testing of rigid plastic containers

Testing of Plastic Rigid Containers

Bhupendra Singh

Testing of Rigid Containers

Testing can be divided in to two parts :

• Quality Control : Testing of incoming raw materials

• Quality Assurance : Testing of finished products

Plastics testing can be divided into testing of plastic raw materials (generally granules) & testing of finished products after moulding.

Testing procedures for Laboratory

Quality Control on plastic raw materials − Melt Flow Index − Notched Izod Impact − Flexural Modulus

Quality Assurance of finished product − Stacking Test − Test for drop impact strength − Test for closure effectiveness − ESCR tests − Vibration tests − Storage tests − Test for ink adhesion of printed container − Test for product resistance of printed containers − Other tests as per requirement

by – Bhupendra Singh


Test Method No. 1:

Test Method for Measuring Melt Flow Index (MFI) / Melt Flow Rate (MFR):

Purpose

− It measures the flow of a molten polymer through an extrusion plastometer

under specific temperature and load conditions

− Used for differentiating various grades of plastic material.

− It is a quantitative technique for the Quality Control of Incoming Raw

Material.

Reference

− IS: 7328: 1992; ASTM D 1238

Method

− An extrusion plastometer consists of a vertical cylinder with a small

(0.0825 - inch diameter) orifice at the bottom and removable piston on top.

A charge of granules is placed in the cylinder and preheated for several

minutes. The piston is placed on top of the molten polymer and its weight

forces the polymer though the orifice to a collecting plate. The amount of

polymer collected after a specific interval is weighed and normalized to

the number of grams that would have been extruded in 10 minutes at 2.16

Kg weight and at 190° C.

Report

− The result is stated as MFI / (MFR) of a material in gm/10min at 2.16 Kg

weight and at 190° C.



Test Method No. 2: Test Method for Measuring Stack Load Stability

Purpose

− To observe buckling of containers under constant load or when stacked

during transportation.

− The stack load test is used to determine the ability of a package to hold

pressure for an extended time period.

− Transport worthiness viz: ability to withstand compression loads occurring

during warehousing and transportation

Reference

− IS 10840, IS 6312: 1994, IS 2798: 1998

Method

− 4 containers shall be used for test. Fill containers with water to normal

capacity and close it with the closure. A force is applied to the top face of

the container equivalent in magnitude to the total weight of identical

packages stacked on top to a minimum stack height of 3 m for 24 hours

duration. The top load should be uniformly distributed on the containers.

Report

− Look for permanent deformation and damages on the packages, if not it

passes the test.



Test Method No. 3: Test Method for Measuring Drop Impact Stability

Purpose

− To ascertain the bottles / containers manufactured pass drop impact as

some of them may carry chemicals which in contact may be hazardous.

− This test is a qualitative as well quantitative technique for the Quality

Assurance of the outgoing Plastic Blow Molded Container as finished

good.

− Transport worthiness viz: ability to withstand drops occurring during

loading /unloading.

− Significance: to check overall performance against handling and

distribution.

Reference

− IS 7408- 2000; IS 6312-1980; IS 6312 - 1980

Method

− Select 6 containers divide 2 sets of 3 each. Fill each container to its

nominal capacity with water. First set of containers shall be dropped on

the base from a height of 1.2 mtrs. Second set shall be dropped on the side

or on any external feature such as handles. Examine containers for signs

of rupture or leakage.

Report

− If containers failing in the first drop and on the same position on

subsequent containers, then the same has to be reported.



Test Method No. 3 contd . . . DROP IMPACT TEST (IS-6312) Drop sequence Details

1st diagonally on closure 2nd diagonally on bottom 3rd flat at top 4th flat at bottom 5th flat on shorter side 6th flat on wider side

one drop on each container from 1.20 meter ht.

DROP IMPACT TEST (IS-7408) Set – I (5 containers) Drop height

Drop flat on base 100 cm + 15cm… till container fails

Set – II (5 containers) Drop height Drop flat on side 100 cm + 15cm…

till container fails DROP IMPACT TEST (IS-7394) Drop sequence Details

1st flat on bottom 2nd diagonally on bottom

both drops on same container from 2.0 meters ht.

Fill with 50% ethylene glycol & water mixture, expose to 00C for 1 hr.and drop flat on bottom

same container from 1.5 meters ht.



Test Method No. 4: Test Method for Closure Effectiveness

Purpose

− The test is conducted for observing effectiveness of closure and to check

for leakage if any.



goods.

− Indicates defect in closure system.

Reference

− IS 7408: 2000; IS 6312-1980; IS 2798: 1998

Method

− 3 containers shall be used. Fill each container to its nominal capacity with

the test load at ambient temperature. Close each container with closure as

per recommended torque. Invert closure and keep for 24 hours. Examine

for leakage after 24 hrs.

Report

− If the liquid spills out, that implies the closure is not effective.



Test Method No. 5: Test Method for Environment Stress Crack Resistance (ESCR)

Purpose

− To test the bottle / closures for stress cracking



goods.

− To detect the processing defects and resistance of container against

repetitive washing.

Reference

− IS 6312; IS 8747; IS 2798: 1998

Test Chemical

− Teepol B300

Method

− The container is filled to nominal capacity with the test liquid and secured

as for transport. The container is then placed in oven: 60°C for 48 hours

for containers up to 25 liters, 80°C for 48 hours for containers more than

25 liters.

− Fill the containers with 0.5% Teepol solution & exposed to 60+/-2° C for 48 hrs

− Pieces dipped into test liquid & exposed to 80+/-2° C for 48 hrs. and observed for surface cracks (IS-6312)

Report

− The container is then checked for cracks developed if any and reported.



Test Method No. 6: Test Method for Vibration Stability of the Plastic Containers

Purpose

− The method helps to determine the ability of a closure (on a container) to

prevent leakage due to transportation in vibration.



goods.

− Transport worthiness of filled Blow Molded Containers can be determined

as per Indian Standard.

− This test is used to determine and evaluate the ability of Blow Molded

Plastic Container to withstand shock and vibration encountered during the

course of transporting products.

Apparatus

− A vibrating table, aptitude of vibration 25mm and frequency 8 HZ

Reference

− IS 12512; IS 2798: 1998

Method

− Fill the container to normal capacity with product / water and then close

the closure. Mount the container upside down on the table for 1 hour.

Check for leakage

Report

− If the liquid spills out, then the closure is not effective.



Test Method No. 7:

Test Method of Storage Stability of Plastic Containers

Purpose

− To test the loss in product filled in container

Reference

− IS 7394

Method

− Fill the container to its nominal capacity. Seal the closure and weigh the

container accurately. Store the container for a period of 30 days at 27+/-

2°C. Determine the loss of mass from the container

Report

− The loss in weight as per specifications of the Chemical filled, or as

agreed between the purchaser and the supplier.



Test Method No. 8:

Test for Ink Adhesion on the Container

Purpose

− To test the adhesion of ink to the bottle / container surface

Reference

− IS 7408 - 2000; IS 2798- 1998

Method

− Apply two strips of 25mm wide transparent adhesive tape on the printed

area, one down the length of container and other around the

circumference. Pass the tape on the container and leave it for 15 hrs. Pull

it slowly

Report

− Record the degree of print removal as nil, slight and severe



Test Method No. 9:

Test for Product Resistance of Printed Containers

Purpose

− To test the resistance of ink on the containers, getting washed away due to

incompatibility of the product

Reference

− IS 7408- 2000

Method

− The containers should be printed at least 24 hrs before conducting the

tests. Immerse or smear the containers with the product to the packed and

leave for 1 hour. Rinse with cold water and leave to stand till dry. Rub

container with dry paper.

Report

− Record degree of print removal as nil, slight or severe.



Test Method No. 10:

Test Method for Determining Brimful Capacity of the Container

Purpose

− To test the brimful capacity of the bottle / container.

Reference

− IS 7408- 2000, IS 2798- 1998

Method

− Weigh the empty container. Fill the container with water at ambient

temperature up to the brim of the container. Place the rigid transparent

plastic disc on the neck face and top-up by carefully pouring water

through the slot until the water is seen just contacting the underside of the

disc. Weigh the filled container with the disc. The difference in the weight

recorded in grams is reported as brimful capacity.

Report

− Record the weight of the water in gram as the Brimful capacity of that

container.

Nominal & Brimful Capacity (IS-7408)

Nominal Capacity (ml) Min. Brimful Capacity(ml)100 108200 212500 5251000 10352000 20603000 30755000 512510000 1050020000 2100025000 26250



Test Method No. 11:

Test Method for Dimensional Tolerances of the Container

Purpose

− To test the Dimensional Tolerance of the bottle / container.

Reference

− IS 7408- 2000

Method

− Container Height to Neck Face: The highest point of the neck face of the

finished empty container.

− Container Overall Height: The height of the finished empty container at

its highest point with closure and fitment.

− Container Diameter: The external diameter of the finished empty

container at a specified height, expressed as the mean of the two

perpendicular diameters, or as the circumference multiplied by 0.318 at

the same specified height.

− Neck Height: the perpendicular distance from the highest point of the

plane including the neck face to the nearest point of the finished containers

shoulder along a line passing through:

In the case of screw threaded necks, the outermost edge of the

thread; a feature below the thread of greater diameter than the

thread is considered as a part of the containers shoulder

In case of plain cylindrical necks, the outermost diameter point

excluding flash

In the case of necks having a bead or beads only, the outermost

point of the bead

− Neck Diameter: The external diameter of the neck, excluding thread and

/ or prominences, measured as the mean.

− Thread Diameter: The external diameter of the neck thread measured as

the mean of two perpendicular diameters avoiding the part line.



− Neck Bore: The diameter of the inner periphery of the neck at a

specified depth.

− Neck Ovality: the difference between the maximum and the minimum

neck diameter.

Report

− Record as per the table given below.

Dimensional Tolerances

Container Overall Height

Tolerance on Overall height ± 2.00 % or 1.00 mm, whichever is greater

Container Diameter

Tolerance for Container Diameter 1.5% or 0.1 mm, whichever is greater

Neck Height

Up to and including 75 mm overall height

± 0.25 mm

Over 75 mm ± 0.40 mm

Neck and Thread Diameters

Tolerance for Neck and Thread Diameters

± 1.25 % or ± 0.25 mm, whichever is greater

Wall Thickness

Minimum Wall thickness at any point of the container shall be not less than 0.20 mm

Neck Bore

Shall be as agreed between purchaser and supplier

Neck Ovality

Shall be as agreed between purchaser and supplier



Test Method No. 12:

Test Method for Leakage Test of the Container

Purpose

− To test the Leakage of the bottle / container.

Reference

− IS 2798- 1998;

Method

− The test is carried out by maintaining the specified pressure in the container and detecting any leakage with water or soap solution.

HYDROSTATIC PRESSURE TEST

Purpose

− To detect the performance of the container against internal pressures.

Reference

− IS 2798: 1998

Method

− A regulated water pressure of 0 to 15Kg/cm2 is applied for period of 5 minutes and observed for localized bulging or leakage.

Report

• Any sign of Rupture or leakage from the container other than from around

the mouth or localized bulging of the container shall be deemed to indicate

failure.



AIR PRESSURE TEST

Purpose

− to detect the performance of the container against internal pressures.

Reference

− IS 2798: 1998

Method

− A regulated air pressure of 0.35 kg/cm2 is applied for period of 5 minutes and observed for leakage.

Report

− Any sign of Rupture or leakage from the container other than from around

the mouth or localized bulging of the container shall be deemed to indicate

failure.



Test Method No. 13:

Test Method for Compatibility of the Container

Purpose

− To ascertain the bottles/container is reported to Pass / Fail the

compatibility test with the product.

− It checks the compatibility the Product-Package Compatibility.

Reference

− IS 2798-1998; IS-7551 -1975

Method

− Containers are filled with the product/ water to nominal capacity, closed

& exposed to 50 +/- 2°C for 28 days OR

− Pieces of equal Size (at least 15 cm2) from any part of the container

weighed, measured for dimensions and then cleaned, Test pieces are then

immersed in the liquid product & exposed at 50+/-2° C for 28 days.

(liquid and test pieces are agitated every 24 hrs).

• Visible Cracks

• Change in Weight

• Change in colour & shape

– For dry products the test may only be carried out on container but for

products which are not stable above 50° C storage test shall be carried out

at room temp.

– Based on the results the purchaser & supplier reach an agreement about

the stability of the plastic material for the intended purpose.

Report

− The Compatibility of the container with the product is reported as

compatible or not compatible.



Test Method No. 14:

Test Method for Migration of the additives from the Container in the product

Purpose

− To ascertain the bottles/containers if they Pass/ Fail the compatibility test

with the product.

− It checks the migration of the additives and other constituents to product.

Reference

− IS 9845-1981

Method

− Representative samples are subjected to overall migration test with

simulating liquids like n-Heptane, at 27 +/- 20 C for 30 minutes and

extract is determined gravimetrically.

− Maximum limit for extraction values 60 mg/liter.

Report

− The Migration level is reported in mg/liter.



Test Method No. 15:

Test Method for Top Load or Compression Strength of the Container

Purpose

− To check the load bearing capacity of the Container.

− This test also provides the Top Load Bearing Capacity of the Container.

Reference

− IS 7028

Method

− Compress the container vertically between two platens of the compression

strength tester and observe for vertical deformation

− Speed: 10 mm/minute

Report

− The Values of Compression are reported in Kg force



Test Method No. 16:

Test Method for Leakage of Container under Vibratory Condition

Purpose

− To test the Leakage of the bottle / container under Vibratory condition.

Reference

− IS 7408- 1998;

Method

− Filled Containers are mounted on a vibration table in upside down position

and vibrated for 1 hr. and observed for leakage & closure tightness.

− Amplitude of 25 mm and frequency 180 c.p.m. is maintained during the

test.

Report

− The Leakage of the container through the Closure is evaluated. And the

Report is made as either container passing the test or any leakage is a

failure of the container.



Test Method No. 17:

Test Method for Leakage Test of the Container

Purpose

− To test the Leakage of the bottle / container.

Reference

− IS 6312;

Method

− Filled containers are placed on ground in upside down position for 30

minutes(IS-6312)

− Significance: to detect the perfect ness of closure system

Report

− Any sign of leakage from the container around the mouth of the container

shall be deemed to indicate failure.



Test Method No. 18:

Test Method for Handle Pull of the Container

Purpose

− Indicates ability of the handle to bear weight of the filled container.

− Performed on containers with detachable handles.

Reference

− IS 10840; IS 6312-1980;

Method

− The filled container is subjected to a vertical pull of double its nominal

filling capacity for 10 minutes and observed for damage.

Report

− Any sign of Rupture or leakage from the handle area of the container shows failure of the container.


testing of rigid plastic containers

Documents

plastic rigid

bottle container

drop impact

finished empty

method filled

plastic material

brimful capacity

nominal capacity