Polymers Flashcards
Thermoplastic
Can be reshaped and reheated Extreme heat turns it into liquid softened when heated recycable made with long polymer chains with few cross links
Thermosetting Plastic
Set by heat by a chemical reaction
Can’t be reshaped
Polymer chains which have cross links in between
Strong and durable
Often used for powder and liquid resign forms
Thermosetting platsic polymers can be flexible
What is thermoplatsic examples
pan handles and kitchen benchers
What process do we use for shaping our objects
Vaccum forming
How to turn a monomer to a polymer
process called steam cracking, takes place around 800 degrees
What are the long interconnected lines in thermosetting plastic
Bonds
What are the more connected lines called in thermoplastic
It makes the structure stronger and are called polymer chains
What happens when the thermosetting plastic are heated
The additional cross-links prevent the molecules moving
Why is it important to put labels on plastic containers
To recycle the right type of plastic
Why is plastic washed before it is recycled
So that the plastic can be recycled into new material
Plastic is melted before it is shredded down. Why?
It makes it easier to be broken down because the polymer chains are partialy broken down which reduces the tensile strength
What is natural polymer
Natural source of polymer is extracted
3 natural polymers
Amber
Biteuman
Rubber
3 man made polymers
Acrylic
Nylon
Polythene
What is injection moulding
Manufactoring process for making parts by injecting material into a mould
Extrusion
Extrusion happens when you appy a force which pushes a material out of the syringe.
Diagram of Extrusion
Place the plastic powder into the funnel which travels towards the steel die and softens it because of the heat. Motor is the big thing at the right hand side
Injection Moulding
Injection moulding is the process of melting plastic pellets which are injected at pressure into a mould
Diagram of Injection moulding
The material comes out and goes to the platen which forces the two polymers together
Rotational moulding
Rotational moulding heats a hollow mould which is filled with shot weight of material. Then it is rotated causing the materials to stick to the walls of the mould
Diagram of Rotational moulding
Fill the funnel with polymer powder
Then heat it
then let it cool down
then let it rotate which lets the two polymers merge and sticks to the walls of the mould
Blow moulding
Forming and joining hollow plastic parts Glass bottles for example
Blow moulding diagram
The heated material then goes through the slot and goes through the blow pin which squishes the material to form the hollow plastic parts
