Rayon Fibers Research Articles

IT IS SNOWING MICROPLASTICS IN WESTERN SIBERIA

The atmosphere is an important transport medium for polymeric anthropogenic particles such as microplastics (MPs). The analysis of particles deposited on the snowpack enables monitoring the abundance and transport of MPs and semi-synthetic fibers. In the current study, the abundance of MPs and man-made textile fibers in deposited snow in Western Siberia, Russia, was investigated in a large area ranging from the Altai Mountains (52°01"N) to the Arctic Circle (66°30"N). Rayon fibers accounted for 44 % of all detected particles, while the remaining 66 % were MPs made of PET, PA, PC, PP and other plastics. The highest number of MPs and fibers per unit area was 2,817 ± 915 items m-2 with an estimated daily deposition rate of 25.8 items m-2 d-1. The maximum calculated mass particle load was 4,444 ± 1,530 mg m-2 or 34.9 ± 12 mg L-1 of melted snow. Particle concentrations in snow were generally higher in the southern parts of Western Siberia but did not significantly correlate with population density. The Lagrangian dispersion model FLEXPART was used to estimate the geographical patterns of potential sources of the fibers detected in the snow in Western Siberia. Our analysis shows that particles can reach the sampling sites via both short-range and long-range atmospheric transport, including the possibility of cross-border transport for the smaller particle sizes.

Wastepaper-Based Cuprammonium Rayon Regenerated Using Novel Gaseous-Ammoniation Injection Process.

Rayon is an extremely valuable cellulosic fiber in the global textile industry. Since cuprammonium rayon is more eco-friendly than other types of rayon fabrics, it was synthesized by regenerating α-cellulose isolated from wastepaper using a novel gaseous-ammoniation injection (GAI) process. This was achieved by preparing tetra-ammine copper hydroxide (cuoxam solution) via reacting copper sulfate and sodium hydroxide to produce copper hydroxide that was, finally, ammoniated by injecting the gas directly to the reaction vessel instead of using ammonium hydroxide applied by prior art. After that, the air-dried cellulose was chemically generated by dissolving it in a freshly prepared cuoxam solution and, subsequently, was regenerated by extruding it within a hardening bath constituted mainly from citric acid, producing the cuprammonium rayon (c. rayon). The properties of the fibrous, structural (XRD and mechanical), physical, and chemical features were investigated. It was found that the rayon was produced in a high yield (90.3%) with accepted properties. The fibrous properties of the rayon staple length, linear density, and fiber diameter were found to be 44 mm, 235 Tex, and 19.4 µm, respectively. In addition, the mechanical properties determined, namely tensile strength, elongation at break, modulus of elasticity, and breaking tenacity, were found to be 218.3 MPa, 14.3 GPa, 16.1%, and 27.53 cN/Tex, respectively. Based on this finding, and upon injecting the ammonia gas through the α-cellulose saturated and immersed in the Cu (OH)2 to complete producing the cuoxam solvent, we find that theuse of an injection rate of 120 mL/minute to obtain the highest fibers' tensile strength for the final product of the c. rayon is preferable. Utilization of higher rates will consume more amounts of the ammonia gas without gaining noticeable enhancement in the c. rayon's mechanical quality. Accordingly, the GAI invention rendered the c. rayon favorable for use in making sustainable semisynthetic floss for either insulation purposes or spun threads for woven and nonwoven textile clothing.

Considering microplastic characteristics in ecological risk assessment: A case study for China

Microplastics (MPs) pose a significant global concern, requiring a multifaceted approach to their risk assessment procedures, especially concerning their characteristics in the environment. The Horqin Left Middle Banner in Northeast China was chosen for the research region to investigate the abundance, composition, distribution, and ecological impact of MPs in surface agricultural soils. The concentrations of MPs ranged from 300 to 12800 items/kg, with a median concentration of 1550 items/kg (average = 1994 items/kg). The normal-sized MPs (500–5000 µm) had a higher relative abundance than small MPs (<500 µm). MPs were mainly derived from textiles and packaging and were affected by atmospheric transportation. Rayon and PET fibers were the main polymers identified. Furthermore, the potential environmental risks posed by the fundamental characteristics (abundance, chemical composition, and size) of MPs were quantified using multiple risk assessment models. The conditional fragmentation model indicated a propensity for MPs to degrade into smaller particles. Ecological risk assessments using pollution load index, pollution hazard index, and potential ecological risk index models revealed varying levels of risk. This study conducted a comprehensive assessment of the ecological risks of MPs based on their environmental characteristics, emphasizing the importance of considering multiple factors in the risk assessment process. Environment implicationThis study investigates the occurrence, distribution, and ecological risk of microplastics (MPs) in agricultural soils of the Northeast Plain of China, a major food production area. MPs are persistent organic pollutants that can pose threats to soil health, crop quality, and food security. By analyzing the composition, size, and source of MPs, as well as their fragmentation and stability in soil, this study provides valuable data for assessing the environmental risk of MPs in agricultural regions. The study also suggests strategies for mitigating MPs pollution and protecting soil ecosystems.

Physiological response of mussel to rayon microfibers and PCB's exposure: Overlooked semi-synthetic micropollutant?

Rayon microfibers, micro-sized semi-synthetic polymers derived from cellulose, have been frequently detected and reported as "micropollutants" in marine environments. However, there has been limited research on their ecotoxicity and combined effects with persistent organic pollutants (POPs). To address these knowledge gaps, thick-shell mussels (Mytilus coruscus) were exposed to rayon microfibers at 1000 pieces/L, along with polychlorinated biphenyls (PCBs) at 100 and 1000 ng/L for 14 days, followed by a 7-day recovery period. We found that rayon microfibers at the environmentally relevant concentration exacerbated the irreversible effects of PCBs on the immune and digestive systems of mussels, indicating chronic and sublethal impacts. Furthermore, the results of 16 s rRNA sequencing demonstrated significant effects on the community structure, species richness, and diversity of the mussels' intestinal microbiota. The branching map analysis identified the responsive bacteria to rayon microfibers and PCBs belonging to the Proteobacteria, Actinobacteriota, and Bacteroidota phyla. Despite not being considered a conventional plastic, the extensive and increasing use of rayon fibers, their direct toxicological effects, and their interaction with POPs highlight the need for urgent attention, investigation, and regulation to address their contribution to "micropollution".

Microplastic contamination in the dominant crabs at the intertidal zone of Chongming Island, Yangtze Estuary

Crabs are one of the most critical and dominant species of the intertidal zone. Their feeding, burrowing, and other bioturbation activities are common and intense. However, baseline data on microplastic contamination in wild intertidal crabs are still lacking. In this study, we investigated the contamination of microplastics in the dominant crabs, Chiromantes dehaani, of the intertidal zone in Chongming Island, Yangtze Estuary, and explored their probable relationship with the microplastic composition in sediments. A total of 592 microplastic particles were observed in the crab tissues, with an abundance of 1.90 ± 0.53 items·g−1 (1.48 ± 0.45 items·ind−1). The microplastic contamination in the tissues of C. dehaani varied significantly among different sampling sites, organs, and size groups, but not among different sexes. Microplastics in C. dehaani were mainly rayon fibers with small sizes (<1000 μm). Their colors were mostly dark, which is consistent with the sediments samples. A linear regression showed significant correlations between the composition of microplastics in the crabs and that in sediments, although they differed in various crab organs and sediment layers. The target group index identified the feeding preference of C. dehaani on the microplastics with specific shapes, colors, sizes, and polymer types. In general, the microplastic contamination in crabs is affected by both objective environmental conditions and subjective feeding habits of crabs. In the future, more potential sources should be considered to completely distinguish the relationship between the microplastic contamination in crabs and adjacent environment.

Vertical distribution and transport of microplastics in the urban atmosphere: New insights from field observations

The distribution and transport of atmospheric microplastics (AMPs) have raised concerns regarding their potential effects on the environment and human health. Although previous studies have reported the presence of AMPs at ground level, there is a lack of comprehensive understanding of their vertical distribution in urban environments. To gain insight into the vertical profile of AMPs, field observations were conducted at four different heights (ground level, 118 m, 168 m and 488 m) of the Canton Tower in Guangzhou, China. Results showed that the profiles of AMPs and other air pollutants had similar layer distribution patterns, although their concentrations differed. The majority of AMPs were composed of polyethylene terephthalate and rayon fibers ranging from 30 to 50 μm. As a result of atmospheric thermodynamics, AMPs generated at ground level were only partially transported upward, leading to a decrease in their abundance with increasing altitude. The study found that the stable atmospheric stability and lower wind speed between 118 m and 168 m resulted in the formation of a fine layer where AMPs tended to accumulate instead of being transported upward. This study for the first time delineated the vertical profile of AMPs within the atmospheric boundary layer, providing valuable data for understanding the environmental fate of AMPs.

Atmospheric deposition of microplastics in a rural region of North China Plain

Microplastics (MPs) pollution is becoming one of the most pressing environmental issues globally. MPs in the marine, freshwater and terrestrial environments have been fairly well investigated. However, knowledge of the atmospheric-mediated deposition of MPs within rural environments is limited. Here, we present the results of bulk (dry and wet) atmospheric MPs deposition in a rural region of Quzhou County in the North China Plain (NCP). Samples of MPs in the atmospheric bulk deposition were collected for individual rainfall events over a 12-month period from August 2020 to August 2021. The number and size of MPs from 35 rainfall samples were measured by fluorescence microscopy, while the chemical composition of MPs was identified using micro-Fourier transform infrared spectroscopy (μ-FTIR). The results showed that the atmospheric MPs deposition rate in summer (892–75,421 particles/m2/day) was highest compared to 735–9428, 280–4244 and 86–1347 particles/m2/day in spring, autumn, and winter, respectively. Furthermore, the MPs deposition rates in our study were 1–2 orders of magnitude higher than those in other regions, indicating a higher rate of MPs deposition in the rural region of the NCP. MPs with a diameter of 3–50 μm accounted for 75.6 %, 78.4 %, 73.4 % and 66.1 % of total MPs deposition in spring, summer, autumn, and winter, respectively, showing that the majority of MPs in the current study were small in size. Rayon fibers accounted for the largest proportion (32 %) of all MPs, followed by polyethylene terephthalate (12 %) and polyethylene (8 %). This study also found that a significant positive correlation between rainfall volume and MPs deposition rate. In addition, HYSPLIT back-trajectory modelling showed that the farthest source of deposition MPs may have come from Russia.

Effect of Eco-friendly Bamboo Rayon, Lyocell, and Seacell Fibres on the Properties of Blended Knitted Melange Fabrics

Effect of Eco-friendly Bamboo Rayon, Lyocell, and Seacell Fibres on the Properties of Blended Knitted Melange Fabrics

Application of Thermochemical Method to Determine the Crystallinity Degree of Cellulose Materials

Currently, to characterize the crystallinity of cellulose, such an estimated parameter as the crystallinity index is used, measured by various methods and techniques. The main purpose of this article was to develop a thermochemical method for determining the real degree of crystallinity (X) of cellulose based on the measurement of the enthalpy of wetting. Various cellulose samples, such as MCC, pure cotton cellulose, bleached wood pulps, mercerized celluloses, and viscose rayon fibers, were used. For these samples, the exothermic wetting enthalpy (ΔHw), the maximum amount of sorbed moisture (Ao), as well as the X-ray index of crystallinity (CrI) were studied. The dependence of ΔHw on Ao was linear and can be expressed by the equation: ΔHw = k Ao, where the coefficient k = −336 (J/g). After substituting the theoretical value Ao,a = 0.5 (g/g) into this equation, the numerical value of maximum wetting enthalpy ΔHw,a = −168 (J/g) for completely amorphous cellulose was obtained. As a result, the equation for calculating the real crystallinity degree (X) expressed in mass fractions was derived: X = 1 − (ΔHw/ΔHw,a). Analysis of the obtained results showed that only the X parameter can characterize the real content of crystallites in cellulose samples, instead of the approximate CrI parameter.

From lab-scale to pilot-scale treatment of real wastewater from the production of rayon fiber

The subject of our study involved the treatment of real process wastewater from the production of rayon fiber. During the annual monitoring of the production facility, we performed a mass balance of three problematic sources of process wastewater and analyzed them repeatedly. All three sources showed high values of COD = 0.4–30 g/L, TOC = 0.09–7.1 g/L and the concentration of Zn2+ 0.09–0.5 g/L. At a total volume of 1.84 million m3, this represents a significant pollution source for the Elbe River. At lab-scale, we tested a combination of filtration, microfiltration, and oxidation using the Fenton, electro-assisted Fenton, and the electrochemical oxidation methods, both on the plate and newly developed macroporous BDD electrodes on a ceramic substrate, along with the final adsorption of Zn2+ emissions on the strongly acidic cation exchange resin Lewatit Mono plus S108. It was tested in Na+ and H+ cycles. Using an optimized technological sequence, we have achieved a COD reduction of up to 98%, and a TOC reduction of 85%. During the H+ cycle cation regeneration by sulfuric acid, Zn2+ emissions were converted to zinc sulfate that can be recycled in the spinning bath of the production process. The method was verified at a pilot scale.

Gamma Radiation Induced Mutual Grafting of Quaternary Ammonium-Based Monomer on to Rayon Fibers to Improve its Water Absorbency and Antibacterial Efficacy

Gamma Radiation Induced Mutual Grafting of Quaternary Ammonium-Based Monomer on to Rayon Fibers to Improve its Water Absorbency and Antibacterial Efficacy

Oil Palm Empty Fruit Bunches as Raw Material of Dissolving Pulp for Viscose Rayon Fiber in Making Textile Products.

The creative fashion industry produces several textile products that play an important role in the national economy. In various countries, this industry has continued to grow along with the strong flow of information technology and e-commerce. The development of textile products for fashion is very dynamic and competitive. Competition is not only about price, but also the quality of organic/synthetic materials, the comfort provided, and designs that change every 4–6 months. Recently, creative fashion not only relies on natural and synthetic polymer-made fibers but also biomass-based waste materials. Therefore, this study aims to manufacture textile products from biomass-based waste materials that can be applied to the creative fashion industry. Two types of raw materials from oil palm empty fruit bunches (EFB), namely, whole-empty fruit bunches (WEFB) and stalk-empty fruit bunches (SEFB), are used as an excellent innovation of rayon viscose fiber (RVF), a noncotton organic yarn capable of providing a solution to the 99% import of global cotton needs. This is expected to increase competitiveness, as well as the added value of palm oil products and their derivatives. The process of manufacturing DP chemically includes prehydrolysis, cooking, bleaching to dissolve the lignin and noncellulosic materials as well as isolation to purify POEFB fiber. Furthermore, DP testing is carried out to determine product quality and compare it with the national product standards. The results show that the alpha-cellulose content reaches >94% with variations in the active alkali of 18%, 20% and 24%. This implies that the WEFB and SEFB are used to fulfill the first requirements of the national standard (SNI 938:2017). The WEFB with an active alkali variation of 24% meets the SNI standard for rayon pulp with a value of S10 = 3.07 and S18 = 7.14%, while all variations of SEFB show opposite results. The use of active alkali at 24% had a brighter color than between 18% and 20%. Additionally, the fiber density of WEFB appears to be higher than that of SEFB. These results correlate positively with DP prepared using 24% alkali as the optimum treatment for all products, as well as the morphological observations performed with scanning electron microscopy (SEM), which shows that WEFB fixated fiber had a larger diameter than SEFB.

Manufacturing of high brightness dissolving pulp from sansevieria-trifasciata fiber by effective sequences processes

The need of dissolving pulp (DP) for rayon fiber production is increasing rapidly in recent years. Sustainable sources of DP raw materials and an effective manufacturing process are urgently required. This study aims to manufacture dissolving pulp (DP) with high brightness from Sansevieria-trifasciata (ST) fiber through the pre-hydrolysis, soda-Anthraquinone (Soda-AQ) cooking, and chlorine-free bleaching processes. The cellulose content, kappa number, pulp yield, and viscosity were analyzed. The results showed that the ?-cellulose content in ST raw material (39.43%) was relatively similar to the ?-cellulose content in Acacia pulping kraft (39.2%). Furthermore, the variations in pre-hydrolysis time affected the Kappa number, pulp yield, and viscosity. The DP obtained by the elementary chlorine-free (ECF) bleaching process had a viscosity of 9.3 cP, ?-cellulose content of 97.7%, and the brightness of 90.1% which was higher than the ISO standard of pulp brightness. The high DP brightness obtained from this unique combination of pre-hydrolysis, soda-AQ cooking and chlorine-free bleaching sequences has great potential for further development, as it can be used in viscose rayon staple fibers production.

The population of textile fibres on parapets of high-rise housing in Singapore

A fibre population study was conducted on the parapets (a low wall along the edge of the walkway) of ten housing estates in Singapore. For each location, the ninth and tenth storeys were investigated and a total of 1256 fibres were classified according to colour and generic fibre class. Being a cosmopolitan city with tropical rainforest climate and no true distinct season, the predominant clothing style in Singapore is one that is light, comfortable and modern. Approximately half of the fibres recovered were cotton (48.3%), with polyester fibres making up the next one-third (31.4%) and rayon fibres in the third place (16.2%). Grey/black (27.7%) and blue (24.2%) constitute the top two most popular colours, together accounting for approximately half of all classified colours. The possibility of establishing subgroups of indistinguishable fibres was investigated by microscopical and fluorescence properties. The number of groups found per location varies from 1 to 3, with each group containing between 2 and 3 fibres. The findings of this study would provide the forensic fibre examiner an overall outlook on what are the abundant (or uncommon) fibre types in Singapore context, thereby assisting the examiner to assess the strength of fibre evidence in casework.

Features of water vapor sorption by cellulose materials

In this research, the sorption of water vapor (WV) by various cellulose samples (microcrystalline cellulose, cotton cellulose, Kraft pulp, mercerized cellulose, and rayon fibers) has been studied. The sorption isotherms of WV for various samples have a sigmoid shape. To describe such isotherms, various models have been proposed, including mono- and multimolecular adsorption, formation of hydrates and solid solutions, as well as mixed models combining various sorption mechanisms. After critical analysis of known models, the improved absorption model was proposed to explain the interaction of VW with cellulose samples. It was confirmed that crystallites are inaccessible for water, and therefore water molecules can be trapped only by polar groups of non-crystalline (amorphous) domains of cellulose materials. The developed model permitted obtaining the general absorption isotherm of water molecules in amorphous domains of cellulose. Moreover, the equation was derived, which describes both the general isotherm and isotherm of any semi-crystalline cellulose sample, when its crystallinity or amorphicity degree was pre-determined. Based on the proposed absorption model, various characteristics can be found, e.g., degrees of amorphicity and crystallinity, the maximum amount of absorbed water, the specific surface area of wet cellulose sample, the amount of capillary condensed water, etc.

Reinforced cementitious composite using viscose rayon fiber from textile industry waste

This study presents an analysis of the possible use of a viscose rayon (CV) fiber from textile industry wastes to develop a reinforced cementitious composite as an alternative for textile discharge valorization. Several techniques were used to characterize precursor fibrous waste material such as SEM, FT-IR, DSC, and TGA. The experimental studies were conducted based on a conventional cementitious mortar (control) and four different fiber contents (0.5, 1, 2, and 4 wt%). For mechanical behavior analysis, uniaxial compressive strength tests were carried out at different ages (7, 14, and 28 days after production). The results showed favorable CV fiber addition as reinforcement up to a maximum limit. The optimum concentration of fiber was 0.5 wt% (FRC0.5), which provided 28 days of higher compression strength. The addition of CV waste as reinforcement in cementitious matrix resulted in an improved compressive strength above 20.6% compared to the conventional non-reinforced mortar. Furthermore, CV fiber addition improved the ductile behavior of the new composite allowing a controlled failure, even after maximum rupture loading.

Optimization on Filtrating Process in Using the Integration of Statistical Method and Mathematical Programing

Conventionally, the process parameter determinations in producing rayon fiber are acquired through the trial-and-error method during the chemical reaction. However, the found parameter levels lack optimization. This study combined statistical method and mathematical programming to obtain the optimized production parameters for the filtrating process in the production of rayon fiber.

Business Strategy of Indah Kiat Pulp and Paper Perawang Mill, Riau, Indonesia using PESTLE, Porter’s Five Forces, and SWOT Analysis under SOSTAC&lt;sup&gt;®&lt;/sup&gt; Framework

According to the company annual report (INKP Annual Report, 2019), PT. Indah Kiat Pulp and Paper (INKP) experienced a decrease in net sales of 3.4% and net profit of 53.4% from the previous year. The decline was followed by the Covid-19 pandemic which could affect the company's sales and profits. The study was conducted using a descriptive approach in order to capture the phenomena that occur through analysis of current conditions both internal and external using PESTLE, Porter, and SWOT analysis. Afterwards, it formulates the company objective, strategy, tactics, action, and evaluation or control using the SOSTAC® framework based on the analysis result. Data are obtained from interviews, observations, documentation, and publication reports. The results of the research describe that the predominant internal strategy factors on the Strengths of INKP are the product quality and production process efficiency, and the Weaknesses are product distribution and its distribution channels. Meanwhile, the predominant external strategic factors on Opportunities are other needs in pulp derivative product, availability of raw materials and fiscal policy, and as for Threats are a decrease in fine paper demand and technology adaptation. Using the Cartesian SWOT diagram, it is found that the results of EFAS and IFAS are in the ST main strategy quadrant, which is Diversification. Based on the results of the analysis, it can be formulated that the objectives of the INKP strategy are to make diversification product such as rayon fiber with masks as the final product from pulp as the raw materials in 1 year and shifting production from 56% paper and 43% pulp to 45% paper, 34% pulp, and 20% rayon fiber in 3 years to maintain sales volume and gain increased profit. The corporate level strategy is a diversification product while the business level strategy is a differentiation product in accordance with Porter's Generic Matrix. This investment has a positive value of both CAPM and NPV while CAPM has 0.0708 value. As for the IRR, the rate of return is 39.87%. Planned tactics and actions using project management with Gantt Chart within a project period of 1 year in the main activities of building production lines and marketing. Control and evaluation are carried out through the implementation of targets or KPI in accordance with work functions. EBIT and EBITDA is used at the final level of overall production and marketing.

The Impact of Textile Waste on the Features of High-Density Polyethylene (HDPE) Composites

An increased amount of textile waste will be available in the future, and its utilization requires attention from various perspectives. The re-utilization of textile waste in a second material cycle is an option for dealing with a global problem that puts stress on the urban environment. In this study, almost 30 kg of clothing were recycled as a raw material in the structure of a composite, whose structural properties were analyzed. The studied materials were made from high-density polyethylene (HDPE), anhydride modified polyethylene, lubricant, and either polyethylene terephthalate (PET) or rayon fibers from recycled clothes. The recycled clothes were identified by a near-infrared (NIR) analyzer, followed by treatment of size reduction and materials compounding by agglomeration and compression molding technologies. The material properties were characterized by thickness swelling, water absorption, impact, and tensile testing. The recycled clothes fibers, acting as a filler component in the structure of the composite, could maintain the properties of the material at the same level as the reference material. PET fibers being used as a component resulted in a significant improvement in impact strength. The study showed that recycled clothes can be re-utilized as a substitute for raw materials, and can be part of a solution for future challenges involving textile waste, following the principles of the circular economy. Textile recycling create opportunities to improve the quality of urban life.

Intake of microplastics by commercial fish: A Bayesian approach.

The disordered growth of large cities around water bodies causes environmental damage due to discarded plastics and microplastics (MPs) that aquatic organisms can ingest. This study analyzed the occurrence, type, and abundance of MPs in the gastrointestinal contents of four species of commercial fish (120 total specimens), namely, Brazilian mojarra (Eugerres brasilianus) and mullets (Mugil curema, Mugil curvidens, and Mugil liza), obtained in Porto Seguro in Bahia, Brazil, between March and May 2019. A priori probability distributions were generated using a Bayesian approach and simulations to assess MP intake based on varying exposure amounts (θ = 0.2, θ = 0.5, and θ = 0.8). E. brasilianus (53.33%) and Mugil spp. (41.66%) were contaminated with some types of MPs. Black, blue, and green MPs dominated in the extracted samples, and most measured 1.0mm in length or smaller. The dominant polymers identified using Fourier transform infrared spectroscopy (FTIR) were polyester, polypropylene, semi-synthetic rayon fiber, and polyamide 6 (nylon). The a posteriori probabilities of more than half the E. brasilianus and Mugil spp. ingesting MPs were 0.336 and 0.008, respectively, indicating that E. brasilianus is much more likely to ingest MPs. These simulations can be useful tools for assessing the environmental quality and local anthropic impact of MP ingestion by fish populations.