Thermoplastics

PLASTICS AND TYPES
SUBMITTED BY – DEVESH TRIPATHI
B ARCH

Introduction
Plastic as a material for construction
• The birth of plastic industry took place in nineteenth century.
• The first natural plastic was prepared by a Scottish chemist
named Alexander parkes by mixing camphor with nitro cellulose.
• The significant development was the invention of bakelite by a
Belgian named dr. l. bakeland in 1909.

Composition
Plastic is an organic compound made up of natural or
synthetic blinders or resins with or without molding compounds.
this can be stated that plastics are compounds of carbon
with other substances as hydrogen, nitrogen and oxygen.
the finished product of plastic is a rigid and stable at normal
temperature.
plastics are capable of flow when necessary heat and
pressure is applied at some stage of their manufacture.

Polymerization
polymerization is a process of combining or
synthesizing the primary chemicals named monomers to
form polymers or the macromolecules.
the properties such as strength , rigidity and elasticity
are considerably improved by polymerization.

Methods ofPolymerization
• Addition polymerization
in this method, similar or different molecules join together due to the
opening of double bands and the molecular weight of the resulting polymer
is the sum of the molecular weights of the reacting molecules.
there is no loss of any substance in this process.
the process takes few seconds to complete.
the polymers obtained by this method are polyethylene, polypropylene,
polyvinylchloride, polystyrene, polyacrylates etc.

• Condensation polymerization
in this method, the low molecular substances are
removed high molecular substances formed from a large
number of identical or different molecules.
condensation polymerization takes the time of days to
complete.
polymers obtained by this method are phenol
formaldehyde, carbamide, melamine-formaldehyde etc.

• Co- polymerization
the co-polymerization is the addition polymerization of
two or more different monomers.
a co-polymer may have properties quite different from
other polymers. Thus a wide variety of plastics may be
obtained by this process.
the polymers obtained by this process are vinyl
chloride acetate and butadiene-styrene co-polymers.

Types of plastics
There are basically two types of plastics, namely: -
• Thermosetting plastic.
• Thermoplastic.

Thermoplastic
thermoplastic in general is like wax, hat is, you can melt it and shape it
several times. The ‘thermoplastic’ materials are either crystalline or
amorphous. Advances in chemistry have made the distinction between
crystalline and amorphous less clear, since some material like nylon are
formulated both as a crystalline material and as a amorphous material.
again the advances in chemistry make it possible for a chemist to
construct a material to be either thermo set or thermoplastic. The main
difference between the two classes of material is whether the polymers
chains remain linear and separate after molding or they undergo changes
and form a three dimensional network.

some examples of various types of material are:-
• Linear thermoplastic
1. PVC
2. Nylon
3. Acrylic
4. Polycarbonate
5. Abs
• Thermoplastic cross linked after processing
1. PEEK
2. Polyamide-imides
3. UHMWPE

Formation of thermoplastic
both type of plastic, thermoplastic and thermosetting
plastics, can be formed through casting and expansion
processes. Castinf forms object in a mould. After the
plastic is poured in the mould, additives mixed into the
plastic cause the resin to harden. Expansion processes
inject gases into the plastic melt, creating a foam plastic
from tiny bubbles trapped inside.

Acrylonitrile butadiene styrene (ABS)
.
 It is a copolymer made by polymerizing styrene and acrylonitrile in the
presence of polybutadiene. The proportions can vary from 15% to 35%
acrylonitrile, 5% to 30% butadiene and 40% to 60% styrene.
The nitrile groups from neighbouring chains, being polar, attract each other and
bind the chains together, making ABS stronger than pure polystyrene.
The styrene gives the plastic a shiny, impervious surface.
 The butadiene, a rubbery substance, provides resilience even at low
temperatures.
ABS can be used between −25 °C and 60 °C.
Is a common thermoplastic used to make light, rigid, molded products such as
pipes, golf club heads (used for its good shock absorbance), automotive body
parts, enclosures, protective head gear, and toys including

PMMA
• Polymethyl methacrylate (PMMA) or poly(methyl 2-methylpropenoate) is
the synthetic polymer of methyl methacrylate.This thermoplastic and
transparent plastic is sold by the trade names Plexiglas, Perspex,Acrylite,
Acrylplast,
• PMMA has a good degree of compatibility with human tissue, and can be
used for replacement intraocular lenses in the eye when the original lens has
been removed in the treatment of cataracts.
• In orthopedics, PMMA bone cement is used to affix implants and to remodel
lost bone. I

is a category of polymers, or, more specifically condensation polymers, which
contain the ester functional group in their main chain. Although polyesters do
exist in nature, polyester generally refers to the large family of synthetic
polyesters (plastics) which includes polycarbonate
Synthesis of polyesters is generally achieved by a polycondensation reaction.
See "condensation reactions in polymer chemistry".
The first synthetic polyester, glycerin phthalate, was used in the First World
War for waterproofing. Natural polyesters have been known since around 1830
A common usage of the word polyester refers to cloth woven from polyester
fiber. Polyester clothing is considered to have a "less natural" feeling to it
compared to natural fibers. Polyester fibers are often spun together with fibers
of cotton, producing a cloth with some of the better properties of each.
casting materials, fiberglass laminating resins, and non-metallic auto-body
fillers. Dielectric film for capacitors and film insulation for wire, and insulating
tapes
Liquid crystalline polyesters are among the first industrially used liquid
crystalline polymers. In general they have extremely good mechanical
polyesters

Polyethylene
Polyethylene or polyethene is a thermoplastic commodity heavily used in
consumer products (over 60M tons are produced worldwide every year). Its name
originates from the monomer ethene used to create the polymer.
The ethene molecule (known almost universally by its non-IUPAC name
ethylene), C2H4 is CH2=CH2, Two CH2 connected by a double bond, thus:
Polyethylene is created through polymerization of ethene..
polystyrene
 Pure solid polystyrene is a colorless, hard plastic with limited flexibility. It
can be cast into molds with fine detail.
Polystyrene can be transparent or can be made to take on various colors.
It is economical and is used for producing plastic model assembly kits,
plastic cutlery, CD "jewel" cases, and many other objects where a fairly rigid,
economical plastic of any of various colors is desired.

Polycarbonates
Polycarbonates are a particular group of thermoplastics.They are easily worked,
molded, and thermoformed; as such, these plastics are very widely used in modern
manufacturing.
They are called polycarbonates because they are polymers having functional
groups linked together by carbonate groups (-O-CO-O-) in a long molecular chain.
The most common type of polycarbonate plastic is one made from BisphenolA, in
which groups from Bisphenol are linked together by carbonate groups in a polymer
chain.
This polycarbonate is a very durable material, and can be laminated to make bullet-
proof "glass“.
The characteristics of polycarbonate are quite like those of polymethyl
methacrylate (PMMA; acrylic), but polycarbonate is stronger and more expensive.
This polymer is highly transparent to visible light and has better light transmission
characteristics than many kinds of glass. CR-39 is a specific polycarbonate material
with good optical and mechanical properties, frequently used for eyeglass lenses.
Polycarbonate is becoming more common in housewares as well as laboratories
and in industry. It is often used to create protective features, for example in banks
as well as vandal-proof windows and lighting lenses for many buildings.Other
products made from polycarbonate include sunglass/eyeglass lenses, compact
discs, DVDs, and automotive headlamp lenses.

Polyamide-imides
Polyamide-imides are thermoplastic amorphous polymers that have
exceptional mechanical, thermal and chemical resistant properties.
These properties put polyamide-imides at the top of the price and
performance pyramid..
possess high strength, melt processabilty, exceptional high heat
capability, and broad chemical resistance.
Polyamide-imide polymers can be processed into a wide variety of
forms -- from injection or compression molded parts and ingots -- to
coatings, films, fibers and adhesives.Generally these articles reach
their maximum properties with a subsequent thermal cure process.

POLYOXYMETHYLENE (POM
Acetal)
• These polymers are highly crystalline thermoplastics that
are commercially available as homopolymers or
copolymers.
• POMs are superior to Pas in stiffness, creep resistance,
fatigue strength and water absorption, but have inferior
impact and abrasion resistance.

APPLICATION
• The greater stiffness add strength of the homopolymer
have promoted its use in cams, gears and exterior car
door handles, electric kettles, wash basins and shower
heads as well as snap fit components and toys.

POLYPHENYLENE OXIDE (PPO)
• PPO is a high strength, tough and heat resistant polymer,
but in the unmodified state it is extremely difficult to
process.
• It is also relatively expensive.
• Stiffness and strength are approximately 50% higher than
high impact ABS, with similar creep behavior.
• Resistance to solvents is poor, a characteristic of styrene-
based polymers.

• As well as glass fiber reinforced grades, these materials
are available in structural foam grades
• APPLICATION
• Modified PPOs are used for electrical fittings, car fascia
panels,TV components, and computer housings..

POLYARYLETHERKETONES(PEEK,
PEK)
• These semi-crystalline polymers have excellent
mechanical properties, good thermal stabilty and good
chemical resistance.
• PEEK is inherently fire retardant.
• It is easier to burn a hole through an aluminum sheetthan
made for PEEK.
• These materials are, however, very expensive and
difficult to process.

APPLICATION
• High temperature wire covering and printed circuit
boards.
• Fiber reinforce grades are used in demanding application
that include valves, pumps and missile nose cones.

POLYSULPHONES (PSuL, PES)
• Polysulphone (PSuL) is an amorphous,transparent
polymer with good heat resistance and stiffness.
• Polythersulphone (PES) has a higher continuous use
temperature (180 c) and a modified PES has been shown
to operate for tens of thousands of hours at 200 c without
significant loss in properties.

• This high temperature stability is not matched by
weathering or UV resistance which is poor.
• APPLICATION
• The polysulphones are used in electrical and electronic
applications, medical components requiring repeated
sterilisation, microwave cookware and under bonnet and
aerospace components.

POLYPHENYLENE SULPHIDE(PPS)
• PPS is a crystalline material, usually supplied
reinforced with glass fibers or glass fibers and
mineral fillers.
• The maxi recommended service temperature for PPS
is about 200 c, although it will withstand 350 c for
short period of time.
• While PPS will burn and char in the presence of a
flame, it is self extinguishing and any smoke that
does form is lower in toxicity compered to that given
off by many polymers.

APPLICATION
• Used of PPS include chemically resistant coatings,
chemical pumps and electrical components.

LIQUID CRYSTAL POLYMERS
(LCPs)
• Offer the best high temperature and fire resistance
properties of all the thermoplastics, with certain grades
able to operate temperature around 300 c,CPs are
relatively easy to process, although the higher the
temperature resistance to solvents, industrial chemicals,
and UV and ionizing radiations

APPLICATION
• They are expensive and apart from dual use (conventional
and microwave oven) cookware, production volumes are
anticipated to be low.
• Further uses of LCPs are envisaged in electronic and
automotive markets, replacing die cast and machined
metal parts as well as thermo sets.

TESTS OFVARIOUSTYPES OFTHERMOPLASTICS
PVC/Upvc polystyrene polyethylene phenolic acrylic
TEST 1
APPEARAN
CE
CAN BE
PLASTICISE
D
VARIOUS
GRADES
TOUGHENE
D
TRANSPAR
ENT
LOW OR
HIGH
DENSITY
DARK
COLOURED
CLEAR,TRAN
SLUCENT OR
OPAQUE
TEST
2RIGIDITY
CAN BE
CUT WITH A
SHARP
KNIFE
CAN BE
CUT WITH A
SHARP
KNIFE
SOME
SHATTERS
WHEN
STRUCK
CAN BE CUT
WITH A
SHARP
KNIFE
SHATTERS
WHEN
STRUCK
SHATTERS
WHEN
STRUCK
TEST 3
BENDING
PLASTICISE
D (bends
easily)
TOUGHENE
D
DOESN’TBE
ND
OTHERS
BENDS
EASILY
DOESN’TBE
ND
DOESN’TBEN
D

TEST 4
HEATING
AND
RESULTAN
T SMELL
GOES
‘FLOPPY’O
N
HEATING/P
UNGENT
SMELL
GOES
‘FLOPPY’O
N
HEATING/M
ARIGOLD
SMELL
GOES
‘FLOPPY’O
N
HEATING/C
ANDLE
SMELL
RESISTS
HEAT/BURN
ING WOOD
SMELL
GOES
‘FLOPPY’O
N
HEATING/F
RUITY
SMELL
TEST 5
BURNING
DIFFICULT
TO
BURN,SOO
T,WHITE
SMOKE,SE
LF
EXTINGUIS
H
DENSE
BLACK
SMOKE,ME
LTS
BUBBLES
AT EDGES
PLASTIC
DRIPS ON
MELTING
SELF
EXTINGUIS
HING
SWELLS
&CRACKS
WHEN
HEATED
BUBBLES
AND
BOILS,BLA
CK BITS
PRODUCED
TEST 6
DENSITY
SINKS SINKS FLOATS SINKS SINKS

(1) Blowing
• This method of lubrication of articles of plastics is more or
less the same as that one employed in the glass industry.
A lump of plastic material is taken and by blowing, it is
converted into hollow plastic articles

(2) Calendaring
•In this process, the plastic material is allowed to pass
between the cylindrical rollers.The process is used to
prepare flat sheets of plastics.

• The process consists of closely placed four revolving cylinders.
First three cylinders are heated and the last one is kept cold
plastic material passes between first three cylinders and it is
converted into thin sheets. It is cooled while passing through
the surface of cold cylinder. If cloth is to be provided with
plastic coating, the cloth is inserted along with plastic
material between second and third heated rollers; the roller
may be provided with artistic designs which will appear on the
finished product.

(3) Casting
• This process is similar in principle to that of metal casting.
The resin is heated and when it is in plastic form, it is
poured into the mould.The curing of articles is then done
either with or without the application of heat. During
curing, the low pressure may be applied, if necessary.

• This process is used to prepare plastics of beautiful colors and
it is most suitable for cellulose plastics. Apart from molding
the useful products, the casting is also widely used for potting
and encapsulation, particularly in the electrical industry.

(4) Laminating
• In this process, the thermo-setting resins are just applied
on sheets of paper, or other material. and they are
subjected to heavy pressure by allowing them to pass
through rollers to form plastic laminates.The thickness of
sheets varies from 0.12 mm to 15 mm.They possess
excellent mechanical and electrical properties.

(5) Moulding
• This is the most commonly adopted process for the
fabrication of plastic articles.The general process consists
in placing the raw materials in a mould and then heating
it.The moulding can be done by various methods.The
choice of moulding method will depend on the article to
be prepared.These methods are briefly described as
follows:

Compression moulding
• In this method, the moulds, to receive the plastic
material, are prepared.The moulds are usually heated
and then the plastic material is placed in the moulds.The
moulds are closed and they are heated to a temperature
of 100°C to 200°C under a pressure of 10 to 50 N/sq.mm.
The plastic material gets the shape of moulds on account
of heat and pressure.

INJECTION MOULDING
• IT MAKES USE OF HEAT SOFTENING CHARACTERISTICSOFTHE
THERMOPLASTIC-MATERIALS.THESE MATERIALS SOFTENWHEN HEATED
AND REHARDENWHEN COOLED.
• THE CHANGE BEING ENTIRELY PHYSICAL.
• THE GRANULAR MATERIAL IS LOADED INTO A HOPPER FROMWHERE IT IS
METEREDOUT AND DELIVEREDTO A HEATING CYLINDER.THE EXACT
AMOUNT OF MATERIAL IS DELIVEREDTO A CYLINDERWHICH IS REQUIREDTO
FILLTHE MOULD COMPLETELY.THE INJECTION RAM PUSHESTHE MATERIAL
INTOTHE HEATING CYLINDER AND IN DOING SO PUSHESA SMALL AMOUNT
OF HEATED MATERIALOUT OFTHE OTHER END OFTHE CYLINDERTHROUGH
THE NOZZELAND SCREW BUSHINGAND INTOTHE CAVETIESOFTHE CLOSED
MOULD.
• THE MATERIAL ISTHEN COOLEDTO A RIGID STATE .THE MOULD ISTHEN
OPENEDAND PIECE IS EJECTED OUT.
• EVERYTYPE OF MATERIAL HAS A CHARACTERISTIC MOULDING
TEMPERATURE.INTRICATE PIECES,SEVERALCAVETIES INTHE DIEAND LONG
RUNNERSALLTENDTO INCREASETHETEMPERATURE REQUIREMENTS.

Extrusion moulding
• In this method, the resin powder is led through hopper at
the inlet end of the revolving screw. At the outlet end, the
material is heated and it is extruded or forced through a
nozzle.The plastic material as it comes out from nozzle is
received in moulds and it is cooled with air jets or water
bath

The principle of extrusion moulding is simple
and hence it forms a large percentage of the
plastic processed throughout the world.

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 thermo-plastics as well as
for thermo-setting materials.

BLOW MOULDING
THIS TYPE OF MOULDING IS APPLIED TO ONLY THERMOPLASTICS WHICH
ARE USED FOR PRODUCING HOLLOW OBJECTS SUCH AS BOTTLES AND
FLOATABLE OBJECTS BY APPLYING AIR-PRESSURE TO THE SHEET
MATERIAL WHEN IT IS HEATED AND SOFT PLIABLE CONDITION.
•DIRECT BLOW MOULDING
•INDIRECT BLOW MOULDING
IN THE FORMER CASE,A MEASURED AMOUNT OF MATERIAL IN THE FORM
OF A TUBE IS INJECTED IN A SPLIT CAVETY DIE.THE AIR UNDER
PRESSURE IS BLOWN INTO THE TUBE, WHICH CAUSES THE TUBE TO
EXPAND TO THE WALLS OF THE CAVITY.
IN THE LATTER CASE A UNIFORMLY SOFTENED SHEET MATERIAL BY HEAT
IS CLAMPED AT THE EDGES BETWEEN THE DIE AND COVER, WHICH
CAUSES THE SHEET TO ATTAIN THE CONFIGURATION OF THE MOULD.
INDIRECT MOULDING GIVES EXCELLENT APPEARANCE BUT ARE MORE
COSTLY AS ONLY 50% OF THE SHEET STOCK IS UTILIZED AND ALSO
THERE IS A TENDENCY FOR EXCESSIVE THINING OF SHEET AT THE
DEEPEST POINT.

VACUUME FORMING
THIS PROCESS IS ALSO SIMILAR TO INDIRECT BLOW MOULDINGM, WITH
THE ONLY DIFFERENCE THAT THE THINNING OF SHEET AT THE DEEPEST
POINT DOES NOT OCCURE, AND IS UNIFORM THROUGHOUT.
THE EQUIPMENTS AND DIES USED ARE LESS COSTLY AND ANY DESIRED
CONTOURS CAN BE FORMED BY VACUUM FORMING.
THE COMMERCIAL MATERIALS USED FOR VACUUM FORMING ARE
POLYETHYLENE, CELLULOSE NITRATE AND ACRYLICS.
ATOMISER BULBS, COSMETIC CONTAINES,BOTTLES, FLOATS,HOT
WATER BOTTLE AND CHRISTMAS TREE ORNAMENTS ARE THE
EXAMPLES OF THIS CLASS.

JOINING OF PLASTICS
SEVERAL TECNIQUES EXIST FOR JOINING PLASTIC PARTS.EQUIPMENT
COST FOR THESE TECHNIQUES VARIES CONSIDERABLY AS DOES THE
AMOUNT OF LABOUR INVOLVED.MORE SO MOST OF THE METHODS HAVE
LIMITATIONS REGARDING THE SIZES AND /OR TYPES OF PLASTICS THEY
CAN JOIN.THE VARIOUS METHODS ARE :
MECHANICAL FASTENING. THIS IS THE SIMPLEST WAY TO JOIN PLASTIC
PARTS.IN THIS A FASTENING ELEMENT IS FORMED INTO THE PARTS TO
THE JOINED AND THUS COST THE LEAST.ONLY THE STRONGER
TOUGHER PLASTICS ARE SUITABLE FOR THIS METHOD SINCE THE JOIN
TMUST SURVIVE THE STRAIN OF ASSEMBLY,SERVICE LOAD AND
POSSIBLE REPEATED USE.THIS TYPE OF FASTENING IS SUITABLE ONLY
FOR LIGHTLY LOADED,NON RIGID ASSEMBLY WHERE PRICISION IS NOT
CRITICAL.
MECHANICAL FASTENERS(SCREWS,RIVETS,PINS,SHEET-METAL
NUTS)ARE THE MOST COMMONLY USED JOINING METHODS.
THREADED FASTENERS WORK BEST ON THICK SECTIONS.THRESD
FORMING SCREWS ARE PREFERRED FOR SOFTER MATERIALS WHILE
THREAD CUTTING SCREWS WORK BETTER FOR THINNER SECTIONS.
IF A FASTENER IS TO BE REMOVED A NUMBER OF TIMES,METAL INSERTS
ARE RECOMMENDED.

SPINWELDING
IN THE SPIN WELDING OF PLASTICS, ONE PART IS HELD
STATIONARY,WHILE THE OTHER IS ATTACHED TO A SPINDLE WHICH IS
BROUGHT UPTO PREDETERMINED SPEED AND THEN FORCED AGAINST
THE STATIONARY PART.PARTS THUS FUSE TOGETHER UNDER THE HEAT
GENERATED BY FRICTION.ONE LIMITATION OF THIS METHOD IS THAT THE
ROTATING PART MUST BE SYMMETRICAL.FOR JOINING A FEW
PIECES,ARRANGEMENTS CAN BE MADE IN WORKSHOP.

SOLVENT BONDING
IN THIS METHOD OF JOINING,PLASTIC
(THERMOPLASTICS ONLY) ARE JOINED BY
SOFTENING THEM BY SOLVENT, AND THEN CLAMPING
OR PRESSING TOGETHER.IN THIS WAY PLASTIC
MOLECULES INTERMINGLE AND THE PARTS BOND
TOGETHER WHEN THE SOLVEN T EVAPORATES.
THE FUSION TIME IS THE DIRECT FUNCTION OF THE
SOLVENTS EVAPORATION RATE AND MAY BE
SHORTENED BY HEATING. PRESSURE TO BE APPLIED
IS ALSO CRITICAL AS TOO MUCH PRESSURE MAY
DISTORT THE PARTS. THIS IS OFCOURSE ASLOW
PROCESS.

ULTRASONIC WELDING
IN THIS METHOD TWO PARTS TO BE JOINED ARE PLACED TOGETHER
AND THE PULSE3 ARE TRANSMITTED FROM THE GENERATOR TO THE
PARTS BY A RESONANT VIBRATING TOOL (CALLED HORN) CAUSING
THEM TO VIBRATE AGINST EACH OTHER AT FREQUENCIES AROUND
20 KHz. THE PARTS ARE HEATED AND FUSED TOGETHER.THIS
PROCESS IS SUITABLE ONLY FOR THERMOPLASTICS WITH THE
EXCEPTION OF THERMOSETTING RESINS AND TEFLON.THE
PRESSURE AT CONTACT BETWEEN TWO PARTS IS CRITICAL AND IT
SHOULD BE JUST SUFFICIENT TO CAUSE HEATING BY FRICTION. IT IS
A VERY FAST PROCESS. THE PROCESS REQUIRES FAIRLY RIGID
MATERIALS.
IT IS POSSIBLE TO JOIN ASSIMILAR METALS ALSO, PROVIDED BOTH
HAVE SAME MELTING TEMPERATURES.IT IS BEST USED TO SPOT
WELD PLASTIC SECTINS.

INDUCTION WELDING
IN THIS METHOD TWO PIECES OF SAME THERMOPLASTICS TO BE
JOINED TOGETHER ARE PRESSED TOGETHER WITH A METAL WIRE OR
INSERT IN THE JOINT AREA AND THE HEIGH FREQUNCY (ABOUT 450
KHz) FIELD SWITCHED AROUND IT, WHICH CAUSES THE ENCASED
METAL TO BE HEATED UP THEREBY MELTING THE PLASTICS, AND THE
COMPRESSION PRODUCES A GOOD FUSION WELD.THE MATERIAL
REMAINS INSIDE THE PART. IN CASE IT IS DESIRED NOT TO ADD THE
METAL PIECE INTO THE JOINT, THEN METAL POWDER MAY BE ADDED TO
THE ORIGINAL PLASTIC MOULDING, BUT A MUCH HIGHER FREQUNCY OF
ABOUT 3 TO 5 MHz IS NEEDED TO EFFECT THE WELD.IT IS A HIGH COST
TECHNIQUE AND IS SUITABLE FOR DIFFICULT TO WELD PLASTICS SUCH
AS POLYPROPYLENE, AND FOR SHAPES THAT CAN,T BE FITTED INTO
ALL ULTRASONIC WELDING MACHINE.

DIELECTRIC WELDING
THIS METHOD FINDS APPLICATIONS IN WELDING
FIRMS AND THIN SHEETS IN PACKAGING PROCESSES.
IT UTILIZES THE TECHNIQUE OF BREAKING DOWN
THE PLASTIC UNDER HIGH VOLTAGES AND
FREQUENCIES (10 TO 100 MHz) TO PRODUCE
DIELECTRIC HEATING AND FUSE; THE PLASTIC.
WELDING SPEED IS A FUNCTION OF DIELECTRIC –
LOSS FACTOR, MATERIAL THICKNESS, AND THE AREA
SUBJECTED TO THE IMPRESSED VOLTAGE.

HOT PLATE WELDING
IN THIS METHOD, THE THERMOPLASTIC IS FIRST SOFTENED BY
CONTACTING IT WITH A HEATED TOOL AND THEN PRESSINGTOGETHER .
WITH FILM SOR SHEET, THE MATERIAL IS PASSED UNDER A HOT ROLLER.
THE STICKING BETWEEN THE HOT TOOL AND THE PLASTIC MATERIAL IS
PREVENTED BY COATING THE TOOL WITH A FLOROCARBON.
TEMPERATURE CONTROL IS CRITICAL SO THAT THE BOND OR PART
DOES NOT DETERIORATE.
A VARIETY OF THIS PROCESS IS THE HOT PLATE WELDING WHICH CAN
BE USED FOR WELDING LARGE, IRREGULAR SHAPED MOULDED OR
EXTRUDED PARTS. THE PARTS TO BE JOINE DARE PLACED INTO
FIXTURES. A HEATED PLATTEN IS POSITIONED BETWEEN THE PARTS AND
EDGES TO BE JOINED ARE PRESSED AGAINST IT. THE PLATEN IS
REMOVED AND THE PARTS WITH THEIR EDGES NOW PLASTICIZED ARE
PUSHED TOGETHER. AFTER A BRIEF HOLDING AND COOLING PERIOD,
THE FIXTURE IS OPENED AND THE COMPLETEED ASSEMBLY REMOVED.

HOT GASWELDING
INTHIS METHOD THE WELDING ROD – COMPRISES A
THERMOPLASTIC ROD – COMPRISES A
THERMOPLASTIC ROD WHICH IS HEATED ALONG WITH
THE PARTS. TO BE JOINED BY AN INERT GAS UNTILL
THE PARTS SOFTEN AND CAN BE PUSHED TOGETHER .
THIS IS A LOW SPEED PROCESS FOR FABRICATING
LARGE STRUCTURE PARTS FROM SHEET STOCK. IN
THIS METHOD, THE OPERATOR SKILL IS VERY
CRITICAL FOR BOTH WELD STRENGTH AND
APPEARANCE.

VIBRATION WELDING
THIS IS A NEW TECHNIQUE FOR JOINING,PLASTICS AND PRODUCES
PRESSURE TIGHT JOINTS IN CIRCULAR, RECTANGULAR OR
IRREGULARLY SHAPED PARTS MADE FROM ALMOST ANY
THERMOPLASTIC MATERIAL EVEN IN DISSIMILAR MATERIALS HAVING A
MELTING TEMPERATURE SPREAD AS GREAT AS 350C. THE PROCESS IS
PERTICULARLY SUITED FOR HOLLOW, CONTAINER TYPE COMPONENTS
HAVING THE WELD JOINTS IN A SINGLE PLANE. IN THIS METHOD, THE
FRICTION HEAT IS DEVELOPED BY PRESSING THE TWO PLASTIC PARTS
TOGETHER AND VIBRATING THE PARTS AT 120 CYCLES PER SECOND IN
THE PLANE OF THE JOINT. AFTER 2 – 3 SECONDS, VIBRATION IS
STOPPED AT THE EXACT REQUIRED RELATIVE POSITION OF THE TWO
PIECES. PRESSURE IS MAINTAINED BRIEFLY WHILE THE SOFTENED
PLASTIC COOK JOINT STRENGTH IS VERY NEARLY THAT OF THE
PARENT MATERIAL. THE PROCESS IS ADAPTABLE TO FULLY AUTOMATED
SYSTEMS.

• Construction Design
• PVC is versatile to meet modern and future design needs. In addition to
use in new projects, PVC also has wide application in refurbishment where
PVC commonly replaces traditional materials such as clay and wood. For
example, PVC windows provide a cost-effective restoration or
refurbishment option which can blend in sympathetically with the original
structure.This use of PVC upholds traditional construction virtues of
strength and longevity for window frames
What is PVC?
PVC stands for polyvinyl chloride and is also known as “vinyl” .It is a
synthetic polymer (or resin), formed by combining ethylene and
chlorine.
it is commonly used in building construction, interior
furnishing, electronics ,appliances and other building services material

The key benefits of PVC are that it is:
Strong And Lightweight
PVC's abrasion resistance, lightweight and good mechanical strength and
toughness are key technical advantages for its use in building and construction
applications.
Fire Resistant
PVC is inherently difficult to ignite and stops burning once the source of heat is
removed. This makes it particularly suitable for rigid applications eg: windows,
doors and cladding.
Durable
PVC is resistant to weathering, chemical rotting, corrosion, shock and abrasion.
It is therefore the preferred choice for a range of customers for many different
long-life and outdoor products. In fact, medium and long term applications
account for some 85 percent of PVC production in the building and construction
sector.
For example, it is estimated that more than 75 per cent of PVC pipes will have a
lifetime of more than 40 years with potential in-service lives of up to 100 years.
In other applications such as window profiles and cable insulation, studies
indicate that over 60 per cent of them will have working lives of over 40 years.

Cost-Effective
PVC compounds used in construction offer excellent cost-performance advantages
Environmentally Sound
In lifecycle analyses and independent studies, PVC's environmental impact has been
found to be favorable when compared with other manufactured materials used for
construction.
Good Insulator
PVC does not conduct electricity and is therefore an excellent material to use for
electrical applications such as insulating sheathing for cables.
Versatile
The physical properties of PVC allow designers a high degree of freedom when
designing new products.
Recyclable
Facilities exist so that construction materials such as pipes, window profiles and
flooring can be recycled at the end of their useful lives

•PVC Used In Construction Applications Is Safe
•PVC meets all international standards for safety and health for the
products and applications for which it is used.
•It has been used for more than half a century and is the world's
most researched and thoroughly tested plastic.
•Claims made by Greenpeace and other campaigning pressure
groups about the safety of PVC are unfounded.
•PVC Used In Construction Applications Is Environmentally Sound
•Environmental advantages of PVC include:
•Comparatively low energy and resource use in production, as well as in conversion
to finished products.
•Lifecycle analyses have shown that PVC is a very competitive and environmentally
acceptable material.
•As a thermoplastic, PVC can be recycled, after it has been sorted into a single
material stream and can also play its part in mixed plastics recycling.
•buildings.

•At the end of a product's useful life, if not recycled, it can be safely incinerated or
deposited in landfill.
•PVC building products are lighter than those made of concrete, iron or steel. This
requires less fuel and generates fewer emissions during transportation.
•PVC products are durable, so frequent replacement is unnecessary.
•Good thermal insulation of windows and cladding helps to increase the energy
efficiency of
Additives
All polymers, including PVC, require additives of one sort or another. The
essential additives for all PVC materials are heat stabilizers and lubricants, and in
the case of flexible PVC, plasticizers are also added. Other additives which may
also be used are fillers, processing aids and pigments.
Stabilizers
Stabilizers are necessary in all PVC formulations to prevent the decomposition of
the PVC by heat and stresses during processing. They can also give PVC
enhanced resistance to daylight, weathering and heat ageing and have an
important influence on the physical properties of the PVC formulation

•PVC Used In Construction Applications Is
Cost-Effective
•PVC has been a popular material for construction
applications for decades due to its material, technical and cost
advantages:
•PVC building products are durable and tough at reasonable
cost.
•PVC products can be mass produced.
•Its light weight strength and design flexibility bring cost
benefits for many applications.
•PVC is competitive, in terms of price, compared with other
materials used in building and construction.
•PVC is durable and is very suitable for long-lasting and
maintenance-free applications.
•Its fire retarding properties make it the most suitable material
for a range of safety applications such as cables.

•Uses Of PVC In Building
And Construction
•These include all PVC components used
in the construction industry:
•Wiring and cable insulation.
•Window and door profiles.
•Pipes and ducts.
•Cladding and roofing membranes.
•Flooring.
•Wall coverings

•Window And Door Profiles
•One of the major uses of rigid PVC in construction is
profiles for windows and doors. The alternatives to PVC
for window frames are wood, aluminum and steel.
Various ecobalances have been undertaken to compare
the materials used in window profiles. These have
shown that PVC occupies a good ecological balance. In
terms of energy consumption, studies give the lowest
value for wood and the highest for aluminum. On air
pollution, wood and PVC have equivalent profiles with
aluminium the least favourable
•Specifiers and consumers choose PVC windows because they
are tough and durable, require low maintenance, do not rot, offer
design flexibility, are competitive in terms of price, and can be
easily processed and fabricated

Pipes And Ducts
•PVC pipes possess excellent technical
qualities. In a range of applications from gutters
to sewerage pipes they are able to fulfill
demanding specifications. They are competitive
in terms of cost, are easy to install and require
only low maintenance. Pipes can be made in a
range of profiles, round, square or rectangular to
meet a range of needs
.
•The extrusion process, plus the fact that PVC is
light in weight, allow long sections of pipe to be
made, minimizing the number of joints which
reduces the cost of assembly.
•PVC has very good chemical resistant
properties and can be used above or below
ground for the transport of many substances
including oil, potable water and gas. PVC pipes
are also used in the telecommunications
industry for carrying cables and wiring.

•Pipes made from PVC have good abrasion resistance, are not
damaged by special equipment used for clearing blocked pipes
and are resistant to damage from sharp edged backfill materials.
•PVC pipes can be easily colored for different applications in line
with EU regulations for underground pipe installations.
•
•In domestic plumbing applications, PVC pipes are light and easy
to install. They are also less likely to burst in freezing weather
than the traditional alternatives and do not build up scale
deposits. PVC pipes have the advantages of being a poor
conductor of heat or sound.

Comparison of the conventional pipes
ITEM ASBESTOS
CEMENT
PIPES
CAST IRON
PIPES
G.I. PIPES P.V.C PIPES
Corrosion
problems
Slight
corrosion in
aggressive
area
moderate severe nil
Flow quality 130 100 100 150
installation difficult difficult difficult easy
Length
obtained
160m 66m 143m 1100m
Raw materials Overwhelming
ly indigenous
Some imports Some imports Some imports
weight 6 W 15 W 7 W W

•Recent Developments
•Several pipe designs for sewerage have been
developed; solid, corrugated and foam-core twin-
wall pipes. Ribbed PVC designs used for
underground pipes have increased rigidity and
provide potential for weight savings. The ribbed
designs have a smooth inner wall to allow free flow.
•Foam-core PVC pipes have solid PVC inner and
outer walls which enclose a cellular core layer. This
technique can save up to 35 per cent of material
weight.
•PVC liners and inserts can be used to repair
damaged concrete or clay pipes

•Cladding And Roofing Membranes
•PVC cladding is designed as a long life product
requiring little maintenance. PVC's durability, high
thermal insulation and excellent weathering
performance with good resistance to UV light and
ozone, mean that cladding can remain in place for
many years.
•PVC roofing membranes are easy to install, totally
waterproof, maintenance free, economically priced
•Flooring
•PVC is the main plastic used for sheet and tile flooring.
Some 243 million square meters of PVC flooring were
used in Western Europe in 1996.
•Vinyl flooring is hard-wearing, warm underfoot, cost-
effective and easy to keep clean as it has a pore-free
surface.
•It is low maintenance, needs no polishing or treating,
and is hygienic and fire resistant.
•It is also easy to join separate sheets together by
welding which prevents water or moisture from seeping
through gaps.

Wall coverings
Vinyl coated wallpapers offer durable, washable wall
coverings. They are long lasting and are available in a
wide range of colors, patterns and textures
PVC sheets

POLYCARBONATE
SHEET
PVC SHEET
FIBRE SHEET
ACRYLIC
SHEET
POLYCARBONATE
SHEET
FIBRE SHEET

FIBRE SHEEETS OF DIFFERENT TEXTURE AND COLORS
Polycarbonate sheet Acrylic sheet

Fencing
Previous Material: Wood, Metal
Current Material: PVC
Benefits: Weather ability, Durability
Transformation Date: 1996
Weather ability and durability are clearly the leading factors in the high
acceptance world has realized with its PVC fencing materials. In
addition, quick assembly and the ease of installation or repair, which
translate into reduced labor costs, are added benefits of the
transformation of many fencing projects from wood or metal to
thermoplastics

Foundation Water Drain System
Previous Material: Gravel, Stone
Current Material: HDPE
Benefits: Improved Water Flow, Durability
PolyDrain is a waterproofing product from Pro-Tec Industries. PolyDrain
increases water flow into a standard drain tile system. It allows faster water
flow due to less resistance.

Security Windows
Previous Material: Glass
Current Material: Acryshield L3
Benefits:
Safety, Aesthetics, Weight,
Fabrication

Storm Doors
Previous Material: Aluminum
Current Material: WeatherPro, PVC
Benefits: Durability, Cost, Weight
Colors, traditionally not available in outdoor storm door
applications due to weather ability issues, are now
being made possible through the use of
thermoplastics. As a replacement to aluminum,
WeatherPro and PVC are allowing for this flexibility,
while also offering the advantages of lighter weight,
reduced costs, and enhanced durability over the
traditional material

Residential Window Sills
Previous Material: Wood
Current Material: HDPE
Benefits: Durability, Aesthetics, Cost
High density polyethylene (HDPE) is continuing to replace
wood in many of today's residential window sills. The
chief driver behind this transformation is the increased
durability the HDPE material is offering to consumers.
Improved aesthetics and lower costs are also key to
the move from wood to HDPE for this application

FIBRE GLASS
REINFORCED
PLASTIC
The fiberglass reinforced plastic or FRP is formed
by using two materials in conjunction with each
other to form a composite material of altogether
different properties. It is sometimes referred to as
the glass fiber reinforced plastic or GRP in FRP or
GRP, the glass fiber provides stiffness and
strength while resin provides a matrix to
transfer load to the fiber. The use of various
additives lends special properties to the FRP. The
combination of glass fibers, resign and additives
to fabricate the FRP can be done in Number of
ways.

PROPERTIES:
1. AESTHETIC APPEAL
2. CORROSION RESISTANCE
3. DIMENSIONAL STABILITY
4. DURABILITY
5. EASY TO REPAIR
6. EFFECT OF HEALTH
7. ENERGY SAVING
8. FREEDOM OF DESIGN
9. LIGHT TRANSMISSION
10. LIGHT IN WEIGHT
11. LOW INVESTMENTS IN TOOLING
12. MAINTENANCE

APPLICATION IN BUILDING INDUSTRY
1. CONCRETE SHUTTERING
The moulds and forms of FRP give the concrete shape
of very high quality
2. DOMES
The domes in enhancing shapes and unique design
with wide dimensions can be created for eye catching.
3. DOOR AND WINDOW FRAMES
The light weight flush doors and factory made standard
window frames of FRP can be suggested for housing
schemes due to their long life, easy maintenance and
overall reduction in cast.

DOMES
POLYCARBONATE FIBRE
FIBRE

4. INTERNAL PARTITION AND WALL PANELLING
t is possible to adopt flat, corrugated or fancy FRP
sheets for internal partitions of industrial and
commercial buildings.
5. ROOF SHEETS
The translucent FRP sheets provide a versatile medium
of lighting. The sheets are available in varieties of forms
with the corrugated type being very common.
6. STRUCTURAL SECTIONS
The available cross-section profiles in steel aluminum or
PVC can also be made in FRP with advantage of equal
strength in low weight.

7. WATER STORAGE TANKS
The FRP water storage is found to be superior to
steel, concrete or galvanized iron tanks.
8. MISCELLANEOUS USES
The properties of FRP are multiple and the
applications are limitless. For instance, the FRP
chairs and benches can be used for auditoriums,
hotels, restaurants, gardens, parks, lounges,
theaters, waiting rooms etc.

Thermoplastics

More Related Content

What's hot

Similar to Thermoplastics

More from Devesh Tripathi

Recently uploaded

Thermoplastics