Home

Textile Testing Methods

In any good dye house a Quality Control and Quality Assurance systems should go hand in hand. The knowledge of QC operations should lead to the formation of good QA systems.

Let us discuss with some of QA and QC operations, test methods, frequency etc in details.

Let us list down the important QA and QC points and relevant test elements to be considered, as below:
 

Quality Assurance Elements: 
In QA elements we should consider the quality of all raw materials, right from the processing of fabric or yarn to all the dyes and chemicals used and in QC elements we should test the quality of finished products for the required level of standards. In both cases the following Textile Testing Methods can be applied for.

I. Raw Materials and other inputs:
     1.  Water Quality
           a. Hardness
               i. bi-carbonate
               ii. Carbonates. sulphates and chloride
          b. TDS (Total Dissolved Solids)
          c. Turbidity
          d. Other metals –iron, copper

     2. Quality of Auxiliary Chemicals used.
          a. Quality of surfactants like wetting, scouring agents
              i. Wetting time of wetting agents
              ii. Solid content
              iii. Ionic nature
              iv. Cloud point of non-ionic products
              v. foaming characters
         b. Quality of sequestering agents
              i. Chelating power
              ii. pH
              iii. solid content
         c. Quality of leveling/dispersing agents
              i. Ionic nature
              ii. concentration required
              iii. solid content
              iv. suitability for metal complex dyes
        d. Quality of Peroxide Stabilizers
              i. Solid content
              ii. Concentration required for bleaching
        e. Quality of peroxide killers
              i. Whether it is an enzyme or inorganic product
              ii. concentration required for treatment
              iii. If it is enzyme, get the test method from the manufacturer himself.
        f. Quality of Cationic dye fixing agents
               i. Solid content
               ii. Free Formaldehyde content
               iii.. Degree of Change in tone of a shade
               iv. How much light fastness is affected?
         g. Quality of Softeners
               i. Ionic nature
               ii. Degree of softness acquired for a standard concentration
               iii. Degree of tone change of a shade
               iv. wash Durability. Solid content

         h. Determination of Acid Value of a product?
               Detailed method to find out the acid value of a product      

          i. Determination of Polymer content of a binder?
               Detailed method to find out the polymer content of a binder.      

         j. Quality of Dyestuff:
               Dyestuff properties and selection method for a combination

    2. Quality of Basic Chemicals used and its concentration. 
                   i    Caustic soda – purity and concentration percentage
                   ii   Soda Ash – purity and concentration
                   iii. Acetic Acid, Hydrochloric acid, Sulphuric acid, Oxalic acid – purity and concentration
                   iv. Hydrogen Peroxide – purity and concentration
                   v.  Common Salt – purity, hardness of a particular concentration
                   vi. Sodium Hypochlorite - concentration
    3. Test for Iron and Copper in cotton fibre

II. Quality Control Elements:

    1. Physical Properties:
           a. Appearance – color and uniformity of finished yarn or fabric - visual assessment only.
           b. Tensile strength of finished yarn
           c. CSP of finished yarn
           d. Tear strength of finished fabric
           e. GSM of fabric of finished
           f.  Shrinkage Test of Woven fabric and Knit fabric.

    2. Finished goods’ Qualities:

1. What is a Grey Scale and Staining Scale? How Fastness grading is done?
2. Fastness to Washing
3. Fastness to Crocking or Rubbing fastness
4. Fastness to water
5. Fastness to perspiration
6. Fastness to peroxide bleach
7. Fastness to Chlorine or Chlorinated Pool water fastness
8. Fastness to Mercerising
9. Fastness to Hydrolysis
10. Fastness to Dry-cleaning
11. Fastness to light
12. Pilling Tests
13. What is whiteness Index
14. What is total color difference or DE
15. Method of Detecting Starch and PVA
16. Method of testing desizing efficiency
17. Measurement of Absorbency
18. Antimicrobial Tests
19. Flammability Test