Saturday, October 12, 2019



It is manufactured from vegetable protein ( soybeans). This fibre is also known as SPF. The SPF is a regenerated fibre and is made of soybean cake.

The SPF shows improved fibre properties like tensile strength, touch, feel, handle, moisture absorbency, lustre, and dimensional stability when it is blended with other fibres.

SPF is the only renewable vegetable protein fibre. It is composed of 16 amino acids. These amino acids show nutritional influence on people's skin. And help to keep user skin healthy. SPF shows the superiorities of many natural and synthetic fibres in many aspects. STF also contains anti-bacterial elements. SPF protects our skin too. It is an active, new green and advanced textile fibre. It is also known as “vegetable cashmere” or “soy silk”. It is made from soybean cake after oiling by new bioengineering technology.

“Organic chemist Percy Lavon Julian designed the world’s first plant for the isolation of industrial-grade soy protein in 1936 called alpha protein”.

Ford’s Robert Boyer and Frank Calvert spun it into artificial silk that was then tailored into that now-famous “silk is soy” suit that Henry Ford wore on special occasions.

Glidden sent a sample of Julian's isolated soy (alpha) protein to National Foam System Inc. (today a unit of Kidde Fire Fighting) at the start of the 2nd  World War, which used it to develop Aero-Foam, used by the U.S. Navy for fire fighting and referred to as "bean soup.

Soy protein isolate has been used since 1959 in foods for its functional properties.                                           


• Soy protein fibre ( SPF) is a man-made regenerated fibre and is derived from vegetable protein.

• Soy protein fibre ( SPF) reflects a cream colour light.

• The diameter of soy protein fibre (SPF) is around 20 µm.

• The microscopic examination of soy protein fibre ( SPF) indicates longitudinal striations on the surface parallel to the axis, varying in length and depth.

•The cross-section of soy protein fibre( SPF)  shows a kidney-bean-like cross-sectional shape.


• Soybeans are very rich in proteins (about 37% - 42% of dry bean) in comparison to milk (3.2%), corn (10%) and peanuts (25%).

• Soybean proteins are used for food and feed and in many industries as adhesives, emulsions, cleansing materials, pharmaceuticals, inks, plastics and also textile fibres.

“Raw material for spinning textile fibres is obtained from soybean remaining flakes after the extraction of oils and other fatty substances”.

• Soybean proteins consist of 18 various amino acids. There are about 23% of acidic amino acids (glutamic acid and aspartic amino acid).

• 25% of alkaline amino acids (serine, arginine, lysine, tyrosine, threonine, tryptophane) are found in soy protein approximately.

• 30% of neutral amino acids (leucine, phenylalanine, valine, alanine, isoleucine, proline, glycine) are found in soy protein approximately.

• There are amino acids having sulphur also found in soy proteins.

• Approximately 1.0% of cysteine and 0.35% of methionine get presented in soy protein.

• Soybean proteins consist of various groups of polypeptides with a broad range of molecular sizes. Almost 90% are salt-soluble globulins (soluble in dilute salt solutions) and the remainder is water-soluble albumins.

• Very important as raw material for producing textile fibres are storage globulins with predominant β-conglycinin (30 - 50% of the total seed proteins) and glycinin (ca 30% of the total seed proteins).

• Beta conglycinin is a heterogeneous glycoprotein composed of three subunits (a', a, beta) containing asparagine, glutamine, arginine and leucine amino acids. Subunits are non-covalently associated with trimeric proteins by hydrophobic interactions and hydrogen bonding without any disulphide bonds.

• Glycinin is a large hexamer, composed of acidic and basic polypeptides linked together by disulphide bonds.


The production process of soy protein fibre completes  in the following three steps:

•  The spherical protein is distilled from the soybean cake and is refined.

• The space structure of spherical protein changes under the functioning of auxiliary agents and biological enzymes. Now, protein spinning liquid gets confected by adding high polymers.

• The 0.9 - 3.0 dtex fibre is produced by wet spinning after cooking of liquid. Then it is stabilised by the acetalisation process. Finally, the filaments are cut into short staples after curling and thermoforming processes.


Soy protein fibre has the following characteristics:


The soy protein fibre poses a very good appearance. The fabric surface has very good seen. The feel and touch is very smooth. The fabric made of soy protein shows silk-like lustre and smoothness. The fabric woven from SPF has tremendous draping characteristics. 

Colour fastness

The unprocessed SPF look almost ivory in colour. It has a very good dyeing affinity. It is coloured with acid dyes and reactive dyes. It poses very good light fastness, washing fastness, fastness to perspiration.

Skin friendly characteristic:

The soy protein fibre shows no harmful effect on human skin.  The presence of many amino acids in the SPF keeps the skin healthy.
Many herbal medicines are added during the wet spinning process of SPF with the side chain of SPF in the manner of chemical bonds. The medical effect gets permanent in this process. 


Its low specific gravity makes it almost equivalent to wool. The moisture regains and the moisture transmission rate is excellent. This fibre feels more comfortable than cotton. The lustre, touch and feel are almost similar to that of silk. All these properties make it an ideal fibre. 

Ultraviolet protection characteristic:

The SPF fibre has better protective capabilities against ultraviolet radiation. It is better than silk, cotton, and viscose rayon.

Antimicrobial characteristic:

Soy protein fibre has an antimicrobial characteristic. It helps to prevent the development of bacteria in the fabric. It is very suitable for underwear during summer.

Physical properties:

Fabrics from SPF have the following physical characteristics:

SPF has the lustre like silk fibre.

The SPF poses excellent draping characteristics. 

 The SPF  shows a very soft handle and smooth touch

It is low specific gravity fibre. 

It has a moisture absorption rate similar to cotton but it has a better moisture transmission rate than cotton fibre.

The SPF shows very good dyeing affinity and colour fastness characteristics.

It has higher breaking strength than cotton, silk and wool but less than that of polyester fibre.

The SPF doesn’t get shrunk in hot or boiling water.

The fabric made of SPF shows anti-crease characteristics.

The fabric made of SPF is easily washable. The fabric gets dried very fast.

The production of SPF doesn't harm the
environment in any ways. It is produced by
waste getting after extraction of proteins and
fats from soybeans.

It is made from renewable and biodegradable natural resources - the leftovers of non-genetically modified soybeans. No pollutants are used in its manufacture and the residual waste after production is biodegradable and can be used as fertilizer.

The breaking strength of the single SPF is over 3.0 CNdtex, which is higher than that of wool, cotton and silk and only lower than that of polyester fibre of high intension. By now, 1.27 dtex fibre can be spun into 6 dtex yarn with high quality, which can be used for high-quality and high-density fabrics. Also, the fabric of SPF has outstanding anti-crease, easy-wash and fast-dry property

Please click on the below video link to watch the full article in Hindi:

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