Series on Unusual Fibres: Soy Fabric
A closer look at unusual fibres: How is soy fabric made?
The History of Soy Fabric
While it is still relatively unknown to the general population, the first attempts to manufacture fabrics from soybean were actually carried out in Japan during the 1940s and in the United States in 1945. Although the final fibres were successfully manufactured, they were never commercially produced due to the lack of functional characteristics. This was further hindered by the rise of petroleum after World War II, which soon became the major raw material used to create textile fibres due to it's low processing cost. This synthetic alternative soon lessened the need for many man-made protein fibres. During the last decade there has been a renewed interest in soybean fibre, particularly heightened by environmental concerns. Offset Warehouse often stock soy fabric, as an alternative sustainable material.
How Is Soy Fabric Made?
Soy fabric is derived from the soy bean. The soy bean contains natural fibres within each bean. When these fibres are stripped from the bean they are too coarse to be spun and so they have to be processed. This extensive production process involves breaking down the proteins in the soybean by exposing them to heat, alkalis and/or enzymes. They are then filtered and pushed through a spinneret to separate the fibres into long strands. As natural fibres have a tendency to crease easily, some manufacturers cross-link the fibres using formaldehyde to lengthen them and therefore increase it's crease resistance. Formaldehyde has been classified as a probable human carcinogen, so alternatives have and are still being investigated, such as polycarboxylic acids.
Once the bean fibres are spun, they can then be woven into fabric. Here'a a little more information on how to make fabrics, that I wrote a few months ago. The dyeing process happens once the fibres have been twisted into yarns (known as yarn dyeing), or once the yarns have been made into fabrics, or finally, once the end product has been made (known as piece dyeing).
The fabric is very soft and flows beautifully. The most popular garments to be made out of soy fabric are dresses, women’s cardigans, and women’s jumpers, although the possibilities are endless!
Characteristics of Soy Fabric
You would think that a garment made out of soy protein would feel slightly coarse and irritating against the skin, but it is the complete opposite. Instead, soy fabric has a cashmere feel because the fibres from the soybean are very light and flexible. This also gives any fabric constructed from soy a very luxurious feel, and it drapes as elegantly as silk. While many cling to cotton as their fabric of choice, soy fabric is actually more absorbent with better breathability, so is a great choice in all weathers. When dyed, soy fabric holds its colour for ages, wash after wash, because the dye clings to the tiny individual soy fibres. Lastly, there are many people that believe that soy fabric actually has a beneficial effect on our bodies because it contains many amino acids that we can absorb through our skin.
Pros & Cons of Soy
Soy fabric really is beautiful, and it can be used for a huge range of different garments and soft furnishings. As some fabrics become difficult to manufacture, and we move away from environmentally damaging synthetic materials, natural fabrics such as soy will become more and more in demand. It also has the huge benefit of being relatively cheap to make.
One downside of soy fabric, which should change in the future, is that currently around 70% of the world’s soy fabric is manufactured in China, which uses almost exclusively genetically modified soy. The plant requires a large amount of water and pesticides for cultivation, although organic soy can successfully be grown on a smaller, more low-impact scale. Another agricultural and environmental issue with soy production is the amount of rainforest land becoming compromised for the sake of this crop, which is causing habitat destruction, food shortages and rapid environmental change. Soy’s sustainability and whether it is an eco-friendly fabric, like many other naturally grown fibres, can vary depending on how responsibly the farmers decide to grow the crop.
Firstly, anything that moves away from cotton, but is still a natural raw material is a great start in my book. You can read more about cotton's hugely damaging impact in one of my previous articles. Soy fabric is not synthetically made. Where synthetic fabrics use up resources that can not be reproduced, such as petroleum, the soy bean regrows quickly, and so is a more frequently renewable raw material. Secondly, the raw material used to create soy fibres are a natural by-product of extracting soy oil and soy foods like tofu. Similarly, any fibres that are not of a high enough quality to be used in the fabric are then fed to cattle, making it a zero waste material.
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