What is Milk Fiber Yarn and How is it Produced?
Updated: Nov 22, 2021
A milk protein called casein is used to make innovative fibers that resemble wool. New technologies have been constantly being researched and incorporated by the textile industry for a long time. These researches result in innovative textiles such as fabrics made from milk.
What is Milk (Casein) Fiber?
Waste milk unfit for human consumption is used to produce innovative fibers called milk fiber or casein fiber. Milk fiber fabric is a blend of casein protein derived from milk and acrylonitrile, the same chemical used to make acrylic. Or it is made from pure casein protein. Waste milk still contains valuable ingredients and offers great potential for technical purposes as well.
Milk-blend cotton yarn was first created in Italy and the USA in the 1930s and was called milk casein. It was made to compete with wool, but production stopped during WWII. Initially, formaldehyde and large amounts of water were used in the manufacturing process. However, this resulted in an unprofitable production method.
In the 1930s, Italy was a pioneer in making Lanital, a wool-like textile made from milk. Production started with the separation of milk and cream. The cream is used to produce butter, and skim milk is then coagulated to remove casein.
By mixing acid with milk, chemists can extract casein protein, which looks like cheese in appearance. Casein is dissolved in a liquid resembling molasses and passed through nozzles. It is put in a chemical bath. The resulting milk fiber fabric is hardly distinguishable from wool.
Historically, milk fiber yarn was mixed with various substances to give them a cotton-like texture and tension. But these days it's mostly made with a mix of casein protein and acrylonitrile. Therefore, it is not a true organic or natural fabric as it is semi-synthetic.
Traditional Production Process of Dairy Fiber Fabric
Converting milk waste into fabric requires a very technical process. To make milky fabric yarn, the casein protein must be extracted. Casein is obtained when milk is acidified. Different sub-processes are used and these are the two main production processes. Both will have the first step of obtaining the waste milk.
The milk is skimmed to extract the fat and then dehydrated and fermented. At this point, it is similar in appearance to a milk-based protein powder.
The casein fiber is extracted - the casein is coagulated, washed and dried, and then ground into a fine powder. The milk powder is dissolved and purified to remove non-casein substances.
Casein is then dissolved in caustic soda solution and left to mature until it reaches a certain viscosity. It is then filtered and vented.
The spinning solution is then wet spun by extruding from the spray nozzles into a coagulation bath.
The coagulation bath consists of 2 parts sulfuric acid, 5 parts formaldehyde, 20 parts glucose, and 100 parts water. The filaments coagulate in a similar fashion to viscous filaments.
The fiber must then go through a chemical treatment to harden it. Formaldehyde forms the basis of most curing techniques. As the filaments exit the coagulation bath, they are aggregated and immersed in formaldehyde solution. At this stage, the filaments are subjected to the drawing process.
The next step is to wash and dry, and then it is mechanically crimped before being cut into staple fibers. Casein fiber is produced almost entirely as staples, tows, or balls.
Alternative Production Method
This is another process that is similar but with minor differences and involves fewer steps and chemicals:
The milk is fermented, then de-fatted and dehydrated.
The casein fiber is extracted and the milk powder is dissolved and purified. Non-casein substances are removed.
Powdered casein is dipped in alkali and passed through nozzles to make a solution.
The solution is dipped in sulfuric acid to remove the alkali.
The fibers are then stretched and spun into milk fiber yarn.
It is then tanned with aluminum salts and formaldehyde into a usable textile for food-made clothing.
The production process has changed due to the toxicity of formaldehyde and the harmful effects of other chemicals.
The modern method of producing casein fiber goes through a process called graft copolymerization. This is the chemical inoculation of pure casein with acrylonitrile. It doesn't require the use of formaldehyde, but acrylonitrile is also toxic and carcinogenic, so it's still a chemical we want to avoid.
Milk fiber fabric made in China is normally made with acrylonitrile, so it still cannot be classified as eco-friendly or sustainable.
A new process that is more environmentally friendly and does not use formaldehyde or any other chemicals has been developed by a German company called QMilch GmbH.
What Does QMilk Company Do?
QMilk was started by Anke Domaske, a microbiologist, after searching for clothing that had not been treated with chemicals. Milk proteins caught his attention. But since the original textile process used in the 1930s was complex and involved a variety of chemicals, he established QMilk as a classic kitchen startup.
QMilch GmbH was founded in April 2011 and there is currently a group of companies involved in the development and production of biopolymers. They are based on milk proteins and other natural and renewable raw materials.
The fabric called QMilk is made from milk fiber yarn using waste milk that is not suitable for human consumption. Milk was normally obtained from a dairy. QMilk has developed a process that is 100% natural and uses renewable resources. No plasticizers, solvents, or chemical crosslinkers are used. The fiber can be composted at home and will decompose and biodegrade in the environment within a few months.
Environmentally friendly QMilk Procedure
QMILK is a patented, specially designed manufacturing process. Part of the process includes:
heating casein powder to 80°C in a meat grinder,
Adding natural ingredients like zinc and beeswax.
The fibers come out in strips and are then spun into yarn.
As it is a patented process, no further details are available on the individual steps for making milk cotton yarn. Thus, no formaldehyde is used and certain cost efficiency and minimum CO2 emissions are achieved. It is 100% natural, soft and smooth as silk. It is skin-friendly and meets the requirements of innovative material developments.
QMilch received the Green Tec Award in 2015. QMilk fiber has also passed the OEKO TEX standard 100 green certification for international ecological textiles. It answers the call for sustainable natural fibers and opens up exciting new possibilities for innovative textiles.
You need about a hundred pounds of powdered milk to make three pounds of milk fiber. The fibers are white, fluffy, and emit a pleasant smell. Innovative fibers can be dyed using acid, reactive or cationic dyes.
QMilch Fiber Applications
QMILK is a protein fiber and is ideal for direct skin contact as it feels like silk on the skin. QMilk fibers do not contain the following harmful substances usually found in textiles and products:
isocyanate and halogens.
silver, zinc oxide, and triclosan
So what is the milk fiber material used for? QMilk fibers have fashion and technical applications in hygiene and medicine.
1. Fashion applications of QMilch Fibers
QMilk can be combined with any type of wool, but can also be spun with cotton, cellulose, or other natural fibers. It can be used as an alternative to cotton or silk. But it can be combined with silk and cotton to create a smoother texture. Milk cotton yarn is perfect for underwear because of the healthy and bacteriostatic nature of the milk fiber.
Besides being good for underwear, it is also used for socks, home textiles, and garments made from wool.
Milk fiber fabric is compostable, has a silky touch, is natural, heat-sealable, temperature-regulating, and flame-retardant. It is naturally antibacterial and hydrophilic. QMilk is the only natural fiber with thermo-bonding properties. Therefore, it can replace traditional plastics and resins as binders.
Bonding and stabilization are done by pressure and heat treatment up to 100°C. Thus, products with natural fibers such as linen and hemp can remain 100% natural. It can be considered a “green” product as no formaldehyde or other chemicals are used.
2. Technical Applications of QMilk Fibers
Milk fiber can also be used in non-woven applications such as toilet paper and baby wipes. QMilk wipes meet the demands of being "washable" as they dissolve in water without leaving any residue. Thus, it will not affect the infrastructure of the sewage system.
QMilk biopolymer is a 100% natural plastic that meets the requirements of a home compostable bio-plastic. Casein has excellent barrier properties that make it suitable for applications in the food industry. QMilk plastic can replace plastic made from petrochemical materials and make these innovative fibers environmentally friendly.
3. QMilk Beauty Apps
QMilk cosmetics use microbeads, a natural material that can be used in skincare. Milk fiber contains 18 amino acids beneficial to human health. It has the function of nourishing and caring for the skin. Milk fiber has a pH of 6.8, the same as human skin, making QMilk beauty products compatible with your skin.
It is made with casein powder found in milk. Organic fats and milk proteins without alcohol and glycerol. It can be used for deep cleansing as it stimulates the cell renewal and collagen formation of the skin. QMilk also acts as a powerful antioxidant and has an anti-inflammatory effect.
QMilk microbeads create a gentle exfoliating effect where old skin cells are removed without damaging the underlying healthy skin. Circulation to the skin is also stimulated, leaving your skin with a youthful glow.
Properties of Milk Fiber Fabric
Because it is a regenerated protein fiber, milk fiber yarn reacts like wool and has many of the properties of wool.
Milk cotton yarn is both comfortable and permeable.
It has a soft, warm handle and is flexible like wool.
It is so similar to wool that the difference can only be determined by a burn test with wool.
Naturally antibacterial and highly hydrophilic.
It provides natural fiber with thermal adhesion and good thermal insulation.
Thanks to its high moisture absorption feature, it removes moisture from the skin.
It can be washed hot.
It absorbs moisture easily, and the fibers become soft and swollen.
Milk fibers lose their strength when wet, so when wet, handle gently and dry flat.
It is easily damaged by alkalis and mold, so do not keep it damp.
The Future of Dairy Fiber Yarn
Worldwide production of milk cotton yarn is currently minimal. Currently, garments made from milk have a limited market as they are expensive. The fabric produced by QMILK is about forty times more expensive than regular cotton. If you are looking for vintage clothing, there are different brands such as Aralac, Merinova, and Lanatil.
Using milk fiber reduces the waste of milk produced by dairies. In Germany alone, two million tons of milk are thrown away every year. So just imagine the global waste.
Scientific advances are also helping companies experiment with fabric. Dairy waste offers new business opportunities to develop local textiles and a garment industry with clothing made from food. By using waste, the negative environmental impact of the dairy industry can be reduced.
The main disadvantage at the moment is the high cost. If a cheaper manufacturing process is used, it means that carcinogenic chemicals are being used that we all want to avoid.
QMilk is sustainable and environmentally friendly, but not suitable for vegans as milk fibers are derived from animal protein.
If you have any questions about what milk fiber material is, or comments about milk fiber fabric or QMilk's innovative fibers, please leave them below and I will get back to you.