What is milk fiber? Describe production process of milk fiber with after treatment.

Introduction

Milk fiber was first introduced in Italy and America in the 1930s to compete with wool. It is made with a new generation of innovative fibers and a type of synthetic fiber that has passed the international environmental certification of Oeko-Tex standard 100. There are several different brands for the same fiber made from milk casein known as milk Aralac, Lanatil, and Marinova. 

Milk fiber

Milk protein fiber is made from dairy milk and new bio-engineering technologies to make protein spinning fluids suitable for the wheat spinning process and combine with them to create new high-grade textile fibers. Milk protein fiber is healthy for the skin, comfortable, has bright colors due to good pigmentation, etc. The milk protein fiber can be spun or cut properly in cashmere, silk, cut silk, cotton, wool, radium, and other fibrous fabrics. It can also be used to make top-level underwear, shirts, t-shirts, loungewear, etc. to satisfy the pursuit of people in comfortable, healthy, high, and fashionable clothing. Milk fabric made from milk protein fiber is extracted from commercial milk that does not meet hygiene standards. Produced entirely without chemicals, this fabric contains 18 beneficial amino acids that are antibacterial, anti-aging, and capable of regulating blood circulation and body temperature.

Properties of milk fiber

1. Milk fiber is light, soft, comfortable fiber.

2. It is colorful, and elegant fiber, generally white fiber.

3. It has a good hand feel.

4. It has good thermal insulation nature.

5. Fiber burning smelt like protein fiber wool.

6. Its flammability is similar to wool fiber.

7. When it is wet, loses its strength.

8. It tends to absorb moisture readily and fiber becomes swollen and soft.

9. It may blend with other fibers like wool, and viscose.

10. It is easily damaged by alkali and mildews. 

Milk/casein fiber blending

When blended with other fibers casein adds soft-dropping quality and elasticity to the fabrics. The fiber was mixed with wool to make it and mixed with spun rayon, wool, mohair, and cotton for attractive knitting and woven fabrics in various weaves, textures, and prints.

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 products, but most casein fibers are blended with wool, cotton, rayon, nylon, and other staple fibers. Caseinized mixtures can be spun into all common systems.

The production process of milk fiber

Milk fiber is obtained by acid treatment of skimmed milk. Milk fiber solidifies as yogurt which is washed and dried and then ground into a fine powder. Milk fiber is dissolved in a caustic soda solution. The solution is allowed to ripen until a suitable viscosity is obtained and then filtered and detached. The spinning solution is spun wet by extrusion through spinnerets in a frozen bath containing sulfuric acid, formaldehyde, glucose, and water. The jets of solution solidify the filament in the same way as the viscose filaments.

The next process is highly critical because the fiber has to be chemically treated to harden it. The process is usually described as rigid, in that it reduces the flexible effects of water. Treatment with formaldehyde forms the basis of many hardening techniques. At the time of leaving the freezing bath, the filaments are collected together in the plant scalp and steeped in a formaldehyde solution.

Filaments are the subject of drawing at this stage. After treatment, the tow is washed and dried, mechanically crimped, and then cut into the staple fiber. Otherwise, the tow-to-top converter makes tops for blending with wool.

After treatment of milk fiber

Milk fiber has different physical and chemical construction from natural protein fiber, care is taken in the following steps-

Desizing: Enzyme products can be used, normally at pH 4.0 to 6.0. When water-soluble sizes have been used, then sizing is not necessary.

Scouring: Souring is a process that removes oil, wax, and natural impurities from fiber or fabric. For milk fiber, synthetic detergents should be used, generally under acid conditions, e.g. pH 6.0.

Bleaching: Bleaching is a process that removes natural color from fiber or fabric and gives permanent white color. Milk fiber is generally white, and bleaching is not necessary. If needed, it should be carried out under weak conditions, e.g. pH 4.0-6.0 as milk fibers retain maximum strength and minimum swelling under these conditions. Hypochlorite bleaches should not be used in milk fiber. Bleaching may be carried out with Hydrogen Peroxide – 2gm/l at a pH of 8.0 using Sodium Pyrophosphate. It must be washed carefully with acetic acid and acidification rules are followed. Normal optical bleaching agents can be applied.

Dyeing: Milk fiber absorbs moisture readily and does not have a highly orientated structure. Dyes can penetrate the fiber without difficulty. Milk fiber can be dyed with dyestuffs used for wool. Acid, Basic, Direct, and Disperse dyes are used that good wash fastness is noted as a prime essential. Metal complex dyes give high wash fastness. For milk pH of the dye, liquor should be between pH 4 & 6. Dyeing is generally carried out at 90-95 °C.

Printing: Fabrics containing milk fiber may be printed by block, screen, & roller. Acid, basic, direct, chrome, mordant, azoic, vat, or pigment dyes can be used.

Advantages of milk fiber

Milk fiber is environmentally friendly, high in strength, and much more advanced than man-made fiber. Some of the advantages of milk fiber as given below-

1. As it is having a continuous graft polymerization technique hence it is totally eco-friendly in nature.

2. It can be considered a green product as no formaldehyde is present in the product.

3. Milk fiber is made from milk casein instead of fresh milk. We can use acid, reactive, or cationic dyes, especially for this type of fiber.

4. Milk Fiber contains seventeen amino acids & the natural anti-bacterial rate is above eighty percent. Hence milk fiber has a sanitarian function.

5. It is a new synthetic Fiber having milk protein as the main material based on a highly technical process. It has the advantages of natural fiber combined with synthetic Fiber.

6. These are more comfortable, excellent water transportation & air permeability.