Dyeing lab

Lab dip is a process by which buyers supplied swatch is matched with the varying dyes percentage in the laboratory with or without help of “DATA COLOR” 
Lab dip plays an important role in shade matching & and detaching the characteristics of the dyes and chemicals are to be used in the large scale of production. So this is an important task before bulk production.

1. Dyeing Lab MD.Khairul Bashar

2. Dyeing Lab Physical Testing Lab Dip/Chemical Tests Mechanical Physical Tests »   GSM »  Fiber Diameter »  Ends per inch »  Linear Density

3. Chemical »  PCP »   Blend composition »   Identification of Fiber »   Identification of Dyes »   Solvent Extractable matter »   Chloride Content »   Sulphate Content »   pH value of water extract »   Moisture Content »   Shrinkage to Water »   Colour Fastness Tests

4. Mechanical »   Tensile Strength and Elongation »  Breaking Strength »  Bursting Strength of Paper »  Tear Strength »  Elmendorff Tear Strength »  Air permeability of Paper »  Pilling Test »  Dry and Wet Rubbing (Crock Meter)  »  Ether Soluble Matter »  Water Absorbency »  Lead and its compounds »  Scouring loss »  Flammability

5. Generally some Testing here Dimensional Stability to washing(Shrinkage) Spirality /Twisting Colorfastness to washing Colorfastness to Water Colorfastness to Perspiration Colorfastness to Rubbing/Crocking Colorfastness to Saliva Colorfastness to Actual Laundering Print Durability Other Tests (please secify ) Fabric Weight Thread Count

6. Pilling Resistance P H Test Yarn Appearance Yarn Count Quality Control Testing Broad range of testing facilities are available for finished products, materials or components based on defined standards, regulations and customer's requirements.

7. Standard Methods adopted »   American Society of Testing &Materials (ASTM) »  American Association of Textile Chemists and Colorists (AATCC) »  International Organization for Standardization (ISO) »  European Norms (EN) »  British Standards (BS) »  British Standards for European Nations (BSEN)  »  Deutsches Institut fur Normung (DIN)  »  Japanese Industrial Standards (JIS)  »  Bureau of Indian Standards (BIS)

8. Shrinkage test Method Shrinkage: Shrinkage is the process in which a fabric becomes smaller than its original size, usually through the process of laundry. Cotton fabric suffers from two main disadvantages of shrinking and creasing during subsequent washing. There are two types of shrinkage occurs during  washing 1) Length wise  2) Width wise Shrinkage % = (length of fabric before wash)-(length of fabric after wash))/ (length of fabric before wash) *100 

9. Example: For Length , length of fabric before wash=55 cm length of fabric after wash=52 cm So, Shrinkage % = 55-52=3/55*100% =5.45 % For Width , Width of fabric before wash=36 cm Width of fabric after wash=35cm So , Shrinkage % = 36-35=1/36*100% =2.77% Here, Shrinkage is 5.45%. Normally shrinkage is acceptable less than 5%. But it Can Be change in case of buyer requirement. 

10. DYEING LAB DEPARTMENT CALCULATION AND OTHERS Lab dip is small swatch of fabric to define color and its recipe before it goes for bulk  dyeing . Developing Lab dip is one of the primary jobs for a  merchandiser to start an order execution. Lab dip is very important for dying factory. Because bulk production order depends on lab dips. Besides, lab dip plays an important role in shade matching & this is an important task before bulk production. 

11. Lab Dip : Lab dip is a process by which buyers supplied swatch is matched with the varying dyes percentage in the laboratory with or without help of “ DATA COLOR ”  Lab dip  plays an important role in shade matching & and detaching the characteristics of the dyes and chemicals are to be used in the large scale of production. So this is an important task before bulk production.

12. Recipe preparation in lab dip Common Stock Solutions: Red – 0.1%, 0.5%, 1.0%, 2.0% (very common) Yellow – 0.1%, 0.5%, 1.0%, 2.0% (very common) Blue – 0.1%, 0.5%, 1.0%, 2.0% (very common). Preparation: To prepare 0.1% Stock solution, it is necessary to mix 0.1 g dye and 100 cc water. To prepare 0.5% Stock solution, 0.5 g dye stuff is mixed with 100 cc water. To prepare 1.0% & 2.0% Stock solution similar procedure is followed. To prepare 10% Stock solution of Soda ash, 10 g Soda is mixed with 100 cc water. Depth of Shade:    0.5% to 5% shade for the goods.

13. Lab Dip Calculation  : Usually following calculations are followed: Dye Solution  = (Shade % * Sample Weight) / (Stock solution %)   (cc).  Salt  = (Shade % * Liquor) / 1000  (gram per liter, gpl ).  Soda Solution  = (Shade % * 100 * Liquor) / (1000 * Stock solution %)    (cc).  Sample Calculation for 0.5% Shade:  Sample wt.  = 5 mg  Material liquor ratio  = 1: 10  Total liquor  (5 * 10) = 50 cc  Dye solution required  = (5 * 0.5%) / 1% = 2.5 cc  Salt solution required  = (50 * 25) / (20 * 10) = 6.25 cc  Soda ash solution required  = (50 * 10) / (20 * 10) = 2.5 cc  Water required  {50 – (2.5 + 6.25 + 2.5)} = 38.75 cc 

14. Lab Dip: A lab dip is a swatch of fabric test dyed to hit a color standard . It is a process by which buyer’s supplied swatch is matched with the varying dyes percentage in the laboratory with or without help of   spectrophotometer.  Lab dip plays an important role in shade matching & this is an important task before bulk production. In previous article of this author we have to learn on  flow chart on dyeing lab .

15. Objectives: The main objectives in lab dip are as follows:  To calculate the recipe for sample dyeing. To compare dyed sample with swatch by light Box or Spectrophotometer. To calculate revise recipe for sample dyeing. Finally approved Lab Dip (Grade: A, B, C & D)

16. Process Sequence of Lab Dip : Lab Dip Requisition from buyer  ↓  Entry in the computer  ↓  First recipe is given by swatch/pantone number  ↓  First correction  ↓  Second correction  ↓  Grading of sample (A, B, C, D)  ↓  Yarn and knit sample send to buyer  ↓  Approved by buyer  ↓  Order for bulk production  ↓  Production card with approved sample and recipe send to production section.

17. Referance : Lab, Book, Internet, etc.