14 practice sets · Page 1 of 1
Why are the plasticisers added with polymers?
To hold other constituents of plastic together
To reduce the cost and enhance the strength and hardness of plastics
To improve flexibility and to reduce the temperature and pressure required for moulding of plastics
None of the abov
The plastics which soften when heat is applied with or without pressure, but requires cooling to set them to shape are called as
thermosofting materials
thermosetting materials
thermoplastic materials
thermostatting materials
The materials such as lead and barium, which are added with polymers to minimize the effect of heat, sunlight and ozone are called as
binders
blenders
stabilisers
fillers
Specific gravity of the plastics is usually
less than the specific gravity of metals
more than the specific gravity of metals
similar to the specific gravity of metals
Unpredictable
Which of the following is used to make CDs?
PVC
PTFE
Polycarbonate
Polypropylene
Which of the following is used to manufacture carrier bags?
LDPE (Low Density PolyEthylene)
HDPE (High Density PolyEthylene)
Polycarbonate
PVC
Which plastic is used to laminate kitchen worktops?
Epoxy resin
Polyester (PET)
Melamine
PVC
The process of combining two or more distinct polymer molecules to form a new product with different characteristics is called as
binding
stabilizing
filling
blending
Which of the following is an example of thermoplastic material?
Camera bodies
Automobile parts
Electric plugs
Electric insulation
Which plastic materials contain strong cross linkings in their molecular structure?
Thermoplastic materials
Thermosetting materials
Both a. and b.
None of the above
Thermosetting materials are
the plastics which can be softened even after they have set and hardened
the plastics which require heat and pressure to mould them into shape
both a. and b.
none of the above
Which of the following characteristics does not affect the properties of plastics?
Their molecular structure
Their degree of polymerization
Both a. and b
None of the above
Which process is used to manufacture plastic pipes?
Injection moulding
Extrusion moulding
Blow moulding
Vacuum forming
Which of the following is commonly used in schools for vacuum forming?
Melamine (MF)
HIPS
Polyester
PVC
