- June 7, 2024
- Posted by: Bikramjit Singh
- Category: Sustainability
Biodegradable textiles are defined as those fibers and /or fabrics that disintegrate by the action of bacteria/ fungi or by some other form of biological breakdown. Biodegradation is simply the process by which nature disassembles and decomposes materials into their basic substances. Majority of fruits, vegetables and other food items, which are plant products, can be considered as biodegradable Chemicals percentage employed in the textile material life cycle tends to define the biodegradability of textiles.
The more chemical inputs that are applied on the fabric the more the time required by the fabric to decompose naturally and destroy the environment. A number of biodegradable textiles are categorized according to the degree of biodegradability, the time taken for the fabric to decompose fully and environmental effects.
Biodegradation is a term relating to recycling natural wastes and impurities to degrade natural matters into products that other organisms use as nutrients.
Factors Influencing Biodegradation of Textiles
Several factors affect the biodegradation process of textiles, including:
Fiber Composition: It was found that natural fibers such as cotton, wool, or silk degrade much faster than synthetic fibers like polyester or nylon. Biodegradation can also be expressed differently in blended fabrics with differences in the content of natural and synthetic fibers.
Molecular Structure: The polymers with lower molecular weight, lower crystalline structure, and greater hydrophilic tendency are proved to be more biodegradable in nature. This is because microbial enzymes are in a position to get easy access to them and also easily degrade them.
Environmental Conditions: Temperature, humidity, oxygen availability and the pH levels of the soil always affect the rate of biodegradation. Condition favourable for microbial growth are in most cases conducive for biodegradation processes.
Microbial Community: The presence and the variety of microorganisms as inhabitants of the soil are inarguably the main component in biodegradation. Bacteria and other microorganisms are enable to decompose any type of organic matter available in the environment.
Stages of Textile Biodegradation
Initial Decomposition: The first step is microbial adhesion on the textile substance that is very crucial in the formation of biofilm. Proteins produced by the above microorganisms start penetrating and attacking the outer layers of the textile fabric, thus causing a more general fiber degeneration of the textile.
Primary Biodegradation: In this stage, mechanical properties of the textile fibers change from that of the original polymer material in a relatively large measure. The fibers are further decomposed by microorganisms and enzymes which are constantly being formed for the purpose. This stage leads to loss or this inherent properties of textile material such as mechanical strength and soundness.
Ultimate Biodegradation: The final stage involves the complete breakdown of the textile materials into simple molecules. These molecules are fully reduced or oxidized into basic inorganic compounds like CO₂, methane (CH₄), nitrate (NO₃⁻), ammonium (NH₄⁺), and H₂O. The end products of ultimate biodegradation are non-toxic and can be assimilated into natural biogeochemical cycles.
What Fabrics are Biodegradable?
Several types of fabrics are known for their biodegradability, primarily those derived from natural sources. Here are some common biodegradable fabrics:
Cotton
Cotton is still one of the most used natural fibers, which biodegrades very easily, especially when it is not chemically processed at all or is processed to the least extent. It degrades rapidly under composting conditions and thus contributes nutrients back to the growing environment. The decomposition of cotton depends on factors such as the presence of moisture, oxygen and the microbial activity in the soil. Cotton can rot in as little as a few months if left untreated, which has significant implications for sustainability.
Wool
Another is the wool that comes from the skin of a sheep and it is also a biodegradable textile. It can be biodegraded in the soil, yielding compacted nitrogen for compost, but perhaps at a slower rate than cotton because of its protein base. Biodegradation of wool, is a process in which microbial action degrades the keratin proteins of the woollen fabric. If all requirements are met, wool can take as long as several months to a few years to biodegrade and return beneficial nutrients such as nitrogen and sulfur to the soil.
Silk
Silk is a protein fiber, made by silkworms and is proved to be biodegradable having the capability to degrade into amino acids under proper ecosystem. Silk is biodegradable but has a slow decomposition rate, especially in environments with low microbial activity and moisture. The breakup of the silk fibre can take anything from a few months up to two years depending on the conditions prevailing at the place. In this process, silk liberates properties which might enhance the fertility of the soil.
Linen
It is a natural textile that possesses strength, and flexibility obtained from the flax plant. It biodegrades quite fast in composter as it is the case with cotton. As a result, the fibers of linen are subjected to microbial degradation as well as deterioration due to environmental factors. Being a cellulosic material, linen can decompose in less than few months, if exposed to composting environmental factors adding organic content to soil and enhance its fertility.
Hemp
This type of fiber is abundantly found in the hemp plant and is reputed for its features like high strength and biodegradability. Hemp textiles can be disposed in the ground where it will decompose and return the organic material back to the soil. Because hemp fibers are strong and durable they cannot be easily degraded through wearing out while at the same time they readily decompose in composing. Nonetheless, hemp can decompose in a span of several months to a year and contributes to nutrient-rich compost by providing cellulose and lignin on the soil.
Bamboo
The bamboo fabric is produced from the bamboo plantations and the pulp is derived from the bamboos hence it is biodegradable. Nevertheless, there is a difference in the biodegradability of the bamboo fabric depending on the cooking techniques used to make it. Raw bamboo fabric, also known as bamboo linen, is less chemically treated than mechanically processed bamboo and thus environmentally superior because it biodegrades more easily. The bamboo rayon can be chemically processed and therefore, when they get into the soil, it may take longer to disintegrate due to the number of synthetic chemicals that may be involved. Consequently, bamboo fabrics have a short degradation period of between several months and approximately 24 months depending on the processing type and the surrounding environment.
Jute
Used primarily in producing burlap and hessian fabric, Jute is a vegetable breed fiber, which is also known for its environmental sensitivity due to its biodegradable nature for usage in different purposes. The material used in production of jute fiber is cellulose and lignin which is expected to degrade easily in composting ground. The degradation of the jute material may take a few months or more and when it degrades, it turns into organic matter which improves the soil structure, composition and fertility. Stakeholders in packaging and agriculture industries should consider using jute because it has an incredibly swift biodegradation rate.
Recent Developments in Biodegradable Textiles
Spinnova and Renewcell Collaboration
On the 6th September 2023, Spinnova which produces a sustainable textile material joined forces with Renewcell which is a Swedish textile recycling company. They came up with another strategy to bring innovation to market and increase the use of recycled textile waste to manufacture fiber. This synergy involves Renewcell’s CIRCULOSE® pulp from 100% recycled textiles furthermore, Spinnova’s technology that creates new fibers without using chemicals. The first consumer products are expected to be ready by end of 2024.
MIT and FIT Partnership
MIT and FIT launched a partnership in 2017 in an effort to push forward the field of textile engineering and create eco-friendly fabrics. This partnership comprises interactive sessions in which students engage in activities such as developing lifestyle shoes made of bacterial cellulose and mycelium or apparel using advanced fiber theories. Currently, the plan has the backing of the Advanced Functional Fabrics of America (AFFOA) network.
Clariant International Ltd. Initiatives
In 2024, Switzerland-based Clariant International Ltd. introduced dope-dyed yarns that use significantly less energy and water compared to traditional methods. They also developed new functional additive masterbatches to aid in recycling polyester and creating eco-friendly textile products
Uwila Warrior and CiCLO Technology Partnership
In 2024, Clariant International Ltd. from Switzerland launched dope-dyed yarn that consumes energy and water in minimal quantity as opposed to conventional methods. They also introduce innovative functional additive masterbatches for recycling polyester and manufacture environmentally friendly textile products.
The North Face and Bottle Consortium Partnership
In January 2024, Uwila Warrior, a Boston-based intimates brand entered into a tie-up with CiCLO Technology to launch the world’s first-ever biodegradable synthetic fiber undergarments. CiCLO Technology alters the polymer structure of synthetic fabrics such as nylon and polyester, which would normally take centuries to break down in a landfill, to biodegradable ones and can be disposed a few years in a landfill. That is why Uwila Warrior’s new “Better Briefs” collection that consists of underwear and camisoles has CiCLO fibers. This partnership focuses on overcoming the negative effects of using synthetic fabrics on the environment by minimizing the instances of microplastic shedding.
Patents in Biodegradable Textiles
WO2006129731A1 – Biodegradable Polyester Fiber
This patent examines the issues surrounding more traditional natural fiber biodegradables such as cotton, hemp, wool, and rayon. These fibers, though biodegradable, have high hydrophilicity and low water absorption where fabric should not have any wet feel such as the top sheets of diaper.
In other words, the patent describes a novel biodegradable polyester fiber made from the aforementioned biodegradable polyester material. This composition contains:
- 70 to 99% by weight of a biodegradable polyester (A).
- 30 to 1 proportional ratio of a modifying material (B) that is an ester compound
The innovative aspect of this fiber includes:
- Good flexibility and resistant to the thermal contraction.
- Fabrics made from these fibers: Nonwoven fabric suitable for sanitary products.
- Enhanced hydrophobicity and low water absorbing properties which is ideal for use in dry feeling end products.
Everywhere Apparel Inc – Manufacture of Biodegradable Textile Yarn from Recycled Materials and Textiles Made by the Process
Fashion industry is one of the worst polluters as it uses excessive water and releases several toxic pollutants. The currently prevalent polyesters, when used to manufacture clothing and accessories, cause long-term environmental issues as they are non-biodegradable and emanate micro-fibers that accumulate in aquatic environments and human bodies.
In the patent US20210206964A1, the innovation is the process of creating biodegradable textile yarn from recycled polyethylene terephthalate (rPET) and biodegradable PET additive (between 0.5% wt and 3% wt). This bio-rPET fiber is further blended with Recycled Natural Fibers in order to develop a biodegradable textile yarn. This method gives a robust and durable yarn fit for commercial use in textile industry and which is ecofriendly, and is fully biodegradable.
Intrinsic Advanced Materials LLC – Biodegradable textiles, masterbatches, and method of making biodegradable fibers
Nylons, polys, and other synthetic textile fibers may be long-lasting and waterproof, but these same qualities make the fibers difficult to break down naturally. These fibers cause long-term landfill and marine pollution as millions of pounds end up in landfills daily, and micfibers in water bodies.
The patent (US10683399B2) discloses the formulation of a masterbatch as follows: 0. An example of a substrate includes 2 to 5 mass % CaCO3, an aliphatic polyester and a carrier polymer, namely PET or nylon. It enables the formulation of synthetic textile fibers which are biodegradable though having a durability of the fabric in addition to breaking down at a faster rate than the other fabrics. The method focuses on compounding this masterbatch with a polymer, followed by processing through extrusion to yield filaments which are then solidified into biodegradable fibers and textiles.