Life Cycle of Cellulose Fiber to make Lyocell: Materials
Lyocell, a synthetic fabric derived from cellulose fibers, is advertised to be one of the most sustainable and environmentally friendly fabric. It’s used in many different products such as furniture to clothing, and can even be given a suede or silk like texture. This versatile fabric is produced by the company Lenzing under the brand name Tencel. The life cycle will be done from wood to fabric, because the fabric has many uses after that point it would be difficult to track all the final products. Lyocell is sustainable because a majority of the raw materials used for production are renewable and reusable. The process of how lyocell is manufactured and what key materials are used to produce it will be explained and an analysis of each material will be done to then determine if lyocell as a whole is a sustainable fabric.
The first step of the production process is to acquire dissolving pulp, fibers stripped down to a pulp. Tencel is made of a combination of beech and eucalyptus wood pulp. Beech wood pulp, known as Lenzing pulp is produced by Lenzing themselves. The beech wood used to make Tencel originates from Austria and other European countries. It doesn’t require irrigation, is not fertilized, and is machine harvested. Because of the woods low maintenance and availability, it is sustainable. Eucalyptus pulp, also known as market pulp isn’t produced by Lenzing and is acquired from outside plantations. Eucalyptus can be grown on low grade land so many areas that are deemed dead and wastelands can be used. It also can grow in almost any climate, making it an easily accessible wood. Eucalyptus requires only a small amount of nitrogen and phosphate fertilizer. It doesn't require much water and is fast growing. Because of these qualities the turnover rate of eucalyptus plants is very high making it an easily renewable material. The land to grow the wood required for lyocell is about 0.24 hectares per ton. This is a low amount if compared to other Lenzing fabrics and cotton, as seen in the chart below. Since the amount of land to ton of fabric is low, the land is used efficiently, making the harvesting cellulose for environmentally friendly.
Once the dissolving pulp is gathered, the next step in the manufacturing of lyocell is to dissolve the pulp. N-methylmorpholine-N-oxide, otherwise known as NMNO, is an organic compound that is mixed with water to create a solvent used to dissolve the wood pulp. Then when the process is done, the wash water is sent through a purification process that extracts the NMNO and is returned to its usable state. According to a report done by researchers for Lenzing, 99% of the solvent is recovered, making this part of the production process a closed cycle. Although NMNO is a petrochemical, meaning it is derived from fossil fuels, because of its reusability it is a sustainable practice to keep using it in lyocell production and only adds to the overall sustainability of the fabric.
Water is used throughout the manufacturing process. Water usage is an aspect of the lyocell production process, as well as other textile processes, that isn’t ideal but is required and unavoidable. Therefore to help understand how efficient the water usage is in producing Tencel, a comparison to other fabrics should be made. As seen in the chart below, Tencel production uses the least amount of water out of all Lenzing fibers. Tencel uses 263m3 of water to produce one ton of fabric. Out of that, 20 m3 is processed water such as deionised and soft water. The rest is cooling water, this water is unprocessed water and derived from natural sources such as rivers and lakes. Lyocell only requires a small amount of processed water, which takes resources to create. It doesn’t require much irrigation water, as mentioned above. Therefore the water usage is controlled, therefore making lyocell and environmentally conscious fabric.
One of the final steps that Lenzing is involved in before the fabric is sent to manufacturers, is bleaching the fabric so it’s ready to receive dyes. To do this a chemical called tetraethylene diamine, or (TAED) is mixed with hydrogen peroxide to produce a bleaching agent. Although other chemicals can substitute TAED, the TAED and peroxide mix is the most efficient because it achieves the maxim bleaching power that the lyocell fabric can withhold while doing so at a low temperature, therefore saving energy as other chemicals would require a higher heating point. TAED and its reaction product when mixed with peroxide is non-toxic and non-sensitising so it’s better for the fabric and consumers who are sensitive to bleaching chemicals. It biodegrades to help make many useful by products such as ammonia and water. Because of it’s non toxic and biodegradability the bleaching agent is another sustainable raw material that goes into the manufacturing of lyocell fibers.
A final raw material that should be mentioned is fuel. It’s used during both acquisition of materials as well as the manufacturing process. All of the fuel is used for acquisition and production of the dissolving pulps, the eucalyptus collected for the market pulp uses fuel mainly to transport the wood by ship because only about 20% of the harvesting is done by machine. For the Lenzing pulp, the beech wood collected from Europe requires is harvested by machines and transported by railways and roads. From pulp to finished fiber, this is the only fuel that is used. The energy used to process the cellulose fibers, or the kraft process, is recovered from municipal solid waste incineration. Therefore no additional fuel is used for the manufacturing process, making the energy for Tencel a closed cycle. With low fuel usage, Tencel is sustainable.
When an analysis of the raw materials used in creating lyocell fibers is done it’s clear that Lenzing is practicing a sustainable method. The the wood is grown on sustainable farms, the manufacturing process reuses the key chemical required, and the bleach is repurposed after it’s use on the fabric. From the wood to the finishing lyocell has very little waste and the materials are reused sometimes indefinitely. The product has many closed cycles and which makes it renewable and reusable, therefore sustainable.
Bahia, Hardev Singh. Process of Making Lyocell Fibre or Film. Tencel Limited, Derby, assignee. Patent US 6,258,304 B1. 10 July 2001. Print.
Chavan, R B, and A K Patra. "Development and Processing of Lyocell." Indian Journal of Fibre & Textile Research 29 (2004): n. pag. Web.
Carrillo, F., X. Colom, and X. Canavate. "Properties of Regenerated Cellulose Lyocell Fiber-Reinforced Composites." Journal of Reinforced Plastics and Composites 29.3 (2008): 359-71. Web.
Kasahara, K., H. Sasaki, N. Donkai, and T. Takagishi. "Effect of Processing and Reactive Dyeing on the Swelling and Pore Structure of Lyocell Fibers." Textile Research Journal 74.6 (2004): 509-15. Web.
Luo, Mengkui, and Amar Neogi. Method of Making a Modified Unbleached Pulp for Lyocell Products. Weyerhaeuser Company, assignee. Patent US 7,097,737 B2. 29 Aug. 2006. Print.
Mathews, Jane, Susan Scarborough, and Jenny Wilkinson. Lyocell Bleaching Process. Patent EP 0 989 224 A1. Print.
Perepelkin, K. "Lyocell Fibres Based On Direct Dissolution Of Cellulose In N-Methylmorpholine N-Oxide: Development And Prospects." Fibre Chemistry 39.2 (2007): 163-172. Academic Search Complete. Web. 3 Feb. 2016.
Peterson, William S., Jr., and Roman O. Marchak. Closed Loop System. The Bendix Corporation, assignee. Patent 4,241,710. 30 Dec. 1980. Print.
Shen, LI, and Martin K. Patel. "LIFE CYCLE ASSESSMENT OF MAN-MADE CELLULOSE FIBRES." Lenzinger Berichte 88 (2010): 1-59. Web. 12 Mar. 2016.
Woodings, Calvin. "Industrial Cellulose." Regenerated Cellulose Fibres. Boca Raton, FL: CRC, 2001. 22-32. The Library of Congress. Web.
March 14, 2016
The Embodied Energy of Creating Cellulosic Fibers from Wood
The life cycle of cellulosic fibers by the Lenzing Group uses a fair amount of embodied energy, but the production process and waste disposal is largely self-sufficient and features environmentally sound practices. Cellulosic fibers are an artificial alternative to common clothing materials such as cotton or wool, and are described as “synthetic polymers made from natural resources,” (Shen, Patel, pg 2). The production of cellulosic fibers is a relatively recently developed method for the production of clothing from wood pulp (“Tencel Clothing”). The Lenzing Group, the main producer of cellulosic fibers, focuses on production methods that foster a strong relationship with both the environment and the materials used. For the sake of clarity, the Lenzing Group is the name of the company responsible for the majority of the production of cellulosic fibers, while lyocell and viscose fibers are different varieties of cellulosic fibers that the Lenzing Group produces. “Tencel” is the brand name associated with products made from cellulosic fibers produced by the Lenzing Group. The Lenzing Group is notable for using practices such as planting the trees used in their fibers on land “unsuitable for crops or grazing,” just one example of many ways the process is done with the environment in mind (“Tencel Clothing”). The life cycle of cellulosic fibers places massive emphasis on the environment and maintaining an equilibrium within the embodied energy used in the gathering, processing, and distribution of lyocell products. The Lenzing group pays extremely close attention to the amount of energy used in its production processes, as well as the sources of energy drawn upon for each part of the life cycle.
The life cycle begins with the harvesting of the natural resources and materials necessary for the production of the fibers. Because viscose lyocell fibers are cellulose based, the primary raw material is trees, and planting, growing, and harvesting the necessary trees to provide the cellulose is the most energy intensive aspect of this stage of the life cycle, (“Tencel Clothing”). The Lenzing Group is a fairly large company, with multiple locations across Europe and Asia each producing a number of different kinds of fibers under the brands of both Lenzing and Tencel, (Shen, Patel, pg 4). The breakdown for the types of energy used in the gathering of the raw materials differs between locations and the type of fiber being produced. For their location in Asia, the raw material gathered is Eucalyptus wood, which is used to produce viscose fibers, (Shen, Patel, pg 6). This location is the least environmentally friendly of all of the Lenzing Group locations, and uses local electricity, coal, gas, and oil to fuel these gathering processes, (Shen, Patel, pg 6). However, the production of lyocell and viscose fibers from the Austrian location demonstrates a very different approach to energy use. This facility gathers both European Beech and Eucalyptus wood, for the production of both lyocell and viscose fibers, (Shen, Patel, pg 6). The energy use for the gathering of materials in the Austrian facility is much more environmentally friendly, and uses significantly less fossil fuels, if any at all. For the gathering of materials for the production of lyocell for use in Tencel clothing specifically, the energy used is completely harnessed from the incineration of solid waste from other parts of the life cycle, (Shen, Patel, pg 6). For the raw materials for the production of viscose, the energy used is partly the incineration of solid waste, and partly the use of biomass as a fuel source, (Shen, Patel, pg 6).
While the types of energy used in this part of the life cycle was readily available, it was not possible to discover exactly how much energy was used in the production and preparation of the raw materials. Because the Lenzing Group has so many good environmental practices, it is not surprising that they want to publicize information about their energy sources. Their use of biomass and their own industrial waste as a fuel is extremely low in greenhouse gas emission, even if it may have a greater impact on issues like deforestation. However, it is possible that the Lenzing Group are less likely to produce their actual energy use in numbers in order to avoid tarnishing the “green” image they have worked so hard to construct. A high energy use in spite of these practices could indicate that even a low percentage of fossil fuels used could result in high emission rates. Similarly, the use of biomass could be so significant that it is contributing to deforestation or other similar environmental depletion issues, which the Lenzing Group may understandably wish to keep out of the view of the public.
The bulk of the embodied energy in the life cycle of cellulosic fibers comes with the production and processing of the wood into pulp and eventually fibers, which take place at the various Lenzing establishments across Europe and Asia. The Lenzing Group uses highly green and energy efficient practices overall that help limit the emissions of greenhouse gases and cut down the use of fossil fuels. The Lenzing Group’s energy in both pulp and fiber production comes from either Lenzing owned and operated power stations, or from working with local power plants, (Sustainability in the Lenzing Group, 56). The energy sources used are heavily reliant on the waste products and by products of the production process itself, (Sustainability in the Lenzing Group, 56). The production process uses all available energy in a productive manner during the process, and very little energy goes unharnessed. All of the unused biogenic materials from the process are used as a fuel source, and the trees used as raw materials are used as fuel to generate heat and eventually steam, (Sustainability in the Lenzing Group, 56). Similarly to the process of gathering the raw materials, waste is also used as a fuel source to help to generate electricity (Sustainability in the Lenzing Group, 57). Another distinct part of the process is the energy efficiency across aspects of the production process. Energy that is released as heat during the pulp production process is harnessed and repurposed to provide heat to generate electricity to turn the pulp into fibers, (Sustainability in the Lenzing Group, 57). While a majority of energy used in production by the Lenzing Group is sourced from biogenic fuel sources and waste repurposing, a minority of the energy used comes from the burning of fossil fuels. In 2011, 54% of the Lenzing Group’s energy use was powered by biogenic renewable fuel sources, while the remaining 46% was entirely powered by coal, gas, and a very small minority of oil. With this breakdown, the overall energy consumption of the Lenzing Group in the year 2011 came to total at approximately 13,000,000 gigajoules, the majority of which was renewable energy sources, (Sustainability in the Lenzing Group, 57). However, as previously mentioned, the Lenzing Group has a large number of facilities around the world, and each operates at a different level of energy use with a different breakdown of types of fuel used. While a small minority of the larger facilities use almost entirely biomass and renewable energy sources, a larger majority of the smaller facilities use a large amount of fossil fuel based energy, usually in the form of purchased electricity from coal powered power plants, (Sustainability in the Lenzing Group, 58). Each facility required a different amount of electricity in total, usually depending on the size of the facility. For their largest production facility in Austria, the embodied energy use in megawatts was 77 megawatts, on average, while using a variety of fuels including waste, biogenic fuels, and self generated electricity, (Sustainability in the Lenzing Group, 58). The majority of the other locations did feature some form of self generated energy, but primarily used fossil fuels or purchased electricity to power the processes. The electricity used by these smaller scale locations ranged, on average, from 10 megawatts to 30 megawatts annually, (Sustainability in the Lenzing Group, pg 58).
Though the energy uses may appear to be high, especially when examining the total energy used annually, it is important to acknowledge that this usage includes the use of waste and biomass as fuel sources, which are the majority of the energy used and are sustainable overall, and do not contribute to emissions.
Many products and companies have high energy uses even after production, in the disposal and elimination of waste materials. Many companies expend additional energy to move their waste to landfills or other refuse sites, and many must expend even more to deal with hazardous materials that cannot be disposed of normally. However, instead of throwing away their waste and byproducts, the Lenzing Group makes special efforts to reuse every single aspect of the production process. As mentioned previously mentioned, these waste and excess materials are all incinerated and used to self-generate electricity for the process itself, (Sustainability in the Lenzing Group, 56). This creates what is known as a “closed loop system,” in which the process feeds energy into itself. As a result, instead of using untold amounts of energy in the disposal of waste, the Lenzing Group actually ends with a positive net gain of energy after the loop has ended, (Sustainability in the Lenzing Group, 55).
It was very difficult to obtain actual figures regarding the amount expended in this production process. Most sources on the topic offered percentages or ratios of types of fuels used, but failed to offer any types of electrical or energy units. However, after emailing the company’s representative, we received links to special sustainability reports that detailed and outlined the energy uses of each facility, as described above. While we were able to discover just how much energy was being used at each location, and how much from each source, the only main expenditure of energy that was not described was the shipping process of the final products from the factories to their final destinations, and this was missing from all of the sources we examined. Upon inquiring further with our company contact, we were politely informed that the Sustainability reports were the only publically available information on the Lenzing Group’s energy use. We can assume that Lenzing uses standard shipping methods through trucks and planes to distribute their products, and assume all of those energy costs through the operation of those vehicles.
The life cycle of cellulosic fibers, as produced by the Lenzing Group, is a relatively closed and self-contained process that is both sound in energy consumption and in its environmental impacts. Across embodied energy, waste, and materials, the Lenzing Group takes advantage of all resources and available energy at every stage of production. At the end of its life cycle, these fibers are compostable, meaning that the materials are used to provide even more of a surplus of energy. Overall, this is an extremely efficient life cycle, and is a model example for other companies that rely on factory driven manufacturing.
"Sustainability Reports." Sustainability Reports. Lenzing Group. Web. 10 Mar. 2016.
“LIFE CYCLE ASSESSMENT OF MAN-MADE CELLULOSE FIBRES” Li Shen and Martin K. Patel, Web. 04 Mar. 2016
Mechanical Properties and Biodegradability of Green Composites Based on Biodegradable Polyesters and Lyocell Fabric." Web. 03 Feb. 2016.
Chavan, R.R. "Development and Processing of Lyocell." Web. 3 Feb. 2016.
Farley, Jennifer, and Colleen Hill. Sustainable Fashion: Past, Present, and Future. Print.
"Lyocell." How Lyocell Is Made. Web. 03 Feb. 2016.
Tencel Production Process." Lenzing. Web. 3 Feb. 2016.
"Properties of Regenerated Cellulose Lyocell." Sagehub. Web. 29 Feb. 2016.
Analysis of Lyocell Fiber Formation." Springer. Web. 7 Feb. 2016.
“One day you’re in, and the next, you’re out,” is a common phrase reiterated amongst the textiles industry. This fluid and ever changing cycle of trends, styles, and resources explains why the textiles community can’t seem to commit to one specific and concise attitude. Currently, the industry has taken into favor the trend of being “eco-friendly,” mainly due to the fact that there has been a growing demand by society for conscious friendly fibers with the need hinging on sustainability, comfort, and fashion. Lenzing Group, is the worldwide company that caters to these demands by manufacturing and producing man-made cellulose fibers. According to S. J Eichhorn, he states in his article, “Current International Research into Cellulosic Fibres and Composites,” that cellulosic fibers are the call to solution due to them being either native (natural from plants or animals) or regenerated (man-made) as well as the fact that they are relatively cheap to produce, express a variety of versatile purposes, and contain an ease of recyclability (2108). Although Lenzing Group makes a variety of man-made cellulosic fibers within their company, it is essentially Lyocell (produced by under the brand name, Tencel) that trumps and surpasses them all. Constructed from wood pulp, Lyocell proves to be the leading cellulosic fiber not only in the textile industry, but as well as the sustainability community due to it’s remarkable safe acquisition of raw materials, essentially non-existent byproducts from manufacturing, and the simple fact that the product itself is biodegradable, leaving virtually no waste!
From the Earth, for the Earth: that is essentially the lifestyle that Lyocell strives to maintain, incorporate, and protect. Like any other product, the process of manufacturing and creating begins with the acquisition of the raw materials needed to make it. Unlike numerous other companies, Tencel prides itself on being one of the rare few where extracting their materials to construct their product doesn’t detrimentally impact or destroy the environment it takes it from. First things first, they use a unique main renewable raw material in their production: wood pulp! Coming from the Lenzing Group website itself, they state that their primary source of pulp is through harvesting the evergreen Eucalyptus tree. They state that this species of trees is so unique amongst others in the sense that it grows extremely rapidly and without any artificial irrigation and/or gene manipulation; unlike other wood farms that the industry manipulates. The eucalyptus tree is also incredibly more logically ecological in the sense that there is absolutely no water or pesticide-play in their cultivation. Knowing this, Lenzing Group also proclaims on their website that their gathering process is heavily guided by sustainability, which means that the forest industries that they practice with are only managed in such a way that no more wood is taken out of the forests than can be replaced by new growth. This mentality promotes the structure of renewable raw materials and ensures that the company is not hindering for other generations to come and grow. Again, preaching to the choir that from the Earth, for the Earth is such a crucial concept to maintain and protect.
However, another vital concept to maintain and protect regarding the efficiency of Lyocell is the fact that their manufacturing, processing, and formulation is incredibly eco-friendly, sustainable, and overall conscious of its procedures. Tencel practices a “Closed Loop” concept that is based on the solvent spinning system in order to produce their cellulosic fiber. Featured on the article, “Process for the Manufacture of Lyocell Fibre,” by James Martin Gannon; it states that the present spinning system is simply summarized by these three steps: one, dissolve the wood pulp into a tertiary amine solvent, N-Methyl morphine-N-Oxide (or NMMO for short), to form a solution. Two, extrude this solution to replicate a die that produces a plethora of cellulosic filaments. Three, wash the filaments to remove the initial solvent, thus formulating the Lyocell fibers (2). What makes this entire process completely ecological is the fact that there are minimal to almost no byproducts that are produced from it. Researchers from the article, “Tencel or Lyocell ecofriendly- caution for those with MCS,” proclaims that the regenerated fiber has little impact on the environment due to the fact that the amine oxide solvent that Tencel uses is essentially 99% recovered at the end of the system and is recycled back into their manufacturing process, which explains why it is labeled as a “closed loop” system. Did I also forget to mention that not only is this solvent almost completely repurposed; but it is also non-toxic? Double win! Alongside this, the website also proclaims that the plant emissions from the production into the air from the various smokestacks are significantly lower in comparison to many other man-made fiber operations. Lastly, the website states that a majority of the surplus water that remains after the cycle is eventually evaporated off and if by chance there is any remaining waste-water, it is then purified by a biological waste-water treatment plant. This goes to show that being environmentally forward doesn’t only focus on the end result of what you’re trying to change, but it is also incredibly relied upon the juxtaposition of the steps in between.
In regards to endings, the last reason that Lyocell surpasses leading cellulosic fibers in the textile industry, as well as paves the way for being environmentally sound is the fact that the materials itself can be completely biodegradable without any assistance. In the journal, “Mechanical Properties and Biodegradability of Green Composites based on Biodegradable Polyesters and Lyocell Fabric,” researchers conducted an experiment to observe whether or not the regenerated fiber could truly prove what it proclaims to do: decompose itself. Scientist called it the, “Soil Burial Test,” where they cut a 40x20mm piece of Lyocell and placed it in a 1:1 mixture of leaf mold and black gardening soil. They then stored the layering’s in a room at a constant temperature (25-30°C) at relative humidity (80%), where after 60 days, researchers observed that there was a significant amount of weight loss from the sample and the recovery of the decomposed fragments were extremely difficult to reconstruct. These observations and scientific evidence all support the concept that Lyocell is a cellulosic fiber that is able to decompose itself and become biodegradable. This fundamental characteristic gives Lyocell the award for being immensely un-wasteful and shows its prohibition of the support of further contaminating our Earth with trash, debris, and pollution. Other ways Lyocell can be properly disposed of is by being incinerated or recycled as stated by the piece, “Life Cycle Assessment of Man-made cellulose fibres,” by Li Shen and Martin K. Patel. The irony in allowing for proper disposal and/or repurpose of one’s finished lifecycle, is that it essentially gives birth and rise for other creations to grow, expand, and thrive on.
With the tides of reform, renewal, and sustainability sweeping the nation, it has since left a high demand for friendlier, ecological, and more recyclable materials that won’t heavily detriment or impact the Earth we live on. These waves have since created numerous sources and operations that allow our species to live greener and more consciously. Some include extensive recycling programs, repurposing old materials, and designing innovations that propel our humanity into the future. One of these unique innovations is the renewable cellulosic fiber: Lyocell. What makes this man-made textile so incredibly ecologically forward is the fact that extracting and acquiring the raw materials to produce it uses only a resource that is renewable and they don’t heavily leave a huge imprint on the surroundings the companies take it from. Lyocell is also remarkably eco-friendly because the exact process to make it is a “closed loop” system, which almost virtually leaves no byproducts, wastes, or emissions. This allows for Lyocell to be extremely efficient and sustainable, especially in the sense that it is able to biodegrade itself!
Living on this Earth for almost 21 years now, I have watched the world I love grow in despair, dirt, and pollution. The trees I once climbed are now disappearing, the water I once swam in is drying up, and the soil I once laid in is contaminated. And although I have watched the world grow old, I have also watched it become more kind to itself by the people who love and care for it. It is only possible to climb those trees again, and swim in that water, and lay in the grass if we think innovatively and keep designing ecologically forward inventions, like Lyocell, that take care our of our world. Because one day our Earth “may be in, but the next day, it may be out.”
Chavan, R. B., and A. K. Patra. "Developement and Processing of Lyocell." Developement and Processing of Lyocell 29 (2004): 483-92. Web. 12 Mar. 2016. <http://nopr.niscair.res.in/bitstream/123456789/24664/1/IJFTR 29(4) 483-492.pdf>.
Eichhorn, S. J. "Current International Research into Cellulosic Fibres and Composites." Journal of Materials and Sciences 36 (2001): 2107-131. Web. 12 Mar. 2016. <http://www.srs.fs.usda.gov/pubs/ja/ja_eichhorn001.pdf>.
Farley, Jennifer, and Colleen Hill. Sustainable Fashion: Past, Present, and Future. Bloomsbury Academic, 2015. Print.
Gannon, James Martin. "Process for the Manufacture of Lyocell Fibre." Courtaulds Fibres (Holdings) Limited (1998): 1-5. Web. 12 Mar. 2016. <https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US5725821.pdf>.
"Lyocell." How Lyocell Is Made. Web. 13 Mar. 2016.
"EUCALYPTUS. ECOLOGICAL THROUGH AND THROUGH." Lenzing Fibers. Lenzing Group: Leading Fiber Innovation. Web. 13 Mar. 2016.
"“Tencel® or Lyocell Ecofriendly – Caution for Those with MCS”." Natures Crew Eco Store. Web. 13 Mar. 2016.
Shen, LI, and Martin K. Patel. "LIFE CYCLE ASSESSMENT OF MAN-MADE CELLULOSE FIBRES." Lenzinger Berichte 88 (2010): 1-59. Web. 12 Mar. 2016. <http://www.lenzing.com/fileadmin/template/pdf/konzern/lenzinger_berichte/ausgabe_88_2010/LB_88_2010_paper_1.pdf>.
Shibata, Mitsuhiro, Shingo Oyamada, Shin-Ichi Kobayashi, and Daisuke Yaginuma. "Mechanical Properties and Biodegradability of Green Composites Based on Biodegradable Polyesters and Lyocell Fabric." Journal of Applied Polymer Science J. Appl. Polym. Sci. 92.6 (2004): 3857-863. Web. 12 Mar. 2016.
"Focus Sustainability: Sustainibility in the Lenzing Group." Www.lenzing.com 4 (2012): 1-82. Web. 12 Mar. 2016. <http://www.lenzing.com/fileadmin/template/pdf/konzern/nachhaltigkeit/Sustainability_Report_2012_EN.pdf>.