mercerization effect

1. MERCERIZATION
BY
ASAD SALEEM

2. John Mercer invented a process which gives cotton a lustre
resembling silk - a process known as 'mercerization'.
John Mercer (1791-1866)

3. Mercerizing Definition :
The treatment of cellulosic textiles in yam or fabric form with a
concentrated solution of ammonia(NH3) (or) caustic alkali whereby
the fibers are swollen, the strength and dye affinity of the materials
are increased.
Mercerization

4. Types of Mercerization
APPLICATION STEPS:-
The whole process can be divided into four steps
Step #1:- Impregnation – fabric is impregnated
with liq. Ammonia
Step #2:- Aged time—fabric is aged under
tension
Step #3: - Drying—fabric is dried under tension.
Step #4:- Recovering of ammonia -- ammonia
recovered and reused.

5. APPLICATION
• Mercerization is widely used, and in the
mercerization of different kinds of cellulose products,
including blended products, the machine used and the
treatment conditions must be selected in accordance
with the type of fiber, the form that it is in and its
properties, and also in accordance with the aims and
the timing of the mercerization.

6. Generally 2 types of
mercerization
• NAOH(caustic soda)
• NH3(ammonia mercerization)

7. AMMONIA MERCERIZATION
Ammonia solution is used for swelling the
fabric (or) yarn this process is called ammonia
mercerization.
In this process ammonia is penetrate in the
fiber & effect the crystalline and amorphous
region of the fiber and swell them.

8. Objective
 To improve strength and mechanical properties.
 To improve luster
 To improve dye ability and moisture absorbency
 To improve dimension stability.
 Improving elasticity
 Improve smoothness
 Improved reactions with variety of chemicals

9. RECOVERY OF AMMONIA
Mercerization is possible
- after desizing
- after desizing and scouring
- after bleaching
The ammonia recovery is the key element to the cost
efficient operation of this process., Morrison developed a
process that results in the minimal amount of aqueous
ammonia by-product. Aqueous ammonia can only be
disposed of by shipment to fertilizer plants or other non-
textile process that can use this liquid, or, it must be
recovered in an expensive distillation process.

10. ADVANTAGES
ADVANTAGES OF LIQUID AMMONIA MERCERIZATION:
Following are main advantages of using the liquid
ammonia for mercerization instead of NaOH.
• Improved strength (up to 90%)
• Enhance luster
• Better dye ability
• Stability to laundering greater thermal resistance
.

11. DISADVANTAGES
WHY LIQUID AMMONIA TREATMENT IS NOT SO POPULAR:
The liquid ammonia(NH3) treatment is not too popular
in the textile industry and (NaOH) is used commonly
to mercerize the cotton.
 To keep liquid ammonia in liquid form it must stored
below 33 OC.
 It forms explosive moisture with air
 When leakage in machine it is highly affected to
workers.

12. Note: Fabric Mercerization is Cheaper than double Mercerization which provides a softer hand
Mercerization

13. MORRISON'S LIQUID AMMONIA PROCESS
AMMONIA RECYCLE
• Liquid ammonia (NH3) is pumped into the treating bath.
• Ammonia gas from the heat treatment is pumped out to the
recovery unit.
• Recovery unit converts the gas back to liquid form for re-use.
• Residual gas, air and steam that cannot be recycled goes to a
secondary recovery system for other chemical uses.

14. In mercerizing followings are important:
 Temperature
 Tension
 Time
Factors of Mercerizing:

15. (1) Temperature:
High degree of luster is attained at temperature 18-20 C. As
the temperature is increased the quality of luster is adversely
affected but on lowering the temperature no improvement in the
luster is obtained.

16. (2) Tension:
For acquiring better luster the material must be stretch to its
original dimension (both in warp and weft direction during
mercerization)..
(3) Time:
The optimum time for mercerizing is depend upon fiber, which
fiber we use for this process, seconds by increasing the duration of
time no applicable improvement in the quality of mercerization can
be achieved

17. A. Fiber level
1. Swelling
2. Cross sectional morphology changes from beam shape to round
shape.
3. Shrinkage along with longitudinal direction.
B. Molecular level
1. Hydrogen bond readjustment
2. Orientation (parallelization) of molecular chains in amorphous
region along the direction of fiber length.
3. Orientation of the crystalline in the direction of the fiber length.
Changes during mercerizing process

18. Generally non crystalline type of wetting agents are
used in mercerizing,
which Gives uniform wetting and better penetration
of ammonia liquor of mercerizing.
Properties of wetting agents in mercerizing

19. Study of Mercerizing machine.

20. Machine name: Jaeggli-Meccanotessile
Manufacturer: COMO-Italia
Machine type: HD-2000 / HL-2000
Serial no.: 0008/021
Years of manufacture: 2001
Yarn Mercerizing Machine

21. Fabric Mercerizing
Brand Name: Dornier
Origin: Germany
Type: CM B/2
Serial No.: 100625
Year: 1999
Maximum Width: 36 inch