 DEAS 256 :2021  
ICS 59 .080.01  
 
© EA C 2021                                                                                                                          Second Edition 2021   
 DRAFT EAST AFRICAN STANDARD  
Textiles — Method for determination of scouring loss in grey and 
finished cotton materials  
EAST AFRICAN COMMUNITY  
 
 DEAS 256 :2021  
ii © EAC 2021  – All rights reserved  
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 DEAS 256 :2021  
© EAC 2021  – All rights reserved  iii 
 Foreword  
Development of the East African Standards has been necessitated by the need for harmonizing requirements 
governing quality of products and services in the East African Community. It is envisaged that through 
harmonized standardization, trade barri ers that are encountered when goods and services are exchanged 
within the Community will be removed.  
The Community has established an East African Standards Committee  (EASC)  mandated to develop and 
issue East African Standards  (EAS) . The Committee is comp osed of representatives of the National 
Standards Bodies in Partner States, together with the representatives from the public and private sector 
organizations  in the community .  
East African Standards are developed through  Technical Committees that are rep resentative of key 
stakeholders including government, academia, consumer groups, private sector and other interested parties. 
Draft East African Standards are circulated to stakeholders through the National Standards Bodies in the 
Partner States. The comme nts received are discussed and incorporated before finalization of standards, in 
accordance with the Principles and procedures for development of East African  Standards.  
East African Standards are subject to review, to keep pace with technological advances . Users of the East 
African Standards are therefore expected to ensure that they always have the latest versions of the standards 
they are implementing .  
The committee responsible  for this document is Technical Committee EASC/TC 061, Textiles, textile prod ucts 
and accessories . 
Attention is drawn to the possibility that some of the elements of this document may be subject of patent 
rights. EAC shall not be held responsible for identifying any or all such patent rights.  
This second edition cancels and rep laces the first edition (EAS 256 :2001 ), which has been technically revised. 
The main changes compared to the previous edition are as follows:  
— A clause on normative references has been added;  DEAS 256 :2021  
iv © EAC 2021  – All rights reserved  
 Introduction  
In the textile industry, yarns and fabrics undergo trea tments during manufacture in the course of which 
extraneous matter of various types is gathered by or added to the original textile material.  The standard, 
therefore, lays down standard methods for estimating the quantity of each and for determining the w ater-
soluble matter, which if present beyond certain limits in the textile materials adversely affect their quality.  
 DRAFT EAST AFRICAN STANDARD  DEAS 256 :2021 
 
© EAC 2021  – All rights reserved  1 
 Textiles — Method for determination of scouring loss in grey and 
finished cotton materials   
1 Scope  
This D raft East African Standard  describes two methods for determining the scouring loss (loss in mass on 
scouring) of grey and finished cotton textile materials . 
The methods apply to grey and finished cotton textile materials wherein only starch or tamarind kernel powder 
or both, and wate r-soluble or easily removable finishing agents, such as fats, and china clay have been used 
and which would normally be removed during the scouring process.  
2 Normative references   
There are no normative references in this document.  
3 Terms and definitions   
No terms and definitions are listed in this document.  
ISO and IEC maintain terminological databases for use in standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
4 Principle  
The test specimen  is taken and its moisture content is determined. Another test specimen is scoured, washed 
and its oven -dry mass is determined. The scouring loss is calculated on the basis of oven -dry mass of the test 
specimen.  
5 Sampling  
Samples shall be selected so as t o be representative of the lot. Samples drawn in accordance with the 
procedure laid down in the specification of the material shall be taken as representative of the lot.  
6 Apparatus  
6.1 Soxhlet apparatus  
6.2 Drying Oven  — Capable of maintaining a tempera ture of 105 ± 3°C.   
6.3 Weighing balance  — Capable of weighing to an accuracy of 0.001 g.   
6.4 Weighing bottle  DEAS 256 :2021  
2 © EAC 2021  – All rights reserved  
 6.5 Desiccator  
7 Reagents  
7.1 Analytical reagent grade chemicals shall be employed in test and distilled water shall be used where the 
use of water is intended.   
7.2 Desizing enzyme  — Diastase (or other suitable enzyme).   
7.3 Sodium chloride  — Solid.   
7.4 Caustic soda solution  — 2 % (m/v), containing 1 per cent turkey red oil Grade 2 (total fatty matter, per 
cent by mass, min. 50 per cent). 7.5 Acetic acid solution  — 1 per cent (v/v).   
7.6 Trichloroethane or dichloromethane .  
8 Estimation of moisture  
8.1 Draw from the sample (see Clause 4) at least two specimens (see NOTE), each weighing 
approximately 3 g. Take one test specimen and weigh it  accurately in a clean, dry and tared weighing bottle. 
Place the weighing bottle containing the test specimen in the drying oven and dry the specimen at 105 ± 3° C 
to constant mass. Cool it in a desiccator to room temperature and weigh the oven -dry specime n accurately. 
Calculate the percentage of moisture in the test specimen, by the following formula:  
 
where,  
a = original mass, in g of the test specimen, and   
b = oven -dry mass, in g of the test specimen.   
NOTE  If the sample under test is fabric, the spe cimens drawn shall preferably be square in shape.  
8.2 Similarly determine the moisture content in the second test specimen and take the average of the two 
values.  
9 Preparation of test specimens  
9.1 Draw from the sample at least two test specimens each wei ghing about 5 g. If the sample under test is 
yarn, cut each test specimen separately into pieces about 15 cm long, form into separate bundle loosely round 
the middle. If the sample -under test is fabric, trim each test specimen parallel to the directions o f warp and 
weft and pullout, to form a fringe, 5 threads all round.   
10 Procedure  
10.1 Method A (Severe Method)   
10.1.1  Weigh accurately one test specimen drawn as in 8.1. Dip the specimen in a solution (weighing 20 
times the mass of the specimen), cont aining, 5 g of diastase and 10 g of sodium chloride per litre, at 50° C 
and at a pH of 6.5 to 7.7 (see Notes 1 and 2). Allow the specimen to remain in the solution for 1 h 30 min. 
During this period, take it out from the desizing bath and wring it by hand four times. At the end of the period, DEAS 256 :2021  
© EAC 2021  – All rights reserved  3 
 remove the specimen, wash it thoroughly (without wringing) four times in hot and cold water successively, 
using  50 ml of water for each wash.  
NOTE 1  The temperature and pH given for the desizing solution are the optimu m for bacterial diastase. If any other 
type of desizing enzyme is added, then the temperature and pH should be modified to that recommended by the supplier. 
As many enzymatic desizing agents slowly deteriorate in storage, great care should be taken to see that the sample of 
desizing agent, at the time of test, is of satisfactory desizing efficiency.   
NOTE 2  If any doubt exists as to whether the size or finish has been completely removed, the treatment with the 
enzymatic de sizing solution should be repeate d, the specimen being again weighed after drying to constant mass at 105 
± 3 °C and the percentage loss in mass again calculated. If the percentage loss in mass has increased by not more than 
0.25, then it may be considered that complete desizing has been affected and the second figure be accepted as the final 
figure. If the percentage loss in mass has increased by more than 0.25, then the desizing treatment should be repeated 
until the figure for percentage loss in mass does not differ from the previous fi gure by more than 0.25.   
10.1.2  Put the specimen in a 500 -ml conical flask containing caustic soda solution (see 6.4) weighing 20 
times the mass of the specimen and boil for one hour. Add adequate quantity of water to make up for the loss 
during boiling. At the end of the period remove the specimen, wash it thoroughly (without wringing) in hot 
water and dip it for 5 minutes in acetic acid solution (see 6.5). Finally wash (without wringing) the specimen in 
cold water. Dry the specimen in a drying oven at 10 5 ± 3°C to constant mass, cool it in a desiccator to room 
temperature and weigh it accurately.  
10.2 Method B (Mild Method)   
10.2.1  Weigh accurately one test specimen drawn as in 8.1. Extract the specimen for one hour with 
trichloroethane or dichloromethan e in a Soxhlet apparatus at the rate of 6 cycles per hour. Allow the 
trichloroethane or dichloromethane to dry off in the air, and wash the specimen by alternate immersion in hot 
running water and wringing by hand 12 times in succession. Immerse the specim en in 0.5 per cent aqueous 
solution of diastase (20 to 30 times the mass of the specimen) at 50° C and wring by hand repeating the 
process three times in succession. Finally, return the specimen to the solution and heat to 70°C. Allow the 
specimen to remai n in the solution for 15 minutes and then wash it well in hot running water. Squeeze and dry 
the specimen at 105 °C ± 3 °C and cool it in a desiccator to room temperature.   
11 Calculation   
11.1 Calculate the percentage of scouring loss by the following f ormula:   
 
where;   
M1 = original mass in g,   
m = moisture content, per cent (see 8.1), and   
M2 = oven -dry mass in g of the specimen after treatment (see 10.1 or 10.2).  
11.2 Repeat the test with the remaining test specimen(s) and find out the average of  all the values.   
12 Report  
The report shall include the following information:   
a) Type of material;   DEAS 256 :2021  
4 © EAC 2021  – All rights reserved  
 b) Method used (A or B);   
c) Scouring loss, per cent; and   
d) Number of test specimens tested.  DEAS 256 :2021  
© EAC 2021  – All rights reserved  5 
 Bibliography  
EAS 256 :2001, Textiles — Method for determination o f scouring loss in grey and finished cotton materials  
 DEAS 256 :2021    
 
© EAC 2021  – All rights reserved  
  
  