properties of plastics

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.