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

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

4. 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

5. 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

6. 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

7. Pilling Resistance
PH 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.

8. 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)

9. 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

10. 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.

11. 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.

12. 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.

13. Recipe preparation in lab dip
Common Stock Solutions:
1. Red – 0.1%, 0.5%, 1.0%, 2.0% (very common)
2. Yellow – 0.1%, 0.5%, 1.0%, 2.0% (very common)
3. Blue – 0.1%, 0.5%, 1.0%, 2.0% (very common).
Preparation:
i. To prepare 0.1% Stock solution, it is necessary to mix 0.1 g dye and 100
cc water.
ii. To prepare 0.5% Stock solution, 0.5 g dye stuff is mixed with 100 cc
water.
iii. To prepare 1.0% & 2.0% Stock solution similar procedure is followed.
iv. 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.

14. 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

15. 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.

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

17. 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.

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