Calculation of Lab Dip | Working Process in Lab Dip

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.
 
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:
  • 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.

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

Working Procedure in Lab Dip:
All ingredients had been taken according to the recipe into the pot of sample dyeing machine. At a room temp the material had run then after 10 minutes started to rise the temperature at 1°C/ min. to get 60°C temperature. For performing the required dyeing temperature it took 30 minutes. The material had dyed at 60°C for 45 minutes. Then the temperature was reduced at room temperature within in 10 minutes. The fabric washed in cold water & then the material was washed in 1 gm/l soap solution (liquor ratio 1:20) at 90°C temperature for 15 minutes. Then after rapidly cold washing the material was dried & preserved. And then check the shade match with the required sample by the lighting box. Then send to buyer or merchandiser for approval.
Shade check in light box
 
 

1 comments:

Anonymous said...

Hi I'm doing lab dip approvals for a short period of time and I would like to get better at commenting..... When I say a lab dip is too dark or too light vs the standard what colors should I say to add or reduce for example say "too light add more -----" and too dark add more ----"

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