2. Definition
• Broadly Speaking any Material that shows
the property of Plasticity, i.e. The capacity to
undergo a change in shape under external
pressure and retain the new shape even when
the pressure is withdrawn , is called a Plastic
Material.
• Plastic have found very wide applications in
every major Industry and in manufacturing
of many items of engineering importance.
4. General Properties
• Plastic are a group of materials which possess many
useful properties which have made them most popular
engineering materials in certain fields, among such
applications following need special mention;
Light Weight
• Plastic are undoubtly the lightest of engineering
materials, their density varies between 1.1 g/cc to 1.6
g/cc compared to 1.75 of magnesium, the lightest metal.
High Resistivity
• To Corrosion and also to electric current makes them ideal
material for insulators.
Low Thermal Conductivity
• Makes them suitable material for use as thermal Insulator.
9. General Properties
Easy Formability
• Many intricate shapes and complicated design can be
given to Plastics with considerable ease and at
economical Cost. Hence, these offer unlimited choice in
product design.
Appealing Color and Finish.
• Plastics are amenable to acquire any desired color
besides taking the desired shape and smooth excellent
surface finish.
Low Cost
• Compared to Similar Products made from other
material, plastics are generally very economical in cost
11. Classification
• All the plastics are Grouped under two main Classes
depending upon their behavior towards heat;
Thermoplastics
• All those varieties of Plastic which becomes soft on
heat, so much so that they can be remolded again
and again are classed as thermoplastics.
• These plastics harden on cooling and soften on heating.
Their hardness is, therefore, a temporary property
subjected to change on heating. Examples; acrylic
plastic, celluloid plastics, polystyrene and asphalt.
13. Manufacturing of Plastics
Thermosetting Plastics
• This Group of Plastics harden on heating and
curing at a particular range of temperature
once ‘cured’ or set they do not become soft by
any further heating.
• Their set and Hardness is, therefore, a permanent
property that does not change on heating again.
They may get destroyed but do not become soft
on reheating. Example are Bakelite, epoxy and
silicones provide the best example of thermosets.
15. Constitution of Plastics
• Plastic are sometimes called “Organic
Polymer”.
• The polymer are made by combining or
‘Uniting’ the building units of Smaller
organic compounds called monomer, the
process of combining these monomers to make
polymers is called polymerization.
17. Manufacturing of Plastics
• The raw material used in Plastic Manufacture
and the process of fabrication of Plastics
Raw Material
• There are at least four basic raw materials
for manufacturing of plastics: Resins or
binders, Fillers or extenders; and plasticizers
and pigments
19. Manufacturing of Plastics
Resins (Binders)
• These are the starting material in the Plastic Industry. They are
natural or Synthetic product of organic constitution. The most
common resins belong to two groups: Thermoplastic resins and
thermosetting resins.
• Resins These are either of Cellulose type or of non-cellulose type.
(a) The Thermoplastic Resins
• These are either of Cellulose type or of non-cellulose type.
• The Cellulose Resins are derived from cellulose material like esters
and ethers.
• The Non Cellulose Resins include Vinyl Resins and Polyamide
Resins.
22. Manufacturing of Plastics
Vinyl Resin
• It is a group of colorless, transparent and non
toxic resins. Most commonly used members are
Polymers of Vinyl Chloride, Vinyl Acetate,
methyl metharylate and acrylics.
• Some of them are included among the lightest
Binders, they possess such Useful Properties as
low electrical conductivity which makes them
eminently suitable for insulation at radio
frequencies.
24. Manufacturing of Plastics
The Thermosetting Resins
• These Include the following common types;
Phenolic Resins
• They are made by condensation of phenol and
formaldehyde. In fact, phenol formaldehyde
plastic with the trade name Bakelite was the
first from the group of thermosets. When a
Suitable type of filler is combined with these
resins. A plastic material of desired quality is
obtained.
26. Manufacturing of Plastics
• Urea Formaldehyde Resins are specially suited for making
electrical and mechanical products. These resins have a high
resistance to oil, water weak acids & alkalis. They can be Given
any Color because Urea is basically light colored.
Melamine Formaldehyde
• They make the tableware Plastics. This Group is Characterized with
high Impact Strength & Durability.
• Furfuryl Resin They are dark colored resins ,They are slightly
better then phenol resins and can be used in place of them.
These resins harden or set at Uniform Rate. The source of
Material for furfurly are oat shells, sugarcane refuse and husk
of rice.
Shellac
• It is also a thermosetting binder. It is used extensively in
manufacturing Insulating Plastics.
29. Manufacturing of Plastics
Fillers
• These include a number of materials that are
used in the manufacturing of Plastics with a
view of Increasing their bulk weight without
interfering adversely in their properties.
• Wood pulp, corn, husks, cotton, fibers,
asbestos, micas, clays, leads and zinc oxide,
metal powders and Glass fibers are some
commonly used fillers. These material impart
useful properties of shock resistance and
strength against fracturing to plastics.
31. Manufacturing of Plastics
Plasticizers
• These are substances which are added to
obtain improvement in Certain Properties in
which the resin may be lacking. Such
Properties like Shock resistance, toughness
flexibility and non inflammability can be
greatly improved by addition of plasticizers to
resins.
• Plasticizers are essential constituents of
thermoplastics. In those the thermosets, they are
seldom Used.
33. Manufacturing of Plastics
Pigments
• Pigments are added to the plastic at the time of
manufacture to impart them a desired color.
Zinc Oxide, Barites and other metallic
pigments may be used improper proportions. It
is essential that the type of pigment selected
should be durable and inert towards plastic
resin.
• Besides the above material certain other
substances may also be required in the
manufacturing of some varieties of plastics.
35. Fabrication of Plastics
• Casting and moulding are two main processes commonly used to
fabricate end product from plastic resins. The selection of method
depend upon the type of plastic resin being used and the design of the
end product.
Casting
• In this method, desired objected are made by
• (i) Heating the resins to their melting points to make hot liquid melt from
them;
• (ii) Pouring the liquid into the moulds of desired shape and design;
• (iii) Curing the product in the mould itself for a definite time.
• The curing may require much time ranging from few hours to few weeks, it
is expensive method but the product obtained are quite strong & hard.
37. Moulding
• It is very common method in plastic
Industry. It involves shaping the material
under high pressure or temperature or both
factor operating simultaneously.
Compression Moulding
• This is the most prevalent moulding
method. In this the plastic is pressed into the
mould in a heated state. Thus both pressure
and temperature are required.
39. Moulding
Injection Moulding
• In this method, the plastic material is first
heated in a chamber. When it is sufficient
hot, it is then forced into the mould through
a duct under requisite pressure. It is
common Process for Producing shapes of
thermoplastic materials.
41. Moulding
Transfer Moulding
• It is special type of Moulding process
applicable only to thermosetting plastics. It
Combines principles of Both the Compressive &
Injection Moulding
• The material is first heated in a heating
chamber. It is then forced into a mould which
is kept hot. In the mould, the plastic is pressed
hard till it confirms to the final shape of the
product. The Product is Cured under Pressure
and in a hot State.
43. Moulding
Extrusion
• This is an exclusive Process for
thermoplastic and is similar to injection
moulding in principle. Hot Material is
excluded through a die of required shape.
Thus there is a die in place of a mould in the
extrusion process. Plastic Conducts, rods,,
bars, tubes, and Sheet material is obtained by
extrusion.
45. Moulding
Cold Moulding
• In this process, shapes are obtained by
applying pressure on the selected type of resin.
The Product However may be Cured by
baking in an Oven. The Process has Limited
Application and is used in phenol-
formaldehyde resins
47. Moulding
Calendaring
• It is a process of converting thermo plastic
Material into thin sheet of desired thickness
A heated mixture of the resin and Plasticizer
is Passed through, a series of heated rolls The
Gap between the two rolls give the thickness to
the Sheet.
49. Moulding
Laminating
• This is a process of Obtaining plastic
impregnated laminates of Wood, Clothes,
Glass, fibers and Paper.
• Exact technique will differ from material to
material Commonly the material to be
laminated is first soaked in the desired plastic
resin Liquid.
• It is then Squeezed through a set of rolls and
dried. The Product is then cured under controlled
conditions of temperature & Pressure.
51. Specific Properties
• Plastics form a big group of resins showing a wide
range of properties. Their Properties depend on
grade, the method of Manufacturing, the resin and
other fillers and additives such as Plasticizers etc.
used along with the resin in their manufacture. Most of
the properties of Plastic are however Characterized
with,
• Excellent Corrosion Resistance
• Excellent Electrical Resistance
• Good Tensile Strength
• Amenability to Variety of Colors
52. Uses of Plastics
• Plastic offers some definite advantage over all the
other materials both in cost and in Quality in the
competitive market. A few advantage of plastic are:
• Excellent Combination Of Mechanical &
Electrical Properties.
• Easy fabrication into most intricate design
• Uniform finish and color adaptability
• Much lower Cost
54. Uses of Plastics
Most Significant field of application of Plastic
are:
Aeronautical Engineering.
• In the manufacturing of Control and
navigational instruments, pipelines and
fuselage. An reinforced fibre glass plastics, these
have found use in aerospace engineering for
Space Crafts.
• Automotive Engineering Plastics are widely used
for making windshield , Instrument Panels, tail
light lenses and other such accessories.
56. Uses Of Plastic
•There are more than 10000 different kinds of plastics available in the
market and their performance abilities span those of every other known
material from soft rubber to steel.
• The typical uses of plastics in building are summarized as follows:
•Bath and sink units
•Cistern ball floats
•Corrugated and plain sheets
•Electrical conduits
•Electrical Insulators
•Films for water proofing, damp
proofing and concrete curing
•Floor tiles
•Foams for thermal insulation
• Jointless flooring
• Lighting fixtures
• Overhead water tanks
•Decorative laminates and mouldings . Paints and varnishes
• Pipes to carry cold water
• Roof lights
• Safety glass
• Wall tiles
•Water resistance adhesives
57. Uses of Plastics
Electrical Engineering
• In Electrical Engineering Insulation, Power
transmission and Communication Equipment. Also,
in part of generators, motors, switchboards,
condensers, fluorescent light fixtures and Cabinets of
Most of the electronic Gadgets.
Industrial Engineering
• For Making Pipelines, tanks, towers, conveyors etc.
Civil Engineering
• For fabrication of doors and Windows, Knobs,
handles, and other ornamental structures.
61. Advantages of Plastic
• Corrosion resistance
• Low electrical and thermal conductivity, insulator
• Easily formed into complex shapes, can be
formed, casted and joined.
• Wide choice of appearance, colors and
transparencies
62. Disadvantages Of Plastic
• Low strength
• Low useful temperature range (up to 600o
F)
• Less dimensional stability over period of time
(creep effect)
• Aging effect, hardens and become brittle over time
• Sensitive to environment, moisture and chemicals
• Poor machinibility
63. Plastics in Civil Engineering
• The inherent qualities of Plastics such as
their capacity to be molded in any shape,
Design, color & appearance coupled with
resistance to corrosion and Insulation
against thermal & electrical shocks have made
them popular material in most part of a
building.
65. Plastics in Civil Engineering
• Few typical Uses are as mentioned Below:
Flooring And Wall Tiles
• In many new models construction tiles made
up one or other type of plastic are used as a
matter of Choice because their ;
Resistant to many types of Chemicals
• Are easy to Clean & Maintain
• Keep the original beautiful appearance till end
and
• Are light in weight and easily replicable.
68. Plastics in Civil Engineering
Water Storage and Conducting
• Plastic tanks, Cisterns, tubing and
Connections are fast replacing cast Iron,
Steel and Concrete material in the housing
and dwelling because of their low weight,
better adaptability and appealing looks are
also due to their low Cost.
70. Plastic Sheeting and Panels
Plastic Sheeting and Panels.
• Resin impregnated paper or Glass or Cloth or any
other type of fibre marketed as laminated plastics
find many application in Civil Engineering as well.
These mixed plastics are lightweight and can be Used
for roofing Purpose, Similarly plastics mixed with craft
paper form good Cladding Material.
• Doors and Window handles, Grips rods and such
accessories made from metals like aluminum, Iron,
and Copper etc are easily available in Plastics and
find extensive application as they do not require
further surface Treatment.
72. References
• Building Construction : Dr B.C. Punmia
• Civil Engineering Material : Prof. Singh
• Internet Web Sites
• https://www.cipet.gov.in/
• http://www.ipiindia.org/
