i 
 Tbs                                           TDC3 (6747 ) P3   
                     Third edition  
 
 
 
 
DRAFT TANZANIA STANDARD  
 
 
Textiles — Open  mouth woven poly -sacks made from High Density 
Polyethylene (HDPE)/ polypropylene  (PP) tape-yarns - Specifications.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ii 
 Foreword  
 
This third e dition of this Draft Tanzania Standard  was improved to include other requirements which were 
not specified in the Second Edition.  
 
It has been improved to assist manufacturers of woven poly sacks produced from polypropylene tape 
yarns by specifying the characteristic requirements of various sa cks for packing different products.  
 
This Draft Tanzania Standard  is a revision of the second version finalized in  the year  2010. This third 
edition cancels and replaces the second edition TZS 1257: 2010 which has been technically revised.  
 
In the prepar ation of this Draft Tanzania Standard  assistance was derived from:  
 
BS 6162, Specification for open mouth sacks manufactured from woven polyolefin tape yarn  
 
IS11652, Woven sacks for packing cement — High density polyethylene/polypropylene, published 
by Bureau of India Standards  
 
ISO 23560: 2015 Woven Polypropylene sacks for bulk packaging of food stuffs  
 
In reporting the results of a test or analysis made in accordance with this Draft Tanzania Standard , if the 
final value, observed or calculated is to be rounded off, it shall be done in accordance with TZS 4, 
Rounding off numerical values (see clause 2) . 
 
 
 
 
 
 
  
  
1 
 1. SCOPE 
 
This Draft Tanzania Standard  specifies  requirements and test methods for open mouth poly – sacks made 
from HDPE/PP tape yarn . 
 
2. NORMATIVE REFERENCES  
 
The following referenced documents are indispensable for the application of this standard. For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
 
TZS 4, Rounding off numerical values  
 
TZS 20, Textiles — Woven fabrics — Determination of number of threads per unit length and per 
unit width  
 
TZS 21:, Textiles — Woven or knitted fabrics — Determination of  mass per unit length and per 
unit area  
 
TZS 22 , Textiles — Woven fabrics — Determination of breaking load and extension  
TZS 44 , Textiles — Woven or knitted fabrics — Determination of width and length  
 
3. TERMS AND DEFINITIONS  
For the purposes of this Draft Tanzania Standard , the following terms and definitions shall apply.  
 
3.1Polymer (polymerization)  
combination or association of molecules that may be of one compound or two or more reacting 
simultaneously to form a regular system of molecules behaving as one unit  
 
3.2 P olypropylene tape yarns  
Flat yarn composed of polypropylene polymer  
 
3.3 Pabrics  weaves  
pattern of interlacing of the warp (the tapes running in the machine or longitudinal direction of the woven 
material) and the weft (the tape yarns in the transverse direction)  
 
3.4 S ack weave  
number of tapes per 100 mm running in the longitudinal directi on of the sack by the number of tapes per 
100 mm in the transverse direction  
 
3.5 W oven polypropylene fabric  
sheet material woven from polypropylene tape yarns  
 
3.6 C oated fabric  
fabric coated on one or both sides with suitable polymer  
 
3.7 P oly–sack  
 flexible container, made from fabric manufactured from woven polypropylene tape yarns  
 
3.8 L iner  
single ply flexible container which may be bonded or loosely inserted in the sack   
2 
  
4. MATERIALS  
 
4.1 Fabric  
The weave of the fabric shall be plain, woven from polypropylene tape yarns and its construction 
described as warp by weft in tapes per 10 cm, and the fabric shall be uncoated or coated on one side or 
both.  
 
4.2 Stitch threads  
The stitching thread shall be made from either;   
a) Polypropylene, or  
b) Other materials provided they are not adversely affected by the expected climatic conditions in 
transit, storage and use.  
 
5. DIMENSIONS  
Expression of dimensions  
5.1 The dimensions of a sack shall be expressed as follows;  
 
a) face width x length, in centimetres, for an open mouth flat sack (see figure 1).  
b) face width x length, of gusset in centimetres, for an open mouth gusseted sack (see figure 
2); regardless of whether  the length is greater or less than the face width.  
 
5.2 The dimensions of a tape yarn shall be;  
 
a) Tape width shall be between 1.5mm and 6mm.  
b) Monofilament continuous tape shall be used for fabric weaving  
c) Tape width shall have a tolerance of ±2 mm. (see  table 1)  
 
 
6. CONSTRUCTION  
6.1 Sack  
The sack shall be produced either;  
a)  From material woven as a tube, or  
b) From Flat woven material, and cut to the required length.  
 
6.2 Edge sealing  
All edges shall be sealed to prevent flying.  
 
6.3 Base closure  
The base closure shall be such as to ensure compliance with the performance required.  
6.4 Turned -over and stitched  
Where the base closure is affected by a turned -over and stitched seam, the turn over shall be 2.0 cm 
minimum, and the stitch line shall be 1.0± 3 cm from the base so formed and shall pass through all four 
thicknesses of the material.  
 
6.5 Seam  
The stitching shall be done at the bottom and at the mouth of the sack excluding value. It shall be done 
with a single or two rows of the lock or chain stitches.  
 
  
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 6.6 Mouth  
The mouth of the sack shall be either;  
 
a) plain, formed from the selvedge or from sea led raw edge,   
 
b) hemmed with a single or double fold over stitched continuously round the mouth of the sack.  
 
6.7 Liners  
Where liners are used they shall be either;  
 
a) Loosely inserted or,  
b) Anchored with adhesive (or other suitable medium) or,  
c) Stitched at the base closure or,  
d) Stitched at the mouth.   
 
7 SACK IDENTIFICATION AND REQUIREMENTS  
 7.1 S ack performance requirement.  
a) Sacks shall confor m to the requirements shown in T able 1  
b) Various dimens ions and capacity are shown in T able 2  
c) If the sack has a liner, the liner shall confo rm to the requirement shown in Table 2 . 
 
7.2 Identification of a sack  
For the purpose of identification, coloured tape yarns shall be incorporated into the weaving process of a 
sacking fabric as per customer’s requirement .  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
4 
 Table 1 -Perfomance Requirement s for the wovensacks . 
 
 
S/N  
Characteristics   
Requirements   
Tolerance   
Test method  
1 Capacity  The capacity of the sack shall be 
upon agreement between buyer 
and seller however, it shall not 
exceed 100kg.  - - 
2 Dimension  The dimension of the sack shall 
be upon an agreement between 
buyer and seller  with a tolerance 
of ±2cm of the declared value  ±2 TZS 
3 Average breaking strength 
(ravelled strip method, 
(200mm x 50mm), minimum, N  
a) Width wise  
b) Length wise   
 
 
500 
500 -  
 
ISO 13934: 1  
4 Elongation at break of fabric 
(%)  
i) Length wise  
ii) Width wise   
 
20 
20 - IS 196 9 (part 1)  
5 Minimum breaking strength of 
bottom seam, ravelled strip 
method, N  250 - IS 9030  
6 Mass per unit area of fabric 
g/m2 65 - TZS 21  
7 Number of yarns per 
decimetre  
I) Ends/dm  
II) Picks/dm   
 
40 
40 - TZS 20  
8 Average breaking strength and 
elongatio n at break of UV 
stabilized HDPE /PP fabric 
after been exposed to UV 
radiation and weathering, min.   
Not less than 50% of original 
strength  - Annex A  
9 Ash content ( for UV stabilized 
fabrics), max percent.  2.2 - ISO 3451 – 1: 2008  
Method A.  
 Note 1 – Requirement number 8 and 9 are subjected to the agreement between manufacturer and buyer.  
 
Table 2  – Performance requirement of the liner (in case the sack is attached with a liner)  
SN Characteristics  Requirements  Tolerance  Test methods  
1 Weight of the liner (micron), 
min 30 - TZS 21  
2 Bottom seam of loose liner  At least 25mm from the bottom edge.  - IS 1969 (Part 1)  
3 Dimension  of liner  
a) Width of loose liner  
 
b) Length of loose liner   
At least 20mm more than the specified 
width of the sack  
At least 50mm more than the specified 
length of the sack  
 - IS 9030  
  
5 
 8. PRINTING, MARKING AND PACKAGING.  –packaging to be included  (printing, 
packing and marking).  
8.1 Printing  on sacks  
The sacks shall be print ed with food grade printing ink with identification mark of sack manufacture, size 
of the bag along  with other information as required by the buyer.  
 
8.2 Marking of packed bale  
 
The following information shall be marked on each bale with indelible ink.  
 
a) Name of the manufacturer;  
b) Type and/or size of the sack;  
c) Gross mass of the bale;  
d) Net mass of the bale;  
e) Date of manufacture;  
f) Any other information required by the buyer;  
g) Identification Mark;  
h) Number of sacks.  
 
Note 2 - Each sack shall be compulsory marked with visible recycling logo as given below at a space on 
bottom of the bag compatible  with the art work of the buyer for printing the sack and bale.  
 
 
 
 
Fig 1 Recycling Logo  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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ANNEX A 
(Normative)  
UV RESISTANCE TEST  
B – 1 To determine the effect of UV radiation and weathering on the breaking strength, the HDPE/PP 
Woven fabrics shall be exposed as given in A - 2 and A – 3. 
 
B – 2 TEST PROCEDURE  
The test shall be carried out with fluorescent UV – Lamp type B (313nm or its equivalent).  
The duration of the test shall be 192h (that is eight days) in continuous mode.  
The test cycle shall be: 8h at 60 ℃ ± 3℃ with UV – radiation alternating with 4h at 50 ℃ ±3℃ 
condensation. Irradiance level throughout the test shall be maintained at 0.63 (+0.04/ -0) W/m2. 
B – 3 TEST PROCEDURE  
B – 3.1 Determine the original average breaking strength of fabric as per test method  specified in IS 
1969 (part 1)  
B – 3.2 Expose the specimens alternately to ultraviolet light and condensation in respective test cycle 
in continuous mode for total 192h.  
The type of fluorescent UV lamp, the timing of the UV and condensation exposure and th e 
temperature of the UV exposure and condensation shall be specified in A -2. 
B – 3.3 Determine the average breaking strength of the fabric separately after UV exposure as 
mentioned above.  
B – 3.4 Determine the percent retention of original strength as foll ows: 
Percentage retention of original breaking strength = 𝑎
𝑏  𝑥 100 
Where  
a) a= average breaking strength before UV exposure as obtained in A – 3.1 
b) b= average breaking strength after UV exposure as obtained in A – 3.3 
NOTES  
1. The UV source is an array of fluorescent lamps (with lamp emission concentrated in the UV range).  
2. Condensation is produced by exposing the test surface to a heated, saturated mixture of air and water 
vapour, while the reverse side of the test specimen is exposed to the cooling influen ce of ambient room air.  
 
 
 
 
 
 
 
 
 
  
7 
  
ANNEX B  
(Informative)  
Diagram showing open mouth flat sack and open mouth gusseted sack  
 
 
   Figure 1 – Open -mouth flat sack                                     Figure 2 – Open -mouth gusseted sack