Denim finishing

2. Presented by
Md.Ibrahim Khalil
Intake:19
Department of Textile Engineering
Bangladesh University of Business & Technology

3. Presentation On
Denim Finishing

4.  Introduction of Denim Finishing
 Generally denim fabric is a 100% cotton woven fabric and
exceptionally solid and strong. Denim fabric is courser than as
usual woven fabric. Normally courser yarn is used for making
denim fabric. The look and nature of the denim fabric should
be enhance subsequent to coloring. Generally blue denim is
twist-confronted cotton fabric with 3 × 1 twill development with
the twist colored in a strong shading and the weft left
uncolored. Denim fabric is widely accepted fabric for its
appearance and durability. In this article we will discuss about
different finishing process of denim fabric.

5. Provide aesthetic value
Soften fabric or change the hand
Adds to durability
Adds to comfort
Provide safety
Improves performance
Why Finishing of Denim

6. Singeing
Overdyeing
Preshrinking
Calendaring
Mercerizing
Softening
Foam finishing
Resin applications
Coating
Some of the major finishing processes for denim fabrics

7. Singeing:
Singeing is a process that uses a gas flame to burn
off the fluff or tiny hairs on the surface of denim
fabric. This process burns away surface material that
makes the fabric look fuzzy. It is carried out to obtain
a cleaner and smoother appearance of denim
fabrics. This process enhances the color, and the
fabric wettability is also increased.

8. Overdyeing:
Traditional indigo dyed denim fabric can be overdyed
as part of a finishing process. Overdyeing can take
place between desizing and the addition of softeners.
The best results, however, are achieved after stone
washing and subsequent bleaching. The preparation
requirements for overdyeing are the same as for any
other dyeing process.

9. Calendering:
Calendering is a processes in which denim fabric is
passed between rollers or calenders, usually under
controlled heat and pressure, to produce a variety of
surface textures or effects in fabric such as
compactness, smoothness, glazing, etc. The process
involves passing the denim through a calender in which
a highly polished, usually heated, steel bowl rotates at a
higher speed than the softer bowl against which it
works, thus producing a glaze on the face of the fabric
that is in contact with the steel bowl.

10. Mercerising:
Mercerisation is an industrial process involving sodium
hydroxide for cotton yarns or fabrics to increase the lustre and
dyeability. But the mercerisation of denim is usually carried out
after the denim is woven, and so it is different from the more
common method of mercerising cotton yarn. Mercerisation of
denim may be used for achieving ring dyeing thus keeping the
dye on the surface of the yarns or fabrics and to prevent dyes
from fully penetrating the fibres. In addition to increasing the
fabric lustre, it also improves its strength. As it significantly
increases the cost and lead times of denim production, at
present, it is a relatively rare process.

11. Softening:
Due to the removal of impurities such as wax, paraffin and oil
after pretreatment processes, denim fabric loses its natural
hand feel and therefore it is necessary to regain its softness.
Softeners improve abrasion resistance, increase tearing
strength and diminish the risk of stitching thread and needle
breakage during garment sewing. A wide range of softeners is
used in the aftertreatment of denim fabrics. The major softener
types are cationic, anionic, nonionic, silicones and special
softeners.

12. Resin applications:
Resin is a chemical solution that fills into the
amorphous area of a fibre, penetrates thorougly by
drying and curing and polymerises inside the fibres.
The resin amount, fixation temperature, pH and
process time are the critical parameters of a proper
resin application on denim fabric. A post curing can
activate the resin after garment production.

13. T

14. Any Question