This document discusses different types of insulating materials used in building construction and engineering. It defines insulating materials as those that retard or stop the flow of heat, electricity, or sound. There are three main types of insulators: thermal insulators, electrical insulators, and sound insulators. Some common thermal insulators mentioned include magnesium plastic, aluminum foils, asbestos, cork, cellular rubber, and mineral wool. Common electrical insulators include mica, asbestos, rubber, paper, synthetic resins like Bakelite, porcelain, glass, and cotton. Sound insulators discussed are cellular concrete and acoustic plaster and boards.

1. Insulating Material
Building Construction Material

2. Insulating Material
All those material that retard or stop the flow of
• Heat
• Electricity
• Sound
through them may be broadly defined as insulating materials.
The same material may not be insulator against all the three types of
energy waves; it may not be insulator against heat or electricity or
sound or more than one of the two transmissions.
• The importance of Insulating material cannot be over
emphasized in engineering practice. Since heat and electricity
are the main source of energy in many important operations, a
safe handling of these source may be impossible without
insulators. The insulator may be studied under three general
headings, thermal insulators, electrical insulators and sound
insulators.

3. Insulating Material

4. Thermal Insulator
• The main function of thermal insulator is to act as a
partial or total barrier in the passage of heat. A
thermal insulator, therefore, should posses following
properties;
• It should have very low thermal conductivity;
• It should have a very high softening point.
• It should be stable to thermal shocks, i.e. should not
break on repeated heating and cooling.
• It should be stable chemically and physically at high
temperature for prolonged period at stretch.
• It should be resistant to moisture and vibration and
have good strength too.

5. Thermal Insulator

6. Thermal Insulator
• The situation where a thermal insulator may
be required are varied.
• The flow of Heat has to be stopped from a
working place to the outside environment, such
as furnace to outside;
• The flow of heat has to be stopped from an
outside source to a place, for instance in special
rooms where equipment is to be worked at low
temperature or comfort has to be insured in a
hot climate from inside living.

7. Thermal Insulator

8. Types of Heat Insulators
• Following are some common heat Insulating materials
used in engineering Industries;
Magnesium Plastic
• This consist of thoroughly blended mixture of
hydrated magnesium carbonate and asbestos. It is
applied as a plastic mass cover over the surface from
which the escape of Heat is to be controlled.
Aluminum foils.
• These are essentially thin sheets made from
aluminum and its alloys. When wrapped over steam
pipes and other appliance, it serves as a good
insulating material.

9. Magnesium Plastic

10. Aluminum Foils

11. Types of Heat Insulators
Asbestos
• It is one of the best heat insulating material for
big and small applications alike. Insulating
sheets made from asbestos mixing some clay in
the presence of a suitable binder are used for
insulating boilers and also for bulk head lining
in ships.
Cork
• It is light weight external tissue or bark of the
oak tree. It has been found to be good heat
insulator and is used much for the same purpose.

12. Asbestos

13. Cork

14. Types of Heat Insulators
Cellular Rubber
• It is special variety of rubber made extra porous
during manufacture. This rubber is used as an
insulator in cold storage.
Mineral Wool
• It is also called rock wool . This material is obtained
commercially from impure limestone. The rock is
first heated to melting temperature, Jet of air or water
is made to fall on streams of this molten rock which
solidifies into wool like structure. Clay and dolomite
are also used for making mineral wool.

15. Cellular Rubber

16. Mineral Wool

17. Vermiculite
Vermiculite
These are group of mica like foliated minerals,
some variety of vermiculites are processed
for manufacturing of heat insulators that are
specially useful for furnace insulations

18. Vermiculite

19. Electrical Insulators
• Following are the requisite qualities for an
electrical insulator,
• A very poor electrical conductivity i.e. a very high
electrical resistivity
• Resistance to deterioration on heating
• Very low thermal expansion
• Non-Inflammable
• Chemical Stability at high temperature,
• High Strength, hardness and resistance to
abrasion.

20. Electrical Insulators

21. Electrical Insulators
Mica
• The name indicates a group of natural minerals
having a sheet like structure by virtue of which they
can be separated into thin elastic sheets of this group
two members, named Muscovite and Phlogopite are
used extensively as electrical insulators.
• These minerals have very low thermal conductivity,
high electrical resistance, great toughness, flexibility
and resilience a unique combination for an ideal
insulator. Mica in different forms is used in a variety
of electrical devices such as resistance to electrical
heating appliances,

22. Mica

23. Electrical Insulators
Asbestos
• Highest Grade of asbestos which occurs in
long fibre and is free from iron oxides is a
commonly used insulator in many electrical
appliances.
• It is used for covering electrical covering in
traction type electrical motor or coil.

24. Asbestos

25. Rubber
• Rubber It is one of the very common used
electrical Insulator it has following Special
properties
• Very low electrical conductivity
• High resistance to moisture and abrasion
• High flexibility
• High Resilience

26. Rubber

27. Electrical Insulators
Paper
• Paper is also classed among very useful
insulators for common Use.
• Insulation paper is specially made without
addition of fillers. When impregnated with
oil, its properties as an insulator get further
improved.

28. Paper

29. Electrical Insulators
Synthetic Resin
• These artificial materials have occupied a
place of great importance in the field of
electrical insulation.
• They are available both in solid and liquid
form among the solid product of cellulose
ester and phenolic vinyles etc are important
Bakelite is an outstanding example of this
group

30. Synthetic Resin (Bakelite)

31. Electrical Insulators
Porcelain
• It is a burnt mixture of Clay, feldspar and
Quartz It forms an important group of
insulating material which are characterized with :
High Stability
• Sufficient Hardness
• Imperviousness to moisture
• These properties make ceramic material more
suitable for high Voltage Insulation, switch boxes,
condensers and other heating elements.

32. Porcelain

33. Electrical Insulators
Glass
• It is also an insulating material having many
applications among the main qualities of glass
may be mentioned chemical inertness, stability at
high temperature resistance to moisture.
Cotton
• In the form of cloth, cotton finds extensive use
as an insulating cover, its properties are also
improved by impregnating it with oils and
coating varnishes.

34. Glass

35. Cotton

36. Sound Insulation
• High noise is fast becoming acute problem in many cities
and tow and.
• Insulation against noise is an important an engineering
problem as against heat in fact in cosmopolitan cities
“Noise Pollution” is one of the biggest challenges for the
citizens
Following material are used at present as acoustic
Insulator:
Cellular Concrete.
• It is a variety of concrete in which voids are created
during manufacturing stage. Generally it is made by
adding powdered aluminum and water to a cement used
for making concrete.

37. Cellular Concrete

38. Sound Insulation

39. Sound Insulation
Acoustic Plaster
• This is made by mixing together magnesium
oxychloride granulated slag and some gelatin
Acoustic Boards
• These are made by bonding together fibrous
materials like wood and vegetable fibers in a
matrix of plaster, they are light in weight and
can be cut and joined on the ceiling and partition
wall.
• Acoustic boards are also made by using
Vermiculates and Perlite.

40. Acoustic Plaster

41. Acoustic Boards

42. References
• Building Construction : Dr B.C. Punmia
• Civil Engineering Material : Prof. Singh
• Internet Web Sites

43. Thanks…