contacts made of ductile materials.

• Located on either the substrate or component.

• Describes a water bonding technique

• Two metals, e.g. gold, are brought into atomic contact applying force and heat simultaneously.

Extrusion moulding• Extrusion moulding is a manufacturing process.

• Granules melt into a liquid.

• Forming a long 'tube like' shape

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Blow Molding

• Manufacturing process by which hollow plastic parts are formed.

• Begins with melting down the plastic.

• The parison (tube like piece) is then clamped into a mold and air is blown into it.

3rd Synthesis of the basic polymer

Polymerization: Process in which many monomers are combined.

• Chain-growth polymerization: monomers are added to the chain one at a time only

• Step-growth polymerization: chains of monomers may combine with one another directly

STUDENT 2

Explain the third and the fourth steps of the process of obtaining plastics

4th Incorporation of additives

Additives: • Materials mixed with polymer to make plastics.

• Additives turn basic polymers in to useful plastics

• Additives make plastics clean and healthy, safe, work longer, look good…

Some types of additives:

• Antioxidants: to protect the polymer from degradation by ozone or oxygen

• Ultraviolet stabilizers: to protect against weathering

• Plasticizers: to increase the polymer’s flexibility

• Lubricants: to reduce friction problems

• Pigments: to give the plastic colour

Explain the following methods of shaping and finishing plastics. Mention at least one object that could be made with each technique

• Injection molding: It is the process by which a material is injected into a mould so it takes the mould’s form.

• Foam molding: It is the process which combines plastics and gas.

• Vacuum forming: Sheets of plastic are heated, streched into a single-surface mold and pressed against a mold by a vacuum.

• Calandering: This process consist of multiple hard pressure rollers used to give form and smooth a material (plastic)

Provide information about the following properties in plastic material Physical properties:

• Electrical conductivity: Ability to transport an electric charge.

• Thermal conductivity: Capacity of a body to store thermal energy.

• Expansion: The size and the temperature increase.

• Density: Mass per unit of volume.

• Melting point: State in which the temperature changes from solid to liquid. This process depends on pressure.

• Fussibility: State in which a material melts. Refractory materials are those that melt at high temperatures.

STUDENT 3

Mechanical properties• Types of stress: • Traction: Two opposite forces that pull it to the sides• Compression: Two opposite forces that pull it to the centre.• Bending: Forces that bend the object• Shearing: Deformation of a material in two opposite directions.• Torsion: Spin around it axis• Plasticity: Capacity os a material to undergo a deformation when

it is compressed.• Elasticity: Flexibility of an object.• Malleability: Ability to deform a under pressure object.• Ductility: Ability of a solid material.• Resistance: Ability to undergo a stress without breaking.• Hardness: Ability and resistance without scratching.• Weldability: Ability to join with another materials using heat.

Chemical properties

• Permeability,NO: Property of being permeable.• Solubility,NO: Ability to mix in a homogeneous mixture.• Combustibility,YES: Ability to burn.

Biological properties• Reciclability,YES: Ability to transform materials into useful

objects.• Toxicity, YES: When a material is affected by toxic substances.• Biodegradability, NO: Effect of environmental decomposition.

Plastic materials are classified in three groups:

Thermosetting polymer (thermoset): • Petrochemical material

• Liquid or malleable prior

• Others are solid (molding compound used in semiconductors and integrated circuits)

STUDENT 4

Thermoplastic (thermosoftening plastic):• It is a plastic material (polymer)

• High molecular weight

Elastomers (elastic polymer):• It has viscoelasticity

• Very weak intermolecular forces

Bibliography• http://www.investopedia.com/terms/r/rawmaterials.asp• http://

global.britannica.com/EBchecked/topic/369072/materials-processing• http://

www.finetechusa.com/bonders/technologies/thermocompression.html• http://en.wikipedia.org/wiki/Thermocompression_bonding• http://en.wikipedia.org/wiki/Polymer#Polymer_synthesis• http://www.bpf.co.uk/plastipedia/additives/default.aspx• www.thomasnet.com/about/thermoset-plastics-61020277.htmls• www.ehow.com/about_5545184_properties-thermoplastic.html• www.adhesiveandglue.com/elastomer.html• www.dupont.com/products-and-services/plastics-polymers-resins/elastome

rs/articles/guide-to-elastomer-properties.html