Polymers Flashcards
What two groups are plastics divided into?
-Lucas M
Thermoplastics and thermosetting plastics
What are thermoplastics made of?
-Lucas M
Long chain molecules
What holds the long chain molecules together?
-Lucas M
Van de waals forces of attraction.
Polythene and acrylic are examples of thermoplastics or thermosetting plastics?
-Lucas M
Thermoplastics
What happens to thermoplastics when they are heated?
-Lucas M
They soften
Name 2 of the 4 examples of Thermosetting Plastics?
- Humphrey Marsh
GRP
Bakelite
Phenol
Epoxy resin
The process of injection moulding is controlled by what?
- Humphrey Marsh
A central processing unit in a CIM environment
Moulds in injection moulding can be what?
- Humphrey Marsh
Complex and expensive
The long chains of molecules in thermosetting plastics are held together by bonds known as what?
- Humphrey Marsh
Covalent bonds
What type of plastics are flexible?
- Humphrey Marsh
Thermoplastics
In school what can injection moulding be used to make?
-Ssnehnil G
A screwdriver
Examples of Thermoplastics
-Ssnehnil G
Acrylic Polythene Polypropylene PET ABS PVC
Properties of Thermoplastics
-Ssnehnil G
Will soften when heated
Tend to be flexible (more or less)
Impact resistant
Can be coloured
What are Thermosetting plastics made of?
-Ssnehnil G
Cross linked chains
Do Thermoplastics have a One shot cycle or Continuous cycle?
-Ssnehnil G
Continuous cycle
What can moulds be?
Ed H
Complex and expensive
Moulding is what?
Ed H
Only suited to volume production
What is now highly automated?
Ed H
Injection Moulding
What do you feed an injection mould?
Ed H
Granules
What Will soften when heated?
Ed H
Thermoplastic
What is another name by which the bonds in thermosetting plastics are called excluding covalent bonding?
Caspar Tyser
Cross Linked Chains
What plastics can only be formed once?
Caspar Tyser
Thermosetting Plastics
Injection moulding is now controlled by a central processing unit in a …….. environment?
Caspar Tyser
CIM (Computer Integrated Manufacture)
In ejection moulding where are the granules fed through into the barrel?
Caspar Tyser
The Hopper
In injection Moulding moulds can be ………?
Caspar Tyser
Complex and Expensive
What is the force of attraction that hold the long chains of molecules together called?
-Alfie Turner
Van Der Waals forces of attraction
When do thermoplastics soften?
-Alfie Turner
When heated
Why would you heat thermoplastics?
-Alfie Turner
To enable them to be reformed and moulded
List the properties of thermoplastics:
-Alfie Turner
Will soften when heated, tend to be flexible, impact resistant and can be coloured
Moulds can be complex and …
-Alfie Turner
Expensive
What does CIM stand for
Oli Shaw
Computer integrated manufacture
What process would you use to make wheelie bins
Oli Shaw
Injection Moulding
Phenol is an example of…
Oli Shaw
A thermosetting plastic
Cross linked chains may also be known as…
Oli Shaw
Covalent Bonding
How do thermoplastics react to heat
Oli Shaw
They soften
How do thermosetting plastics react to heat?
- Krystian Shanahan
Can withstand high temperatures without losing rigidity
What are the properties of melamine?
- Krystian shanahan
Can be printed , heat resistant and can be coloured
What is required to cause epoxy resin to set ?
- Krystian Shanahan
A hardener
What property to thermosetting plastics lack?
- Krystian Shanahan
Plasticity
Which type of plastics are used in compression moulding ?
-Krystian Shanahan
Thermoplastics
