Apparel brands are in love with a new concept - bio-based.
Carbon neutral and sustainable, giving bio-based fibers two buffs, became a new business for domestic and foreign companies such as DuPont, Asahi Kasei, Kaiser Bio, and Wanhua Chemical.
But are bio-based materials good and how are they produced? Can garment companies afford to use them? What technical problems are still unsolved? This article will answer for you one by one.
Spinning food into thread
The current large-scale use of textiles are cotton, linen, silk and wool, or new pineapple leaves, palm leaf fibers, are natural fibers or direct biological fibers, the production process does not occur at the molecular level of structural changes.
Biobased fibers, on the other hand, are polymeric materials obtained by biosynthesis and bioprocessing from renewable biomass, and they are polymerized with acids, alcohols, esters, and polysaccharides such as lactic acid and 1,3-propanediol of biological origin. Depending on the source of raw materials and processing, they can be divided into three categories: marine bio-based fibers, bioprotein fibers and bio-based synthetic fibers.
Marine bio-based fibers
The two main types of marine bio-based fibers are chitosan fibers and alginate fibers.
The advantages of marine bio-based fibers are environmental protection, flame retardant and good degradability, but high manufacturing cost, poor functional and environmental characteristics, while their good moisture absorption and moisturizing properties are difficult to use in garment making. Therefore, marine bio-based fibers are mainly used in the medical field to make trauma dressings, either blended with cotton or synthetic fibers to improve their properties.
Bioprotein fiber
Bioprotein fiber is a fiber made from protein of biological origin, similar to wool and silk. The common ones include spider protein fibers, soy protein fibers, milk protein fibers, etc. By blending them with polymers such as acrylonitrile, polyvinyl alcohol, cellulose, etc., protein fibers with different properties can be made.
However, natural bioproteins are expensive and too extravagant to be used for spinning yarn for garments. The price of a pound of soy protein is 14 yuan / kg, by the subsequent processing, spinning and other links, the cost of soy protein fiber will be higher, while the average price of secondary cotton in Xinjiang in 2020 is 7.14 yuan / kg.
Bio-based synthetic fibers
Bioprotein fibers instead of cashmere, silk, fur and other luxury fabrics, while the medical use of marine bio-based fibers is much greater than the textile use. And is expected to replace the "six spandex", is a bio-based synthetic fibers.
Bio-based synthetic fibers, which are fibers made from renewable biological resources. Generally, the raw materials of these fibers are natural carbon sources such as glucose, oil and cellulose, which are made into bio-based monomers by microbial fermentation or chemical methods, polymerized to obtain polymer of high molecules, and then selected to be processed into fibers by suitable spinning companies.
Based on the degradability of the material, we can further divide the bio-based synthetic fibers into two categories: biodegradable bio-based synthetic fibers such as PLA, PHA, PCL, PBS, PGLA, etc., and non-degradable bio-based synthetic fibers such as PE, PDT, PTT, PEF and various bio-based polyamides.
Among them, PDT and PTT can be used to replace polyester, bio-based polyamides can replace petroleum-based nylon, and PLA and PHA are similar to some polyester and cotton threads.
The commercialization of bio-based PTT has progressed the fastest. As early as the 1990s, DuPont made bio-based PTT polyester fiber from corn using a biological method and registered a trademark for it, which is now known as Sorona® fabric.
In recent years, PLA, PHA and bio-based polyamide have become hot research topics.
PLA and PHA benefit from the trend of plastic restriction and plastic ban because of their good biodegradability. Both have good physical and mechanical properties, thermal stability and thermoplasticity, as well as good biocompatibility, and their fibers are used in a wide range of textile applications.
But overall, there are still many bottlenecks in the bio-based fiber industry.
There are still technology gaps in some bio-based synthetic fibers with excellent performance in China.
Another issue is how to control the production cost of bio-based fibers.
Although bio-based fibers have renewable raw materials and low energy consumption in production, for investors and customers do not care about their environmental value, "If it saves cost, it has value; if it does not save cost, it has no value." Some investors told the shell hard technology, "Want to reduce emissions can go to engage in carbon capture technology well."
Also plagued by cost issues are PLA and PHA.
In addition to cost reduction and efficiency improvement, the competitiveness of bio-based fibers lies in suitable selection and raw material innovation.
Prospects
In terms of product selection, products in high demand are more advantageous, such as bio-based nylon and other alternatives to the "Big Five".
Among them, polyester is the world's largest production, the most widely used varieties of synthetic fibers, polyester currently accounts for more than 60% of the world's synthetic fiber production.
Therefore, bio-based alternatives to polyester are relatively more promising, such as PDT and PEF.
