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PLASTICS

María Paula Jiménez Noa Lindo CaleroRocío MosqueraAbigail Sanchez

Polymers.

Ability to be shaped

Derived from organic products.

There are two families:

•Thermoplastics •Thermosets

Plastics

PLANT ORIGIN

Latex found in nature is a milky fluid found in

10% of all flowering plants

Wood and cotton cellulose

Cellophane: thin, transparent sheet made of regenerated cellulose. Rayon: comes primarily from wood pulp.

Drying oil

is a type of plant oil that hardens after been exposed to the air during a period of time. It is used for varnishes.

Sourcing of raw materials

ANIMAL ORIGIN

Casein protein component of milk. manufacture of wood glues.

The resin secretion from the lac bug Used to produce shellac. Shellac is primarily used as

a wood sealer and finisher today

Sourcing of raw materials

MINERAL ORIGIN

Monomers extracted from petroleum, coal and natural gas

1. These gases are broken down into monomers.

2. Polymerisation

3. The compounds formed as called polymers.

4. Combining the element carbon with one or more other elements makes most polymers.

Sourcing of raw materials

Plastic pellets are fed into a heated cylinder and driven forward by a turning screw which compacts and melts them and forces the melt through a die at the end, creating continuous lengths of shapes with the desired profile. It is a system much like that of a mincing machine except for the addition of heat. Once the plastic shape is formed it is cooled by air or water

Methods of shaping and finishing plastics

Extrusion

Fed into a heated cylinder driven forward by a turning screw melt through a die at the end given different shapes cooled.

Blow moulding

Hot air is blown into a pre-formed tube injection moulded it takes the shape of the container.

Compression moulding

A measured amount of material is added to a two part mould and subjected to heat and pressure

Mixing components in specific quanties.

Raw materials

chemical processes.

Synthesis of the basic polymer:

Incorporation of additives• Plasticizers Improve plasticity Intensify

shine.• Antistatic agents less static charge no dirt,

no dust.• Fireproof of fire-retardant agents delay the

flame.• UV stabilizers protect it from UV radiation

prevents descomposition.• Fillers, reinforcements, and lubricants better

mechanical proerties and easier manufacturing process.

• Mold release agents piece comes out easily.• Antioxidants prevents reactions with oxygen.

Methods of shaping and finishing plastics

Vacuum molding glasses, packaging and boxes.

Calendering platic tablecloths, plastic wrap and plastic sheets.

Vacuum molding glasses, packaging and boxes.

Calendering platic tablecloths, plastic wrap and plastic sheets.

Electrical conductivity ---- very low

Thermal conductivity ---- very low

Density ---- low

Expansion ---- high coefficient of expansion

Melting point ---- is not ususally above 200 ºC

Fusibility ---- a certain amount of heat is needed

Physical properties

Types of stress

· Traction- increases the length of a piece in the direction of the forces

· Compression- reduces the length of the piece in the direction of the forces

· Bending- makes the piece curve

· Shearing and Torsion- produce deformations in the piece

Mechanical properties

Elasticity- it undergoes low-intensity

Plasticity- it undergoes stress of an intensity

Malleability- produces slabs and sheets

Ductility- produces bars and wires

Resistance- plastics are not resistant at all

Hardness- plastics have a wide range

Permeability- plastics are impermeable

Solubility- plastics are not soluble

Combustibility- plastics burn easily

Chemical properties

Recyclability- many materials that could not be recycled in the past, now can

Toxicity- toy,glues and paints (made of plastics) can be toxic

Biodegradability- the period of decomposition of plastics is very long

Biological properties

THERMOSSETTING PLASTICit polymers

can’t be fuse or soluble,

It’ s heated and shaped

once

It shape is permanent

It’s not recicable

Thermossetting estructure

EPOXY RESIN

MELAMINE FORMALDEHYDE

POLYESTER RESIN

UREA FORMALDEHYDE

PHENOL FORMALDEHYDE

types of thermossetting

It can be flexible and malleable

It’s a reversible material

can be melted to a liquid and cooled to a solid

It is the oldest plastic material

It polymers, that are capable of recovering their original shape after being stretched to great extents

any rubbery material composed of similar molecules

This material is taken from a tree called Hevea

http://www.natursan.net/caseina-de-la-leche/

http://www.madehow.com/Volume-4/Shellac.html#ixzz3LFqjCe1O

http://www.plasticseurope.org/what-is-plastic/how-plastic-is-made.aspx

http://www.design-technology.org/plastics

BIOBLIOGRAPHY