title>Desizing Efficiency Testing Method- TEGAWA rating

Test for desizing efficiency - TEGAWA rating


Desizing Efficiency Test:
Desizing efficiency is found in two ways conventional and TEGEWA method.

Conventional Method:

In this method we first take the weight of the sized fabric, let it be W1. Then desize the fabric, dry & take the weight, let it be W2. After that the fabric is treated with 3gpl (35%) HCl at 700 C for 30 min. dry & take the weight of the fabric. Let it be W3.

Total size = W1-W3.

Residual size = W2-W3.

Desizing Efficiency = (Total size – Residual size)/Total size X 100.


Reagent: potassium iodide (10 gm. Of KI (100%) in 100 ml water, add 0.6358 gm of iodine (100%) stir and shake; iodine is completely dissolved. Fill up to 800 ml with water then complete to 1000 ml with ethanol. (Shelf life approx 6 months only).


1. Spot drop wise solution onto fabric.

2. Rub in gently.

3. Assess change of color.

Note: the test must be carried on fabric cooled down to room temperature; residual alkalinity has to be neutralities prior to the test.

Grey fabric:

No change of color = no starch size present.

Pale blue to bluish = presence of starch size or blend

Violet =of starch size with synthetic size

Desized fabric:

Pale blue to bluish violet = refer to violet scale TEGEWA This indicates residual Starch content.