Are biobased synthetics environmentally sound or just as bad as their petrochemical alternatives?
How cool would it be if cities could produce polyester from their own biofuel made from residents’ food waste? What if large companies could begin to implement systems that managed entire supply chains, ensuring a clean and fairly produced textile? What if we could develop schemes where we could always recycle or easily compost anything we produce, and eliminate landfills?
Biobased synthetic textiles like Tencel, Modal, and corn and soy fabrics have become a heavily invested area of research and development in modern textile experimentation in the more than $400 billion textile industry. Recent technologies have provided a platform for manipulation of natural plant matter, producing engineered textiles that are essentially considered “natural” as they are derived from plants. This chemical manipulation has allowed fiber and textile producers to come up with amazing, high performance materials that are especially sought after by the sportswear and outerwear industries. Although made from the fiber of trees and plants, can these manipulated textiles really be considered natural?
Scientists and developers at various fiber producing companies have been experimenting with manmade fibers made from cellulose since 1980. Cellulose is an organic compound that makes up 33 percent of all plant matter, and is commercially derived from natural sources such as wood and cotton. Manmade cellulose fibers are usually spun and woven into the fabrics commonly known as rayon viscose, however, the chemical processing used to produce conventional rayon is very energy intensive and wasteful. Often made from bamboo nowadays, rayon viscose manufacturing consists of a process using approximately 13 toxic chemical solvents, as verified by reports from SRI Consulting for the chemical industry.
However, scientists have come up with a different method of cellulose textile production. Currently, cellulosic raw materials such as eucalyptus wood, beech wood, corn, hemp, flax and even nettles, are undergoing lab experiments for genetic manipulation and nanotechnology. This means that these plant fibers are changed at a microscopic scale, which allows them to be engineered for high-performance qualities. Various, proprietary production methods for these cellulose fibers have been developed in the last 10 years, which integrate low-impact practices. For example, the production of Lenzing’s Tencel fiber leaches no toxic chemicals into the air or water, and re-uses 99.5 percent of the solvent needed for processing the fiber into a spinnable form.
Tencel, Modal, and Ingeo textiles all belong to the manmade cellulosics group, and have been showing up on the clothing tags at several brand-name stores. These fibers are often spun with other natural fibers like cotton or silk to produce some of the most comfortable and wearable fabrics. Although environmentally sound production processes have been developed, the main issue with these fibers is the land and resources necessary for growing raw material crops. The use of pesticides, water, and energy, along with soil erosion for cultivation are also issues that can negate positive impacts of a ‘natural’ material. The long supply chain of yarn-spinning, knitting, weaving, dying and garment making that follows fiber production also complicates and effaces much of the sustainability efforts practiced in fiber production, as do the effects of consumer use through washing and wear. Cellulose fabrics do not always accept dyes well, necessitating possible use of harmful chemicals, complicating matters even further.
Another revolutionary, manmade material is plant-based PET, which is a type of polyester. Polyester is conventionally made through refining oil and natural gas but Japanese company Toray has developed a method for producing the fiber from biofuel rather than crude oil. Conventional polyester contains phthalates, or chemicals used to make plastic more flexible, which can leach into our bodies through our skin. Phthalates have been proven to disrupt the normal functioning of reproductive organs, which can lead to early breast development, testicular atrophy and reduced sperm counts. Toray has worked with biofuel producer Gevo to develop the fiber, which reportedly is made with ethanol derived from sugar cane. Crop cultivation and land management also become issues with this process, although the reduced amount of oil drilling and chemical intensive processing is a great step forward.
There is no doubt that biobased synthetics are more environmentally sound than their petrochemical alternatives. However, unless they prove to be solutions that create new, closed-loop systems for the production of textiles, they only become processes that make a slightly smaller negative impact than our current ones. Instead of growing acre upon acre of sugar cane or corn for ethanol production, engineering and technology could help create solutions that utilize our waste as a resource.
Image: Lenzing AG