Plastics Flashcards
What are thermoplastics made from
Thermoplastics are made up of lines of molecules with few cross linkages.
Properties of Thermoplastics
- They soften when heated
- Can be bent into a variety of shapes or forms
- This process ^ can be repeated many times over
- They are suitable for injection moulding, vacuum forming and blow moulding
Types of thermoplastics
Acrylic
Polythene
Polyvinyl chloride
Properties of acrylics (list at least three)
- Produced in sheets
- Can be translucent, transparent or opaque
- Resistant to acid and most weather conditions
- Easily machined, cemented and polished
- Good insulator
- Safe with food
- Scratches and splinters easily
- Ten times more impact resistant than glass
Uses of acrylic (list at least two uses)
Car rear light units Aircraft canopies + windows Simple lenses Light units Illuminated signs Watch and clock glasses Skylights Furniture Baths
Properties of Polythene (list at least two)
Excellent moulding qualities
Two types; high density which is rigid and hard
Low density which is tough and flexible
Purchased in large sheets
Uses of polythene (list at least two)
Bottles (low density) Bowls Toys Tubes Machine parts
Polyvinyl chloride properties (list at least two)
Tough material
Can be hard or flexible
Can be bonded or welded with an adhesive
Polyvinyl chloride uses (list at least two)
Water pipes
Raincoats
Long play records
Coating on electrical wires
Thermosetting plastics are
Thermosetting plastics are made up of lines of molecules which are heavily cross linked.
Properties of thermosetting plastics (list at least two)
Rigid
Can only be heated then shaped once
After this they become permanently stiff and solid
Can’t be reshaped again
Uses of thermosetting plastics
Sauce pan handles
Kettle handles
Plugs
Types of thermosetting plastics
Polyurethane
Melamine Formaldehyde
Polyester resins
Polyurethane properties
Very tough
Water resistant qualities
Uses of polyurethane
Basis of many paints and varnishes
