lyocell & spundex

LYOCELL AND

Roksana Akther

B.Sc. In Textile Eng.

9th Batch

ID No: BTE00905469

Port city International university

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

Tencel is the brand name of Lyocell

RAW MATERIALS Cellulose • Most abundant natural resource on earth.

• It is obtained from wood pulp.

• Trees like Eucalyptus , bamboo and pine tree are used.

• Eucalyptus is primarily used to produce the Tencel fibre.

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.

Dissolving Cellulose

• Spools of cellulose are unrolled

and broken into one square

inches.

• It is then loaded into heated

pressurized vessel containing N-

methyl morpholine N-oxide.

• Cellulose dissolves into a clear

solution.

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 fiber comes out.

• These fibres are then dissolved in dilute Amine Oxide solution and is later

washed with water.

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.

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

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.

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.

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.

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

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

There are three types of spinning are available for

spandex, these are-

Melt-spinning process.

Dry-spinning process.

Wet-spinning process.

Melt-spinning process :

athletic, aerobic

exercise apparel

swimsuits

ski pants

disco jean

hosiery

socks

underwear

surgical hose

support hose

motion capture suits

Home furnishings

Garments made with LYCRA® fiber are comfortable, durable

and keep their fit.

THANK YOU!