2. DEFINITIONS
• DENIM : A Firm 2/1 or 3/1 cotton twill-weave fabric with
dyed blue warp and raw white weft. ( similar to yarn dyed
fabric )
• Warp is dyed with indigo dyes .
• Various dyeing methods, recipes, concentrations, the
reactions and oxidation time influences the effect and
characteristics of the finishes
3. Basic Process line
Stone
washed
Desized
Fabric is
converted into garments
Sized Indigo-dye
warp and raw white weft
Woven in a 2/1 or 3/1 twill weave
4. Garment process
DENIM PROCSSING
DRY PROCESS WET PROCESS
Scraping Sand blasting KMnO4 Spray Acid wash
5. Dry process
• Sand blasting : to produce localized
abrasion
• Scraping : manual scraping using sand
paper or grinding machine as per design
• KMnO4 Spraying : an alternative blasting
technique
• Acid wash : use of thremocol ball and
bleach in a single belly machine
6. Denim Wet processing
• Desizing : a process intended to remove size finish
constituents from fabric before enzyme wash or
bleaching
• Abrasion : a process which facilitates the indigo dye to
be removed from the surface of the cotton fibre .
• Bleaching : a process intended to decolorize indigo by
using bleach liquor (NaOCl)
• Softener wash : to improve the hand feel of the garment
by cationic or silicone softener
7. Chemicals and their uses
• Non ionic wetting agent : to increase the absorbency of the
garments
• Lubricating agent : to avoid streak formation
• Amylase : an enzyme used to break down insoluble starch to
soluble glucose ( 90 % of sizing material contains insoluble starch )
• Pumice stone : used during denim washing to get the grain effect
( replaced by enzyme to large extent )
8. Continued …
• Anti back staining agent : to avoid re deposition of the indigo dyes
on the fabric surface
• Cellulase : an enzyme used to weaken the cotton fiber and hence
increase abrasion
• NaOCl : Sodium hypochlorite used to lighten the shade of indigo
• Laccase : enzyme used to decolorize indigo ( by converting indigo
into colorless compound called Isatin )
• Softeners : to improve hand feel and protect the denim from Ozone
9. Benefits of using enzymes
• Maximized fabric strength retention
• Stone free processing
• Fast processing
• Improved wash look
• No or less Garment damage
• No machine damage
• Easy handling and cost effective
10. Desizing
• MRL : 1: 5 to 1 : 10
• pH : 5 to 6.5
• Temp : 60 Deg C
• Time : 20 min
• Chemicals ad dosage :
• non ionic wetting agent ( 1 gpl )
• Lubricating agent ( 0.5 gpl )
• Anti back staining agent ( 0.5 to 1 gpl )
• Amylase ( 0.5 to 1 gpl ) ( enzyme for breaking down starch
into soluble glucose )
11. Abrasion
• MRL : 1: 5 to 1 : 10
• pH : 6.5
• Temp : 55 Deg C
• Time : 20 to 45 min
• Chemicals :
• Anti back staining agent ( 0.5 gpl to 1 gpl )
• Cellulase( 0.5 to 1 gpl )( enzyme for weakening cotton fiber
by converting the cellulase into glucose )
12. Bleaching
• MRL : 1: 5 to 1 : 10
• pH : neutral
• Temp : Room Temp
• Time : depends on the shade
• Chemicals :
• NaOCl
13. Bio bleach
• MLR :1:5 to 1:10
• pH : 4 to 5.5
• Temp : 60 to 70 Deg C
• Time :15 to 20 min
• Chemical used :
– Laccase :1 gpl to 2 gpl
14. Special finishes
• Pigment spray
• Direct and reactive dye tinting
• Transfer printing
• Rubber feel
• Indigo retention
• Permanent crease
• Raw ( or undesized ) look
