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Updated: Jan 8, 2021


Milk/casein fiber is a synthetic fiber manufactured from milk casein through bio-engineering method. This fiber comes under regenerated protein fiber class. This fiber is first manufactured by Antonio Ferretti in the early 1930s. Manufacturing process The raw material for this process is soya milk, process this milk naturally until it is converted into casein. Dissolve the casein in water which contains 2% by weight of alkali to make a viscous solution with 20 to 25 % protein. Filter the casein solution by pumping it through metering pump through a platinum-gold alloy disc or spinneret with thousands of holes. The solution, streaming from the holes of the spinneret is immersed in water that contains an acid. The acid neutralizes the alkali used to dissolve the casein. The small continuous fibers are then stretched, treated in various solutions, and collected by the spinning machinery. The tensile strength of the yarn (just like regular thread) is enhanced by stretching the fiber while it is being tanned with aluminum salts and formaldehyde.

SEM analysis of casein fiber

Types of casein fiber:

  1. Rennet Casein

  2. Acid Casein

Advantages of Casein fiber:

  1. Milk protein is hygienic and flexible.

  2. It is highly smooth, sheen, and delicate.

  3. It is moisture absorbent, permeable, and heat resistant.

  4. It is colorfast and easily dyeable and requires no special care because of its natural protein base. It can be blended with other fiber.

  5. It is renewable, biodegradable, and eco- friendly fabric.

Disadvantages of casein fiber:

  1. It gets wrinkled easily after washing and needs to be ironed every time.

  2. It has low durability-though caseins can be laundered with care the same as wool but they lose strength when wet and must be handled gently.

  3. It is expensive.

  4. They cannot be kept damp for any length of time due to quick mildewing.

Properties of casein fiber:

Flame test: Burns slowly and brightly in air, but extinguishes with the removal of flame source.

Applications: 1. Apparels 2. Innerwear 3. Sportswear 4. Ladieswear 5. Sweaters

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