Fiber foods

Soy Protein Fiber (SPF): an eco-friendly textile material you know

Known as “vegetable cashmere”, soy protein fiber (or SPF for short) is the textile every sustainable fashion lover should know. Super soft and naturally cream-colored, this durable fiber hasn’t hit the mainstream market yet – but that doesn’t mean it doesn’t deserve a little spotlight!


It is difficult to say who is the source of soy protein fiber. Some insist Henry Ford invented the FPS in 1937 and called it “soy wool”. There is even a photographer of him wearing an SPF suit or his 78th birthday. Others say Japanese scientists started looking at SPF in 1940. This also makes sense since the Japanese produced 450,000 kg of SPF before WWII. Finally, Robert Boyer presented the FPS in 1940 and patented in 1947. The “new” SPF was invented in 1998 and is used today in various textile products.

How is it done?

New bio-engineering technology is essential in the manufacture of SPF. Here is the simplified SPF manufacturing process:

  1. Protein is distilled and refined from soybean meal
  2. The enzyme and the auxiliary agent are added to modify the “spatial structure of a spherical protein”
  3. The fiber is made with a wet spinning process
  4. Looping thermoforming
  5. The fiber is cut into short stirrups

Although there is a lot of science involved in the production of SPF, the process does not create pollutants and any waste material can be used as fertilizer!

Why is it so awesome

Don’t let the scientific words put you off, SPF is still great. Because it is made from plant materials, it is biodegradable. It is also breathable while being warm and has enough water absorption. Water absorption is very important for textiles because it keeps our skin dry in case we run in the rain or spill a drink. Lyocell was designed with water absorption in mind, so the fact that SPF is also absorbent is fantastic! The soft SPF fibers also offer more UV resistance than cotton, so your delicate skin can stay protected from harmful UV rays all year round.

All around, SPF maintenance is incredibly simple. Unlike some pickier fabrics, SPF cleaning is quite energy efficient as it can be easily washed in cold water and dries fairly quickly. Because of his anti-crease characteristics, ironing is not as much of a concern with FPS.

Debunking the myth that soy is bad for the environment

The reality is that soy is not bad for the environment, but animal agriculture’s insatiable need for land and resources is. The animal agriculture industry has given soy a bad name with all its deforestation of the rainforest and other destructive practices.

From 2017 to 2019, 77% of soybeans grown were used to feed livestock, the most important being poultry. Only 19.2% of soybeans grown are actually for human consumption, with soybean oil making up the bulk of that number. Only 3.8% of the soy grown is destined for industry, which includes products like SPF. In the end, growing soybeans to wear isn’t the point – growing them to feed animals that produce far less food than the amount of food they consume!

In conclusion…

Keep your eyes peeled for soy protein fiber! Some niche independent clothing companies have already started selling it, but it is not very popular. It is an innovative textile that highlights how unsustainable polyester and other plastic-based textiles are. From hemp to linen to cotton, biodegradable textiles are essential in a world where more and more clothes end up in landfill.

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