This is a very knowledgeable presentation for textile engineering students.

1. A Presentation
On
Milk/Casein Fiber
COURSE NO: TE-2603
COURSE TITLE: FIBROUS MATERIALS & TEXTILE PHYSICS-2
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2. Welcome to our Presentation
Presented By: Presented To:
Md. Mosaddek Jaman ID: 175056 Abu Yousuf Mohammad Anwarul Azim, CSCA
Md. Shafiqul Islam ID: 175057 Assistant Professor
Md. Jashiar Rahman ID: 175058 Department of Textile Engineering
Dhaka University of Engineering & Technology
(DUET), Gazipur-1707
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3. Introduction
Milk fiber or milk wool is a type of Azlon a regenerated protein fiber
based on the casein protein found in milk. There are several trade
for milk casein based fibers including Lanital, Fibrolane and Aralac.
Milk fiber is basically a combination of casein protein and acrylonitrile.
This milk or casein fiber is prepared in the same process as viscose /
rayon. Since it is a regenerated protein fiber, it usually exhibits the same
properties as wool fiber.
The superior physical properties of wool have for long been the subject
investigation by scientists, and therefore it is not unexpected that at this
particular period of civilization a fiber aiming at the chemical constitution
and physical properties of wool should have been developed and made
available commercially. This fiber is one which we are here called “Casein
Fiber”
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4. History of Milk/Casein Fiber
First produced and patented in Italy in 1935 by Antonio
Ferretti and sold under the name Lanital, milk fiber was created
under a national self sufficiency drive and was intended to
capitalize on previous successes with rayon Milk fibers enjoyed
brief period of success in the 1930s and 1940s. The popularity of
milk fibers declined rapidly once full-synthetic fibers were
developed. Fully synthetic fibers such as acrylic were able to
significantly undercut milk fiber on price while being more
durable. During the 2010s several producers tried to reintroduce
milk fibers to commercial production.
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6. Production of milk fiber:
 Casein is obtained by the acid treatment of skimmed milk. The casein coagulates as a
which is washed and dried, and then ground to a fine powder. Casein is dissolved in
caustic soda solution. The solution is allowed to ripen until it reaches a suitable viscosity,
and is then filtered and deaerated.
 The spinning solution is wet spun by extrusion through spinnerets into a coagulating
containing sulphuric acid (2 parts), formaldehyde (5 parts), glucose (20 parts) and water
(100 parts). The jets of solution coagulate into filaments in a manner similar to the
coagulation of viscose filaments.
 But the next process is very critical as the fiber has to be treated chemically to harden it.
The process is commonly described as “hardening”, in that it minimized the softening
effects of water. Treatment with formaldehyde forms the basis of many hardening
techniques.
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 In the plant scale bunches of filaments are collected together into a tow as they leave the
coagulating bath, and are then steeped in formaldehyde solution.
 The filaments are subjected to drawing at this stage. After treatment, the tow is washed and
dried, crimped mechanically, and then cut into staple fiber. Otherwise, the tow to top convertor
makes tops for blending with wool.
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8. Various names of Milk/Casein fiber in different countries:
1. Lanital in Belgium and france.
2. Fibrolane in Britain.
3. Merinova in Italy.
4. Wipolan in Poland.
5. Aralic in America.
Characteristics of milk / casein fibre:
1. This fiber is thermal insulation. So the fabric made with this fibre can easily hold the body
temperature.
2. It has elasticity religion.
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3. Milk fibre cannot be separated from wool fibre by chemical test or burning
test, it is only possible with a microscope.
4. It is quite smooth fibre.
5. Its natural colour is bright white.
6. Can easily absorb moisture.
7. The fabric made of this fibre is quite comfortable.
8. This fibre can be easily dyed.
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11. Physical Properties of Milk/Casein Fiber:
1. Tensile Strength: Milk/Casein fiber has the tenacity of 2.8 Cn/tex when it is dry. When wet the
fibers lose much of their strength then tenacity falls to, 2.4 to 2.6 Cn/tex.
2. Thermal Properties: Milk/Casein fibers generally soften on heating, particularly when wet.
Fibers become brittle and yellow on prolonged heating.
3. Effect of Moisture: Milk/Casein fiber tends to absord moisture realidy and the fibers become
swollen and soft. They my become plastic and sticky as the temperature is rasied.
4. Elongation: 60-70% wet or dry.
5. Effect of age: Very resistant.
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12. Chemical Properties of Milk/Casein fiber:
1. Effect of acids: Milk/Casein is stable to acids of moderate strength under
normal conditions.
2. Effect of Alkalies: Milk/Casein is sensitive to alkali.
3. Effect of organic solevnts: Dry cleaning solvents do not cause damage.
4. Insects: Milk/Casein fiber is not attacked by moth grubs to the same
degree as wool.
5. Micro-Organisms: Casein fibers are attacked by mildews, particularly when
moist.
6. Electrical properties: Dielectric strengthnod casein fibers is low.
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13. Main properties of Milk/Casein fiber: 13
Properties Index
Length(mm) 38
Fineness(dtex) 1.52
Dry tensile strength (cN/dtex) 2.8
Dry breaking elongation rate% 25-35
Wet tensile strength (cn/dtex) 2.4
Wet breaking elongation rate% 28.8
Friction Co-efficient(Static) 0.187
Friction Co-efficient(dynamic) 0.214
Logarithm of mass specific
resistance(wg/cm2)
9.1
Initial modulus (cN/dtex) 60-80
Moisture regain% 5-8
Specific weight(g/cm3) 1.22

14. Comparison of properties of Casein, silk, wool and cotton fiber: 14
Properties Silk Silk wool Cotton
Tenacity
gm/den
1.1-0.9 1-1.15 1.5-2.0 2-5.5
Elongation% 60-70 25-45 25-40 6-10
Density 1.30 1.34-1.38 1.33 1.50-1.54
Moisture
Regain%
14 11 14-16 9
U.V Resistance Bad Bad Bad Bad

15. The blending of milk fiber:
When blended with other fibers casein added a soft draping quality and resiliency to fabrics.
fiber was blended with wool for creating felt and with spun rayon, wool, mohair and cotton for
attractive woven and knitted fabrics in a variety of weaves, textures, and prints.
The popular blends were wool- 94% and casein fiber -6%., viscose-50% and casein fiber- 50%.
Casein/cotton blends are popular for hosiery and carpets. A small amount of fiber is used for
100% casein goods, but most casein fiber is blended with wool, cotton, rayon, nylon and other
staple fibers. Blends containing casein may be spun on all the usual systems.
Cotton system – viscose/casein blends.
Woolen system – Casein/ wool or viscose blends.
Worsted system – Casein /wool or viscose blends.
Flax system – Casein/viscose blends.
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16. Chemical processing of Milk Protein Fiber (Casein):
Milk protein fiber has different physical and chemical construction from natural protein fiber, care is taken
in the following steps;
Desizing- Enzyme products may be used, preferably at pH 4.0 to 6.0. If water-soluble sizes
have been used, sizing is not necessary.
Scouring- Synthetic detergents should be used, preferably under acid conditions, e.g. pH 6.0.
Bleaching- Casein fiber is generally white, and bleaching is not usually necessary. If required, it should be
carried out under weak conditions, e.g. pH 4.0-6.0 as Casein fibers retain maximum strength and
swelling under these conditions. Hypochlorite bleaches should not be used. Bleaching may be carried
with Hydrogen Peroxide – 2 GPL at a pH of 8.0 using Sodium Pyrophosphate. It must be followed by
washing and acidification with acetic acid. Normal optical bleaching agents may be applied.
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Dyeing- Casein absorbs moisture readily and does not have a highly orientated
structure. Dyes can penetrate into the fiber without difficulty. Casein can be dyed with
dyestuffs used for wool. Acid, Basic, Direct and Disperse dyes are used where good
washing –fastness is noted as a prime essential. Metal complex dyes give high wash
fastness. PH of the dye liquor should be between pH 4 & 6. Dyeing is usually carried
out at 90-95 deg c.
Printing- Fabrics containing casein may be printed by block, screen, & roller. Acid,
basic, direct, chrome, mordant, azoic, vat or pigment dyes may be used.
Crease –resist finishes may be applied to blends containing casein fiber, using
temperatures not higher than 160 deg c. for approximately 2.5 mins.
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18. Advantage of Milk/Casein fiber:
 It is environmentally friendly.
 It can be called a “green product” because it does not contain any formaldehyde.
 This fiber has a pH of 7.8, which is close to human skin. So products made with this fiber
more suitable for people.
 It is more comfortable, water transportable and air permeability is good.
Disadvantage of Milk/Casein fiber:
 The clothes made by it are folded after washing and have to be ironed every day.
 It should not be machine washed, as it is not too hard.
 It’s a bit expensive.
 It is less durable.
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19. Application of Milk/Casein fiber:
One of the earliest uses for casein fiber was in the making of feeling for hats.
Casein/wool blends are used for knitted berets. Casein/cotton or nylon blended
fabrics are used for,
I. Interlock outerwear,
II. T-Shirts
III. Cardigans
IV. Underwer
V. Jumpers etc.
Casein blended with wool, cotton, viscose, nylon is used in Raschel cloths,
coatings, and blanket fabrics. Blends of casein and wool are made into pressed
felts for use as floor coverings and used in conventional and tufted carpets. Pile
carpets are made using casein -50% and wool or viscose -50%.
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