sunthesis cellulose acetate fiber

1. SYNTHESIS CELLULOSE
ACETATE FIBER
BY DRY SPINNING
by
Nguyễn Thị Cẩm Nhung
MSE- K56

2. OUTLINE
 Definition of dry spinning
 Reaction
 Raw materials
 Process
 Characteristics
 Applications
 References

3. Dry spinning
 The polymer is dissolved in
a volatile solvent and the
solution is pumped through
a spinneret (die) with
numerous holes (one to
thousands).
 As the fibers exit the
spinneret, air is used to
evaporate the solvent so
that the fibers solidify

4. Reaction of cellulose axetate (CE)
 Molecular: [C6H7O2(OH)3-m(OOCCH3)m], m = 0~3


5. Reaction of cellulose axetate (CE)
 Molecular: [C6H7O2(OH)3-m(OOCCH3)m], m = 0~3

6. Raw materials
 CELLULOSE: [C6 H7O2(OH)3]n from pulp
 ACETIC ACID: CH3COOH and ACETIC
ANHYDRIDE: CH3CHO
 SULFURIC ACID: H2SO4

7. Process: Fiber formation
 Purified cellulose from wood pulp or cotton linters.
 Mixed with glacial acetic acid, acetic anhydride and
a catalyst (sulfuric acid).
 Put through a controlled 20 hour partial hydrolysis to
remove the sulfate and the required amount of
acetate molecules to obtain the product’s desired
properties.

8. Process: Fiber formation

9. Process: Fiber formation
 Precipitated as acid-resin flakes
 Flakes is dissolved into acetone
 Solution is filtered

10. Process: Fiber formation
 The liquid substance of
cellulose is forced
through a metal cap
called a spinneret
 The filaments extruded
from the holes in the
spinneret, the liquid
polymer becomes
rubbery and then
solidifies by hot air
 Solvent recovered

11. Process

12. Process: Fiber formation

13. Process: Stretching & Orientation
 While extruded fibers are solidifying, or in some
cases even after they have hardened, the filaments
may be drawn to impart strength
 The filaments are stretched while till plastic to
increase strength
 The filaments are then spun into fiber

14. Characteristics
 Classify: diacetate fiber and triacetate fiber
 Diacetate (acetate): 74% - 92% hydroxyl has been
acetylated
 Triacatate: > 92% hydroxyl has been acetylated

15. Characteristics
 Feels natural and is gentle on the skin
 Elegant gloss and chromogenic quality
 Drapes lightly and flexibly
 Ideal water absorption and quick-drying qualities
 Does not shrink easily, so provides stability for
dimensions and measurements
 Strong pleating durability (triacetate)

16. Applications
 Fabrics: used for linings in suits or coats, for formal
wear including wedding gowns, ribbon

17. Applications
 Filter cigarette tow :good
filtration properties with
good acceptance of the
taste signature, good
biodegradability profile
 Separation technology
Drinking water
purification, waste water
treatment

18. References
 Synthesis of Material: An approach from Chemistry
Dr: Le Minh Thang, HUST, 2008
 www.kpatents.com
 Mitsubishi Rayon Textile Co. LTD
 Wikipedia. Org and other sourses