Academic

1. TEXTILE FIBRE CONTENT
ANALYSIS

2. FIBRE CONTENT/COMPOSITION
Analysis of fibre content:
1) Qualitative analysis
2) Quantitative analysis (for blended material)
Qualitative analysis
1. By Flame/burn test
2. By solubility test

3. Blended yarn : It is the kind of yarn in which several types of fibers are mixed together. They exhibit
a blended characteristic which is entirely new. Mainly, two or more constituents
are blended together to get the product.
Blended fabric: It is created when two or more different kinds of fibres are mixed together to create
a new fabric with unique properties. ... Polyester and cotton, which combines the properties of
natural and synthetic fibres, is one of the most common blended fabrics.
Some common blends in textiles:
• Polyester/Cotton. (PC, TC or CVC)
• Nylon/Wool.
• Nylon/Acetate.
• Ramie/Polyester.
• Ramie/Acrylic.
• Wool/Cotton.
• Linen/Cotton.
• Linen/Silk.
*PC or TC= blends of polyester and cotton (amount of polyester>amount of cotton in blend)
*CVC (chief value of cotton)= blends of polyester and cotton (amount of cotton>amount of
polyester blend)

4. BLEND RATIO/BLEND PERCENTAGE OF
TEXTILES
Amount (on the basis of weight) of different fibres mixed together in a blend.
Example:
• 80/20 PC means a blend of polyester and cotton where the amount of
polyester is 80% and cotton is 20% of the total weight of the blend.
• 80/20 CVC means a blend of polyester and cotton where the amount of
cotton is 80% and polyester is 20% of the total weight of the blend.
*80/20 pc and 80/20 cvc is just opposite to each other according to
percentage of each component

5. Quantitative analysis of different fibres in common blend:
A blend contains two fibres: i. A and ii. B
Let,
Percentage amount of ‘A’ fibre in the blend=PA
Percentage amount of ‘B’ fibre in the blend=PB
Total dry weight or initial weight of the material= x
Oven-Dry weight of fibre ‘B’ (after dissolving ‘A’) = yB
So, PB=
𝑦𝐵
𝑥
𝑋 100 %
PA=
(𝑥−𝑦)
𝑥
X 100% or,
PA= 100-PB
NB:
*YA +YB = X
* PA + PB =100
* Oven-dry weight/dry weight": The constant weight of textile material obtained by drying at a temperature of 105 Oc.

6. Textile Fibres
Solvent
Concentration.(%) Temp(oC) Time(min)
Cotton Sulfuric acid 70 38 20
Polyester m-cresol 100 139 5
Wool Sodium hypochlorite 5 20 20
Acrylic
Dimethyl formamide
(DMF) 100 90 10
Nylon
Formic Acid 85-90 20 5
Hydrochloric acid 20 20 10
Silk Sodium hypochlorite 5 20 20
Sulfuric acid 60 38 20
Acetate Acetic acid 100 20 5
Spandex
Dimethyl formamide
(DMF) 100 90 10
Viscose Sulfuric acid 60 38 20

7. Practice math:
1. A 25 gm sample of Cotton and acrylic blended sample was treated in a solution of 70%
sulphuric acid. After dissolving the cotton part, the residual dry mass acrylic was found to be 5
gm. Find the blend ratio or blend percentage of each content in the blend.
(Ans: cotton/acrylic: 80/20)
2. A sample of 60/40 p/c blended fabric gives an oven dry weight of 15 gm after dissolving
with 70% sulphuric acid. Find i) the total weight of the sample and ii) other fibre weight in the
blend.
(Ans: 25 gm, 10 gm)
3. A sample of 75/25 CVC blended fabric gives an oven dry weight of 23 gm after dissolving with
m-cresol. Find i) the total weight of the sample and ii) other content weight in the blend with
name.
(Ans: 30.66 gm, 7.66 gm (polyester))
4. A sample of T/C blended fabric shows 20 gm in electric balance. Find out the oven dry weight
of residual fibre after dissolving with m-cresol. Given that percentage of cotton in the blend is
30%.
(Ans: 6 gm)

8. 5. A solvent of Sulphuric acid (59.5%) is used at 20oC for 20 min to separate a blend of Cotton/silk sample. After
dissolving one of them the dried solid mass gives 10 gm. The cellulosic content of the blend shows a value of 45% in the
blend. Find out the original weight of the content which was dissolved in 59.5% acid.
(Ans: 8.18 gm)
6. A sample of blended fabric contains an animal fibre and a manmade fibre and shows 15 gm in electric balance. i)
Find out the oven dry weight of animal fibre after dissolving with Dimethyl formamide. Given that percentage of manmade
fibre in the blend is 30% and the animal fibre can be dissolved in Sodium Hypochlorite. ii) Identify the two fibres.
(Ans: 10.5 gm, manmade fibre: Acrylic, animal fibre: wool/ silk)
7. A sample of blended fabric shows 25gm in electric balance contains two fibres ‘a’ and ‘b’. A solvent of Sulphuric
acid (59.5%) or 5% Sodium hypochlorite is used at 20oC for 20 min to separate them by dissolving ‘a’. If the ‘a’ fibre content
of the blend shows a value of 45% in the blend, i) find out the original weight of the other content which could be dissolved
in 100% meta- cresol. ii) Find out the name of fibres too.
(Ans: i) 13.75 gm ii) Polyester and silk )

9. 8. An Acrylic/wool blended fabric shows an oven dry weight of 0.05 ounce after treating with 5%
Sodium hypochlorite solution at room temperature. If the protein fibre content was 40% in the blend, then
find the initial weight of fabric sample taken.
(Ans: .083 ounce)
9. A sample of Nylon/Viscose blended fabric weighed as 1.0 gm. Find out the oven dry weight of
sample after dissolving with Formic acid. Given that percentage of Nylon in the blend is 85%.
[Ans: 0.15 gm]
…………..x……........