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Degradation of Fibrous Microplastics in the Marine Environment
Published in Judith S. Weis, Francesca De Falco, Mariacristina Cocca, Polluting Textiles, 2022
Christian Lott, Andreas Eich, Miriam Weber
Cellulose is a polysaccharide and as the key structural element of plants, cellulose is the most abundant biopolymer in the open environment. Technically, cellulose is used for many applications in its pure form (e.g. as cotton, hemp or jute fibre) or as regenerated material. Cellulose can be dissolved in strong bases or organic solvents and then extruded to fibres or film. Rayon, or also synonymous viscose, usually refers to regenerated cellulose fibres where different names such as Modal, Lyocell, Cupro refer to different processing methods. Chemically, regenerated cellulose is identical to its natural base material, but the regenerated polymer has lower molecular weight and crystallinity. In nature, all organisms that produce cellulose (plants, algae, but also some bacteria, fungi, protists and a group of animals called tunicates) also must be capable of cellulolysis via cellulases. Many microbes use cellulose as nutrition and thus also possess these enzymes (for details see e.g. Thapa et al., 2020). Different grades of cellulose raw materials, e.g. for paper manufacturing, are biodegraded at different rates in aquatic environments (Hofsten and Edberg, 1972). In standard biodegradation tests, cellulose in the form of pure filter paper or as microcrystalline powder is often used as a biodegradable reference material, i.e. as positive biodegradation control (e.g. ASTM 6691, ISO 22404).
Fibres
Published in Ashok R. Khare, Principles of Spinning, 2021
Modal3: It is made from cellulose which is recovered from beech-wood tree. Like cotton, it is hygroscopic and takes-up the dye easily. Its washing fastness with dyed fabrics, especially with warm water is really good. The fabrics made from this variety of rayon are smooth, soft and are resistant to shrinkage and fading. Modal fabric is quite resistant to mineral salts and prevents sticking of mineral deposits when washed with mineral water. It, however, requires ironing at moderate temperatures.
Electrical Safety
Published in Richard Cadena, Electricity for the Entertainment Electrician & Technician, 2021
There a number of common HRC 0 tasks, such as operating a circuit breaker, that do not require arc-rated clothing. But everyday tasks like this should be carried out by production electricians wearing non-melting, natural fibers like untreated cotton, wool, rayon, silk, or blends of these fibers with a fabric weight of at least 4.5 ounces per square yard. (Rayon is cellulose-based, which is made from wood pulp.) These fibers are flammable but non-melting. On the other hand, polyester, acetate, acrylic, nylon, polyethylene, polypropylene, and spandex are all materials that have a low melting temperature and will melt and drip. These fibers should not be worn because in the event of an arc flash, they will make injuries worse. And according to the Occupational Health and Safety Administration (OSHA), “the clothing cannot contribute to an employee's injury,” which means that it should not be worn.
Medical textiles
Published in Textile Progress, 2020
Viscose rayon and its associated industry is the oldest of the existing man-made fibre businesses (slightly older and more extensive than that of cuprammonium rayon) with roots stretching back to the late 19th century. A fibre made from regenerated cellulose, the starting material is purified wood pulp from spruce or eucalyptus trees, but it can also be produced from parts of other plants with a high cellular cellulose content such as soy plant stems, bamboo and sugar cane; when used, these other cellulose sources are often mentioned in the promotional literature presumably with the purpose of making the resulting viscose rayon products sound more acceptable. In fact the process, once the cellulose fibre pulp has been prepared, is the same as for wood pulp from trees. As for wood pulp, the original pulp is purified to remove lignin and undesirable colourants then temporarily chemically modified into sodium cellulose xanthate to render it soluble in sodium hydroxide solution prior to spinning; the syrupy so-called viscose solution is extruded into an acidic coagulating bath (wet-spun) to regenerate the cellulose and yield continuous filaments of viscose rayon. The filaments are then drawn and washed before winding, and depending upon the method of manufacture and extent of drawing, different physical and mechanical properties can be provided to the resulting fibre [94].
Fake Silk: The Lethal History of Viscose Rayon
Published in Ambix, 2018
Rayon and cellophane are major products that are made by chemical treatment of cellulose in the form of wood pulp or linters (cotton waste). As is well known, the breakthrough in the manufacture of rayon was made in the late nineteenth century by consulting chemists Charles Cross and Edward Bevan; it was then taken up by the mourning crape-weaving firm of Courtaulds just as mourning crape was going out of fashion. The early development of rayon was difficult, as no one had hitherto produced a synthetic fibre on a large scale. However, once the process was established, Courtaulds was able to make massive profits from their fibre, as it easily undercut expensive natural silk. Courtaulds perceived that the USA would be a major market for rayon, and set up the American Viscose Corporation. AVC became one of the most profitable subsidiaries ever seen, until the American government forced its sale during the Second World War in return for the Lend-Lease programme. Attracted by these profits, DuPont, hitherto largely an explosives manufacturer, moved into the production of rayon, and then the film version of rayon, cellophane. Rayon also became a major product in many other countries. Seen in this way, rayon appears to have been an unmitigated success, at least until wholly synthetic fibres such as nylon and polyester came along. But rayon manufacture had a major flaw (although the manufacturers did not see it that way): it used carbon disulphide in a crucial step in the process. Commercial carbon disulphide not only has an awful odour, it also has narcotic effects and is extremely toxic. Despite these drawbacks, it was used in the rayon industry without any significant precautions, and even today the permitted exposure limits are relatively high for such a toxic compound.
Upcycling textile wastes: challenges and innovations
Published in Textile Progress, 2021
Zunjarrao Kamble, Bijoya Kumar Behera
Global fibre production was ∼111 million tonnes in the year 2019 (Truscott et al., 2020) and it is expected to be 146 million tonnes in the year 2030 if business continues as usual. Polyester is the most-widely used fibre, with a share of ∼52% of the global fibre production in 2019 (Truscott et al., 2020). In 2017, global fibre production was ∼105 million metric tonnes, at that time the highest fibre production volume ever, with a polyester fibre share of ∼50% (Truscott, Tan, & Opperskalski, 2018). Figure 2 shows the global fibre production in the year 2019. In 2019, the market share of recycled polyester fibres was ∼14%, compared to ∼9% in 2009 (Truscott et al., 2020). At the same time, the biobased polyester market share was less than 1% (Truscott et al., 2020). Recycled polyester fibres (rPET) are produced from waste polyethylene terephthalate (PET) bottles, waste polyester textiles, and cotton/polyester blended textiles (Senthil Kumar & Janet Joshiba, 2020). Of the total amount of recycled PET bottles, 44% was used to produce fibres in 2016, and it has been estimated that around 15 million tonnes of PET bottles were recycled (Sarioğlu & Kaynak, 2018). Companies such as ZARA, H&M, Nike, Adidas are now coming forward to use recycled polyester fibres in their products. The bio-based polyesters are manufactured using biomass (Zia, Noreen, Zuber, Tabasum, & Mujahid, 2016). Cotton is the second-most consumed fibre after polyester and its production share increased to 25% in 2019, compared to 5% in 2013 and global production of regenerated cellulose fibre (RCF) has more than doubled since 1990. These fibres include viscose rayon, cellulose acetate, lyocell, modal viscose rayon, and cuprammonium rayon. Currently, these fibres are mainly produced from wood cellulose. According to Textile Exchange estimates, less than 1% of RCFs are recycled (Truscott et al., 2020). The other plant-based fibres, such as jute, hemp, flax and coir represent a market share of ∼ 6.5 million tonnes in 2019. The wool from sheep represents a market share of ∼1 million tonnes. By contrast, animal hair specialty fibre, such as that from the angora goat, camel, guanaco, llama, vicuna, and yak, represents ∼0.05 million tonnes. It can be understood that synthetic fibre consumption and its waste will increase in the future, and many are not biodegradable, therefore, there is an urgent need to find a sustainable solution for synthetic polymer textile waste.