Determination of Dimensional changes of fabrics containing wool on soaking in water

Dimensional changes of  fabrics containing wool on soaking in water

Dimensional changes of  fabrics containing wool on soaking in water


  1. Container (100mm deep and sufficient Area to Sample horizontally)
  2. Steel rule graduated in millimeters.
  3. Flat horizontal surface (100mm longer in  each direction)
  4. Trays (mesh 10mm on which specimens are dried and condition)  



  1. Sodium Hexametaphosphate 
  2. An efficient wetting Agent For example Sodium dioctyl sulpho-succinate or Dodecylbenzene sodium Sulphonate. 
  3. Distilled water 


  • 1 (not less than 500X500mm)


  1. Do not take any specimen within 1m of either end of the piece.
  2. Do not take samples with selvages.
  3. For knitted fabrics make up the specimens in double thickness, sewing the
  4. Free edges.   


1. Condition the sample to moisture equilibrium in standard atmosphere temperature 27±2oC and HR 65± 2 %.for 24 hours.

2. Determine the mass of the specimen.

3. Lay the conditioned specimen without stretching on the flat surface and measure and record.

4. Soak the measured specimen laid flat for one hour at 35 to 37oC in water to which added 0.5 g/liter of wetting agent 

5. After one hour, pour off liquid remove the specimen without distortion from the tray.

6. Place it flat on a towel in this process handle the specimen with care. The most convenient method is to fold the corners to the center so that the whole sample is on the towel.  

7. Remove the excess moisture by lightly pressing another towel on the tap of the specimen.

8. Dry it at room temperature and condition it to the wet side in the standard atmosphere.

9. Lay the dried, conditioned specimen on the flat surface and remeasure and record the distances between corresponding reference points to the nearest millimeter.

10. Repeat the above procedure with the remaining test specimens.


                                          100 (b-a)

Dimensional change, % = ————



                   a – Mean original dimension before treatment for each test specimen and

                   b – Mean final dimension after treatment for each test specimen

12. Calculate the Mean of dimension changes of all the specimens separately in each direction.

13. Express the Mean of dimension change, percent in each direction to nearest      0.25 percent.


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