Unit 2 glass and plastic

UNIT 2 GLASS AND PLASTIC
RAKESH S
Assistant Professor,
Department of Civil Engineering
Kuppam Engineering college,
Kuppam
Rakesh S, Assistant professor, Kuppam
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INTRODUCTION TO GLASS
• Scientifically, glass is an inorganic product of fusion,
a ceramic material, characterized by transparency,
brittleness, hardness and chemical inertness.
• It is an amorphous mixture of silicates of sodium,
potassium and calcium.
• Glass differs from other ceramics, in that most
ceramics are shaped cold and then fired to obtain theceramics are shaped cold and then fired to obtain the
product, whereas glass is shaped at high temperature
and then allowed to cool.
• Glass can be reheated and reshaped. Glass, therefore,
can be considered as a thermoplastic material
(Thermoplastic – substances that become plastic on
heating and harden on cooling, and are able to repeat
these process)
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2. FUNCTIONS OF GLASS IN BUILDINGS
• In ordinary residential buildings glass is used primarily in windows and sometimes in
doors.
• The main aim of glass is to allow as much daylight into buildings as required.
• Flat glass, either as clear float glass (with undistorted vision and reflection), cast
glass (usually translucent) or special variety(for solar control, thermal insulation ,
decoration) are mainly used for glazing of windows and sometimes for doors.
• Slightly stained glass/coloured glass is generally used in windows to reduce the
glare (of the sun).
• while using glass in buildings, following factors should be considered:-
1. Solar control. 4. Safety and security
2. Sound insulation. 5. Fire resistance.
3. Wind control. Rakesh S, Assistant professor, Kuppam
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1. Solar control
Clear glass used in buildings transmits incident short wave solar radiation which
heats up walls, ceilings, furniture's and other items in the building. This, in turn ,
emits long wave radiation which doesn't exit through the glass to atmosphere.
Thus, solar radiation admitted through the glass trapped in the rooms resulting in
rise in temperature. This is called green house effect.
Solar gain can be reduced by internal shading devices such as screens, blinds,
canopies etc.. or external shading devices.
Another method to reduce this heat is by using solar control glasses which are of twoAnother method to reduce this heat is by using solar control glasses which are of two
types,
• Solar reflecting- heat will be reflected back
• Solar absorbing- heat will be absorbed
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INTERNAL SHADDING DEVICES
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EXTERNAL SHADDING DEVICES
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Solar reflectingSolar reflecting
Solar absorbing
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2. SOUND INSULATION
Properly glazed windows
significantly reduce sound
transmission through them.
Sound Insulation3. WIND CONTROL
In case of buildings in coastal regions or tall buildings, the glass is subjected to the wind
load; this requires proper detailing for fixing the glass sheet.load; this requires proper detailing for fixing the glass sheet.
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4. SAFETY AND SECURITY
To improve its resistance to impact and breakage, glass can be either toughened or
laminated.
(laminated glass is used when both safety and secuity
Are in mind. It is made by bonding two pieces of
Glass together with a middle core of plastic called
Polyvinyl butyral.)
Laminated glassLaminated glass
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CONSTITUENTS AND CLASSIFICATION OF GLASS
1.The most widely used ingredients of glass are the oxides of silicon, sodium and
calcium i.e. silica(sand),soda and lime.
2.Glass is obtained by the fusion of silica, soda, potash and lime at over 1000ᵒC
3.Sodium or Potassium carbonate is added to reduce the melting point of silica and
to provide the viscosity(state of being thick, sticky and semi-fluid) to enable it to be
blown, drawn, pressed or spinned.
4.Lime is added to impart the durability, toughness, brightness, and shine.4.Lime is added to impart the durability, toughness, brightness, and shine.
5.Broken glass , called “Cullet” is generally added as recycled material to the raw
material to acts as flux and to bring down the cost of production.
6.Lead oxide imparts the colour to glass and hence its presence in glass is not very
desirable. However, it increases density, brightness and refractive index.
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CONSTITUENTS OF GLASS
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CLASSIFICATION OF GLASS
• Glass is classified into five categories based on percentage of constituents present in it
1. Soda lime glass
2. Potash lime glass
3. Potash lead glass
4. Boro silicate glass
5. Common glass
1. Soda lime glass also know as soda ash glass / soda glass/soft or window glass is
obtained from the fusion of silica, lime, soda and alumina
Uses:- glazing of windows, doors and ordinary glass ware
2. Potash lime glass also know as hard glass is similar to soda lime glass except that
soda is replaced by potash.
This expensive, high melting point glass used in laboratory glass ware.
3. Potash lead glass / lead glass which as high shining appearance is used for high
class glass ware, bulbs , lens and prisms
4. Boro silicate glass/ pyrex glass can withstand high temperature and hence used for
laboratory equipments and cookware.
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5. Common glass/bottle glass having brown, green or yellow colour is the least costly
and mainly used for house hold bottles and medicine bottles.
Potash lime glass Boro Silicate glass
Potash lead glass
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MANUFACTURING PROCESS
Glass is manufactured by following processes:
• Float glass process
• Rolled glass process
• Architectural glazing systems manufacturing process
• The glass currently used in industry is usually soda-lime float glass.
• The soda-lime glass is manufactured by float process by fusion of silica, soda, lime
and alumina.
• Silica is obtained in the form of pure quartz, powdered sand stone and fresh river• Silica is obtained in the form of pure quartz, powdered sand stone and fresh river
sand.
• Soda ash in the form of sodium carbonate, lime may be in the form of lime stone,
aluminium may be in the form of alumina.
• The raw materials in appropriate proportions are mixed with water, and melted
together in a furnace. Broken glass known as cullet is also added to act as flux.
• Decolorizes such as antimony oxide, nickel are added to avoid the effect of
impurities such as traces of iron oxides.

Manufacturing of glass involves five stages:-
• Collection of raw materials
• Preparation of batch
• Melting in furnace
• Fabrication of glass into desired forms
• Annealing.
1. Collection of raw materials
The raw materials typically collected are:- lime, soda ash and silica(sand).
2. Preparation of batch
The raw materials, cullet and decolorizes are finely powdered separately in grinders;The raw materials, cullet and decolorizes are finely powdered separately in grinders;
accurately weigh batched and mixed in a mixer to a uniform colour. The uniform
mixed mass is called the batch or frit.
3. Melting in Furnace
The batch prepared in step 2 is melted in a pot furnace or in a tank furnace at about
1000 – 1500ᵒC.
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a. Pot furnace
• The pot is a vessel made of fire clay.
• It consists of charging and collecting doors which are kept projecting outside so
that raw materials may be added and molten glass any be taken conveniently.
• The pots are filled with raw materials. The furnace is heated by means of gas.
When the mass has melted down , it is removed from the pot and it is taken for
the next operation of fabrication.
Charging and collecting doors
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b. Tank furnace
• It is constructed with reinforced masonry.
• The roof is given special shape to deflect the
flames of heated gas. The ports are provided for
charging and taking out the molten glass. A bridge is
provided to separate the tank into two unequal
compartments.
• The batch is charged and heated in large
compartments where somewhat impure glass iscompartments where somewhat impure glass is
produced. It then flows to smaller compartments
through the opening in the bridge.
•The floating impurities or gall is collected or
removed at the top of larger compartments while
molten glass is taken out from the discharge outlet in
the smaller compartment.
• The operations of charging and removing the
molten glass are carried simultaneously.

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4. Fabrication of glass into desired forms
The molten glass material is then shaped by:- 1. Blowing 2. Drawing 3. Casting
4. Pressing 5. rolling and 6. spinning.
1. Blowing :- Blowing is done with the help of compressor. This blowing causes
molten mass to assume the shape of cylinder.
2. Casting:- The molten glass is poured in moulds and it is allowed to cool down
slowly.
3. Drawing:- It consists of pulling the molten glass by mechanical equipment. An3. Drawing:- It consists of pulling the molten glass by mechanical equipment. An
iron bar is dipped sideways in the molten mass of glass. It is lifted up horizontally
and it catches up a sheet of molten glass. This sheet is then allowed to pass over a
large rotating roller. The roller helps the molten glass to spread in the form of a thin
sheet
4. Pressing:- In this process, the molten glass is pressed into moulds.
5. Rolling:- Molten mass of glass is passed between heavy iron rollers and flat glass
plate of uniform thickness is obtained.
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RollingRollingDrawing
Pressing and blowingRakesh S, Assistant professor, Kuppam
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5. Annealing
The fabricated glass is allowed to cool in a controlled manner is called annealing.
The process of annealing ensures slow and homogeneous cooling of glass product.
In the absence of annealing, the surface of molten glass will cool faster than the interior,
resulting in internal stresses which weaken the glass.
Annealing can be accompanied by two methods:-
a. Flue treatment:- In this method, the red hot molten glass product placed ona. Flue treatment:- In this method, the red hot molten glass product placed on
travelling band is passed through a long flue with high temperature at the entry and
cool at exit end. The method is suitable for large scale production.
b. Oven treatment:- The red hot molten glass product is placed in the oven called
annealing chamber with a temperature controlled arrangement. The glass cools
slowly and thus gradually relaxes the internal stresses. The method is suitable for
small scale production.
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COMMON TYPES OF GLASS
1.Sheet Glass:- This is the most extensively used type of glass of doors, windows
and partitions in all types of buildings.
It is available in thickness range of 2 to 6.5mm, and sizes upto 1.75m x 1.1m.
2. Float and Plate glass:- They are of superior quality, more expensive and have
better appearance; with no distortion of vision at any angle.
•It is used in showcase windows, picture windows and exposed windows in offices
and commercial buildings.
•They are tough, scratch –resistant and have high light transmissibility.
3. Frosted glass, ground glass and obscured glass:- Frosted glass is translucent3. Frosted glass, ground glass and obscured glass:- Frosted glass is translucent
and obscures(dark) the view while still allowing the light pass through it.
• They are commonly used as in glazing of toilets, office doors, partitions, exterior
windows etc..
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Frosted glass, Ground glass or
obscured glass
Sheet glass
Float glass Rakesh S, Assistant professor, Kuppam
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4. Wired or Reinforced glass :- It is produced by the introduction of wire mesh into
glass during production or rolling operations.
It has impact resistance , similar to that of normal glass, but in case breakage, the mesh
retains the pieces of glass.
It is commonly used for fire- rated glazing applications.
5. Block glass:- Glass blocks are hollow, transparent units. The space between the
blocks is hollow and which is partial vacuum, which adds to the insulating properties
of the block.
Block glass are excellent light transmitters, sound proof and low thermal conductivity.Block glass are excellent light transmitters, sound proof and low thermal conductivity.
BLOCK GLASS Wired glass
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6. Tempered glass:- Tempered glass is a kind of safety glass, made from the normal
glass by strengthening it by a simple physical process.
Tempered glass has enhanced impact resistance, mechanical strength and thermal
stability or thermal cracking.
Uses :- Doors, windows, handrails.
7. Tempered curved or bent glass :- Bent glass is obtained by bending flat glass
during the heat strengthening process (fabrication), to a specified glass to create unique
profiles for installations in commercial and residential applications.
Uses:- Handrails, windows etc..
Tempered curved or
bent glass
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8. Laminated or sandwich glass:-
Laminated glass is made by sandwiching transparent polyvinyl butyral (PVB) layers or
films between two or more glass plates and permanently bonding together under heat
and pressure to create a single glass.
Uses:- Glass will be used in airports, interior partitions in offices, hospitals, hotels.
9. Bullet-resisting or bullet proof glass:-
This is made of four or more layers of plate glass laminated with layers of plastic under
heat and pressure. Thickness of this glass vary from 20 to 75mm.
Uses:- cashier windows, bank teller cages.
Bullet Resisting or bullet
proof glass
Laminated glass
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10. Insulating glass:- Insulating glass consisting of two or more sheets of glass
separated by a dry (dehydrated airspace) or argon gas.
Insulating glass units improve thermal performance, significantly reducing heating and
air conditioning costs due to their excellent heat insulation.
Applications:- windows, doors and curtain walls.
11. Heat- Absorbing and glare reducing glass:-
This reduces heat, glare and a large percentage of UV rays. The heat absorbing glass
contains controlled quantities of ferrous oxide added to glass composition.
Heat-absorbing glass is often used for comfort and reduction of air-conditioning.
Glare Reducing glassRakesh S, Assistant professor, Kuppam
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12. Reflecting glass/coated glass or transparent mirror glass
The glass is obtained by covering one side of ordinary float glass with a thin metallic
oxide coating possessing high reflective properties to control transmission of light , heat
and solar radiation. This special metallic coating also produces a mirror effect,
preventing the subject from seeing through the glass.
13. Engraved glass
Automatic controlled engraving machine are available to engrave different designs and
figures on the surface of glass.
Transparent mirror glass
Engraved glass Rakesh S, Assistant professor, Kuppam
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PROPERTIES OF GLASS
1. The amorphousness property of glass enables it to be continuously worked from
furnaces i.e. it can be blown, drawn, rolled, pressed or spinned in heated state.
2. It absorbs refracts or transmits light. It can be made transparent or translucent and can
take up high polish.
3. It is resistant to weather and chemicals except alkalies.
Physical properties
4. Glass may be clear, colourless, diffused and stained. It is available in variety of
beautiful colors.
5. It can be cleaned easily.
6. It is an excellent electrical insulator. However molten glass is a insulator.
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Engineering or Mechanical properties
1. Glass is hard and tough but brittle material, and does not deform plastically.
2. The theoretical tensile strength of glass is about 7000MPa but failure occurs at
stresses much lower than that which is around 70 to 140Mpa.
3.The strength of glass is improved by heat treatment.
4. Annealed glass typically breaks into large pieces, whereas wired glass breaks
similarly to annealed glass, however more pieces of glass stay in place, because of the
wires.wires.
5.Tempered glass if it breaks , it disintegrates into very small granules, whereas
laminated glass will typically remain intact, because of the plastic interlayer, although it
may be badly cracked.
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ADVANTAGES AND DISADVANTAGES OF GLASS
ADVANTAGES OF GLASS
1. High durability in normal conditions and generally good resistance to chemicals
and biological hazards.
2. In regions with cold seasons, utilisation of solar energy by trapping the heat within
building, provides indoor comfort and saves fuel consumption.
3. Glass can be recycled.
4. Old bottles can be used as substitute for hollow glass blocks. Waste glass, crushed
to a fine powder when mixed with clay acts as flux and reduces the temperature
needed to bake the bricks.
OLD BOTTLES IN CONSTRUCTION
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OLD BOTTLES
IN
CONSTRUCTION
@ State of Michigan USA
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DISADVANTAGES OF GLASS
1. Glass is brittle and thus difficult to transport.
2. Incorrect installations can cause glass to break.
3. Broken glass can cause serious injuries.
4. Although glass is noncombustible, it breaks and later melts in fire.
5. Most modern varieties of glass absorb most of the sun’s ultra-violet rays, which
are vitally important, especially for children for the synthesis of vitamin D and toare vitally important, especially for children for the synthesis of vitamin D and to
destroy harmful bacteria.
6. hydrofluoric and phosphoric acid, and strong alkalis ex:- caustic soda, alkaline
paint, attack the glass.
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PLASTICS
Introduction
Plastic, the newest of the primary construction materials available to the building
industry.
Plastics are made from resin with or without fillers, plasticizers and pigments. These are
organic materials of high molecular weight which can be moulded to any desired form
when subjected to heat and pressure in the presence of a catalyst.
Plastic is a synthetic material made from a wide range of organic polymers such as
polyethylene, pvc, nylon etc.. that can be moulded into shape while soft and then setpolyethylene, pvc, nylon etc.. that can be moulded into shape while soft and then set
into a rigid or slightly elastic form.
Plastic Formwork
RESINS
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PROPERTIES OF PLASTIC
1. Can be moulded to any desired shape or size and have high tensile and compressive
strengths.
2. Easy to work upon.
3. Light in weight and a few varieties are glossy like glass.
4. Not attacked by insects and fungi.
5. Available in desired colour and texture.
6. Require a little maintenance.6. Require a little maintenance.
7. Good electrical insulators and have low thermal conductivity.
8. Shock absorbing material.
9. Can be sawn, drilled and punched and welded easily.
10. High strength to weight ratio.
11. High resistance to weathering conditions.
12. Corrosion resistance.
13. Decorative surface effect—painting or polishing of the surface is not required.

POLYMERISATION
The simplest substances consisting of one primary chemical are known as the
monomers. They are to be combined or synthesized to form polymers by the process
known as the polymerization.
A polymer molecule thus consists of thousands of monomers joined together.
Polymerisation is a process of reacting monomer molecules together in a chemical
reaction to form three dimensional networks or polymer chains.
₂ ₄Ex:- 1.monomer – Ethylene, C₂H₂ and Polymer – Polyethylene, (C₂H₄)n
2. Monomer- vinyl chloride and Polymer – Poly vinyl chloride
Heat /Pressure Catalyst
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Heat /Pressure
Catalyst
Polymerisation can be brought by three methods:-
1. Additional Polymerisation :- In this process, the same molecules are used to form
a bigger molecule.
Ex:- Ethane when undergoes polymerisation under heat/pressure it forms a polymer
called polyethylene or polythene.called polyethylene or polythene.
2. Condensation Polymerisation :- In this process, a large number of identical or
different molecules are combined and in the process a new molecular substance
formed is removed.
Ex:- terylene, a condensation polymer, is synthesized by heating ethanol, ethylene
glycol and a terephthalic acid and eliminating molecules of water in the
process(Dehydration).
3. Co-polymerisation :- In this process, two or more different monomers are added
together to form a polymer.
Ex:- Phenol formaldehyde is produced by reaction of phenol and formaldehyde.

CLASSIFICATION OF PLASTIC
According to thermal property , the plastic can be classified into two main categories as
thermoplastic and thermosetting.
1. Thermoplastic:-
• These are plastic which soften on heating without undergoing any chemical
change and harden again on cooling.
• it is thus, possible to shape and reshape these plastics by heat and pressure any
number of times.
• Thermoplastic can be recycled.
Ex:- Polyethylene terephthalate or PET, Polyvinyl chlorides, and polystyreneEx:- Polyethylene terephthalate or PET, Polyvinyl chlorides, and polystyrene
2. Thermosetting plastic:-
• These are plastic which soften once when heated at 125-175ᵒC during moulding.
Upon further heating, they harden permanently and undergo a chemical change.
Ex:- Polyester, Melamine formaldehyde.
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COMMONLY USED PLASTICS
THERMOPLASTIC
1. Polyvinyl chlorides (PVC):-
• Polyvinyl chloride is one of the cheapest plastic material.
• It is available in three forms, ordinary, plasticised and post chlorinated.
• The post-chlorinated plastic is more resistant to heat upto 120ᵒC which makes it
suitable for hot water pipes.
• One of the popular uses is for the pipes suitable for all situations because of its
high resistance to chemicals.
• Poly vinly chlorides are commonly used for floor coverings in the form of tile and• Poly vinly chlorides are commonly used for floor coverings in the form of tile and
sheet because of their abrasion resistance and low water absorption.
PVC TILES
CPVC PIPES (Elbow, 90 degree bend pipe etc)
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ACRYLICS (PERSPEX)
• Large transparent Perspex sheets are used in building applications.
•They are flexible and rigid.
• Transparent, translucent and opaque sheets are available.
• Uses:- windows
POLYCARBONATE
•This plastic has excellent transparency, high impact resistance and good resistance to
weathering which makes it suitable for safety glazing and for illumination.
• Polycarbonate sheets can be used to make shells, domes, globes etc..
ACRYLICS (PERSPEX SHEETS)
POLYCARBONATE
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POLYVINYL FLUORIDE
• This plastic is inert to chemical and weathering attack.
• It is used as thin film overlays for building boards to be exposed outdoors.
POLYTETRAFLUORETHYLENE
• Chemically inert, high resistance to corrosive agents (chemicals)
• Temperature resistance.
• Low friction applications include bearings for girders, bridges and trusses.
POLYVINYL FLUORIDE
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POLYTETRAFLUORETHYLENE
•PTFE slide bearings have extremely low
friction which means no stick- slip effect.
•Wear and tear isn’t issue with PTFE slide
bearings.
•High load bearing capacity.

ACRYLONITRILE- BUTADIENE-STYRENE (ABS)
• This is co-polymer provides a family of tough, hard, chemically resistant plastics.
• These mainly used for pipes and fittings, especially drain-waste-vent.
• Other uses include buried sewer and water lines, conduits, well casings.
BURIED SEWER
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THERMOSETTING PLASTICS
Phenol formaldehydes
• This plastic is hard and rigid.
• They are strong, fire resistant, light in weight and generally pleasant to eyes.
• They have low water absorption and good resistance to attack by most of commonly
found chemicals
• Uses:- They are used for laboratory Countertops, billiard balls and as adhesives.
LABORATORY COUNTERTOPS
PHENOL FORMALDEHYDE RESINRakesh S, Assistant professor, Kuppam
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Epoxy and polyester casting resins
one of the outstanding of the epoxies is their excellent adhesion to a variety of
materials, including such as metals as copper, brass, steel and aluminium.
Uses:- Crack repair, segmental bridge adhesives, structural repair on porous or cracked
slabs, Bonding agents.
Segmental bridge
CRACK REPAIR
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Polyester Moulding materials
•When compounded with fibers, clay, the polyesters can be formulated into putties.
•Polyesters are often used in geotextiles.
polyester putty is used to level irregularities in surfaces of steel, aluminium, wood,
concrete.)
Polyurethane
•It is used as thermal insulation in the form of foam.
(A geotextile is typically defined as any permeable textile material used to increase
soil stability, to improve the soils, provide erosion control or aid in drainage.
•It is used as thermal insulation in the form of foam.
• Finishes for floors, walls, furniture and casework.
GEOTEXTILES
Silicones
•Silicones are based on silicon rather than carbon, hence
their inertness and durability are very good.
•Moulding is more difficult
•They have lower water absorption.
•In liquid solutions, silicones are used to impart
moisture resistance to masonry walls.
•They also form basis for paint and other coatings,

MOULDING AND FABRICATING FOR PLASTIC PRODUCTS
The raw materials for plastic are usually available in the solid form of resins.
Plastic products are moulded and fabricated from these plastic resins by adding
moulding components.
MOULDING COMPONENTS
To give the desired properties to the finished plastic product and facilitate the fabrication, the
following moulding components are usually added:
1. Catalysts:- They assist and accelerate the hardening of resin.
2. Reinforcement :- Reinforcement in the form of chopped fibers, chopped fabric are added to
plastic, are added to the plastic to improve the strength and impact properties

3. Plasticisers:- Plasticisers are added to many thermoplastics to change the melting
point. Plasticizers, which are mostly liquids, are usually organic compounds.
•These plasticizers are added to impart plasticity and to impart softness to the plastics.
4. Fillers:- These are fibrous or powder inert materials added to the plastic to improve
the mechanical properties such as impact strength, hardness.
5. Hardener:- These are added to increase the hardness of the resin.
6. Stabilisers and antioxidants:- These are added to protect the plastic against aging,
light or biological agents.
7. Pigments:- These are added for colour.
8. Solvents :- These are required to dissolve the plasticisers.
9. Lubricant:- is used to make the moulding of plastic easier to prevent sticking of
materials to the mould for a flawless finish.
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FABRICATION METHODS
The following are some of the processes used in the fabrication of different types of
plastic products:-
1. Blowing:- It is used to produce many hollow plastic products, such as tubes,
bottles, jars etc:-
2. Calendering:- It is carried out by passing through set of rollers for producing
plastic films and sheets.
3. Casting:- The plastics are moulded without application of pressure. The resin is3. Casting:- The plastics are moulded without application of pressure. The resin is
melted and poured into mould. The casting of plastics is similar to that of cast iron.
4. Laminating:-Thin sheets of cloth or paper asbestos are impregnated with
thermosetting resin. These lamins are then pressed by a hydraulic press. Under
temperature and pressure the lamins are bonded together to form one sheet. The
laminated plastics exhibit improved mechanical and electrical properties.
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CALENDERING PROCESS
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5. MOULDING
It is most commonly applied method for making plastic products. It can be performed in
one of the following ways:-
1. Thermoforming and vacuum forming
2. Extrusion moulding
3. Plastic injection moulding
4. Structural foam injection moulding
5. Jet moulding.
1.Thermoforming (Compression moulding) and vacuum forming1.Thermoforming (Compression moulding) and vacuum forming
Compression moulding is the process of heating the plastic material and shaping it
using a mould.
Vacuum forming consists in using vacuum to force the plastic into shape of the mould.
Pressure forming uses pressure along with vacuum, to force the plastic into the mould
cavity.
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2. Extrusion Moulding
In this process, the raw materials are fed into machines and heated till they become soft
malleable. Then this malleable material is pressed through die (extruded) to take the
desired form.
is used for continuous moulding of thermoplastic materials into articles of uniform
cross-section such as tubes, rods, strips, electric cables, pipes etc.
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3. Plastic injection Moulding
In this process, the heated plastic material are injected into mould at room temperature
to form the desired product.
This is applicable to thermoplastic.
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4. Structural foam injection moulding
•Structural foam injection moulding is intended to produce large and thick plastic parts.
•The process involves the incorporation of blowing or foaming agents into a plastic
material to create a cellular structure in the moulded part.
•The foaming agent such as nitrogen is mixed with melted polymer and injected
through multiple nozzles into the mould.
•Injection pressure and expanding gas-polymer mixture act to fill the mould.
•In the inner core of the product the foaming gas expands to form a cellular structure.
•Foaming agents and nitrogen reduce weight and create a cellular structure that imparts
rigidity to the product.
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STRUCTURAL FOAM INJECTION
MOULDING
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5. JET MOULDING
In this method, the plastic material is moderately heated. It is then allowed to pass
through nozzle, which is preheated to a high temperature.
This method of moulding may be adopted for thermoplastic as well as for thermosetting
materials.
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APPLICATIONS OF PLASTIC
1. Rigid plastic have various uses in water supply and sanitation.
2. Transparent, translucent or opaque sheets are used for non load bearing walls and
roofing elements, glazing etc..
3. Plastic films and membranes are used for damp proof courses, concrete curing,
temporary rain and wind protection of openings, tent structures.
4. Foamed plastics are used mainly as thermal insulation materials, light weight
ceiling panels.ceiling panels.
5. Synthetic resins and adhesives are employed for production of various composite
materials, such as plywood and sandwich panels.
6. Plastic are widely used in emulsion paints, distempers, enamel paints.
7. Plastic sealants are used for waterproof joints.
(Sealants is a substance used to block the passage of fluids through joints or openings
in material Rakesh S, Assistant professor, Kuppam
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PLASTIC WALLS
PLASTIC ROOF
PLASTIC WALLS
DAMP PROOF COURSE (DPC)

CONCRETE CURING
PLASTIC SEALANTS
SYNTHETIC
RESIN ADHESIVE
CEILING PANELS Rakesh S, Assistant professor, Kuppam
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DAMP PROOF COURSE
Over ground
CROSS SECTION OF BUILDING
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ADVANTAGES OF PLASTICS
1. Plastics are impermeable and resistant to most of chemicals. There is no corrosion
problems.
2. High strength to weight ratios of most plastics materials make them suitable for
structural applications.
3. Lightness in weight makes handling and transporting of plastic products easier
and cheaper.
4. Due to its mould ability, the plastic is shaped into a wide variety of forms.
Colours and other physical properties make it good architectural material.
5. Plastic, generally, have good resistance to biological hazards.
6. It has excellent electrical insulation properties
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DISADVANTAGES OF PLASTICS
1. Due to high costs and limited availability in many developing countries, use of
plastics is restricted to special purposes.
2. Most of plastics are flammable and develop noxious fumes and dense smoke. Use
of plastics close to combustible materials shall be avoided, and provision of
sufficient ventilation openings to remove smoke and fumes in case of fire, is
desirable.
3. The mechanical properties of plastics rapidly deteriorate at elevated temperatures
which restricts its application to normal temperature conditions.which restricts its application to normal temperature conditions.
4. Most of plastics deteriorate due to prolonged exposure to the sun’s ultra-violet
rays. Use of plastics in sunlight exposed conditions should be avoided.
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INTELLIGENT USE OF PLASTICS IN BUILDINGS
1. PVC PIPES
PVC pipes are ideal for carrying potable water and also for sewerage.
The advantages offered by PVC sewerage pipes are :-
1. flexible in nature, easy to install,
2. have good life expectancy of 50 years,
3. do not crack under loads, good abrasion resistance
4. Quickly restoration/replacement in case of damages.
5. PVC pipes are highly cost effective as compared to metal pipes.5. PVC pipes are highly cost effective as compared to metal pipes.
6. Resistance to chemicals (Particularly Chlorides)
7. They are light in weight and hence easy to transport and handle.
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2.WATER STORAGE AND SEPTIC TANKS
• Plastics have replaced the conventional stone and concrete water storage tanks,
because they ensure safe and effective storage of water for home and industrial
purposes.
• Septic tanks are also available in plastics, which are light weight, easy to install and
clean and resistant chemicals.
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SEPTIC TANKSRakesh S, Assistant professor, Kuppam
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3.PLASTIC SHEETS AND DOORS
1. They preserve the texture and feel of fine wood grain while eliminating the various
problems in wood products.
2. Can withstand continuous temperatures upto 1400 degree Celsius
3. Plastic sheets are light weight, strong, stiff and clean.
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4. PLASTIC INSULATION
Many residential buildings and industrial buildings
rely on plastic insulation to prevent energy losses.
Installing expanded polystyrene (EPS) insulation,
reduces the electrical energy for air conditioning
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5.PANELS AND FRAMES FOR WINDOWS AND
DOORS
• Use of PVC for manufacturing of door frames
and windows are encouraged in India and all over
the world.
• Since, Economic, light weight, fire retardant,
impact resistant, easy to install, low maintenance,
water proof and environmental friendly.
• Don't rust and warp and no paint is required.• Don't rust and warp and no paint is required.
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6.PREFABRICATED PLASTIC BUILDINGS
Prefabricated plastic structures are made
for permanent, semi permanent and
temporary use.
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7.PVC CORRUGATED SHEETS/POLYCARBONATE
PVC corrugated sheets can be used as a substitute for
other roofing materials.
This are used in buildings due to the following
properties:-
• Waterproofing ability
• Fire retardation ability
• Sound insulation ability.
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Unit 2 glass and plastic

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