Estimation of Bleaching Effect on Cotton Fabric by Measurement of Reflectance
Chittagong Textile Engineering College
Bleaching is the process by which natural color of cotton fabric are destroyed. So that fabric will be more bright & light reflectance will be more before one. Also absorbency is increased because sodium hydroxide is used to increase the pH value and which remove oil, fat wax etc. In this article I will estimate bleaching effect on cotton fabric by measurement of reflectance.
The bleaching effect is measured by two ways-
- Measurement of reflectance.
- Measurement of whiteness.
Measurement of whiteness in case of hypochlorite bleaching. But we used hydrogen peroxide so we will measured only measurement of reflectance.
- To know about the bleaching process.
- To know about the estimation of bleaching effect.
- To know about the Measurement of reflectance.
- To know about the process of estimation.
- At first fabric have to be Bleached.
- Stabilizer —————————– 4.5 gm/L
- NaoH ——————————– 8 gm/L
- Na2CO3 —————————- 5gm/L
- Detergent —————————- 1 gm/L
- Anticreasing ————————–1 gm/L
- Sequestering agent ——————- 1 gm/L
- Wetting agent ———————— 1 gm/L
- M : L ———————————1 : 10
- Temp x time ————————–100 0C x 30′
Sample weight = 9.64gm
Total liquor = 9.64 x 10 = 96.4 ml
Water = 96.4- (8.676+4.338+7.112+4.82+1+1+1+1) = 67.454≈68 ml
ESTIMATION OF BLEACHING EFFECT
Measurement of Reflectance: When a fabric is bleached, its light reflecting capacity increases. The reflectance of a bleached fabric is measured by spectrometer. It can measured light reflectance of fabric and can give reflectance curve.
Standard range of reflectance 85% (84%-86%) up to 90%.
A range of 90-94% reflectance is also possible in a high temperature treatment in a kier (120 0C). In high temperature bleaching, we can get high range of bleaching but high temperature bleaching is a risky.
Reflectance Curve & % of Reflectance:
We see that from above chart of reflectance of scoured and non-scoured sample are increased at small amount. And amount of hydrogen per-oxide reflectance are increased respectively but we see that there are vary difference of last person experiment i.e. amount of hydrogen per-oxide 11gm/L used and reflectance is less than from all but there would be more reflectance from others. So I think that there may be problem in his experiment. So we should that, more attention have to be maintain during experiment.
Also in most case, scouring is above 85 at 700 nm which can be said good scouring.
At last we can say that, how to estimate of bleaching effect is known by this experiment. Knowledge is gained from this experiment which is very helpful in our practical life. Special thanks to our honorable teacher who has been help us to complete this experiment.
You may also like:
- Estimation of Scouring Effect by Weight Loss and Absorbency Test
- How to Determine the Strength of HCl
- Determination of Copper Numbers by Copper Number Test of Cellulosic Materials
- Detergency of Soap: Potential Uses of Detergent in Textile Wet Processing
- Factors Influencing the Functions of Optical Brighteners
- Different Types of Textile Chemical Testing Procedure
- How to Determine the Strength of Hydrogen Peroxide (H2O2)
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.