PARTH PACKAGING, DADRA. SPECIFICATION AND TEST METHODS

What is aluminium foil?

Aluminium foil is a continuous laminae of at least 99% pure aluminium metal rolled to thickness ranging from 5 to 200 micron. It is available in hard and soft or any desired variable tempers, in bright or matt finish, in plain, coated, coloured, printed, embossed or laminated with a variety of papers and films. It is available in sheets and reels.

Properties of aluminium foil:

The purpose of packaging is to contain the products, protect it from physical and environmental hazards and to present it in a convenient quantity and in satisfactory functional form. On the shelf it adds to product appeal and aids visual communication between the consumer and the product.

Some Critical questions to be answered for selecting the right packaging construction for your product are:

1. Is the product in solid or liquid state ? If solid, is it in tablet, capsule or powder form?

2. Is it Hygroscopic ?

3. How sensitive is the product to heat and light?

4. What shelf life are you looking for in the packaging?

Economics often influence companies to lean towards thinner gauges of foil, often compromising on the barrier performance required for the particular product.

However, here are some examples:

  • Products not too sensitive to light can be packed in foil / PVC Blister Packs.
  • Heat sensitive products will require low temperature for sealing.
  • Less sensitive tablets are adequately protected in 0.03 mm foil with polyethylene or with heat seal coating.
  • Analgesics and non-critical tablets normally requiring shorter shelf - life can be packed in 0.025 mm or 0.02 mm foil with polythene or with heat seal coating.
  • Powders and other granular pharmaceutical products can be packed in Multiply Laminates to be either used on FORM FILL and SEAL (FFS) machines or to make pre-formed pouches.
  • Product requiring post sterilization
  • with gamma rays will require radiation resistant sealant (which has been developed by IFL)

Tolerances of Aluminium foil

Tolerance of foil guage=+ 8% on average and plus minus (+) minimum 12% on

spot checks

Tolerance on polyethylene=+ 15% on average weight

Tolerance on V type coating=+ 15% on nominal coating weight of 4gm per m sq.

Aluminium foil specifications most commonly used by the pharmaceutical industry

For strip packaging

For packaging of tablets and capsules: (Foil gauge used)

Heat Seal Coated Annealed Foils (S) Polyethylene Laminated Annealed Foils (S)

0.02 mm0.02 mm

0.025 mm0.025 mm

0.03 mm0.03 mm

0.04 mm0.04 mm

For Blister Packaging

For packaging of tablets and capsules: (Foil gauge used)

Heat Seal Coated Annealed Foil (H)

0.02 mm

0.025 mm

0.03 mm

For packing of sterile surgical blades:

0.04 mm annealed foil (S) with Special Heat Seal coating.

For Packing of Sterile Sutures:

Top Component - 50/60 gsm ARSR paper adhesive or poly laminated to 0.04 mm annealed foil (S) with Special Heat Seal coating.

Bottom Component - 0.05 mm annealed foil (S) special heat seal coated on one side and lacquer coated on the other.

For packing specialty pharmaceutical

40 gsm or 42 gsm OLB paper laminated to 0.04 mm annealed foil (S) / 150 gauge poly. or foil laminates tailor - made to suit particular applications.

Operating conditions recommended

Strip Packaging

Temperature 140 – 1700 C

Pressure 2.81 - 5.63 [(kg/Sq.cm) 40-80 lbs/ sq.inch]

Dwell Time 0.25 to 0.50 sec.

Blister Packaging

Temperature 170 – 1800 C

Pressure2.81 - 5.63 [(Kg/Sq.cm) 40 - 80 lbs/sq.inch]

Dwell Time025 to 0.50 sec.

Seal Integrity (For Strip and Blister Packaging)

Vacuum test is a test done at periodical intervals during production to ascertain the reliability of sealing. For this purpose a few packed strips are immersed with suitable weights in a jar of water. The air is then exhausted from the jar and a vaccume of 10 inch. to 12 inch. depression on mercury gauge is maintained for 2 to 3 minutes. The packed strips are removed and wiped thoroughly with a dry cloth and cut with scissors along the edge of the pockets. The tablet is examined separately in each pocket for water contamination. Normal sealing efficiency of 95% is considered satisfactory. If tests show sealing efficiency below 95% and depending on the type of leakage, the setting of temperature, pressure and speed of machines will have to be adjusted to achieve the desired degree of sealing.

Printing of aluminium foil

In addition to barrier properties. Aluminium Foil offers other useful features. It is printable mainly by the Gravure printing process in one or more colours.

Due to its highly reflective surface, attractive designs using transparent and opaque inks can be printed either on the bright /glossy or on the dull/ matt surface.

Generic name, pharmacopea, net contents, formula, batch details, schedule warnings, poison box, manufacturer’s name and address, manufacturing license number, trade marks and logos can be incorporated and printed in continuous repeat designs to appear once or twice in a strip length of 5 or 10 tablets / capsules. The product name in the form of tramlines may also appear on each pocket on either side of the strip.

Foil inks used for strip and blister packaging are heat resistant and can withstand the temperatures used in the sealing operations.

Reels: All heat sealable foils are supplied in reels. It must be clear that it is the packer’s responsibility to specify the inner diameters of plastic, cardboard or aluminum cores used. Also the requirements on maximum outer diameter, width of reel and area on which batch number is to be over-printed are to be clearly stated.

When ordering printed foil please specify type of winding required as illustrated in the drawings below:

Recommended storage conditions

Aluminium Foil is readily corroded when it is wet or becomes moist by condensation on a humid day. A large spool or a reel of Aluminium Foil contains a mass of metal. If this metal is in cold store, and then brought suddenly to warm, humid atmosphere, the foil may expand which can cause corrosion and condensation of moisture on the surface.

Condensation is caused due to extreme environmental changes, often encountered during transit involving a trip of several days.

Warmer air contains moisture or humidity. As the temperature falls, the relative humidity increases, and if the dew point is reached, the air can no longer hold the moisture. It condences on the surface and seeps through layers from edges on foil.

In order to protect foil from condensation, absorbent desiccant bags of Silica Gel are placed along the edges and the bottom of the container. This precaution is taken for plain unsupported aluminium foil.

Pharma foil in reels may be stored in the corrugated cartons used for packing, and/ or on open pallets stored on racks.

The golden rule is to store foil in a dry well ventilated store room which has adequate ventilation.

Polylaminated / heat seal coated aluminium foil for strip packing

Foil
Al Foil thickness (mm) / 0.04 / 0.03 / 0.025 / 0.02
Thickness Tolerance (+ 8%) / +0.0032 / +0.0024 / + 0.0020 / + 0.0016
Al Foil Weight (gsm) / 108.40 / 81.30 / 67.75 / 54.20
Bursting Strength (lbs/sq.inch) / 36 / 27 / 22 / 18
Bursting Strength (Kg/Sq.cm) / 2.53 / 1.90 / 1.55 / 1.27
Al. Foil alloy / AA 1200/AA 8011
Al. Foil finish / Matt / Bright
Temper / Soft
Sealant
a) LDPE LAMINATION
Thickness LDPE Film / 30 to 45 micron (120 TO 180 GAUGE)
Thickness Tolerance / + 15%
Density / 0.92 gm/cc
Peel Strength of Lamination / 3N/25 mm min
Seal Strength between Top and Bottom Foil / 5N / 25 mm min
b) Heat Seal Lacquer
Coating Weight (gsm) / 4.0 to 6.0 or as specified
Tolerance on Coating weight (gsm) / + 0.5
Seal Strength between Top and Bottom Foil / 5N/25 mm min.

Printing

Design / As per customer’s artwork
No. of Colours / 1 to 5
Shade, ink adhesion, print registration and surface of print / As agreed with the customer
OUTPUT Dimensions
Reel Width (mm): plain / 45-950
Printed / 45-900
Reel outside diameter / 250-400
Joints per reel / Average1, maximum 2 in a reel
Core material / Aluminium / Plastic / Cardboard
Core diameter (mm) / 76

Heat Seallacquer coated aluminium foil for blister packing

Foil

Al Foil thickness (mm)0.030.0250.02

Thickness Tolerance (+8%)+ 0.0024+ 0.0020+0.0016

Foil Weight (gsm)81.3067.7554.20

Al.AlloyAA1200/AA 8011

Al. Foil FinishMatt/Bright

Temperhard (unannealed)

Sealant

Heat Sealable Lacquer

Coating thickness4 to 6 gsm or as specified

Tolerance on coating weight (gsm) + 0.5

Seal Strngth with PVC8N/25 mm min.

Printing

DesignAs per customer artwork

No. of ColoursOne on sealant side and max four on the other side

Shade, ink adhesion, print
registration and surface
of printAs agreed with the customer

Output Dimensions

Reel Width (mm): Plainupto a max of 950

Printedupto a max of 900

Reel outside diameter (mm)250-400

Joints per reelAverage 1, maximum 2 in a reel Aluminium / Plastic

Core internal diameter (mm)58/70/76

Covering area of 1 kg finished Material (Nominal)

Strip packaging

Gauge and temper of foil / Covering area in sq.mts / kg
With 4 gsm nominal heat seal coating / With 150 gauge Polyethylene Lamination
0.02 mm (soft) / 17.18 / 11.27
0.025 mm (Soft) / 13.94 / 9.78
0.03 mm (Soft) / 11.72 / 8.64
0.04 mm (Soft0 / 8.90 / 7.00
Blister Packaging
Gauge and temper of foil / Covering area in sq.mts / kg
With 4 gsm Nominal heat seal coating
0.02 mm (Hard) / 17.18
0.025 mm (Hard) / 13.94
0.03 mm (Hard) / 11.72

ACCEPTANCE TEST METHOD

Bursting strength of strip foils

  1. Scope

This acceptance test method specifies a method of determining the bursting strength of strip foils only

  1. Definition
  2. Bursting strength is defined as the pressure applied at an uniformly increasing rate to a circular area of the foil till it bursts. This is expressed in 1 b/sq.inch.
  1. Equipment
  2. Mullen Bursting Strength Testing Machine
  1. Test Specimen
  2. Collect several pieces of laminates from different reels or different areas of jumbo rolls.
  3. Cut with a suitable metal template neat size 10 cm x 10 cm of samples. Keep adequate number of specimen for each specification
  1. Test Procedure
  2. Place the test piece over the rubber diaphragm of Bursting Strength Testing Machine.
  3. Apply pressure either pneumatically or hydraulically and allow the test piece to burst.
  4. Burst value is thus noted as recorded on the dial gauge attached with the equipment
  5. Multiply the value by 14.7 lb/sq.inch if value noted in the dial is in kg/cm2 unit.
  6. Expresses ion of results
  7. Results are expressed in lb/sq. inch upto one place of decimal.

As a general guide minimum bursting strength values for a polybacked strip foil specification should be 2-3 units higher than that value of bare foil considering lb/sq.inch per 0.00 1 mm or 1 micron thickness of aliminium foil.

Peel Strength of Aluminium foil – Ply laminate

  1. Scope
  2. This test method describes a procedure to determine peel strength between aluminium foil and covers all laminates where
  3. Polythene film is laminated to aliminium foil by heat and pressure process
  4. Polythene is coated on aluminium foil by extrusion coating / laminating process irrespective of thickness of aluminium foil and polythene and the structure of the laminate.
  1. Principle / Definition
  2. The peeling force necessary to detach the polythene film from aluminium foil is called peel strength.
  1. Apparatus
  2. Tensile tester with appropriate grips having ± 10 mm per minute of separation
  3. Ethyl Alcohol
  4. Cotton Wool
  5. Hot Plate
  6. Beaker of 500 ml capacity
  7. Blotting paper
  8. Template of size 25 mm x 200 mm
  9. Razor Blade or equivalent
  1. Test piece
  2. Cut three test pieces at least 10 mm away from an edge using the template & blade
  3. Test pieces shall be taken across the width of the web, wherever possible.
  4. Length of the test pieces shall be parallel to the rolling direction of the foil.
  5. Separate a length of about 10 mm of polythene from aluminium foil at one end of a test piece using Ethyl Alcohol soaked in cotton wool.
  6. If necessary, immerse about 25 mm of one end of the test piece in Ethyl Alcohol at 70 ˚C.
  7. Peel off the Polythene film from aluminium foil by smooth steady pull by hand upto the length which can be easily determined.
  8. Use sufficient Ethyl Alcohol to facilitate delamination upto about 50 mm of length. Excess use of Alcohol will weaken peel strength, which cannot be reversed completely by drying the test piece.
  9. Remove excess alcohol from the test piece using blotting paper & dry in air for at least half an hour to allow the entire solvent to evaporate.
  10. Procedure
  11. Place the free ends of the test piece in the jaws of the Tensile Tester &peel at a constant speed of 100 mm ± 10 mm per minute.
  12. Peel for about 25 mm length & note the steady value of peeling force.
  13. Repeat the test for all the test pieces from the sample and calculate the mean value.
  14. If polythene film or aluminium foil breaks during test, material shall be considered acceptable. Indicate film / foil breakage in the report.
  1. Expression of Result
  2. Results are expressed in Newton / 25 mm upto one place of decimal

Pinhole Count in Aluminium Foil

  1. Scope
  2. This method prescribes the procedure for measuring porosity in Aluminium foil in the gauge range of 0.006 to 0.050 mm
  3. f
  4. Principle & Definition
  5. The principal of the test is to examine the foil under a Light Box, installed in a room having low lever of illumination, for the presence of any holes in the foil.
  6. Apparatus
  7. A light box which consists of translucent glass, lit from below by a luminous source giving an illumination of 1000 to 1500 LUX.
  8. The size of the light box should be suited to the dimension of the largest size to be examined.
  9. The room in which the test is carried out should be illuminated to a low level (20 to 50 LUX).
  1. Procedure
  2. The foil should be placed on the light box with its matt aspect facing the observer.
  3. The are of light box not covered by the test sample should be masked.
  4. The sample should be observed from a distance of half a meter.
  5. Take the test sample and deliberately select the worst area.
  6. Count the number of holes in 50 cm 40 cm area by placing the selected portion of the sample on the glass top so marked.
  7. Repeat 5.4 & 5.5 on 5 randomly selected samples fro a coil / batch
  8. Add the number of counts so observed in 5 samples to get total number of holes in 1 sq. meter.
  1. Expression of Results
  2. Pinhole Count is expressed as number of holes per square meter.

Adhesion of Inks & Lacquers Using Cellotape

  1. Scope
  2. This method describes a procedure of determining adhesion of inks and lacquesr on plastic film and aluminium foil. It includes inks and lacquer adhesion on all surface printed and coated materials except paper.
  1. Principle / Definition
  2. This test method involves pasting a length of cellotape across the area of the sample required to be checked and then lifting the cellotape away from the rest area. Te extend of ink / lacquer lifting onto the cellotape from the printed / coated substrate is observed.
  3. A self-adhesive clear polyester of BOPP tape may be used instead of a cellotape.
  4. Rate of pulling of cellotape may be classified as listed below:

Soft PullSlow rate of pulling (approx. 50 mm / sec.)

Medium PullModerate rate of pulling (approx. 100 mm / sec.)

Hard PullFast rate of pulling (approx. 150 mm / sec.)

  • For all practical purposes, material passing adhesion test by medium pull shall be considered acceptable.
  1. Apparatus
  2. 15 mm wide cellotape or equivalent
  1. Test Piece
  2. The Test piece shall be of full width and about 500 mm long
  3. It is common experience to find excellent adhesion in another. It is important, therefore, to check adhesion across the entire width of the printed / coated material.
  1. Procedure
  2. Place a length of cellotape across the printed / coated surface of the test piece so that all the colours / coatings are included.
  3. Press the tape onto the surface firmly using your thumb
  4. Steadily pull the tape away from the printed / coated surface at prescribed speed with the leading end of the tape maintained at about 45 deg. Angle to the tail end.
  5. Inspect both the surfaces for any ink / lacquer remove.
  6. For easy inspection, the affected length of cellotape may be stuck on a piece of white paper, and ink / lacquer lifting viewed against the paper surface.
  7. Repeat the process on other areas of test piece to cover entire width.
  1. Expression of Result
  2. Report extent of ink / lacquer removal according to the scale listed below:

ExcellentNo ink / lacquer removal

GoodSlight ink / lacquer removal, acceptable

PoorSevere ink / lacquer removal, unacceptable

6.2.State which colours or lacquers were involved, if there is a failure.

6.3.If testing has to be done with soft or hard pull, record the same.

Identification of Wash Coating

  1. Scope
  2. This method describes a procedure for identification of shellac in washed aluminium foil
  1. Principle / Definition
  2. Shellac dissolves in neutral ethyl alcohol, which in presence of Universal Indicator Solution gives an orange coloration
  1. Apparatus
  2. Beaker of 250 ml capacity
  3. Ethyl Alcohol (96 % v/v)
  4. 2% Caustic Soda Solution
  5. BDH Universal Indicator Solution
  6. Pipette of 25 ml. capacity
  1. Procedure
  2. Preparation of Neutral Ethyl Alcohol
  • Take 100 ml of Ethyl Alcohol in the beaker.
  • Add 2-3 drops ofUniversal Indicator solution into Ethyl Alcohol
  • Add Caustic Soda solution into the above Ethyl Alcohol drop by drop using pipette and stir it with a glass rod until the colour of ethyl alcohol changes from light orange to light green.
  • Ethyl Alcohol having light green colour is now ready as Neutral Ethyl Alcohol.
  • Pour 4-5 drops of Neutral Ethyl Alcohol on the washed foul and allow Shellac to get dissolved in it for 15 seconds.
  • Pour 1-2 drops of Universal indicator solution on the above area.
  • If orange colouration appears within 15 seconds, Shellac is present
  • If light orange or yellow colouration appears, Shellac is present in small extent.
  1. Expression of Result
  2. Report presence or absence of Shellac Coating

Grammage (GSM)

  1. Scope
  2. This method covers determination of total substance of paper, aluminium and laminates.
  1. Principle / definition
  2. This method involves weighing a sample of known area and computing the weight of one square meter of sample in grams. For convenience this shall be abbreviated to gsm.
  1. Apparatus
  2. Chemical Balance accurate to 0.0005 gm.
  3. A suitably calibrated sheet – weighing balance may be used.
  4. Template of size:-
  5. 250 mm x 250 mm for paper
  6. 100 mm x 100 mm or equivalent for plastic film and laminates.
  7. Each dimension of the template shall have accuracy of 0.02%
  8. Razor Blade or equivalent
  1. Test Piece
  2. Collect full width sample from the reel. Length of the sample shall be about 500 mm
  3. Using the template and razor blade, cut test pieces across the width of the web from flat, uncreased portions.
  • Number of test pieces shall depend upo0n the width of the web.
  • If substance variation across the width of the web is required to be checked, 100 mm x 100 mm or a smaller template may be used. Mark the test pieces suitably to indicate position in the sample web.
  1. Procedure
  2. Weigh the test piece correct to three places of the decimal.
  3. Determine the area of the test piece
  4. Substance in gsm = 1000w

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