Lyocell, also known by the brand name Tencel, is a man-made cellulosic fiber produced by dissolving cellulose in an organic solvent without derivatization. It is produced from wood pulp through a solvent-spinning process using N-methylmorpholine N-oxide (NMMO) as the solvent. The manufacturing process involves dissolving cellulose pulp in NMMO, filtering the solution, extruding it through spinnerets into fibers, and removing the solvent to produce a strong yet soft fiber. Lyocell fibers have properties similar to cotton such as high strength, absorbency and softness but are more durable and easier to care for.

1. LYOCELL
THE NEW AGE FIBRE

2. INTRODUCTION

Lyocell (lyo from Greek: lyein = dissolve, cell from
cellulose)

Man made cellulosic fibres

Produced by regenerating cellulose into fibre form out of
a solution (solvent spinning) of cellulose in an organic
solvent

‘Organic solvent’ - mixture of organic chemicals and
water

‘Solvent spinning’ means dissolving and spinning without
the formation of a derivative

Lenzing AG. is currently (2013) the only major producer
of lyocell fibres

Tencel is the brand name of Lyocell

3. RAW MATERIALS

Cellulose
•
Most abundant natural resource on earth.
•
It is obtained form wood pulp.
•
Trees like Eucalyptus , bamboo and pine tree are used.
•
Eucalyptus is primarily used to produce the Tencel fibre.

4. 
NMMO
•
Chemically produced from N methyl morpholine and hydrogen peroxide
•
Cyclic amine oxides such as N-methyl morpholine oxide have the capacity to
dissolve cellulose in large capacities
•
NMMO exists in several degrees of hydration.
•
At room temperature it is a crystalline mono hydrate and melts at 72 degrees
•
When heated at 100 C, mono hydrate NMMO is able to dissolve readily several
percentages of high molecular weight cellulose
•
Cellulose dissolution in NMMO is found to depend on:
– The temperature of the solution
– The water content of the mixtures
– The concentration and the degree of
– Polymerisation of the cellulose

5. MANUFACTURING AND PROCESSING

Preparing Wood Pulp
•
Hardwood trees are harvested and logs are
taken to mill.
•
Wood is cut into small chip and fed into a
chemical digesters which removes lignin and
softens them into wet wood pulp.
•
It is then washed with water, bleached and
dried into huge sheets of cellulose and rolled
onto spools.

6. 
Dissolving Cellulose
•
Spools of cellulose are unrolled
and broken into one square
inches.
•
It is then loaded into heated
pressurized vessel containing Nmethyl morpholine N-oxide.
•
Cellulose dissolves into a clear
solution.

7. 
Filtering
•
In Amine Oxide solvent, cellulose is dissolved into a clear solution.
•
It is then pumped out and filtered.

Spinning
•
Cellulose is forced through the spinnerets and long strands of fibre comes out.
•
These fibres are then dissolved in dilute Amine Oxide solution and is later
washed with water.

8. 
Drying And Finishing
•
Fibre is passed through drying area.
•
In the drying area, water is evaporated and lubricant is applied which may be
soap, silicone or other agent.

9. 
Solvent Recovery
•
After spinning and drying process, dilute solution is taken passed through the
evaporator where water is removed and amine oxide solvent is fed back to the
Dissolving process.

10. PROPERTIES

Soft, strong, absorbent

Fibrillated during wet processing to produce special textures

It has high wet and dry strength, it is stronger than Cotton and Wool.

Wrinkle resistant

Very versatile fabric, dyeable to vibrant colours, with a variety of effects and
textures.

Can be hand washable

Simulates silk, suede, or leather touch

Good drapability

Biodegradable

Fine yarn counts can be spun

11. 
Comfort
•
Soft, smooth fibre.
•
Ideal for apparel that contacts skin.
•
Thermal retention is poor.

Appearance Retention
•
Resiliency is moderate- Wrinkles but not as severely as rayon.
•
Shrinks, but not progressively.
•
May have problems with fuzziness or piling.

12. 
Aesthetics
•
Lustre, length and diameter can be changed depending upon end use.
•
Processed to produce a range of surface effects.
•
Offers unusual combinations of strength, opacity, absorbency.

Durability
•
Performs more like cotton than rayon.
•
Strongest of cellulosic fibres.
•
Unique combination of soft hand and good durability, produces comfortable,
long-lasting textiles for apparel and interiors.

13. 
Care
•
Either gently machine- Washable or dry cleaned.
•
Sensitive to acids.
•
Resistant to mild alkalis.
•
Sensitive to mildew and some insects.
•
High dye affinity.
•
High inherent whiteness- Bleaching is not necessary.

14. PHYSICAL STRUCTURE

The physical structure is a more rounded
cross section & smoother longitudinal
appearance than rayon.

Since in the case of Lyocell we are just
dissolving cellulose in NMMO and not
making any cellulose derivatives, it has
a different molecular structure than
other regenerated cellulosic fibres.

The structure is ‘Homogeneous’ and
‘Dense’.
Cross Section
Longitudinal Section

15. APPLICATIONS

Professional business wear.

Leotards

Hosiery

Casual wear

Upholstery

Window-treatment fabrics

Filters

Printers’ blankets

Specialty papers

Medical dressings

Conveyer belts for strength & softness

Botanic Tencel bed
Botanic Bed

16. COMPARISON WITH OTHER FIBRES

17. THANK YOU!