properties of plastics
TRANSCRIPT
HOW DO WE OBTAIN PLASTIC?
PROCESSING PLASTICPART:2
SMALL MOLECULES
(monomer)
3rd step: polymerization
LARGE MOLECULES
(polymers)
4th step: Additives
ADITIVESSPECIAL
CHARACTERISTICS
aditive useDyes or pigments Changing
colour
Reinforcements +resistance
Plasticisers + flexibilitie
Antioxidants No reactionsto oxigen
The shaping up! 1
Injection molding:
• For complex or precise shapes
Little pieces are made like this
The shaping up!2
Foam molding:
• For isolation and objects like pillows.
Therapeutic balls are made like this.
The shaping up!3
Vacuum forming
• For packing and soft surfaces.
CD cases are made like this.
The shaping up!4
Calandering
• For making sheets and plastic layers.
Toy windmills are made like this.
REMEMBER
• Objects are not always finished with a pure shaping up, mixtures are aloud.
We also can see the same object made in different ways
Definition plastic is a material made up of resin which is easy tochange it form.
Physical properties.
Four diferent properties Mechanical properties.
Chemical properties.
Biological properties.
Properties of plastics.
Physical properties.
Soundconductivity.
Electricalconcudtivity.
Thermalconductivity.
Density. Melitngpoint.
Fusibility.
It can conductthe soundproperly.
It is aninsulator. Itdoes’tconduct theelectricityporperly.
It is aninsulator. Itdoesn’tconduct heatproperly.
Density=
Mass
Volume
Thetemperaturein which a solid becameliquid.32ºC.
It can fuse at32ºC.
Stress. Elasticity. Malleability. Ductility Resistan-ce. Hardness. Wledability.
Plastics arevery easy tomanufa-cture them
It is a material capacity toman taindeforma-tions
They are easy tomalleblethem.
It is a material capacity todeformperma-nently
It is a material capacity toundergoforceswithoutbreaking
It is a material resistance tobe scratchesor dented
Is thecapacity of somematerials tojointogether.
Mechanical properties.
Permeability. Solubility. Combustibiliy.
Is the ability of water to passthrough thematerials.
It is a material’scapacity to mix with anothersubstance.
It is a material’scapacity to burn, giving off thermalenergy.
Chemical & Biological properties.
Reciclability. Biodegradability. Toxicity.
It is our hability totransform a material already used intoanother product.
It is a material’s capacityto deteriorate as consequence of interacting with theenvironment
It is the property of materials to cause negative effects onliving organism.