Dear Nomalungelo Sibisi,

Process

A rapid sample dyeing machine of “ROACHES” made in England can be used for dyeing (just one example). Dyeing of single jersey, 1×1 rib & pique 100% cotton knitted fabric can be done by using recipe such as (soda, salt, anticreasing agent, antifoaming agenet, detergent etc. ). After dyeing cold wash is performed for 2/3 times and normal hot wash is performed for 2/3 times followed by neutralization with acetic acid & rinsing. After hydro dyed samples can be dried using “Rapid” hydro machine for 3 minute & the maximum temperature of the machine may be around 140°C.

Color strength

Reflectance (%) of the dyed fabric samples can be measured by using Data color 650 TM spectrophotometer. Strength of any colorant (dyestuff / pigment) is related to absorption property. Use Kubelka–Munk theory which gives us the following relation between reflectance and absorbance:

K/S= [ {(1-R)2/2R}]

Where R is the reflectance, K is absorbance and S is the scattering. By using the above equation color strength of different samples were measured. K/S is color strength of textile. Color strength (K/S) of the dyed fabric also influenced by the increase of reflectance (%) value. When shade (%) increase, reflectance (%) & color strength (K/S) decrease.

Hope it work out for you.

Ashish

References:

Rita Kant, Textile dyeing industry an environmental hazard, Natural Science, Vol.4, No.1, 22-26 (2012).

Ashish Thakur thank you

but why do we need to test colour strength?

Dear Nomalungelo Sibisi,

Good morning.

K/S value is an important parameter of modern colorimetry, which can indicate the depth of the color of dyed fabric surface. Measurement of K/S value is easily and simple operation in the applied engineering. Color strength (K/S) is most important parameter to test the quality measurement of a sample in terms of depth of the color dyed fabric. If shade(%) is more your color depth is less and quality of textile does matter a lot for customer and selling manufacturer as well. Color strength yields quality control assurance system of a textile.

For shade matching, it's important to understand about the color tone. It's also important to know about the color combination by which color will be produced. So it makes the necessity of the color strength testing in a textile.

Color strength (K/S) of the dyed fabric influenced by the increase of reflectance (%) value. When shade (%) increases, reflectance (%) & color strength (K/S) decreases. If color strength is less that means shade % is high, and consequently fabric will not pass the textile quality assurance.

Hope it is clear for you.

Ashish

Ashish Thakur thank you so much