MANUFACTURING OF PLASTIC COMPONENTS
1 What are the characteristic of
ANS: Themoplastics polymers soften when heated and
harden, when cooled.These types of polymers are soft and ductile. They have low
melting temperature and can be repeatedly moulded and remoulded to the required
2 List out the material for
processing of plastics?
following metioned are the various polymer additives used in practice:
(1) Filler material (2) Plasticizers
(4) colorants (5)Flame retardants (6)
List the advantage of cold forming of
Cold forming can be carried out at room
It is used to produce filament and fibres
It is a simple process.
What is film blowing?
Ans: In this process a heated doughy paste of plastic compound
is passed through a series of hot rollers, where it is squeezed into the from
of thin sheet of uniform thickness. It is used for making plastic sheets and
What are the types of plastics ?
Ans: Polymers are classified in two major categoies:
o Thermoplastic polymers (Soften when heated and harden when
cooled) o Thermosetting polymers (Soften when heated and permanently hardened
What is compression moulding?
main objective is to melt the material due to compression.
7 Name the parts made by rotational
Ans: Rotational moulding process is mostly used for the
production of toys in P.V.C like horse, boats, etc. Larger containers upto 20 m3
capacity, fuel tanks of automobile are made from polythene and nylon. This
process is also used for production of large drums, boat hulls, buckets,
housings and carrying cases.
8 What is parison ?
Ans: Blow moulding consists of extrusion of the heated tubular
plastic piece called as parison which is transferred to the two piece mold.
9 Define degree of polyenerization.
Ans: It is the number of repetitive units present
inone molecule of a polymer.
Degree of polymerisation =Molecular weight of a
polymer / Molecular weight of a single monomer
10 What is rotational mouldig of
Rotataional moulding also called as roto-moulding.
A measured amount of polyemer power is placed in a
thin walled metal mould and the mould is closed.
Then the mould is rotated about two mutually
perpendicular axes as it is heated.
11.What are the two types of polymerization.
12. Rubber is a ___________________ Polymer
a Organic Polymer.
13.Write the two types of Injection Moulding.
1.Ram Or plunger type injection moulding 2.Screw type
Polymers are long chain molecules
and are formed by polymerization process,linking and cross linking a particular
building block called monomer, a unit cell.
Plastic is defined as the organic
polymer which can be moulded into any required shape with the help of heat and