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Modal is a wood pulp based cellulosic fibre, made out of pure wooden chips

from the beech tree, technically as the European Schneider Zelkova tree.

While viscose rayon can be obtained from the wood pulp from a number of different

trees, Modal uses only beech wood, thus it is essentially a variety of viscose

rayon; a generic name for modified viscose rayon fibre that has high tenacity and

high wet modulus.

Modal was first developed by Austria based Lenzing AG Company who trademarked

the fabrics’ name, but now many manufacturers make their own versions. It was

initially imported from Czech Republic, Slovakia, Hungary and Germany; but now

for the Indian market, it is catered by Lenzing, Austria, which has tied up with

Rajasthan Textile Mills.

History of Modal

Modal fibres’ staple versions were initially developed in 1930s for industrial textiles

(in tires, conveyor belts and hose pipes), and for blending with rapidly growing

synthetics. Changes in viscose rayon processing such as spin conditions; chemical

solutions and stretching sequences produced viscose rayon fibres with increased

crystalline and thus greater strength. Additional developments in Japan in 1951

by S. Tachikawa led to the production of Modal fibre with high wet modulus called

polynosic fibre.

Definition

Modal fibres are defined in International Standard ISO 206: 999 (E) as high wet

modulus, high breaking strength regenerated cellulose fibres produced by using

particular viscose rayon, and regeneration bath compositions which allows greater

molecular orientation during stretch and coagulation of the fibres.

Again, Modal as defined by the International Bureau for Standardisation of Manmade

Fibres (BISFA) is a distinct viscose rayon fibre genre, which has a higher wet

modulus and satisfies a minimum value of tenacity in the wet stage at five per

cent elongation.

Characteristics of Modal

In many ways Modal acts like cotton, but it also have some significant advantages

over cotton.

Modal: Functional utility

1. Modal displays high dimensional stability, both for low shrinkage and low

unrecoverable extension. These benefits can be attributed to the morphological

structure of Modal, which imparts excellent elastic properties. It blends beautifully

with almost all textile fibres, viz. cotton, wool, silk synthetics and elastane

2. It is more hygroscopic in nature i.e. absorbs 50 per cent more water than cotton,

hence, keeps wearer cool during summers and warm during the winters

3. Modal is as strong as polyester with excellent wear resistance

Modal: Aesthetically appealing

1. Garments made from Modal fabrics can benefit by acquiring a desirable clean,

soft touch finish on the surface of finish. Its smoothness makes hard water

deposits less likely to adhere to the surface (say lime from hard water), so the

fabric stays soft through repeated washings. Thus the fabrics have a truly

pleasant touch and are comfort to wear

2. Unlike cotton, Modal fabrics show more resistance to shrinkage, has good

moisture regain and air permissibility, thus considered best for exercising

clothing and health suit

3. Reduced growth of bacteria when compared to cotton, if both stored for the

same long period of time; and doesn’t age like cotton

4. Modal has an advantage that it is less likely to fade or to form pills as a result

of friction

5. Modal imparts colour brilliance to fabrics and garments which remain bright

and true, also retains its appearance after several washes as shown in figure

below. This is because Modal takes up colour uniformly, deeply, and fast which

brings out the natural brilliance. Modal also maintain anti crease properties (in

blends) and have relatively easy care.

Physical parameters of Modal fibre

The “all skin” high tenacity yarns consist of finer and more uniform texture. When

coagulation and stretch occur together, before regeneration and crystallisation of

cellulose, structure has a fibrillar texture. The cross section is either circular or

bean shaped.

Modal: After 25 washes Cotton: After 25 washes

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The cross section analysis of both Modal and viscose rayon fibres are analysed

and are shown in figure below:

• Promodal: Produced by modal and Lyocell’s fibres blend of 65/35 per cent ratio.

Keep cool, 100 per cent natural and harmony is very well with skin. Expel steam

to outside, dimension stability is well. Presents to lower pilling value, better

using values and easy clean

• Modal/Nylon: Modal/nylon blend ratio is 80/20 per cent. Blend has a well-

known characteristics of modal which softness, do not disturbance to skin and

also higher wet and dry tensile strength fastness values, easy iron

Applications of Modal

Modal is preferred, where comfort and aesthetics, brightness and naturalness

are demanded. Today Modal is widely used in clothing as a replacement for

cotton, with an annual production of more than 4,000 tonne with the Indian textile

industries. Modal may be used on its own or in a blend with cotton, wool and other

synthetic fibres viz. spandex etc.

1. It is very soft and thus is popular for both clothing and house hold textiles

2. Used for tablecloths and bed linen (beddings), bathrobes, upholstery and in

home furnishings. Also used as outerwear, sportswear and leisurewear.

Microscopic view of Modal fibres

Physical parameters compared with other fibres

A typical comparison of properties of high wet modulus viscose rayon with

commonly used convectional fibres is as follows:

Blending of Modal

The fibre cross-section of Modal is similar to that of cotton ensuring that Modal

is an optimum blending partner. Modal cannot only be blended with cotton to get

optimum results. Like no other cellulose fibre, Modal® harmonises with other

fibres in a simple and uncomplicated manner, to give the desired properties.

• Modal/cotton: Both fibres’ based cellulosic and being natural presents 100 per

cent naturalness. Blend makes cotton soft and supple. It also improves the

fabric uniformity. Modal and cotton fibre’s colour fastness resembles to provide

uniform appearance which impart sheen and colour brilliance in the final product

• Modal/wool: Modal/wool blend fabric presents climatic, high comfortable,

softer, bright and woollen characteristics thanks to combination of wool fibres’

warm, softer, stuffed handle, taking shape with steam and modal fibre’s superior

characteristics

• Modal/Linen: Brightness, softer handle and comfortable characteristics of modal

and cooler and special effect of linen shows on blend. Presents to comfort and

elegant characteristics for long time by superior tenacity

• Modal/Polyester: Modal/polyester blend yarn presents brightness, softer handle

and comfort with easy clean and higher tenacity characteristics. Fabric has

well-fitting structure

• Modal/Acrylic: Has a softer handle and silky surface. Presents to higher comfort.

Pilling is lower

• Modal/Tencel: Modal/tencel blend presents better dimension stability; good

handle and comfort characteristics due to perfect combination of blend

Regular viscose rayon Modal fibre

Properties High-wet modulus Commonly used

Modal Viscose rayon Cotton Polyester Wool

Density (g/cm3) 1.53 1.51 1.55 1.39 1.31

Moisture regain (per cent) 11.8 per cent 12.5 per cent 8.5 per cent 0.4 per cent 13.5 per cent

Tenacity (GPD) 2.2-4.0 dry 1.2-3.0 3.0-5.0 3.0-5.8 0.8-2.0

3.8-5.0 wet 0.5-0.8 4.0 2.4-3.0 1.0

Bkng elongation ( per cent) 7.0 per cent dry 15-30 per cent 3-10 per cent 19-55 per cent 20-40 per cent

8.5 per cent wet 30 per cent 10 per cent 47 per cent 31 per cent

Work of rupture (mN/tex) 11.5 25 20-23 - -

Initial modulus (mN/tex) 13300 8850 5450 8830-10150 4300

As for 1.3 dtex Modal fibre, given by Ford and Courtaulds

3. Also find applications in undergarments and toweling purposes

4. Lenzing Modal is used exclusively for soft flowing tops and lingerie; exclusively

in knitwear markets having high-end apparel/non apparel products.

5. For socks and stockings, as well as in technical applications, such as tire cord,

abrasive ground fabric, rubber cloths and other coating supports

Advantages

• Absorbs 50 per cent more water than cotton

• Takes dye as well as cotton

• Lightweight fabric

• Has the appearance of silk: Lustre/sheen/gloss

• Holds colour when machine washed in warm water

• Fabric isn’t stiff, doesn’t become rigid when machine washed

• Can be repeatably washed and holds soft and smooth characteristics

Used as Leisure wear Comfortable sportswear

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• Soft and smooth against the skin

• Doesn’t pile as much as cotton

• Resistant to fading

• Resistant to shrinkage

• Resistant to mineral build up when washed again and again e.g. lime from

hard water

• Blends are more crease resistant

• Doesn’t age like cotton

Disadvantages

• 100 per cent Modal requires ironing

• 100 per cent Modal has tendency to pile due to long fibres

• Modal is more expensive than viscose rayon and cotton

• Processing the beech wood into a cellulose fibre is a man made process, whichuses more energy than processing natural fibres

Caring for Modal

Modal fabric needs to be cleaned gently to avoid damage and help the fabric stayflexible and colourfast. When well cared for, this fabric is highly durable. Somemodal fabric items are delicate and should be hand washed in cool water with amild detergent, wrapped in a towel to squeeze out the water, and then dried flat inthe shade. Modal should not be washed or dried in high heat or subjected tobleach and other harsh cleaners.

Stains on modal fabric can be removed with hand scrubbing and a gentle detergent.The fabric should not be soaked or vigorously rubbed to remove stains. The earliera stain is treated, the better; when a stain is brand new, blotting with cool watercan sometimes flush out the stain, especially if a gentle detergent is added toencourage the stain to lift.

If the fabric becomes wrinkled, it can be ironed at a low temperature. Fabric

that is dulled may benefit from ironing to restore the sheen by smoothing the

individual fibres. To avoid wrinkling while traveling, modal garments can be

rolled up as opposed to folded. Modal garments should not be left on hangers

as the prolonged hanging can cause the garments to distort and may also

break some of the fibres, weakening the garment and causing it to lose some

of its elasticity. Such garments should be stored flat or rolled to protect the

fabric while also avoiding wrinkles.

Environmental benefits of Modal

University of Utrecht in Netherlands carried out a life cycle analysis of Modal

fibres i.e. evaluated all of the environmental impacts caused by making fibres. The

topics examined were over fertilisation, the excess acidity of air, water and soil

consumption, global warming and the effects on human health. Another important

point was the consumption of non-renewable resources, as in the case, is raw

material wood. Utrecht came to conclusion that with Modal, the toxic load on

fresh water and soil is 100 times less as compared to cotton.

The yield of Modal is upto six times higher; and for their cultivation, needs 10-20

times less water in contrast to cotton. Since Modal uses beech wood i.e.

sustainably grown forest plantations, thus the land could not have been used for

any other purpose. Cotton on other hand requires agricultural land. Modal is 100

per cent bio-degradable fabric and can be recycled into lesser worth products e.g.

filling materials.

Conclusion

Modal, the second-generation viscose fibre, currently called the new "wonder"

fabric, fulfils man's eternal quest for a textile fibre that combines the best of both

aesthetics and utility performance. Today, Modal fibre is replacing the cotton from

its current dominant market very fast. Its eco-friendly, 100 per cent bio-degradable

characteristics has made it accepted globally within a short period of time

By Vasant R Kothari, Assistant Professor, NIFT, Bangalore andPrashant Verma, MF Tech (Student), NIFT Bangalore

(Author can be contacted @ www.vasantkothari.com)