product_testing.ppt

CONTENTS
• Introduction
• Pipes & Fittings
• Plastic Films & Laminates.
• Containers
• Woven Sacks
• Plastic Flooring
• Cellular Plastics
• Testing of FRP
• References
2
Corporate Training & Planning

INTRODUCTION
Importance of product testing:
• To evaluate the performance of product.
• To identify criticality of component performance in assembled condition.
• To identify necessary changes in process parameters.
• Modification of product or mould design.
• To prepare instructions to avoid end user’s abuse.
• To establish the reputation of the product.
• Conformity of product to particular specifications.
3

Factors Responsible for Performance Products
• Materials and its grade
– Additives,modifiers and processing aids.
– Plastic Processing Techniques e.g.Injection olding, Extrusion, Compression
molding etc.
– Processing Parameters (e.g. Pressure,Temperature & Time etc.)
– Pre Molding Operations e.g.Pre-heating,Pre-forming, compounding, Blending
etc.
– Post Molding operations such as Printing, decoration, drilling, trimming,
electroplating, welding etc.
– Mould & Product Design
– End use conditions(e.g.Environmental condition,final assembly etc.)
4
INTRODUCTION

PLASTIC PRODUCTS COVERED
• Pipes and Fittings
• Plastic Films and Laminates.
• Plastic Containers
• Woven Sacks
• Plastic Flooring
• Cellular Plastics
• Testing of FRP
5

6

PLASTIC PIPES AND FITTINGS
Introduction
Definition :
• Pipe is any round self – supporting continuous hollow cylinder with a minimum
inside diameter of 12mm.
• Fittings
7

PLASTIC PIPES AND FITTINGS
• Advantages of Plastic
• Following are the advantages of plastic pipes
• Low manufacturing cost.
• Lighter in weight and easy to handle.
• Flexibility in design features.
• Easy assembling & installation
• High resistance to corrosion , water & Chemicals
• Good weathering properties.
• Low maintenance cost
• Less chance to microbial growth inside pipe.
• Low friction loss in transportation of water
• More durability ( Life of UPVC pipe is estimated approx 100 years)
8

APPLICATIONS OF PIPES
• Potable water supply
• Tube-well construction
• Domestic/Industrial Plumbing
• Cable Duct Pipes
• Soil, Waste & Rain water systems
• Underground drainage and sewerage systems
• Lift Irrigation system
• Agriculture irrigation distribution systems
• Subsoil drainage systems
• Piping system for both fresh and salt waters
• Effluent Treatment conveyance pipeline systems
• Chemical conveying pipeline systems in industry
• Centrifugal pump suction and delivery pipes
9

MATERIALS FOR PIPES
• Commonly used plastic materials for pipes are
• Polyvinyl Chloride (PVC)
• Chlorinated Polyvinyl chloride(CPVC)
• Acrylonitrile Butadiene Styrene(ABS)
• Polypropylene(PP)
• Polyethylene(HDPE, LDPE etc)
• Fiberglass Reinforced Plastic Epoxy(FRPE)
• Fiberglass Reinforced Plastic Polyester (FRPP)
• Material selection
Selection of correct piping material depends on application and environment.
Ex : PP is preferred for chemical resistant & high temperature applications.
ABS is preferred for high impact and crush resistant applications.
10

PROPERTIES AND APPLICATIONS
OF PLASTIC PIPES
Materials Properties Application
PVC Excellent weather resistance Refrigeration, Sewage & water treatment,
Chemical & food processing industries,
Irrigation and water distribution line,
swimming, drain, waste and vent, conduct for
wiring and vacuum lines
CPVC Stand higher temperature Hot fluid application and water treatment
systems
ABS Good chemical resistance
weather resistance. Does not
crack on impact
Weather and gas marked, food process plant,
chemical, drainage, sewage treatment, sludge
discharge system, electrical conducts irrigation
lines (UHMW-PE)
PP Light weight and good high
temperature and chemical
resistance
Low pressure line and Acid waste drainage
system one and water system

PROPERTIES AND APPLICATIONS
OF PLASTIC PIPES
Materials Properties Application
Polyvinylidene
Chloride
-- Lining material in steel pipes and
fittings
FRP (Epoxy) Resistance to dilute acid, solvents,
caustics
Chilled and hot water line, Air-
conditioned and refrigerator
FRP (Polyester) Good corresion resistance, good
weather resistance
Water line for power plant discharge
line, Water faintain service lines
Petroleum, refining installations

Description IS/ASTM
No.
Specified Tests on pipe as per standard
Unclassified PVC
pipe for potable
water supply
IS:4985 :
2000
 Dimensions( Diameter, Wall thickness, Socket ID, Length, Socket
dimension)
 Opacity,  Sulphated Ash content
 Reversion  Visual appearance
 Density  Resistance to external blow at 00 C
 Hydraulic test  Effect on water test
 Long term (Analysis of Pb, Sn, Cd & Hg in
 Short term water extracted from pipe)
UPVC Screen
and casing pipe
for bore well/
Tube well
IS:12818
: 1992
 Dimensions ( Diameters, Wall thickness, Length)
 Visual appearance  Specific Gravity
 Shore A hardness of Rubber gaskets
 Mandrel test  Impact resistance
 Tensile strength  Vicat Softing Temp.
 Effect on water test (Analysis of Pb, Sn, Cd & Hg
in water extracted from pipe)
COMMONLY MANUFACTURED PIPES
& RECOMMENDED TESTS

PVC pipe Plastic
pipes, Schedule 40,
80 and 120
ASTMD : 1785:04a  Dimension,
 Visual appearance, Flattening test
 Burst pressure, Sustained press.
 Crush resistance,
 Acetone immersion test
UPVC pipe for soil &
waste discharge
system
IS:13592:1992  Dimensions(Diameter, wall thickness, Length,Socket
dimensions)
 Visual appearance
 Reversion  Stress relief test
 Resistance to H2So4
 Impact resistance at 00 C
 Tensile strength,  Vicat Softing Temp.
 Water tightness of joints
HDPE Pipes for
potable water supply
IS: 4984: 1995
Grade PE 63
PE 80
PE 100
 Dimensions(Diameter, wall thickness)
 Reversion  Migration,
 Density  Melt Flow Index(1900C/5kg.)
 Carbon black content
 Carbon black dispersion
 Hydraulic characteristics
 Long term (165 hrs.)
 Short term (48 hrs)
& RECOMMENDED TESTS

PE Pipes for irrigation
laterals
IS: 12786 :
1989
 Hydraulic characteristics
 Reversion  Tensile strength
 Environmental stress crack resistance
PE pipes for sprinkler
irrigation system
IS: 14151:
(Pt-I)1999
 Dimensions(Diameter, wall thickness, Ovality)
 Visual Appearance
 Tensile strength and elongation
 Fusion compatibility,
 Hydraulic characteristic
 Density  Melt Flow Index
 Carbon black dispersion
PE pipes for sprinkler
irrigation system
IS: 14151:
(Pt-II)1999
 Visual Appearance  Leakage test
 Hydraulic proof test  Density
 Melt Flow Index,
 Carbon black dispersion,
 Shore hardness
& RECOMMENDED TESTS
15

PRODUCT SELECTION
The Selection of correct piping material for specific application depend upon
many factors . These are :
• The selection of correct piping depends as the application and environment.
Example
• For chemical resistant & high temperature applications, Polypropylene pipes
are preferred.
• For high impact and crush resistant applications pipes of ABS material are
suitable.
16

PRESSURE RATING OF PIPES
• Almost all the pipes are classified by
pressure rating at a given
temperature
• As per IS : 4984 : 1995 at 300C and IS :
4985: 2000 at 27oC pressure ratings
of pipes are according to their
nominal pressure (PN) as below.
• Other pipes & fittings manufactured
according to IS standards are
classified on similar pressure rating.
• Generally swegger and drainage pipe
are not rated based on the pressure
S.No. Nominal Pressure Class
1. 0.25 MPa Class 1
2. 0.4 MPa Class 2,
3. 0.6 MPa Class 3,
4. 0.8 MPa Class 4
5. 1.0 MPa Class 5
6. 1.25 MPa Class 6
17

PRESSURE RATING OF PIPES
In USA standard dimension ratio ( SDR) is used to classify the pressure rating of
thermoplastic pipe.
Standard dimension ratio ( SDR ) = Outside diameter of pipe
Wall thickness of pipe
Thermo sets pipes are normally rating at maximum temperature where as
thermoplastic at ambient temperature ( 740F – 750F )
The most popular ratings are as below.
Thermo plastic pipes are designated with four digits and product alphabet prefix
1st digit = Type of resin
2nd digit = Grade of resin according to ASTM
3rd & 4th digit = Hydrostatic design stress divided by 100
Example : CPVC 4120 means the resin is CPVC type 4, Grade 1, with a 2000 psi
hydrostatic design stress
S.No. SDR of pipes Nominal Pressure SDR of pipes Nominal Pressure
1. 13.5 315psi 32.5 125psi
2. 17 250psi 41 100psi
3. 21 200psi 64 50psi
4. 26 160psi - -
18

TEST PROCEDURES
Opacity Test : (IS: 4985:2000, 12235-86 (Part-3 )
• This test determines the percentage of visible light transmission through the wall of
PVC pipe. The transmission of the light through the wall of pipe & fitting should not
be more than < 0.2%
Significance : To check the conformity to the pipe & fittings to opacity test as per IS:
4985:2000 of relevant standard.
• The transmission of the light through the wall of the pipe will caused photochemical
reaction inside the pipe in the presence of heat and water
• Such photochemical leads to scaling, algae formation and contaminate the potable
water transported though the pipe and make unsuitable for drinking
• Light transmission is generally high in thin wall pipe & less in thick wall pipes
• When the light transmission is less than 0.2% the effect of Photochemical reaction
and it’s effect will be insignificant
• The additional of small amount of carbon black in PVC compound improves opacity
( reduces light transmission )
Apparatus : Electronic opacity tester is used which consists of light source, photo
electric cell, digital current meter
19

PROCEDURE:
• Cut 2 nos of 50mm x 50mm test pieces from the original thickness of the pipe &
fitting.
• Calibrate the equipment by adjusting the reading to zero by blocking the light from
the light source fully and 100% when the light is switched in absence of test piece.
• Check the precision of reading using standard lens to give absorption of 0.2%
• Place the specimen on the support between the light source and photo detector cell
• The percentage light transmitted is directly read from the opacity indicator
• The percentage of light transmission should not exceed 0.2%
Result : The percentage of light transmission through the wall of the pipes is recorded as
its result
• Factors affecting opacity
• Amount of the carbon black, and other compound in the pipe material
• Wall thickness of the pipe( higher the wall thickness less is the opacity)
TEST PROCEDURES
20

REVERSION TEST
Definition : Change in length along the surface of the pipe due to heat and subsequent
cooling is called reversion. This test is recommended for UPVC and PE pipes.
• The test is carried out by emerging a portion of pipe of a given length in the liquid
or air medium for a specified period of time in relation to wall thickness and dia of
the pipe
Significance : To check the conformity to the pipe to reversion test as per relevant
standard.
• During manufacturing of pipe certain degree of moulded in stresses ( residual
stresses) and high degree of molecular orientation are introduced. These molecular
orientation and stresses get relived by reversing on reheating.
• Due to high day & night temperature variation in different environmental
conditions the pipe undergoes expansion, contraction & stress relaxation process
which leads to the change in dimension.
• The pipe expands and contracts with the rise and fall of the temperature which
leads to the failure of assembly particularly joints and water leakage may occur
• The dimensional change in the longitudinal direction is measure on cooling to room
temperature.
• The acceptable limit of dimensional change is specified as per pipe material.
21

S.N
o
IS No. Pipe Sample
Details
Sample
Size
Test
Temp.
Test Duration Medium
of
heating
A For HDPE pipes
1. IS 4984:1995 HDPE Pipes for
Water Supply
200±20
mm
110+2 60 /120/240 minutes
( for 8mm/8 to
16mm/16mm and above
thick pipe)
Air
2. IS 14151 :
(part-I) 1999
HDPE pipe for
Sprinkler
irrigation
200±20
mm
110+2 60 min Air
3. IS 14333 :
1996
HDPE pipe for
sewerage
200±20
mm
110+2 60 /120/240 minutes
( for 8mm/8 to
16mm/16mm and above
thick pipe)
Air
4. IS 12786:1989 Irrigation
Equipment-PE
Pipes for
Irrigation Laterals
200±20
mm
100+2 60 min Air
SPECIFIED TEST CONDITION FOR REVERSION
TEST FOR VARIOUS TYPES OF PIPES

SPECIFIED TEST CONDITION FOR REVERSION
TEST FOR VARIOUS TYPES OF PIPES
S.N
o
IS No. Pipe Sample
Details
Sample
Size
Test
Temp.
Test Duration Medium
of
heating
5. IS 4985:2000 UPVC Pipes for
Potable water
Supply
200±20
mm
150+2 15min / 30 / 60 minutes
(8.6 mm / 8.6 to
14mm/>14mm & above
respectively.
Liquid
6. IS 13592:1992 UPVC Pipes for
soil & waste
discharge systems
inside buildings
including
ventilation & rain
water system
200±20
mm
150+2 60min / 120 / 240
minutes
(8.6 mm / 8.6 to
14mm/>14mm & above
respectively.
Air
15min/30min/60min
(8.6 mm / 8.6 to
14mm/>14mm & above
respectively)
Liquid

EQUIPMENTS :
 Electrical heated hot air oven (for HDPE pipes) Vernier caliper
 Oil immersion bath ( for UPVC pipes)  Scriber
PROCEDURE :
• Cut the 3 pieces of 200 ± 20mm long piece of pipe in the axial length and scribe
two lines at outside of surface of specimen 100mm apart
• For HDPE pipe >200mm dia test piece from the circumferential arc of length of
200mm is cut from the pipe and scribe two line 100mm apart
• Select the specified test conditions for various types of the pipe as given below in
the table and set the required temperature in the air oven/oil bath as may be
applicable for particular type of pipe
REVERSION TEST FOR HDPE PIPE
• Place the duly marked test sample into the oven for the specified period of time in
the air oven at at the temperature indicated in the table
• Remove the specimen from the oven after specified period and cool in air to
ambient temperature
• The distance between two marked along the surface of the specimen is measured.
24
REVERSION TEST

• The percentage of Reversion is calculated using the following formula
R ( % ) = lo – li x 100
lo
where R is the reversion,
lo and li are the lengths before and after test.
Oil Immersion method : ( For UPVC pipes )
• Marked UPVC pipe specimens are immersed in an oil bath at 150 + 2oC for a
specified duration as given in the table according to the wall thickness of the
pipe.
• After expiry of the test duration specimens is removed from oil bath and cooled
in air to ambient temperature.
• The percentage reversion is calculated using the above formula.
• The maximum reversion percentage limits for HDPE pipes is + 3 % while that for
UPVC pipes is + 5 %.
25
REVERSION TEST

HYDROSTATIC PRESSURE TEST
( INTERNAL PRESSURE CREEP RUPTURE TEST)
• The most important and commonly used pressure tests are
(i) Acceptance or test Short term test
(ii ) Type test or Quality also known as test Long term test
(iii) Brust pressure
(i) Acceptance (Short term test) :- Short term testing is called instantaneous pressure
test. This test is generally used for quality control test and to check batch to batch
uniformity for acceptance of materials. Under this test pipes are brought to
specified temp and pressure and then instantaneously pressure is increased to
burst or maintained for specified test time.
26

(ii) Type test (Long term test) : -
• In this test pipes are held at standard condition of sure and time (between
100 to 1000 hours). The constant temp and pressure is maintained for the
specified period. The failure or bursting of the pipes are observed.
• The long term or Quality test is generally carried out to characterize material
and prove the suitability and performance ( creep resistance ) of new
composition or new size of pipe.
• The test conditions for various pipes is given in table 1
• Brust Pressure :
• Under this test pipe is subjected to Hydrostatic pressure and increased to it’s
maximum brust pressure.
HYDROSTATIC PRESSURE TEST
( INTERNAL PRESSURE CREEP RUPTURE TEST)
27

MECHANISM OF PRESSURE DISTRIBUTION
INSIDE THE PIPE
28

• Pipe failed by two mechanism I.e Creep & Creep propagation
CREEP :
• Creep cause a gradual increase internal volume, thinning of the wall and increased in
pipe diameter and length
• The variation in the dimension or in material causes differential creep with HDPE
pipes
• Localized yielding and ruptured leads to the ductile failure
• When the pipes are subjected to internal hydrostatic pressure test, generally two
types of stress component are developed inside the pipe i.e ( shown in figure )
( i) Longitudinal stress
(ii) circumferential stress or hoop stress.
• The amount of hoop stress is generally two times higher than longitudinal stress.
• Thus it is the single largest stress present in pipe system under pressure responsible
for failure of pipe.
MECHANISM OF FAILURE
29

• The hoop stress is expressed by following formula.
S = P ( D – t ) / 2t
Where, S = Hoop stress ; P = Internal pressure ; D = Outside diameter of pipe
t = Minimum wall thickness of pipes
TYPES OF FAILURE
• Failure in the pipe may be either brittle or ductile.
• Brittle failure is common in rigid pipe such as PVC where as ductile failure in
tough and elongation material such as P.E
MECHANISM OF FAILURE
30

Sl.
No.
IS No. Tests Length of test
sample
Test temp.
(0C)
Test Duration
(Minimum holding
time in hr)
Induced stress
(MPa)
1. IS 4984:1995 Acceptance test X10 of OD of pipe
but less than
250mm & more than
750mm
80 48 3.8 (for PE 63)
4.9 (for PE 80)
5.5 (for PE 100)
Type test -do- 80 165 3.8 (for PE 63)
4.6 (for PE 80)
5.5 (for PE 100)
2. IS 4985:2000 Acceptance test -do- 27 1 4.19XPN
Type test -do- 60 1000 1.16XPN
3. IS 14333-1996 Acceptance test -do- 80 48 4.1
Type test -do- 80 165 3.5
4. IS 12786:1989 Acceptance test -do- 20 1 6.9
Quality test -do- 70 100 2.5
5. IS 14151
(Pt-I):1999
Acceptance test -do- 70 70 5.4
Quality test -do- 70 100 5.0
The standard conditions for hydrostatstic pressure test for various types of pipes
according to IS speciation is as below.
INTERNAL HYDROSTATIC PRESSURE
31

(Acceptance Test for UPVC pipe as IS : 4985:2000)
Definition : It may be defined as ability of the pipe to withstand a specified
constant hydrostatic pressure for specified period of time at specified
temperature without showing any failure
• It consists of subjecting the specified length of pipe to a constant internal
pressure at constant temperature for a specified period of time
Significance : To check the conformity of the pipe to hydrostatic pressure test
(Acceptance test) for one hour to IS : 4985 : 2000
Apparatus : Hydrostatic pressure machine capable to maintain required test
pressure automatically
• Standard end fittings and other accessories
• Thermostatically controlled water bath
Specimens : The pipe samples shall be cut in the length of equal to 10 times of
Outside Diameter of the pipe but it shall not less than 250mm or greater than
750 mm as free length
32

PROCEDURE :
• Attach end plugs at both end of the pipes such that internal pressure is exerted
and transmitted to the pipe.
• Fill the pipe with water at ambient temperature through a closable opening in
end of the pipe
• Immerse the pipe in a water bath maintained at 270C
• Calculate the test pressure by multiplying 4.19 times of working pressure of the
pipe
• Increase the pressure gradually in the test assembly to a test pressure without
sock preferably within 10 to 30 seconds.
• Maintained the test pressure in the pipe for one hour
• At the end of one hour observed the pipe for the any kind of failure
• Record the observation of the test and it’s result
Result :
The pipe should not burst or ruptured or failure with in one hour of the test
(Acceptance Test for UPVC pipe as IS : 4985:2000)
33

(Type Test for UPVC pipe as IS : 4985:2000)
Definition : It may be defined as ability of the pipe to withstand a specified constant
hydrostatic pressure for specified period of time at specified temperature
without showing any failure
• It consists of subjecting the specified length of pipe to a constant internal
pressure at constant temperature for a specified period of time
Significance : To check the conformity of the pipe to hydrostatic pressure test (Type
test) for one hour to IS : 4985 : 2000
Apparatus : Hydrostatic pressure machine capable to maintain required test pressure
automatically
• Standard end fittings and other accessories
• Thermostatically controlled water bath
Specimens : The pipe samples shall be cut in the length of equal to 10 times of
Outside Diameter of the pipe but it shall not less than 250mm or greater than 750
mm as free length
34

(Type Test for UPVC pipe as IS : 4985:2000)
PROCEDURE
• Attach end plugs at both end of the
pipes such that internal pressure is
exerted and transmitted to the pipe.
• Fill the pipe with water at ambient
temperature through a closable
opening in end of the pipe.
• Immerse the pipe in a water bath
maintained at 600C .
• Calculate the test pressure by
multiplying 4.16 times of working
pressure of the pipe.
• Increase the pressure gradually in the
test assembly to a test pressure
without sock preferably within 10 to
30 seconds.
• Maintained the test pressure at
constant temperature of 600C in the
pipe for 1000 hours.
• At the end of 1000 hours observed
the pipe for the any kind of failure .
• Record the observation of the test
and it’s result .
Result : The pipe should not burst or
ruptured or failure with in one hour
of the test.
• The hydrostatic pressure test for
remaining other pipes shall be
conducted following the above
procedure at the pressure,
temperature and duration.
Corporate Training & Planning 35

BURST STRENGTH TEST
Introduction:
• Burst strength test determine the ability of a plastic pressure vessel to resist
rupture when it is pressurized for a short period of time In this test the
plastics pipes are subjected to a very high internal pressure for short period of
time. Time and rupture strength is determined by continuously increasing
internal hydraulic pressure at controlled temperature and environmental
conditional.
Procedure:
• Specimens of 150 mm length are cut from the pipe. Specimens are attached
with end fittings at both the ends and filled with water. Pipes are connected
to hydrostatic pressure testing machine and the pressure is increased
uniformly and continuously until the sample. The pressure at which pipe
bursts and time to failure are recorded.
36

SULPHATED ASH CONTENT TEST
Introduction: The physical properties , dimensions ,finish and performance of pipes is
influenced by the fillers compound. This also influences the specific gravity of the
pipe specific gravity of the pipe. It provides advantageous effects up to certain limit.
But beyond the recommended limit the quality and performance of the pipe is
affected.
• The test is carried out by calcinations with sulphuric acid and treatment after
combustion by burning the substance and transforming the residue into the
sulphates using concern H2So4 and finally heating the residue at 8500C until constant
mass is reached. The detailed procedure is given below.
Definition: It may defend as the percentage of the ash quantitatively present in the pipe
after heating, paralysis and calcinations with sulphuric acid after combustion.
Significance :
– For the quality control of the pipe
– To check the conformity of the pipe to sulphated ash content as per IS:485:2000
37

REAGENT : Concentrated Sulphuric Acid (Density 1840 kg/cm2 )
EQUIPMENTS
i. Crucible : Silica or Platinum crucible having upper diameter between 45 – 75mm
and height equal to diameter of crucible
ii. Analytical : Analytical weighting balance capable of weighing sample and crucible to
the accuracy of 01 mg.
iii. Bunsen Burner: Bunsen Burner and tripod stand or other suitable heating device.
iv. Muffle Furnace : Muffle furnace capable of maintaining temp of 850 ± 100 C
v. Pipette : Glass Pipette of appropriate capacity.
vi. Dessicator : Dessicator with Cacl2 as drying agent for cooling the crucible.
vii. Tongue : The tongue of sufficient length for handling crucible in hot condition.
viii.Sample : Small cut pieces of the pipe approximately 10 to 15gm
ix. Conditioning : Wash and clean the crucible and heat in the muffle furnace at 8500C
until the constant mass is achieved.
38

PROCEDURE :
• Take the mass of crucible and put about
2- 5gms samples cut from pipe.
• The weight of the sample along with the
crucible is taken
• Sample is heated on bunsen burner until
evolving of smoke from sample is ceased.
• Then it is allowed to cool.
• After cooling Sulphuric Acid is added to
the residue drop wise by means of
pipette until residue is soaked completely.
• Subsequently It is again heated on the
burner until evolution of smoke ceases.
• The crucible is placed in a muffle
furnace maintained at 850+10oC and
heated until the constant mass is
reached.
• The crucible is allowed to cool in a
desiccator to room temp and the
mass is taken
• The mass of the residue is recorded
of as sulphated ash content
CALCULATION & RESULT
• The sulphated ash content is
calculated as follows:
% Sulphated Ash Content (By mass)
= Mass of residue x 100
Mass of sample
• The sulphated ash content should be
within the specified limit.

IMPACT TEST
(RESISTANCE TO EXTERNAL BLOW AT 0o C)
INTRODUCTION :
• Impact resistance property of pipe has considerable importance. The ability of pipe
to withstand socking load is a decisive factor. Therefore in order to ensure
satisfactory field performance of unplasticized PVC pipe, the measurement of
impact resistance at low temperature is important.
• SCOPE : This test method covers to the determination of resistance of external blow
at 00 C for UPVC pipe as IS:4985: 2000
DEFINITION :
• TRUE IMPACT RATE : The total number of failure divided by total number of blows
as a percentage as if whole both had been testes
• Failure : Shattering or any crack or spilt on inside of the pipe that was caused by the
impact and that can be seen by naked eye (lightning devices may be used to assist is
examining the specimen
40

IMPACT TEST
SIGNIFICANCE : Impact strength signifies
the toughness of the pipe and hence
that the ability withstand socking load
• The test is used for quality control of
the pipe
• To check the conformity of the pipe to
resistance to the external blow at 00 C
as per IS:4985:2000
FACTORS AFFECTING: The impact
resistance of plastic not only depends
basis properties of materials, but also
on many factors such as environmental
condition, nature of blow frequency of
sock etc.
EQUIPMENTS
• Free falling the impact tester which
mainly consists of a rigidly fixed main
frame
• A striker of standard mass with free
movement on a guide
• A specimen support comprising of
120o steel V block at least 250 mm
long
• A release mechanism for the striker
• Suitable deep freezer/ liquid bath
capable of maintaining temperature
0 ± 10 C

IMPACT TEST
SPECIMEN : Sufficient no. of cut pieces of
pipe of 200± 10mm long to achieve
minimum 40 strike
• The no. of test pieces may be more in
case of failure.
• marked on circumference at
equidistance of 50mm to take one
strike. The pipes
• Pipes below 40mm size are tested for
only one strike
CONDITIONING : Pipe samples are
conditioning in deep freezer/ liquid
bath according to their wall thickness
as given below
Wall
thickness
Conditioning period
minutes
(mm) Liquid bath Air
Up to 8.6 15 60
8.6 to 14.1 30 120
Above 14.1 60 240

IMPACT TEST
PROCEDURE
• The type and mass of the striker and
height of free fall from is selected
according to the nominal diameter of
the pipe from Table – 9 of
IS:4985:2000
• The test height is measured in the
equipment and marked for test
• Condition the specimen at 00C ± 1 for
the specified period is taken out
from the liquid bath/ deep freezer
and is placed on “V-Block”
• The specified mass of the striker is
allowed fall freely on the test
specimen at different marked points
on its outer surface by rotating the
specimen about it’s axis
PROCEDURE
• The process is continued until all
marked lines have been tested or until a
failure as a result of cracking of splitting
is recorded
• Pipes their shall be no failure at the
pipe upto 39 strikes. However, test and
it’s conformity can be made according
table-11 of IS:4985:2000
FACTORS AFFECTING :
• The composition of the material and
filler content in the compound
• Fusion& Homogeneity of the compound
• Processing conditions and parameters
• Amount of impact modifier in the
compound

EFFECT ON WATER TEST
( FOR RPVC PIPES & FITTINGS)
INTRODUCTION:
• In the process of the UPVC pipe some
additives, such as organo –metallic
salts are used as stabilizers. These
stabilizers are based on heavy metal
compounds of Pb, Sn, Cd & Hg. etc
• At a time one are more than one of
these stabilizers in the compound
may be used. As such a portion of
these compounds gets consumed
during the processing of pipe but
remaining portion present in pipe
may leach in when coming in contact
of water and produced a toxic effect
to potable water. This affects the
quality of water as well as causes
health hazard.
SIGNIFICANCE :
• This test is carried out to check that
UPVC pipes manufactured pipe are
safe for transportation of drinking
water or not
• To develop PVC compound and
verify manufacturing process

EQUIPMENT :
• Pre-washing arrangement of pipes
before test, locking with
arrangements PE stopper,
• Arrangement for Extraction and
collection of water sample
• UV visible spectrophotometer/
atomic absorption
spectrophotometer with graphite
furnace and hydradide generator and
lamp for detection of Pb, Sn, Cd & Hg.
SPECIMEN :
• A cut pieces of the pipe of one meter
length
• Extraction of water sample : Test
sample for this test is obtained by
flowing water continuously through
the pipe for six hours. Subsequently
pipes are filled with carbonized water
by closing it’s one end. The extracts
of water are collected at specified
time interval.

PROCEDURE :
• The quantitative analysis of substances present in the extracted water sample like
Lead, Tin, Cadmium, Mercury etc is carried out by analytical or instrumental
method, using UV visible spectrophotometer or atomic absorption
spectrophotometer.
• The quantitative analysis of these toxic substances in water sample by atomic
absorption spectrophotometer is very fast and accurate.
RESULT
The toxic substance shall not exceed the following concentration
• Lead (I ext) 1.0mg/I (1.0 ppm)
• Lead (III ext) 0.3mg/I (1.3 ppm)
• Sn (III ext) 0.02mg/I (0.02 ppm)
• Cd (All III ext) 0.01mg/I (0.01 ppm)
• Hg ( All IIII ext) 0.01mg/I (0.01 ppm)

STRESS RELIEF TEST
( FOR UPVC PIPES & FITTINGS )
INTRODUCTION :
• During manufacturing or fabrication of sockets some degree of moulded in stress
are introduced in the socket particularly in the expanded portion. These moulded in
stress weaken the pipes and fittings this leads to localized failure.
• Test is conducted by subjecting bell ended/ socketed portion of UPVC pipes and
fittings in hot air oven at 150 ± 20C temperature for one hour then cooled slowly to
the room temperature and visually examined for a verity of attributes
DEFINITION :
• It may defined as the process of heating the test portion and subsequently cooling
and examining for the any warpage, blistering, wall separation, fish scaling and
distortion in the component
47

SIGNIFICANCE :
• This test indicates the label of moulded in stress at expanded portion of the
socket/ Bell end portion by observing/ checking of the severity of the war page ,
blistering, wall separation & distortion etc.
• The stress indicates level of weaken of the product
• Test is used for quality control and R&D purpose
• The test is carried out to very the conformity of UPVC pipes and fittings to relevant
IS specification.
EQUIPMENT :
• Hot air oven capable of maintaining 150 ± 20C temperature
• Profile projector, Micrometer etc.
TEST SAMPLE :
• Bell ended/ expanded portion of UPVC pipe & fittings
STRESS RELIEF TEST

PROCEDURE :
• Socket end of pipes & fittings is
taken marked two parallel lines both
side is taken about 25mm apart from
the stress prone area.
• Test temperature of 150 ± 20C is
maintained in air oven and marked
pipes/ fittings are placed in the oven
for one hour.
• After one hour the samples are
removed from oven and cooled room
temperature
• Socketed portion is visually examined
for any blister, excessive delaminating
or cracking sign of weld line splitting
by sectioning the marked line.
RESULT:
• Observation of visual examination is
recorded
FACTORS EFFECTING :
• Design and wall thickness of the
pipes and fittings.
• Process temperature and rate of
cooling during moulding in
fabrication
• Material and it’s composition
STRESS RELIEF TEST

DENSITY
FOR HDPE PIPES
SIGNIFICANCE:
• Density of the polyethylene material is important because properties of pipe
such as rigidity, it’s hydraulic characteristics, creep and other performance of
pipe depends upon the density of base polymer & compounds. Butyl acetate
is for determination of density by displacement method.
PROCEDURE:
• Butyl acetate is taken in suitable container and its density is measured by
hydrometer. Test piece of suitable size is cut from the pipe and is attached
with fine Nylon wire for hanging in weighing balance.
• Mass of specimen in air is taken accurately to 0.1 mg. Beaker filled with butyl
acetate is placed under the sample hanging with wire and mass of sample is
taken in butyl acetate.
50

DENSITY
The Density is calculated as below:
Density of Polyethylene Kg/m3 = a x ρBAC x 1000
a1 - a2
Where, a1 = mass in g of specimen in air
a2 = mass in g of specimen in butyl acetate
ρBAC = Density of butyl acetate.
FOR UPVC PIPES :
SIGNIFICANCE :
• Similarly density of RPVC pipe is used for quality control test.
• This test may be the indicator of compound and batch uniformity and hence
quality consistency of the pipe.
51

DENSITY
PROCEDURE:
• Test is carried out by cutting test piece of suitable size having mass in the range
of 2-5 gms
• Edges of specimens are cleaned so that there are no fibers.
• Tie specimen is with wire/Nylon fiber. and mass of specimen is taken in air and
recorded as ‘a’.
• Specimen is immersed in distilled water and the mass of specimen is taken in
immersion liquid as ‘b’.
CALCULATION :
The density is calculated as: Density = a x d
a – b
Where, d = Density of medium
a = mass in grams of specimen in air and
b = mass in grams of specimen in water.
52

ACETONE IMMERSION TEST
INTRODUCTION:
• This test is used for evaluation of quality of extrusion of UPVC pipes. Due to
some improper fusion and processing defects pipe may exhibit some residual
stress which may cause product failure.
PROCEDURE:
• A specimen is cut from complete circumferential section of the pipe. The
acetone is dried by anhydrous calcium sulphate, which is removed from
acetone by filtering. The specimen is immersed into reagent grade acetone
for 20 minutes at 23 + 2oC.
• After the immersion, the specimen is removed and examined for any failure.
53

DETERMINATION OF WATER TIGHTNESS
OF JOINTS (AS PER IS 13592)
PROCEDURE:
• A piece of plane ended pipe and a piece of socket end pipe & sealing device are
taken and assembled properly. End plug is attached at both free ends of specimen
and is filled with water at ambient temperature through a closable opening at one
end.
• Pressure is increased gradually to 0.5 MPa without sock. The leakage of water is
observed at the joint of fitting & sealing device under pressure.
• Joints of pipe shall not show any leakage at the socket end
54

CRUSH RESISTANCE :
( FOR PVC PIPE AS PER ASTM : 1785 )
DEFINITION : It is defined s the ability of pipe and moulded product to resist
compressive load.
SIGNIFICANCE : To characterized the load defection characteristics of the moulded and
extruded products under parallel plate loading
• For quality control and development of product & material
• To verify conformity of the product to relevant standard and specifications
EQUIPMENT : Crush resistance tester fitted with rigid parallel plate and capable of
apply compressive load and measure the compressive load and resulting deflection
• Vernier caliper & measuring scale for measurement of diameter before or after test
Specimen : Three cut pieces of pipe each of 50mm long
55

CRUSH RESISTANCE :
( FOR PVC PIPE AS PER ASTM : 1785 )
PROCEDURE
• Internal/ external diameter and wall thickness of cut pipe piece of measure
and place between two parallel plates of cross tester
• Machine is brought just in contact of test sample and compressive load is
applied at uniform rate on the sample until the distance between the to plate
is reduced to 50 % of the diameter
• Compression process should be completed preferably within 2 to 5 minutes
• Test sample is relived from compressive load and observed for any splitting,
cracking, fracture or breaking
RESULT : Any splitting, cracking or braking is noted as a failure
• Factors affecting
• Material and it’s composition affect the result
• Design of moulded and fabricated product
• Residual Stress/ moulded in stress in the product
56

CARBON BLACK CONTENT
INTRODUCTION:
• Addition of carbon black in Polythene for pipes and other products for
outdoor application acts as UV radiation screening agent. About 2.0 to
3.0% carbon black gives optimum life and performance to product
• Determination of Carbon black content is based on heating of polymer at
about 5000C in inert atmosphere. At this temp. polymer molecules
volatilize break down into a gas , and leaves the residue as carbon black
and other fillers.
• Further heating of residue in the air i.e in muffle furnace at about 4500C
separates carbon from fillers
EQUIPMENT:
• Carbon black content tester, analytical weighing balance, Muffle furnace,
test boat etc is used.
TEST SAMPLE:
• About 1 gm of sample cut into small pieces are used
57

PROCEDURE:
• About 1g of sample is taken and weighed in analytical balance. Test
temperature of 500 + 50oC is set .Sample is placed in the combustion tube.
• A stopper carrying thermocouple and tube for admission of nitrogen gas is
inserted from one end of combustion tube.
• Nitrogen gas is passed in combustion tube at the specified rate. The furnace
is maintained at 500+50oC temperature for about 10 minutes. During this
period polymer voilatise.
• The boat is removed from tube and placed in a desiccators and cooled for 20
- 30 minutes.
• The content is weighed accurately. Subsequently, the residue is heated in
air/muffle furnace at about 450oC. It is then cooled until to room temp.
Weight is taken recorded as W2 .
58
CARBON BLACK CONTENT

CARBON BLACK DISPERSION
CALCULATION :
The Carbon Black Content is calculated as : % By mass = Weight of Carbon Black
Weight of material
CARBON BLACK DISPERSION :
• Carbon black added to the Polyethylene material for protecting polythene from
UV radiation and improves the performance provided the distribution of Carbon
black in the material is uniform .
• Carbon black is a brittle material so its non uniform distribution can cause
localized brittleness, weakening & inadequate protection UV radiation to material.
• Carbon black dispersion test can reveal whether distribution is satisfactory or not
EQUIPMENT:
• Hot plate, microscope with adequate magnification, glass slide etc
59

CARBON BLACK DISPERSION
PROCEDURE:
• Carbon black dispersion is determined as following:
• First test slide is prepare by heating of few gm of materials on hot plate
• A hot plate is heated at about 170oC to 210oC, two clean glass slides are placed
on the hot Plate.
• About 5 mg is placed over the slides and heated. A piece of metal shim is
placed on hot micro slide. Uniform pressure is applied for about 2 minutes.
• The micro slides are removed from hot plate and allowed to cool to room
temperature.
• Slides are examined in microscope at magnification of 200 + 10.
• Image obtained microscope is compared with the reference photo micrograph
in respect of number and size of agglomerate.
• The uniformity of background is recorded.
• The dispersion of carbon black shall be satisfactory in comparison to
photomicrograph.
60

ACETIC ACID IMMERSION TEST
INTRODUCTION:
• ABS is highly susceptible to residual stress. During processing of ABS pipes
and other product residual stress is commonly introduced. This test is carried
out for evaluation of the residual stresses in ABS pipes as these stresses can
cause localized weakening of the product and failure during its end use
application
PROCEDURE:
• Specimen from pipe is cut in any suitable size and immersed into reagent
grade glacial acetic acid for 30 seconds.
• Immediately after the immersion, the sample is removed, rinsed in running
water and dried. The specimen is examined for cracking.
• The above procedure is repeated for specimen for 2 minutes or for the same
specimen for an additional 90 seconds. Again, the specimen is examined for
cracks.
• The time taken to develop cracks and the degree of cracking indicate the
magnitude of residual stress in the specimen.
61

ENVIRONMENTAL STRESS CRACKING RESISTANCE TEST
( IRRIGATION LATERAL AS IS : 12786 : 1989)
INTRODUCTION :
 Environmental stress cracking resistance is a particular kind of chemical attack
which must be avoided with polyethylene pipes. Certain chemical causes of
premature failure of some polyethylene under the stress in the accelerated
environmental
• ESCR of polyethylene lateral is important when pipes are used in the filled under
pressure they undergo various compressive bending stress and possibility of
premature failure is increased in accelerated environment of heats and chemicals .
• Thus ESCR is determining factor in these applications.
62

Fig. Test specimen for ESCR test
63

PROCEDURE:
• Take test piece of approximately length of 20 times of the diameter of pipe,
• Bend sharply at both ends to form two U – bends, in two different planes
perpendicular to each other as shown in figure.
• Secured bend tightly to maintain in deformed shape throughout the test.
• Coat each bend with surface – active agent (Igepal CO630) by dipping and
place in an oven for 30 minutes at 50 ± 3oC
• Inspect each bend for any visible crack on both sides.
64

VICAT SOFTENING TEMPERATURE
Objective : Determination of Vicat softening temperature of thermoplastic material using
method A or method B. Method A uses a load of 1.0 kg. and method B uses a load of
5.0 kg.
Principle : Determination of temperature at which a standard indentor penetrates 1mm in
to the surface of plastic test specimen under one of the load as given above. During
the test temperature is raised at uniform rate either at 50  50C / hrs. or 1200C  120
C/hrs. The temperature at 1 mm penetration is quoted as Vicat softening temperature
(VST) in 0C
Definition : Vicat softening temperature is the temperature at which a flat ended needle
of 1 mm2 circular section will penetrate a thermoplastic specimen to a depth of 2 mm
under a specified load using a selected uniform rate of temperature rise. The two
standard permissible rate of rise of temperature are 50  500C/hr. and 120  120C/hrs.
Significance : This test is useful for quality control of development and characterisation of
material. Vicat softening data obtained from this test is used for comparing heat
softening qualities of thermoplastic materials.
Safety : Safety gloves should be used.
65

APPARATUS
• Heat distortion and vicat softening apparatus consisting.
• Immersion bath.
• Heat transfer liquid (such as silicon oils, glycerine ethylene glycol etc.)
• Support or stand for specimen and dial range.
• Dial gange (0-25mm) for measuring of 1 mm depth of penetration to accuracy of
0.01mm.
• Temperature indication device (such as thermometer)
• Weight : (1.0 k.g. or 5.0 k.g.) depending on test method.
• Flat ended needle of 1 mm2 circular cross section.
TEST SPECIMEN : Specimen of minimum 12 mm wide and 3.0 to 6 mm thick shall be
used. It is surfaces shall be flat parallel and free form flash.
• Place the specimen on specimen support.
• Position the flat needle in such a way that needle rest in the sample in centre.
• Immerge the specimen support assembly with sample in immersion bath.
• Set the micrometer to zero.
66

PROCEDURE
• Place the weight to load carrying plate on the spindle which is fitted with flat
needle so that total load on test specimen is 1.0 k.g. for method A of and 5.0 kg. for
method B.
• Increase temperature of oil bath at the rate of 500  50C/hr (Rat A) or 1200 120C/hr
• Observe the dial gange for penetration of needle in the specimen.
• Note the temperature of oil bath at which indenting tip has penetrated into test
specimen by 1.0 mm and record it as vicat softening temperature (VST).
• Line diagram to be drawn.
67

PLASTIC FILMS & LAMINATES
68

PLASTIC FILMS AND LAMINATES
INTRODUCTION:
• Plastic films are used for packaging, construction and other industrial
applications. It has to perform various functions of package, fabrications,
product protections, containment & appearance. Hence it require a set of
properties.
• Properties of films are broadly classified as : Physical , Mechanical , Chemical,
Optical and Thermal and other such as mach inability ,printability etc.
69

FACTORS INFLUENCING
Following factors influence the properties of Plastic films :
– Chemical Composition of base polymers
– Compounding ingredients such as additives, colourants.
– Method of manufacturing of film(e.g. Blown Film,Cast Film, TQP processes etc.)
– Post treatments, coating and lamination
Commonly used materials for film are :-
– Polyolefin (LDPE,LLDPE,HDPE & PP)
– EVA
– PVC, PVDC & PVA
– PS
– Polyamide, Polyester &Polycarbonate
– Cellophane etc.
70

PROPERTIES OF FILMS
• The properties of plastic films can be classified as
• Physical Properties
• Mechanical Properties
• Chemical Properties
• Optical Properties
• Thermal Properties
• Printability
• Sealability
71

TESTS ON PLASTIC FILMS
• Broadly tests on plastic films and laminates can be classified as
Properties Concerned with :
– Strength: Tensile strength, Stiffness, Burst strength, Tear strength , Impact
strength, Flex Resistance
– Transmission: Water vapour Permeability Odour Permeability
Light Transmission –
• See-through Clarity or Transparency
• Gloss
• Haze
• Surface: Friction, Mar Resistance ,Blocking ,Electrostatic Charge. Heat
Salability Printability & Print Adhesion etc.
72

Other Properties are :
• Density
• Thickness
• Dimensional Stability
• Orientation and Shrinkage
• Melt Flow Index
• Light Resistance
• Chemical Resistance
• Solvent Resistance
• Toxicity
73

TENSILE STRENGTH:
• Tensile strength is an important property for the quality control of plastic films.
• Used for differentiating different types of film based on strength.
• Used to ascertain the anisotropicity in a film i.e. Different strength in different
direction (Transverse & Machine direction)
• Elongation is useful as a measure of film’s ability to stretch.
74

SIGNIFICANCE OF TENSILE STRENGTH
• Film should have enough tensile strength to withstand the load.
• Yield strength is important in handling on printing & lamination equipment.
• To identify the elongation of film with respect to tensile strength.
75

BURST STRENGTH
DEFINITION
• Resistance offered by film to a steady increasing pressure applied at right angle to
its surface.
• Pressure at the moment of failure of film is taken as the Burst strength.
SIGNIFICANCE OF BURST STRENGTH
• Measures the capacity of the film to absorb energy at the time of failure.
• Indicates the energy absorbing capacity of film.
• Brittle film which can absorb small amount of energy before breaking have low
burst strength.
EQUIPMENT :
• A film burst strength tester is used. It consists of sample clamping device, pressure
gauge and pressure releasing device, air compressor etc.
76

BURST STRENGTH
PROCEDURE:
• Test pressure is normally applied by compressed air. The liquid medium may
also be used. When liquid medium is used, the pressure is transmitted via a
rubber diaphragm. The film to be tested is clamp in form of disc.
• The compressed air or liquid pressure is released through pressure releasing
device.
• The pressure at the moment of failure of film of noted from the pressure
gauge.
Factors affecting burst strength: Following factor affect the burst strength of film.
Speed at which pressure is applied : At low rate of pressure application burst
strength is high.
Diameter of sample in clamp disc: Smaller the diameter of clamp disc, higher is
the burst pressure.
77

TEAR STRENGTH
Definition
• Tear strength is defined as the energy required to propagate a tear through a
specified length of film that has already been initiated in sample by small nick with
a razor blade. Tear resistance measures the tear initiation and tear propagation
energy.
• Generally tear of brittle film is measured as the maximum tear initiation force
whereas for tear propagation is important in tough film. Tear strength is measured
as Tear initiation and Tear propagation.
Significance
• Tear strength measures the resistance to tearing and it may also used to illustrate
the anisotropy of the film.
• Tear resistance measures the tear initiation and tear propagation energy of the
plastics film.
• Tear of brittle film is measured as the maximum tear initiation force
• Tear propagation is important in tough film.
78

TEAR STRENGTH
Test Methods of Tear Test : Following methods are commonly used for measuring
tear strength:
– Elemendorf of tear test
– Trouser tear
– Tongue Tear
– Initial tear resistance film and sheeting
Elemendorf of tear test
• This method measures the energy required to propagate through a specified
length of film.
Equipment
• Elemendorf tear tester consisting of two grips set side by side with small
separation, Test sample template, Razor blade, Thickness measuring devices.
• One grip is stationary and fixed with base of m/c whereas another is movable grip
and it is mounted on the pendulum of m/c.
79

TEAR STRENGTH
PROCEDURE
• Sample from the film is cut using sample template and Razor blade and measure
the thickness of specimen by micrometer.
• Sample is clamped between two grips and a slit of standard dimension is
introduced centrally into the film using a razor blade.
• Pendulum is released to swings down and tears the samples along a continuation
of the slit.
• The energy required to complete the tear is measured on a scale attached with
pendulum by means of a pointer carried by the pendulum on it’s return swing.
80

TEAR STRENGTH
Trouser & tongue tear test
• Trouser & tongue tear test is determined by using the tensile testing machine.
In this tear propagation is measured as the force necessary to keep the
moving at a fixed speed. The stress – strain curves obtained is analyzed in
different ways depending upon their shape.
• The geometry of the test piece is such that a concentration is produced in the
region of the right and the tear initiates at this point, The maximum stress
during the tearing process is recorded as the tear initiation strengths.
• The various types of samples and methods used for tear tests are as under.
81

TEAR STRENGTH
(a) Trouser Tear test
(b) Torque tear test
Test specimen as per ASTM D 1938
82

TEAR STRENGTH
FACTORS AFFECTING TEAR STRENGTH
• Generally films are anisotropy so the strength properties of film are not same
in all the direction.
• Therefore tear strength of anisotropy film depends upon the direction of
orientation. Therefore tear strength widely vary according to direction of
orientation of film. Tear strength in the direction of orientation is less than to
transverse direction.
83

IMPACT STRENGTH
INTRODUCTION:
• It is the ability of film to withstand sudden sock loading. This property
measures the ability of a material to absorb energy in a very short period of
time and it is closely related to toughness of the film.
• Impact resistance is also related to brittleness of film. Brittleness denotes the
lack of ductility, poor flexing properties etc.
DEFINITION:
• Impact strength of the film is defined as the amount of dart weight for a given
height of fall at which 50% of the specimen will fail.
• It is calculated by weight at which it causes 50% failure of film multiplied with
drop height
• Impact strength is measured by various methods such as Dart impact test,
Pendulum impact etc. The most commonly used method for measurement of
Impact strength is falling dart impact test.
84

IMPACT TEST
FALLING DART IMPACT TEST:
• Impact strength of the film is defined as the amount of dart weight for a
given height of fall at which 50 % of the specimen will fail. It is calculated by
weight at which it causes 50 % failure of film multiplied with drop height
EQUIPMENT:
• Dart impact tester consisting of hemispherical striking head fitted with a shaft
to which removable weight can be added / removed, to obtain required
range of test energy. Circular section of film is clamped horizontally at it’s
periphery and dart is dropped from a specified constant height on film
sample at the center.
• Following two methods are employed in Dart impact testing.
( a ) Stair case method
( b ) Probit method
85

PROCEDURE:
• Clamp the specimen horizontally at it’s periphery and take the dart
• Initially few specimens are taken in trial run to obtain indication of impact
energy at which about 50 % failure will occur.
• The first specimen is tested at arbitrary level of dart weight at a given height
of fall and subsequent specimens are tested at half or double of this dart
weight till some specimens fracture and some withstand the impact
IMPACT TEST
86

IMPACT TEST
87

STAIR CASE METHOD
• In this method further 20 specimens are tested using same height as used in trial run
• Weight of dart is increased or decreased about one tenth of dart weight found in
trial run.
• When a specimen fractures, next specimen is tested at lower dart and when does
not fracture the next specimen is tested at higher dart weight
• The Impact strength is defined as the level of dart weight for a given height of fall at
which 50 % of specimen will fail.
• It is the mean of weight of all the values used in the test run.
ALTERNATE METHOD
• In this method impact tester is additionally fitted with two photoelectric cells just
below the test sample and the dart impact energy is adjusted in such a way that all
the test sample rupture. Original potential energy of dart is above the sample is
obtained from it’s mass and height i.e. by mgh. While residual kinetic energy after
impact is calculated using formula of ½ mv2 . The Impact energy absorbed is found as
Impact strength = Potential energy - Residual kinetic energy of film.
IMPACT TEST
88

PROBIT METHOD
• This method assesses impact strength of film by determining the percentage
failures in a given number of specimens with different dart weights.
• Dart weight is selected which will fracture at least one of a group of ten
specimens. The actual number of failures in ten trials is recorded.
• The dart weight is then changed by uniform increments and ten samples are
tested at each dart weight. The number of failure at each weight is recorded.
• The data are plotted on probability graph paper, the dart weights on the
linear scale and the percentage of failures on the probability scale. The
Impact strength is read as the dart weight at which 50% of specimen fails. The
impact failure weight or impact resistance expressed in grams.
• The Impact strength is read as the dart weight at which 50% if the specimen
will fail.
IMPACT TEST
89

PENDULUM METHOD
• In this method impact strength of film is measured by pendulum instead of falling
dart.
• Film is clamped vertically and struck by a pendulum swung from a known height.
• The residual energy of the pendulum after it has ruptured the film, is measured by
a pointer on calibrated scale of by an electric timer activated by a pair of
photoelectric cells.
• The loss in energy is a measure of impact strength of the film.
IMPACT TEST
90

IMPACT TEST OF FINISHED BAG
• The impact test of finished bag is done by bag drop test.
• The bags to be tested are filled with specified weight of sand or other suitable
material and sealed.
• Thus filled and sealed bags are dropped from a test height on to a right angle at
smooth surface.
• The bags is examined to see if the failure was in the seal or in the film.
FACTORS AFFECTING IMPACT STRENGTH OF FILM
• Rate of Impact load applied :
• Impact strength reduces at height rate of impact.
• Size of hemispherical head /striking head :
• Smaller hemispherical diameter of dart lower is the impact strength.
TEST TEMPERATURE :
• At higher test temp the Impact strength shown by film are higher as the molecular
mobility of polymer at higher temperature gets increased.
IMPACT TEST
91

FLEX RESISTANCE (FOLDING ENDURANCE)
INTRODUCTION:
• Various properties of the film are seriously affected by repeated folding . For
example tensile properties are reduced, permeability to gases, water vapor
may be increased, optical properties may be affect.
DEFINITION:
• Flex resistance is defined is the Resistance to repeated flexure or creasing
measured by repeatedly folding the film backward and forward at a given rate.
The number of cycles to cause the failure is called as flex resistance.
• Higher the number of cycle of failure higher is the flex resistance.
92

FLEX RESISTANCE(FOLDING ENDURANCE)
TEST PROCEDURE
• Flex resistance is measured by Schopper folding endurance tester.
• The step by step procedure is as below:
• Film strip of 15 mm x 100 mm are cut.
• Strip ends are clamped between the clamps in such a way that constant
tension in the film is maintained.
• Scotted metal strip is fitted over mid point of sample.
• Sample folded by electric driven motor is back and forward at the rate of
120 double fold per minutes.
• The number of double fold at the time of failure of film is recorded as flex
resistances
93

• The tough and flexible film may not fail even after large number of repeated
flexing so higher thickness of film has to be taken till the failure is observed.
• Alternatively flex resistance of tough and flexible film is also measured by
subjecting the film to a number of cycles in test equipment and relevant test
results are compared with unceased film.
FACTOR AFFECTING :
• Folding endurance of film depend upon the material of the film because the
cheval difference in composition of materials.
• The thickness of film and rate of folding of film per minutes affect the result.
94

95

TROUSER TEAR TEST
96

PROPERTIES CONCERNED WITH TRANSMISSION
GAS PERMEABILITY
INTRODUCTION
• One of the prime functions of a packaging film is to act as a barrier to gases and
vapors. Biscuits, for example, need to be kept in dry, while conversely; cigarettes
and tobacco need to be protected from moisture loss. Fresh produce needs to
be able to lose carbon dioxide and pick up oxygen, while fatty food may go
rancid if oxygen is not kept out. Many foods are packed in a vacuum and a good
barrier is essential.
NEED OF PERMEABILITY TEST
• To maintain the film as a good barrier to gases & vapors.
• To distinguish the packaging film as per the application
(e.g. Biscuits need to be kept dry, while conversely, cigarettes and tobacco need to
be protected from moisture loss).
97

PERMEABILITY CO – EFFICIENT
DEFINITION
(i) Gas Transmission Rate
• The Gas Transmission Rate (GTR) is defined as the volume of gas that passes
through a sample of unit area under unit pressure differential. The rate being
determined after the slope of the transmitted volume – time curve has become
constant. The temperature and specimen thickness must also be given as an
integral part of the GTR.
(ii) Permeability Co – efficient
• The permeability Co – efficient represents the fundamental property and is
independent of the geometry of the test sample. It is the product of the solubility
of the gas in the film and the diffusion rate of the gas though the film. Gas
transmission rate is usually expression in cc(at 0C and 76 mm Hg) per sq.m 24 hr.
atm.
98

TRANSMISSION PROPERTIES
PERMEATION
• The mechanism by which a gas or vapor can pass from one side of a plastic film to
another by a process of solution (or absorption ) and diffusion is known as
permeation. It is a compound process.
• In very thin (i.e. porous) films the gas or vapor can flow through the holes.
• The quantity of gas(Q) passing through the film is
• Directly proportional to:
» The difference in gas pressure on either side of the film ( P1 – P2 )
» The time during which the permeation has been occurring (t)
» The exposed area A)
• Inversely proportional to: The thickness of the film(X)
• The Mathematical expression is define as:Q=[PAt(p1-p2)/X]
Where ‘P’ is the permeability constant.
99

• Thus it may be written as
Q = At ( P1 – P2 )
X
Where : Q = quantity of gas which passes through the film;
A = The surface area in contact with the gas;
t = time;
( P1 – P2 ) = partial pressure differential;
X = thickness of plastic
• This expression can also be put in the form of an equation, thus Q = PA t ( P1 – P2 )
X
Where P is a constant for a specific combination of gas and plastic at a given temperature.
The factor P is known as the permeability factor ( or ‘P – factor’) permeability Co –
efficient or permeability constant.
100

SIGNIFICANCE OF GAS PERMEABILITY
• Permeability of plastics films by gases is described as the volumetric rate of
transmission of the gas
• It is dependent on, both the nature of the plastics material and of the gas.
• Physical nature of the film, its density, degree of crystallinity thickness of the
film etc affect the transmission rate.
• Size and mobility of the gas molecules, play an important role in the rate of
transmission of gas.
• Interaction of gas and polymer film may have significant complex interaction
which affect transmission rate.
101

102

SIGNIFICANCE OF GAS PERMEABILITY
• Permeability of plastics films by gases is described as the volumetric rate of
transmission of the gas
• It is dependent on, both the nature of the plastics material and of the gas.
• Physical nature of the film, its density, degree of crystallinity thickness of the
film etc affect the transmission rate.
• Size and mobility of the gas molecules, play an important role in the rate of
transmission of gas.
• Interaction of gas and polymer film may have significant complex interaction
which affect transmission rate.
103

EQUIPMENT
• Gas Permeability Tester, Consisting of Vacuum pump, Micro Meter and Stop
Watch, Desiccators, The typical Equipment is shown in figure
MATERIAL : Dry and pure test gas , Mercury, Desiccators, Cacl2
TEST SPECIMEN :
• Sample, free from wrinkles, creases, pinholes and other imperfections having
uniform Thickness shall be used.
PROCEDURE:
• Equipment is prepared by filling the required quantity of mercury
• Specimens from the film is cut in the size to fit the test cell.
• Thickness of the film sample is measured and conditioned in the desiccators.
• The test specimen is placed in the test cell between filter papers for ensuring
the uniform gas distribution
104

• The manometer of the permeability tester is evacuated with the help of
vacuum pump,
• Equipment is connected with the test gas from the upper half of the
specimen where as lower half is maintained at vacuum.
• The transmission of the gas through the film w.r.t the time is recorded in the
terms of the fall of mercury in the manometer due to increasing of the
pressure .
• The reading is taken and suitable graph is plotted.
• GTR is calculated by using following formula T.R = (237 x PV) (24 x 104)
A x T x P
Where T.R is ml per m2 / 24 hrs per atmosphere pressure difference
P= rate of pressure changes in capillary in an Hg per hour.
105

ODOUR PERMEABILITY
• Odour permeability is used to compare the efficiency of several films as odour
barriers, to manufacture pouches with each film.
• Odiferous material filled with pouches and then placed in separate clean glass
bottles and sealed by clamping with aluminum foil.
• Minimum time for an odour appeared in the bottle measured.
• Test depends upon the type of odiferous material used.
• There is no standard tests for the measurement of odour permeability.
106

WATER VAPOUR PERMEABILITY
DEFINITION
• The water vapor transmission rate, WVTR or MVTR, is the flow rate of water
through a unit area of film after the steady state has been reached(unit- gm /
24 sq u.m).
• Film used for packing foodstuffs usually have a low water vapor permeability.
• The permeability is measured by method in which the test film is fastened
over the month of a cup containing either a desiccant or water.
EQUIPMENT
• Environmental chamber with temp. and humidity control, Desiccant, Petridis,
Cacl2
, Analytical weighing balance. The apparatus is shown in figure.
PROCEDURE:
• Take a circular mouth cup, and fill water or desiccant in the cup. Cut the film
sample approximately equal to the internal diameter of the cup and seal at its
mouth
107

• Set the test temperature and humidity in the chamber
• Take the initial weight of the cup with sample with the desiccant on the
analytical balance.
• Place the sealed cup containing desiccant or water in the controlled
atmosphere for specified temperature and humidity.
• After a specified period the sample is removed from the chamber and again
it’s weight is taken on the balance.
• The weight gain or loss measured as a rate of water vapor transmission
through the film can be calculated.
ALTERNATE METHOD
• Another method is of measuring water vapor transmission rate is Dish
method as per BS – 2782. The equipment set-up of the same is shown in the
fig.
• The water vapor permeability may also be measured by enclosing the
desiccant in a sachet made from the film itself instead of using a dish
108

Fig. Apparatus for Water Vapor
Transmission
109

LIGHT TRANSMISSION
DEFINITION:
• Light transmission through the film is one of the important properties on the
packaging application. It allows to view the object through the packaging
material.
• It is the ratio of the light intensity measured with the film to that obtained
without it.
• Light transmission is measured by means of a photoelectric cell.
• The intensity of a light source is measured by the cell, both with and without
the inter position of the film samples.
• Other important optical properties of films are: Haze, Gloss and clarity.
– Detail about the equipment and test procedure of measurement is
described in the Optical Properties
110

SEE-THROUGH CLARITY OR TRANSPARENCY
DEFINITION :
• The ratio of the intensity of light to the intensity of the incident beam is a measure
of see – through clarity.
• It refers to the capability of seeing objects through a film without loss of detail
caused by blurring or distortion.
• Narrow angle scatter correlates with see – through clarity.
• The test measures the light transmitted by a film within a cone of semi – angle of
three minutes about the normal to the specimen.
– Detail about the equipment and test procedure of measurement is described
in the Optical Properties
111

HAZE
DEFINITION
• Haze is the property often referred to as cloudy appearance.
• Haze is defined as the percentage of light which is passing through a specimen,
deviates by more than 2.5 on average from an incident parallel beam.
• It is caused by random scatter of incident light upon film.
• This is measured using a haze – meter.
• The ratio of the scattered light (T2) of the photo cell to the incident light (T1) is a
measure of haze. i.e
% Haze = (T2/T1) x 100
 Detail about the equipment and test procedure of measurement is described in
the Optical Properties
112

GLOSS
DEFINITION
• Gloss refers to the shining appearance of a plastic film
• It is defined as the ability of a surface to reflect light regularly.
• Secular surfaces gloss of the film is measured as the portion of light reflected from
the film at an angle of 45o. This is compared with a perfect mirror which is given a
value of 100.
• The maximum value of gloss for low density polyethylene is about 9.9 %.
– Detail about the equipment and test procedure of measurement is described
in the Optical Properties
113

CO-EFFICIENT OF FRICTION
FRICTION: The resisting force that arises when a surface of one substance slides over
an adjoining surface of it-self or another substance.
SLIP : Lubricity of two surfaces sliding in contact with each other is called slip.
• High co – efficient of friction denotes low slip and low co – efficient of friction
denotes high slip.
Co – efficient of friction :- It is defined as the ratio of frictional force to the force
( usually gravitational ) acting perpendicular to the two surfaces in contact.
• Two types of Co – efficient of friction i.e
– Static Co – efficient of friction ( μs )
– Kinetic or dynamic or sliding Co – efficient of friction ( μ k )
114

STATIC CO-EFFICIENT OF FRICTION
• It is related to the force measured to begin the movement of the surface relative
to each other.
• It is defined as the ratio of force required to just begin the movement to the force
acting perpendicular to the surface.
μs = Force required to begin movement
Force acting perpendicular to surface
115

KINETIC CO-EFFICIENT OF FRICTION
• It is related to the force measured for sustaining the movement .
• It is defined as the ratio of the force required to sustain or maintain
movement to the force acting perpendicular to surface.
μk = Average force required to sustain movement
Force acting perpendicular to surface
• Generally the force required to begin movement is more than force required
for sustaining movement. Therefore static Co – efficient of friction is generally
higher of friction than Kinetic Co – efficient of frictions
116

SIGNIFICANCE OF CO-EFFICIENT OF FRICTION
• The frictional properties of films are important in winding while
manufacturing of film, during it’s printing,wrapping and in the form of
finished bags, sacks or over wraps etc.
• Good roll formation depends upon correct level of friction of film.
• Too much slip may cause telescoping during of rolling,handing and
transportation.
• Too little can cause buckling on roll.
• The inadequate slip may cause seizure of film during printing.
117

TEST PROCEDURE FOR CO-EFFICIENT
OF FRICTION
• Co – efficient of friction is measured by following two methods.
– Inclined plane method.
– Method based on ASTMD 1894
118

(A) INCLINED PLANE METHOD
STATIC CO-EFFICIENT OF FRICTION:
• The inclined plane method is simplest method of measuring Co – efficient of
friction. Under this method surface of inclined plane is covered by a sample
of film and weight is placed on the plane The angle of the plane is increased
slowly until weight just start to move. The angle at which it starts moving is
noted. This angle is called repose angle. It is denoted by Q1.
DYNAMIC CO-EFFICIENT OF FRICTION:
• For measuring dynamic Co – efficient of friction the angle of plane at which
weight moves easily is gradually reduced until weight comes to rest. The
angle of the plane at this stage is noted as Q2. The Tan Q1 and Tan Q2 are the
static and dynamic Co – efficient of friction
119

(B) METHOD BASED ON ASTM D 1894
• The apparatus based on this method consist of metal block ( sled ) of about
63.5 , square and 6mm thick . Sled is wrapped with rubber sheet to provide
wrinkle free surface. The total weight of sled is 200 ± 5g. It is wrapped and
tape of with film.
• A table of wood / plastics / metal sheet of Apex 150 mm X 300 mm x 1 mm is
fitted with smooth and flat covering glass on the upper surface to provide
support for the specimen. This table with sled is motor driven at the rate of
150 mm / min.
– The further detail of the equipment and procedure is described in the
chapter Mechanical Properties.

DEFINITION:
• The tendency of two adjacent layers of films to stick together when stacked
under pressure is called blocking. It is an adhesion between touching layers of
plastic film. The blocking develops under variety of condition of temperature
and pressure. Blocking may also arise from processing, under usage or in
storage.
• The blocking in film may occur when film surfaces are extremely smooth or
allowing intimate contact of film surfaces under complete exclusion of air. It
may also occur under fusion of the surfaces under heat and pressure.
• The force required to separate two layers of blocked film when the force is
applied perpendicularly to surface determines the degree of blocking.
BLOCKING
121

BLOCKING FORCE:
• It is the average force per unit width of blocked surface required to separate
two layers of plastic film one from another by a rod of 6.35 mm diameter at
uniform rate of 125 mm / min. This force is expressed in grams per centimeter
of width.
TEST SPECIMEN
• Test specimens of film consists two blocked layers cut in rectangular shape.
The size of specimen is taken as 250 – 300 mm long and 200 – 250 mm wide.
EQUIPMENT
• An universal testing m/c, a metal fixure and a rod of 6.35 mm diameter is
used for separating the blocked film
BLOCKING
122

PROCEDURE:
• Metal fixure is attached with moving jaw of Universal Testing M/C. Specimen
to be tested is clamped in fixed jaw as shown in figure. Machine is started and
blocked surfaces are separated at rate of about 125 mm / min. As the jaw
moves it draws the frame and rod downward.
• The motions of rod cause layers of film separate. The force required to
separate the layers of film apart is recorded. This process continues until
layers of film are completely separated.
• The Actual blocking force is determined from best average load line. The
average load in grams is divided by specimen width in mm. It is expressed in
gmf / mm
BLOCKING
123

BLOCKING TEST
124

BLOCKING TEST
FACTORS AFFECTING:
• The following factor affects the blocking of film.
• Thickness of the film: Low thickness of film has higher tendency of blocking
• Static charges, Surface treatment, Printing, Pre – treatment, Storage condition etc
also affect the blocking.
• Long storage duration increases the tendency of blocking.
125

HEAT SEALABILITY
• Heat sealability of the packaging film is one of the most important properties
when considering its use for wrapping and bag making. Therefore the
integrity of the seal has the tremendous, important in ultimate package.
TEST METHOD:
• The following two methods are commonly used for testing of heat salability
of film.
(A) Dynamic method
(B) Static method
In above test methods two layers of film are sealed under heat and pressure
using suitable heat sealing device. A 25 mm wide strip is cut through the heat
seal. This test sample is used for testing by both methods.
BLOCKING TEST
126

(A) DYNAMIC METHOD
• Under dynamic test method a sensitive tensile testing m/c is used. The two
free ends of film strip are clamed in machine grip and pulled a part. The force
required to peel apart the two pieces is measured.
(B) STATIC METHOD
• In static method one end of filmstrip is clamped and hung from a frame and
other end is attached to a dead weight. The seal are examined at a regular
interval of time for any sign of failure. The weight and duration of load, which
was hung, is taken upto failure and recorded.
• The heat salability of the film is affected by sealing temperature and rate of
heat transfer of sealing and dwell time.
MAR RESISTANCE
• It may be defined as the resistance of the surface to abrasive action of
abrasive particles. The following three methods are used for measuring Mar
resistance.
BLOCKING TEST
127

METHOD I:
• This method is based on AST MD – 1044 – 76. The surface of the specimen is
subjected to an abrasive action and then the light scattering properties of the
abraded area are determined and compared to those of the original unmarred
sample.
METHOD II:
• This method is based on ASTMD– 673 the film surface is abraded by dropping
abrasive particles on to the film from a fixed height. The gloss of the marred area is
measured and Compared to the unabraded film to determine the mar resistance.
METHOD III:
• This method is based on ASTM D – 1242 – 75 surface of film is abraded in a
standard way and the volume of material lost by the specimen due to this abrasive
action is determined. The loss in volume is taken as a measure of the abrasion
resistance.
PRINTABILITY AND PRINT ADHESION
• Printability depends directly on film treatment and while its print adhesion depends
on both ink and film.
BLOCKING TEST
128

PRINTABILITY
• A method for measuring the printability or degree of treatment of film
measures, the force required to peel a strip of pressure sensitive tape from a
section of film. The tape is applied to the film and the assembly is clamped
together for a standard time under standard pressure. Any suitable machine
measures peeling force with an autographic recording device.
PRINT ADHESION
• The Permanence of the printing on the film is measured by subjecting the
printed film to an abrasion test. For testing, the Printed film is mounted in
glass plate and abraded forwards and backwards against metal peg covered
with a strip of standard fabric. The no of cycles required to produce visible
damage to the print is recorded as print adhesion.
BLOCKING TEST
129

DIMENSIONAL STABILITY
INTRODUCTION:
• Dimensional stability is a desirable property in film conversion process particularly
in printing. The small changes in film dimension while passing through printing
process may lead to serious printing problem.
PROCEDURE:
• Dimensional stability of film is carried out by cutting film strips in both machine
and transverse directions. Film is subjected it to varying conditions and noted the
percentage change in dimensions. The test conditions are kept very close to the
conditions likely to be encountered during conversion or end – use process.
• The maximum shrinkage is measured in the case of heat shrink films. This is
determined by immersing the marked film samples for 5 minutes in water or in
silicones oil at 1000 C.
130

LIGHT RESISTANCE
INTRODUCTION:
• Plastic films exposed to sunlight for long period properties and performance of the
film is affected as UV radiation raises the surface of temperature of film. UV radiation
and heat causes the oxidation reaction, evaporation of plasticizers, polymer bond,
chain scission etc This leads to brittlement of film, color change, loss of clarity of film
surface, imperfections, and reduction of strength properties etc.
PROCEDURE:
• This test is carried out by exposing the film samples in weather-O- meter or UV
Chamber. In weather-O-meter light of suitable wavelength or combination of
wavelength is artificially created with the help of UV lamp fitted in the chamber and
sample is exposed to UV light for a given time.
• The film samples are taken out and test for various parameter such as tensile
strength, % elongation, impact strength and various optical properties etc. is carried
out . The result obtained is compared with the result of original unexposed samples.
131

CHEMICAL RESISTANCE
INTRODUCTION
• The effect of chemicals on a packaging film is an important factor when assessing
its suitability for packaging a particular product. Under certain circumstances, it
may also be important from an environmental point of view. Therefore
measurement of chemical resistance is an important property of films.
DEFINITION
• Chemical resistance involves the subjecting of film sample to the chemical under
test. Test sample are immersed in chemical under a specified condition. The
change in appearance and in property such as tensile strength, transmission
properties and other are co – related with the chemical resistance of the film.
132

HEAT SHRINKAGE
DEFINITION
• Heat shrinkage is defined as the dimensional changes of film due to heating and
subsequent cooling.
• Some products are packed in the film package in the hot condition. This raises the
temperature of film material, and on cooling stress reliving takes places. This
causes the dimensional changes.
PROCEDURE:
• Heat shrinkage is determined by immersing marked film sample in water or silicon
oil at 100oC for five minutes and measuring the dimensional changes in with
respect to original marking. It is expressed in percentage.
133

CONTAINER
TESTING
134

Plastics containers are commonly used
To check suitability of container for packaging of food-stuff, liquid, semi-solid and
solid materials
Transportation, handling, storage and sales of of materials
Provide protection during conservation
Preventing from contaminations and maintaining hygienic conditions
Quality control of the containers
PURPOSE OF CONTAINERS
135

COMMONLY USED MATERIALS FOR
CONTAINER
Following materials are used packaging of different kinds of materials
• Polyethylene(HDPE,LDPE,LLDPE)
• Polypropylene(PP)
• Polystyrene(PS)
• Polyvinyl chloride(PC)
• Thermoplastic polyester (PET)
136

MATERIAL SELECTION REQUIRMENT FOR
PLASTIC CONTAINERS
• Easy Process ability
• Good Chemical Resistance
• Good Impact strength.
• Inertness
• Heat stability
• Good Environmental Stress Cracking Resistance
137

COMMON TEST ON CONTAINERS
• Following tests are most commonly
carried out on containers
• Stacking Test
• Drop Impact Test
• Leakage Test
– Closure leakage test
– Vibration Leakage
– Air Pressure Leakage
• Handle pull test
• Environmental-Stress cracking
Resistance
• Transparency
• Overall Migration Test
• Ink adhesion for printed containers
• Product Resistance of printed
containers
• Transparency
• Water potability Test
138

STACK TEST
DEFINITION :
• Stacking is subjecting the plastics containers to a specified load based on the
the capacity of the containers for a specified period of time.
• Significance of the test : To check the ability of the filled containers to
withstand compression loads when the containers are stacked over another
set of containers during the transportation and storage. When the filled
containers the setup
• If the stiffness and strength of container is inadequate the compressive load
of filled container may permanently deform or buckle the container and
content may leak
139

STACK TEST
PROCEDURE
• Block of four containers are taken and used in a
single test.
• Fill the containers with water to their nominal
capacity
• close with their usual closure and heat seal at the
mouth.
• Arrange four containers on a flat level surface
without any outer support.
• Apply a top load on the container for 24 hrs in such a
way that it is evenly distributed on the containers.
• Superimposed load for different sizes of containers
shall be as under
• Examined the containers after 24 hrs of the test for
any leakage, crack and permanent buckling etc.
• The container should not show any leakage, crack
and permanent buckling etc.
Container’s
Nominal
capacity (Kg)
Stack load on
the four
containers (N)
1.0 400
2.0 600
5.0 800
10.0 1200
15.0 1600
140

DROP IMPACT TEST
• This test measures the ability of the containers to withstand damage to the
container and packing material caused by sudden shock induced in accidental
dropping, rough handling, transportation etc.
• This test also provides useful information in improving the design of the
containers.
• The test is carried out by dropping the preconditioned sample freely from a
specified height which is filled with suitable material in it.
• The sample strikes the base in a predetermined position. The sample should
resist the impact.
141

TEST PROCEDURE
Take 6 nos. of containers and divide in to two sets and designate Set – I & Set – II.
Fill the containers with water to their nominal capacity at standard conditions
Close the containers with there usual closure and heat sealed to its mouth.
Drop the containers of set – I under free fall condition squarely on their base on
the rigid flat horizontal surface from the specified height.
Drop the containers of set – II under free fall condition on their side on to a rigid flat
horizontal surface from the specified height.
Specified drop height for different capacity of containers varies from 0.5 m to 1.2 m
Checked the each container for any ruptured , leakage from the wall or closure.
There shall be no ruptured, leakage from the wall or closure
142

LEAKAGE TEST
Leakage may occur due to the top load of the packed product, transportation
vibration or leakage because of internal pressure developed inside container.
Leakage test is carried out to check the defects in the closure system of the
container.
Generally three types of leakage test are conducted on plastics containers
i) Closure Leakage
ii) Vibration Leakage
iii) Air Pressure Leakage Test
Air pressure leakage test is carried out by maintaining the specified pressure
inside container and detecting any leakage with water or soap solution.
143

I. CLOSURE LEAKAGE TEST
Closure leakage test is carried out by placing filled container in inverted
position at a specified condition.
PROCEDURE :
Take a container and fill it to it’s nominal capacity with colored water or
material to be packed at specified condition,
Close the container with it’s usual closure
Keep the container in an inverted position on a white blotting paper without
any external support for a specified period.
Examine the container for any leakage for any visible stains on the blotting
paper.
The container should not show any leakage or stain on blotting paper.
144

VIBRATION LEAKAGE
• Vibration leakage test is carried out on filled containers by subjecting a specified
vibrational frequency for a specified time period.
PROCEDURE
• Take containers and fill it to their nominal capacity with water at specified
condition,
• Close the containers with their usual closure
• Containers are subjected to the vibration on the vibration tester at a specified
frequency and peak acceleration for predetermined time.
• At the end of the test closures are observed for any leakage
• The container should not show any leakage.
145

VIBRATION TESTER
146

AIR PRESSURE LEAKAGE TEST
Air pressure leakage test is carried out by maintaining the specified pressure
inside container and detecting any leakage with water or soap solution.
This test is carried out for particular type of containers such as mineral
water bottle.
PROCEDURE
Take a container to be tested and connect to the container by tightly fitting
the rubber plug in the mouth of container
Emerge the container in the water reservoir or soap solution for detecting
any leakage by bubbles of air escaping through the water.
Regulate the air with the help of air pressure valve
Observe any leakage by bubbles of air escaping through the water or soap
solution
147

HANDLE PULL TEST
 Handles are generally provided larger size of container (5 Ltrs and above) for easy
handling.
 Handle pull test is carried out to check the ability of the handle to bear the weight
of the filled containers.
PROCEDURE
Take the container and fill it with suitable material equal to the double of nominal
capacity or specified load.
Hang the above filled container to a vertical pull from a fixed point for the
specified period.
After the specified period check for any damage to the handle or the hinge.
The handle or hinge should not show any damage
148

ENVIRONMENTAL STRESS CHECKING
RESISTANCE
The plastic containers used for packing and storage of various chemicals,
detergent and other surface active substances which may cause cracking to the
container.
Plastics containers may exhibit mechanical failure by cracking under condition
of internal or external or combination of stresses in the presence of
environments such as soaps, wetting agents, oil, detergent, heat etc.
test is carried out by keeping the specimen in contact with chemical active
agent under specified condition of temperature & time.
Specimen are checked for any cracking or surface irregularities
149

PROCEDURE
• Take about 15 containers and fill with test liquid their nominal capacity
• Heat seal with the laminate and close with usual closure
• Put the containers in plastic bag in vertical position and close by means of rubber
band .
• Place the container in the oven at the test temperature
• Inspect the container for environmental cracking failure after an interval of 24 hrs.
• Remove the failed container and record it’s failure and time.
• Continue the test with remaining container until all fail or to a maximum of 360 hrs.
• Calculate the percentage of failure using following formula
Failure % = (n/N) X 100,
Where, n = Number of containers failed at a given time
N = Number of containers Tested
ENVIRONMENTAL STRESS CHECKING
RESISTANCE
150

OVERALL MIGRATION
DEFINITION
• Migration is the mass transfer
(transport) of material from
plastic( packaging ) in contact with food
under the specified condition is called
Migration.
• When plastic & foods come in contact
the constituents which may be
transported are monomer, oligomer,
additives such as plasticizers, stabilizers,
antioxidant, slip agent, antistatic agent
etc. present in the material.
• Accumulation of toxic materials from
plastic may lead to contamination of
food hazards and may cause serious ill
effects. 151

TYPE OF MIGRATION
There are two types of migrations
1) Specific migration
2) Overall/Global migration
Specific migration : Where the migration of as single chemical species is measured
that is called specific migration.
Overall/Global migration : Where the total migration of all species migrating is
measured
Migration varies with time and is influence by the temperature
152

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