SWICOFIL - Yarn and fiber expert.

Soybean SPF


Fabrics from the soybean fiber have the following features:


  • magnificent and noble appearance
    soybean protein fiber has luster of silk which is joyful and an excellent drape which makes the fabric elegant; fabrics of yarn with high count has fine and clear appearance and is ideal for top-level shirt.
  • cashmere feel
    fabrics made with SPF are soft, smooth and light. It has cashmere feel, but is smoother than cashmere; it is as comfortable as a second human skin.
  • dry and comfortable
    the moisture absorption of soybean fiber is similar to the one of cotton; with a ventilation superior to cotton.
  • good colour fastness
    SPF can by dyed by acid and active dyes and provides fresh and lustrous colour fastness while also being stable in sunshine and perspiration. Compared with silk products, there is no problem concerning freshness of colour or staibility of the dye. Its anti-ultraviolet characteristic is superior to cotton, even more superior than viscose and silk.
  • healthy and functional property
    SPF has a good affinity to human body's skin and possesses many kinds of amino acids that are beneficial for health protection. Meeting people's skin, the amino acid in soybean protein can activate the collagen protein in the skin, resist tickling and provide ventilation for the skin.
    Bacteria resistant elements are integrated in the fiber's molecule chain, which enhances the longevity of the antibacterial property* of the soybean protein fiber.  

    *: including resistance to baterias like coli bacillus, staphylococus aureus and candida albicans


Breaking strengthcN/tex3.8 - 4.0 for dry (2.5-3.0 for wet)
Dry breaking extension%18-21
Bias of linear densiry%± 10
Initial moduluskg/mm^2700 - 1300
Moisture regain%8.6
Alkali resistanceat general level (n.r. to caustic soda)
Acid resistanceexcellent
UV resistancegood
Moth / fungus resistanceresistant




The dyeing property of soybean knitted fabric with different kinds of dyes were tested and compared, as listed in the table below:

The test results indicate the the dyeing property with neutral dyes is relatively bad for soybean protein fiber.Application of neutral dyed must therefore be done with caution.

Weak-acid dyes, reactive dyes and substantive dyed are suitable for sobyean fiber.

The dying fastness on sobean fiber is similar to wool with different dyes.



The crimp value of soybean fiber is relatively low compared to other chemical fibers, where the value is between 10-15%. Cohesion force of soybean protein fiber is therefore rather small and anti-slipping agent is necessary in spinning.

The residual crimp ratio is only 0.88% while the common values of other chemical fibers are 10%. This means that soybean fiber is easy to unwind, but the crimp stability is poor.

The elastic recovery rate for soybean fiber is also lower than the common values of other chemical fibers (70-80%). Therefore, the elastic property of soybean fiber is rather poor.



Heat shrinkage rate of soybean fiber is great, furthermore the fiber has no obvious melting point. Fiber strength decreases largely whereas the colour becomes pale yellow at 160°C. At 300°C, the colour turn brown and the fiber begins to carbonize.

Therefore, temperatures of dyeing and setting soybean fabric should better not exceed 100°C. If the temperature is at 110°C, the fabric handle becomes hard. At this time, fabric handle can only be improved by the washing of soap bath above 60°C.



The light fastness of soybean fiber was tested under outdoor condition for two months. After the test, the color of soybean fiber fades a little, the strength decreases 11%; no mold fungus appears. Furthermore, the strength of soybean fiber decreases only 9.8% under the ultraviolet irradiation for 120 hours. The test results indicate that the soybean fiber has good light fastness property and good resistance to ultraviolet radiation, which is better than cotton, viscose and silk.


Mass specific resistance of 10.33 is simiilar to silk and lower than other man-made fibers.

Soybean protein fiber has a good antistatic effect which is beneficial to the textile fabrication and wearing property.



The pilling property of 3 knitted fabric samples, which are made from 32s soybean yarns, 32s cotton yarns and 32s PAN yarns respectively, were tested with nylon brush for 50 revolutions and with fabric for 50 revolutions. The test results indicate that the pilling degree of soybean sample is similar with that of cotton sample and better than that of PAN sample; while the fuzzy fibers of soybean sample are much longer than that of cotton and PAN samples.            

In a word, due to the low frictional coefficient, low crimp number and low crimp stability of soybean fiber, the soybean fabric sample is easy to fuzz but not easily pilling. According to GB4801.1-84, the pilling property of soybean sample is grade 2, while that of cotton sample is grade 1.5 and PAN sample is grade 1.


Soybean has a good biocompatibility and is beneficial to the human health. Furthermore, the anti-bacterial agents, which were added to the soybean in spinning process, can restrain the growth of colon bacillus, impetico bacteria and sporothric.

Need help with your order? We love to serve you well. Contact us
Need help with your order?