DRAFT TANZANIA STANDARD  
 
TBS/ GTDC4  (5006 ) P3 –Alumin ium foil for Packaging -Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS  
 
 
 
©TBS 2020                                                                                                       1st    Edition
 
1 
 1 Scope  
This d raft Tanzania standard  specifies requirements, method of sampling and test for annealed  
aluminium  alloy foil used  for general  packaging . 
This specification covers annealed aluminium  alloy foil cont aining 98.00 % minimum aluminum and in 
thicknesses 0.0064 mm  up to 0.15 mm . 
This draft standard does not cover  the requirements of aluminium and aluminium alloy foil for 
pharmaceutical packaging applications . 
2 Normative references  
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cite d applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
ISO 7271:2011  Aluminium and aluminum alloys -Foil and thin strip -Dimensional tolerances  
ASTM  B479 – 19 Standard Specification for Annealed Aluminum and Aluminum -Alloy Foil for 
Flexible Barrier, Food Contact, and Other Applications.  
ASTM E 252: 2006  Test method for thickness of foil, thin sheet, and film by mass 
measurement.  
ASTM E 345: 2016 : Standard Test Methods of Tension Testing of Metallic Foil . 
3.Terms and definitions   
For the purpose of this document, the following terms and definitions shall apply ; 
 
3.1 foil 
rolled aluminium alloy sheet  
3.2 aluminium Alloy   
alloy based on aluminium to which other elements are added to bring about an improvement in 
mechanical, physical and/or chemical properties to meet particular end uses  
4. Requirements   
4.1 General R equirements  
 
4.1.1 The material must be suitable for lamination purposes. The foil needs to be plain, free  from streaks,  
unevenness and/or wrinkles, scratches, excessive pinholes,  cracks, rust residuals, oil spots,  oxidation 
and st ains or from any other defects.  Surface of the foil will be one side bright and one side dull, winding 
of the coils with bright side wound to the outside . 
 
4.1.2 Rolls shall be wound firmly on the cores so as to prevent slipping or telescoping and to permit free 
unwinding without sticking or tearing.  
 
 
 
 
  
2 
 4.1.3 Aluminium Foil  
4.1.3.1The aluminium foil used shall be plain or printed, soft or hard annealed and 0. 006mm to 0.15  mm 
thick as specified by purchaser. It shall also comply with the requirements of chemical composition  in 
table 1.  
4.1.3.2 The foil shall be produced with food gra de rolling  lubricant . 
4.1.4  Odour  
The aluminium foil shall not imparts any detectable taste or objectionable odour or taint to foodstuffs.  
4.2 Specific Requirements  
4.2.1 Chemical Composition  
The foil shall conform to the chemical composition  limits in Table 1.  
 
Table  1- Chemical Composition Limits  
  
Elements  Si  Fe Ti Cu Mn Mg Zn Others —total 
Composition 
% maximum  0.50 0.70 0.20 0.20 0.10 0.10 0.20 0.15 
Aluminium minimum composition %  98 
 
4.2.1.1  For applications involving food  packaging, handling, or prese rvation the absolute amounts of lead, 
arsenic, and cadmium shal l be less than 0.01 % each.  
4.2.2 Foil thickness  
 
 4.2.2.1 Aluminium foil shall have a thickness ranging from  0.0064 mm to 0.15 mm.  
 
4.2.3  Dimensional Tolerances  
 
4.2.3 .1 Rolls—Rolls shall be  wound on core having  an inside diameter of , but not limited to 33.3 ± 0.3 
mm, 76.2 ± 0.4 mm  or (152.4 ± 0.8 mm ), as agreed between manufacturer and purchaser.  For specified 
foil widths up through 305 mm the dimensional tolerance shall be 0.4 mm , and for widths over 305 mm  it 
shall be 0.8 mm . The maximum ou tside roll diameter shall be as specified by the purchaser.  
 
4.2.3 .2 The dimensional tolerance for c oreless rolls shall be as agreed between manufacturer and 
purchaser.  
 
4.2.3 .3 Flat Sheets —The nominal width (perpendicular to rolling direction) and length (paralle l to rolling 
direction) of flat sheets shall be as specified by the purchaser and the permissible deviations from 
speci fied width and length shall  be 1.6 mm . 
 
4.2.4  Tensile strength and Elongation  
4.2.4.1 The minimum tensile strength and elongation of aluminium foil shall be 250 N/mm2 and 25 % 
respectively  when tested with accordance with Annex A . 
 
  
3 
 4.2.5 Wettability  
4.2.5.1 The foil must have a wettability A or A -C (see Figure 1) , when tested with accordance with  Annex 
C whereas the surface of the fully annealed  foil is assessed according to its ability to be wetted by  liquids, 
applied under clearly defined conditions.  
 
4.2.5.2 The wettability in dex is shown by the shape of the trace given on t he surface taken from the worst 
area of the foil. The wettability indices a re defined from A to E in below figure 1.  
 
 
 
Figure 1: Wettability  index  of foil  
4.2.5  Covering Area  
The covering area per kg shall be in accordance with the limits given in table 2 and shall be determined in 
accordance with Annex B clause 3.  
Table 2 –Minimum, maximum and nominal covering area s 
Nominal thickness (mm)  Nominal Covering area (m2/ kg) Permissible range of covering area A (m2/ kg) 
Minimum  Maximum  
0.0064  58.3 63.0 64.8 
0.0076  48.6 44.2 54.0 
0.0089  41.6 37.8 46.4 
0.0102  36.4 33.1 40.5 
0.0114  32.4 29.4 36.0 
0.0127  29.1 26.4 32.4 
0.0140  26.4 24.2 29.4 
0.0152  24.3 22.0 27.0 
0.0165  22.5 20.3 24.9 
0.0178  20.8 18.9 23.1 
0.0190  19.5 17.6 21.6 
0.0203  18.2 16.6 20.2 
0.0216  17.2 15.6 19.1 
0.0229  16.2 14.8 18.1 
0.0241  15.4 13.9 17.1 
0.0254  14.6 13.2 16.2 
0.0381  9.71 8.84 10.8 
0.0581  7.29 6.63 6.11 
0.0762  4.86 4.42 5.40 
0.1076  3.64 3.31 4.05 
 
4 
 0.127  2.91 2.28 3.24 
0.13 2.79 2.12 3.11 
0.15 2.045  1.06 2.28 
A range of the covering area based on the standard thickness tolerance of plus and minus 10% per roll or shipment .  
 
5 Packing and marking  
 5.1 Packing  
5.1.1 Each roll shall be banded with a layer of paper  or other suitable material that is free from 
contaminants harmful to the foil.  
 
5.2 Marking  
Each packet or roll shall be marked with the following information  
a) The name and /or registered trade mark of the manufacture;  
b) Address of manufacturer or importer;  
c) Size in thickness, length and  width;  
d) Instructions for disposal;  
e) Month and year of manufacture . 
6 Sampling  
6.1 Unless otherwise agreed to between the purchaser and the manufacturer the following procedure and 
the criteria for conformity shall apply.  
6.2 In a consignment the foils of same width and thickness and of the same surface condition and 
manufactured by a single firm under essentially similar conditions of production shall be grouped together 
to constitute a lot.  
6.2.1 Tests for determining the confor mity of the lot  to the requirement of this standard shall be carried 
out on each lot separately. The number of rolls of foils to be selected for this purpose at random over the 
whole lot shall be in accordance with col umn 2 and col umn 3 of Table 3. 
Table 3 Scale of Sampling and Permissible Number of Defectives (Clauses  6.2.1 and  6.2.2) 
Sn  
(1) No. of Rolls in the Lot  
(2) No. of Rolls to be Selected  
(3) Permissible No of Defectives  
(4) 
i.  Up to 5 All 0 
ii.  6 to 100  5 1 
iii.  101 to 30 0 8 1 
iv.  301 to 500  13 2 
v.  501 and over  20 3 
 
  
5 
 6.2.2 All the rolls shall be individually examined for manufacturing defects, surface defects and 
dimensional tolerances. A sample failing to meet any one of these requirements shall be called defective. 
The lot shall be considered as conf orming to the corresponding requirements of this standard if number of 
defectives satisfy the freedom from defects and dimensions in  less than or equal to the permissible 
number given in  column 4 of Table  3. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
6 
 Annex A  
(normative)  
Tensile strength  
A.1 Significance and use  
Tension test provide information on the strength and ductility of the materials under uniaxial tensile 
stresses.  
The results of tension tests from selected portions of a part or material may not totally the strength and 
ductility of the entire end product of its in -service behavior in different environments.  
These test methods are considered satisfactory for acceptance testing of commercial shipments since the 
methods have been used extensively for these purposes.  
Tensile test provide a means to determine the ductility of materials through the measurement either of 
elongation or reduction of area. However ,as specimen thickness is reduced ,tension tests may become 
less useful for the determination of ducti lity. 
A.2 Apparatus  
A.2.1 Testing machines  
A.2.1.1 Gripping devices  
A.2.1.1.1 General   
Various types of gripping devices may be used to transmit the measured load applied by the testing 
machine to test the specimen. To ensure axial tensile stress within t he ga uge length ,the axis of the test 
specimen must coincide with the center line of the testing machine. Any departure from this center line 
may introduce bending stresses that are not included in the usual stress computation (load divided by 
cross -sectio n area).  
A.2.1.1.2 Wedge grips  
Testing machines usually are equipped with wedge grips. These  wedge grips generally furnish a 
satisfactory means of gripping long of ductile materials in the thicker foil gauge.  If, for  any reason, one  
grip of a pair advances farther than the other as the grips tighten, an  undesirable bending stress may be 
introduced. When  liners are used behind the wedges, they must be of the same thickness and their faces 
must be flat and parallel. For  proper gripping , it is desirable that the entire length of the serrated face of 
each wedge be in contact with the specimen. A  buffer material such as 320 -grit silicon carbide paper may 
be inserted between the specimen and serrated faces to minimize tearing of specimens.  
A.3 Calculation  
Calculate the tensile strength by dividing the maximum load carried by the original cross -sectional area of 
the specimen.  
 
 
  
7 
 Annex B  
(normative)  
Determination of thickness of Aluminium foil  
B.1 Procedure  
Prepare samples of aluminium foil of  known area approximately 500 cm2 from flat uncreased sheets by 
cutting round a metal template with beveled edge by means of sharp knife. Clean the sample with 
suitable solvent to remove all coatings  ,inks, traces of impurities on foil. Dry the sample of f oil to constant 
mass at 105oC.  
B.2 Calculation  
Calculate the t hickness of the foil as follows:  
Thickness of the foil, in cm =  𝑚
𝑑× 𝑎× 𝑏 
Where  
           m=mass ,in g of the sample of foil;  
           d=density, of aluminium (2.71 g/cm3);   
           a=length ,in cm of foil test piece;  
           b= width, in cm of foil test piece.  
B.3 The covering area shall be determined by means of a direct reading basis weight scale. In case of 
dispute, the covering area shall be determined by weighing to the nearest 1 mg a piece of unsliced foil not 
less that 10ft (3m) long and calculating the average area per gram by use of the following equation:  
  
 Coverage area, cm2/g =  453 .6 × area  of sample  
weight  of sample   
 
 
 
 
 
 
 
  
8 
 Annex C  
(normative)  
Wettability  
C1 Principle of test  
The test shall apply to aluminium foil in the gauge from 6  μm to 200 μm. The  surface of the fully annealed 
foil is assessed according  to its ability to be wetted by liquids applied under clearly defined conditions.  
C2 General test conditions  
Carry out the test at ambient temperature. Remove the outside wraps to reduce the coil build up by a 
minimum of 3mm in order to obtain a representative sample before performing the test.  Perform the test 
on the matt side of the foil , where relevant.  
The following liquids shall be used:  
-distilled water; or  
-distilled water mixed with an industrial alcohol to a concentration of 20% by volume.  
Do not repeat tests on the same area of sample.  
C3 Test methods  
C3.1 Test by droplet  
C3.1.1 Test procedure  
Use a droplet bottle to drop 40 mg to 80 mg drops of liquid onto the horizontal metal surface at a rate of 
one drop every 5cm to 10 cm across the width of the web. Tilt the surface between 400 to 600 (see figure 
2).Determine the wettability index from the tail left by the movement of the droplets across the surface.  
 
 
 
Figure 2  : Determination of  the wettability index  
 
 
9 
 C3.1 .2 Acceptance criteria  
If the test is performed with distilled  water, the  wettability is shown by the shape of the trace given on the 
surface taken from the worst area of the foil. The  wettability indices are defined from A to E in figure 
1.Wettability indices included between A to C are acceptable.  
If the test is performed wit h the mixture of distilled water and an industrial alcohol the acceptable surface 
quality shall be comparable with wettability index A.    
 
C3.2 Test by fine spray   
C3.2.1 Test procedure  
Position the metal surface at an angle approaching the vertical. Use  a spray bottle to apply a fine spray 
mist across the width of the metal surface.  
C3.2.2 Acceptance criteria  
The whole surface under the liquid spray shall remain uniformly wetted by the applied liquid .The 
minimum acceptance criterion is that the distill ed /industrial alcohol mixture shall uniformly wet the whole 
surface.  
 
C3.3 Test by liquid stream  
C3.3.1 Test procedure  
Position the metal surface at an angle of between  400 to 600.Using a spray bottle, apply a continuous 
stream of test liquid across the width.  
C3.3.2 Acceptance criteria  
The whole surface under the stream of liquid and its subsequent spread downwards shall remain 
uniformly wetted.  
C4 Frequency of test  
Random testing of sufficient frequency to verify control capability to the satisfaction o f the purchaser shall 
be carried out.