Articoli di riviste sul tema "Staple recycled fiber"
Segui questo link per vedere altri tipi di pubblicazioni sul tema: Staple recycled fiber.
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 articoli di riviste per l'attività di ricerca sul tema "Staple recycled fiber".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi gli articoli di riviste di molte aree scientifiche e compila una bibliografia corretta.
1
Reichert, Olaf, Larisa Ausheyks, Stephan Baz, Joerg Hehl e Götz T. Gresser. "Innovative rC Staple Fiber Tapes - New Potentials for CF Recyclates in CFRP through Highly Oriented Carbon Staple Fiber Structures". Key Engineering Materials 809 (giugno 2019): 509–14. http://dx.doi.org/10.4028/www.scientific.net/kem.809.509.
Abstract (sommario):
Increasing waste streams of carbon fibers (CF) and carbon fiber reinforced plastics (CFRP) lead to increasing need for recycling and to growing amounts of recycled carbon fibers. A main issue in current research for carbon fiber recycling is the reuse of regained fibers. Carbon staple fibers such as recycled fibers hold big potential for mechanical properties of lightweight parts, if used properly. Applying recycled CF (rCF) as milled reinforcement fibers or as nonwoven in carbon fiber reinforced plastic leads to a poor yield of mechanical proper due to low fiber orientation, limitations in fiber volume content or due to short fiber length. The rC staple fiber tape presents a more efficient approach. Recycled carbon fibers are blended with 50 wt. % thermoplastic nylon 6 fibers and processed through a roller card to a sliver, which is a linear fibrous intermediate. The sliver is continuously drawn, formed, heated and consolidated to the thermoplastic rC staple fiber tape. The tape is similar to common carbon fiber tapes or to continuous tows but has different positive properties, such as high fiber orientation, homogeneous blend of fiber and matrix and suitability for deep drawing.
2
Detzel, Martin, Peter Mitschang e Ulf Breuer. "New Approach for Processing Recycled Carbon Staple Fiber Yarns into Unidirectionally Reinforced Recycled Carbon Staple Fiber Tape". Polymers 15, n. 23 (30 novembre 2023): 4575. http://dx.doi.org/10.3390/polym15234575.
Abstract (sommario):
This study describes a novel process in which staple fiber yarns made from recycled carbon fibers (rCFs) and polyamide 6 (PA6) fibers are further processed into semi-finished tape products in a modified impregnation and calendaring process. In this process, the staple fiber yarns are heated above the melting temperature of the polymer, impregnated, and stretched to staple fiber tapes (SF tapes) in the calendaring unit. SF tapes with different degrees of stretching and/or repasses were produced. The individual width and thickness were measured in line by a laser profile sensor. From these tapes, preforms were manually laid and processed into laminates in an autoclave. The important physical properties of the unidirectionally reinforced laminates made of the tapes were compared with organic sheets wound from staple fiber yarns. With increasing stretching, both the fiber orientation and mechanical properties improved compared to the organic sheets made from unstretched staple fiber yarns. An improvement in fiber orientation relative to the process direction from 66.3% to 91.9% (between ±10°) and 39.1% to 71.6% (between ±5°), respectively, was achieved for a two-stage stretched tape. The tensile and flexural moduli were increased by 15.2% and 14.5%, respectively.
3
Goergen, Christian, Stephan Baz, Peter Mitschang e Götz T. Gresser. "Recycled Carbon Fibers in Complex Structural Parts - Organic Sheets Made of rCF Staple Fiber Yarns". Key Engineering Materials 742 (luglio 2017): 602–9. http://dx.doi.org/10.4028/www.scientific.net/kem.742.602.
Abstract (sommario):
In order to sustainably establish carbon fiber reinforced polymer composites (CFRPC) in the market on an industry scale, solutions on how to recycle these new materials have to be developed. Quasi-continuously aligned carbon staple fiber structures in organic sheets made of recycled carbon are one approach which will be dealt with in this article. The process chain as well as the mechanical properties will be presented. Moreover, the specific feature of staple fiber yarns to be able to plastically deform under process temperature, enabling new degrees of deep-drawing of CFRPC organic sheets in the thermoforming process, will be highlighted.
4
Goergen, Christian, Dominic Schommer, Miro Duhovic e Peter Mitschang. "Deep drawing of organic sheets made of hybrid recycled carbon and thermoplastic polyamide 6 staple fiber yarns". Journal of Thermoplastic Composite Materials 33, n. 6 (15 novembre 2018): 754–78. http://dx.doi.org/10.1177/0892705718811407.
Abstract (sommario):
Fully impregnated fiber-reinforced thermoplastic sheets, or the so-called organic sheets, allow the thermoforming of parts within very short cycle times. This article describes the development of the next generation of organic sheet materials based on recycled carbon fibers and polyamide 6 staple fiber yarns. Regardless of the recycled nature of the fibers and an average fiber length of 25 mm, the organic sheets still reach a comparable level of the tensile strength and modulus of continuous fiber-reinforced organic sheets made of virgin CF with the same reinforcement structure. Due to the staple fiber yarn architecture, the organic sheets feature a deep-drawing ability of a total plastic deformation up to 50% in the fiber direction. The effect is enabled via an interfiber sliding when the organic sheet is processed in the molten condition. The creation of a finite element model for the thermoforming process simulation of the material is also presented. Predictions of the plastic strain distribution and its magnitude are shown to agree well with forming experiments where a curved geometry is formed to different depths.
5
Yang, Fan. "The Feasibility Analysis and Development of the PET Regenerated Staple Fiber Industry". Applied Mechanics and Materials 733 (febbraio 2015): 990–93. http://dx.doi.org/10.4028/www.scientific.net/amm.733.990.
Abstract (sommario):
Waste PET bottles which is the main ingredients are PET (polyethylene terephthalate), is not easy to degrade under natural conditions. If without recycling rationally, waste plastic bottles will pollute the environment, that is of no advantage for “the construction of resource saving and environment-friendly society”. This paper introduces a new kind of recycling way – the technology of regenerating fibers – that will process the recycled PET bottle flakes into staple fiber (a kind of textile raw materials). And finally it can produce various raw materials of textile garments by the staple fiber. The process of PET bottle flakes recycling mainly takes five steps: sorting, separation, cleaning, crushing and using. This paper analyzes the domestic and foreign PET processing of technology on regenerating staple fiber. And it puts forward a complete set of modification technology program for regenerating staple fiber by PET on the basic of theory.
6
Goergen, Christian, Stephan Baz, Peter Mitschang e Götz T. Gresser. "Organic Sheets Made of Recycled Carbon Staple Fiber Yarns". Lightweight Design worldwide 10, n. 3 (giugno 2017): 12–17. http://dx.doi.org/10.1007/s41777-017-0024-2.
7
Salmins, Maximilian, Florian Gortner e Peter Mitschang. "Challenges in Manufacturing of Hemp Fiber-Reinforced Organo Sheets with a Recycled PLA Matrix". Polymers 15, n. 22 (8 novembre 2023): 4357. http://dx.doi.org/10.3390/polym15224357.
Abstract (sommario):
This study investigates the influence of a hot press process on the properties of hemp fiber-reinforced organo sheets. Plain-woven fabric made from hemp staple fiber yarns is used as textile reinforcement, together with a recycled poly-lactic acid (PLA) matrix. Process pressure and temperature are considered with three factor levels for each parameter. The parameter influence is examined based on the B-factor model, which considers the temperature-dependent viscosity of the polymer, as well as the process pressure for the calculation of a dimensionless value. Increasing these parameters theoretically promotes improvements in impregnation. This study found that the considered recycled polymer only allows a narrow corridor to achieve adequate impregnation quality alongside optimal bending properties. Temperatures below 170 °C impede impregnation due to the high melt viscosity, while temperature increases to 185 °C show the first signs of thermal degradation, with reduced bending modulus and strength. A comparison with hemp fiber-reinforced virgin polypropylene, manufactured with identical process parameters, showed that this reduction can be mainly attributed to polymer degradation rather than reduction in fiber properties. The process pressure should be at least 1.5 MPa to allow for sufficient compaction of the textile stack, thus reducing theoretical pore volume content to a minimum.
8
Li, Ting-Ting, Rui Wang, Ching Wen Lou, Jan-Yi Lin e Jia-Horng Lin. "Static and dynamic puncture failure behaviors of 3D needle-punched compound fabric based on Weibull distribution". Textile Research Journal 84, n. 18 (9 giugno 2014): 1903–14. http://dx.doi.org/10.1177/0040517514534751.
Abstract (sommario):
Through-thickness reinforcement structure of compound fabric was formed through a two-sided needle-punching and thermal-bonding processes. This study presents static and dynamic puncture resistances of compound fabric comprised of Kevlar®/PA6/low-melting PET nonwoven, low-melting PET/PET nonwoven and woven fabric. The effect of the staple fibers fraction on puncture resistance was investigated to assess optimal fiber content in the nonwoven layer. Static and dynamic puncture failure models of non-thermal-bonded and thermal-bonded compound fabrics were constructed using a Weibull probability distribution to predict puncture failure reliability. Result indicates that puncture forces increased and then decreased with low-melting PET fibers, but steadily improved with recycled Kevlar® fibers. Puncture failure probability models show that thermal-bonding largely improved failure reliability of the static puncture property, but slightly decreased dynamic puncture performance. Puncture failure mechanisms were respectively exposed according to SEM observations.
9
Hengstermann, M., N. Raithel, A. Abdkader, MMB Hasan e Ch Cherif. "Development of new hybrid yarn construction from recycled carbon fibers for high performance composites. Part-I: basic processing of hybrid carbon fiber/polyamide 6 yarn spinning from virgin carbon fiber staple fibers". Textile Research Journal 86, n. 12 (5 novembre 2015): 1307–17. http://dx.doi.org/10.1177/0040517515612363.
10
Lin, Jia Horng, Chen Hung Huang, Yu Chun Chuang, Ying Huei Shih, Ching Wen Lin e Ching Wen Lou. "Property Evaluation of Sound-Absorbent Nonwoven Fabrics Made of Polypropylene Nonwoven Selvages". Advanced Materials Research 627 (dicembre 2012): 855–58. http://dx.doi.org/10.4028/www.scientific.net/amr.627.855.
Abstract (sommario):
The rapid development of textile industry at the beginning of the Industrial Revolution results in the invention of synthetic fibers. As synthetic fibers cannot be decomposed naturally, significant textile waste is thus created. Selvages, which make up the majority of our total garbage output, have a low value and thus are usually sold cheaply or outsourced as textile waste. This study aims to recycle and reclaim the nonwoven selvages which are discarded by the textile industry. The recycled polypropylene (PP) selvages, serving as a packing material, and 6 denier PP staple fibers are made into the recycled PP nonwoven fabrics. The resulting nonwoven fabrics are subsequently tested in terms of maximum tensile breaking strength, tearing strength, surface observation, thickness measurement and sound absorption coefficient.
11
Owen, Macaulay M., Emmanuel O. Achukwu, Hazizan Md Akil, Ahmad Z. Romli, Mohd Shukur Zainol Abidin, Innocent O. Arukalam e Umaru S. Ishiaku. "Effect of epoxy concentrations on thermo-mechanical properties of kenaf fiber – recycled poly (ethylene terephthalate) composites". Journal of Industrial Textiles 52 (agosto 2022): 152808372211274. http://dx.doi.org/10.1177/15280837221127441.
Abstract (sommario):
The effect of different concentrations of epoxy surface coating treatment on the thermal and mechanical properties of kenaf fiber reinforced recycled poly (ethylene terephthalate) (RPET) composites was studied. Silane-treated kenaf fibers (SKF) were epoxy-coated with optimized coating concentrations (in the ratios of 1:4, 1:5, and 1:6 epoxy to acetone solutions) to improve the thermal degradation/decomposition resistance and interfacial bonding with RPET matrix. The different epoxy coated-silane treated kenaf fibers 1:4 ESKF, 1:5 ESKF, and 1:6 ESKF were compounded with RPET at an optimized temperature of 240°C, and their constituents’ composites KF/RPET, 1:4 ESKF/RPET, 1:5 ESKF/RPET, and 1:6 ESKF/RPET were subjected to thermal, mechanical and microstructural investigation. The obtained results showed some remarkable effects of epoxy concentrations on the chemical and surface structures of the treated fibers. Thermal properties of both ESKF and ESKF/RPET composites were more stable and improved with different concentrations of epoxy treatment compared to the untreated counterparts. 1:4 ESKF and 1:5 ESKF were the most thermally stable with onset degradation and DTG decomposition temperatures of 331.6°C and 381.7°C, and 324.0°C and 388.7°C respectively. Mechanical properties of the epoxy-coated composites were higher and further improved with epoxy concentrations and fiber loadings compared to uncoated composites. Hence, the epoxy concentration of 1:4 gave the maximum tensile and impact properties, and at 10 wt. % fiber loading within the lower loading regions, followed by 1:5 with outstanding flexural properties. The coated-treated composites showed strong fiber/matrix bonding with no evidence of fiber decomposition compared to the untreated composites with poor fiber/matrix interaction. The current research findings are original and valid for improving the thermal degradation resistance and stability of natural fibers, and the mechanical properties of natural fiber reinforced engineering thermoplastic composites. The epoxy coated – silane-treated textile kenaf fibers reinforced with recycled PET composites have the potentials to be utilized in high-temperature industrial and engineering applications.
12
Li, Guodong, Li Zhang, Fengnian Zhao e Jiaqi Tang. "Acoustic Emission Characteristics and Damage Mechanisms Investigation of Basalt Fiber Concrete with Recycled Aggregate". Materials 13, n. 18 (10 settembre 2020): 4009. http://dx.doi.org/10.3390/ma13184009.
Abstract (sommario):
This paper presents the compression failure process of basalt fiber concrete with recycled aggregate and analyzes the main factors of basalt fiber and recycled aggregate affecting the compressive strength of recycled concrete. The damage mechanism of recycled aggregate concrete is analyzed by the acoustic emission technique. With the method of acoustic emission (AE) b-value analysis, the evolution and failure process of recycled concrete from the initial defect microcrack formation to the macroscopic crack is studied. Based on the AE clustering analysis method, the damage state of recycled concrete under load grade is investigated. Finally, the failure mode of recycled concrete is explored according to the RA-AF correlation method. The results show that when the concrete reaches the curing age, the strength grade of basalt fiber regenerated coarse aggregate concrete is the highest. The basalt fiber increases the strength of regenerated fine concrete by 4.5% and the strength of coarse concrete by 5%, and reduces the strength of fully recycled aggregate concrete by 6.7%. The b-value divides concrete into three stages: initial damage, stable development of internal damage, and internal damage. The variation of AE energy, count, and event number is related to AE activity and crack growth rate. Matrix cracking is the main damage state of concrete, which is greatly affected by the strength of cement mortar. The load grade of fiber cracking in fully recycled aggregate, recycled fine aggregate, and recycled coarse aggregate concrete is 65, 90, and 85%, respectively. Basalt fiber increases the tensile failure event point of recycled concrete and delays the cracking of recycled concrete under compression. When the load grades of fully recycled fiber, recycled fine aggregate fiber, and recycled coarse aggregate fiber concrete are 65–95, 90–100, and 85–100%, respectively, the tensile failure activity increases.
13
Chuang, Yu-Chun, Limin Bao, Mei-Chen Lin, Ching-Wen Lou e TingAn Lin. "Mechanical and Static Stab Resistant Properties of Hybrid-Fabric Fibrous Planks: Manufacturing Process of Nonwoven Fabrics Made of Recycled Fibers". Polymers 11, n. 7 (3 luglio 2019): 1140. http://dx.doi.org/10.3390/polym11071140.
Abstract (sommario):
With the development of technology, fibers and textiles are no longer exclusive for the use of clothing and decoration. Protective products made of high-strength and high-modulus fibers have been commonly used in different fields. When exceeding the service life, the protective products also need to be replaced. This study proposes a highly efficient recycling and manufacturing design to create more added values for the waste materials. With a premise of minimized damage to fibers, the recycled selvage made of high strength PET fibers are reclaimed to yield high performance staple fibers at a low production cost. A large amount of recycled fibers are made into matrices with an attempt to decrease the consumption of new materials, while the combination of diverse plain woven fabrics reinforces hybrid-fabric fibrous planks. First, with the aid of machines, recycled high strength PET fibers are processed into staple fibers. Using a nonwoven process, low melting point polyester (LMPET) fibers and PET staple fibers are made into PET matrices. Next, the matrices and different woven fabrics are combined in order to form hybrid-fabric fibrous planks. The test results indicate that both of the PET matrices and fibrous planks have good mechanical properties. In particular, the fibrous planks yield diverse stab resistances from nonwoven and woven fabrics, and thus have greater stab performance.
14
Ji, Yongcheng, Wenhao Ji, Ziyi Zhang e Rui Wang. "Road Performance Investigation on Fiber-Reinforced Recycled Cement Base Material". Polymers 14, n. 19 (30 settembre 2022): 4102. http://dx.doi.org/10.3390/polym14194102.
Abstract (sommario):
The characteristics of the materials used in early buildings in China have led to a large proportion of discarded red bricks among the construction waste generated by demolishing abandoned buildings. The application of red brick aggregate with a particle size ≤5 mm and red brick powder with particle size 0.125~0.75 mm (referred to as recycled brick powder) was studied in this study after the crushing of waste red brick in road structures. The research results will provide a theoretical basis for the whole-grain recycling of waste red brick aggregate. The aggregate of red brick with a particle size smaller than 2 mm was mixed with different amounts of cement soil and fiber to prepare a cement-stable binder for the sub-base material. The recycled brick powder of 0.125~0.75 mm was used to replace the quartz sand with different substitution rates. As pavement materials, different amounts of fiber were used to prepare fiber-reinforced recycled-brick-powder cementitious composites. The optimal mixing ratio of the two materials was evaluated from the mechanical properties. The results showed that the optimal mixing ratio of the cement-stable binder was as follows: waste-red-brick-aggregate content was 50%, cement content was 4%, and fiber content was 0.2%. The optimum ratio of fiber-reinforced recycled-brick-powder cementitious composites was determined to be as follows: the replacement rate of recycled brick powder is 25%, and the content of PVA fiber is 1%. The regression analysis was used to fit the equations between the fiber content and the 7d unconfined compressive strength and the tensile strength of the cement-stabilized binder for different red-brick-aggregate admixtures at 4% cement content. A scanning electron microscope was used to observe the failure modes of the fiber. The influence of failure modes, such as pulling out, fracture, and plastic deformation, on the mechanical properties was expounded.
15
Ma, Shengkui, Lei Wang, Yan Zhou e Huiqi Zhang. "Fully Room Temperature Reprogrammable, Recyclable, and Photomobile Soft Actuators from Physically Cross-Linked Main-Chain Azobenzene Liquid Crystalline Polymers". Molecules 28, n. 10 (18 maggio 2023): 4174. http://dx.doi.org/10.3390/molecules28104174.
Abstract (sommario):
Fully room temperature three-dimensional (3D) shape-reprogrammable, recyclable, and photomobile azobenzene (azo) polymer actuators hold much promise in many photoactuating applications, but their development is challenging. Herein, we report on the efficient synthesis of a series of main-chain azo liquid crystalline polymers (LCPs) with such performances via Michael addition polymerization. They have both ester groups and two kinds of hydrogen bond-forming groups (i.e., amide and secondary amino groups) and different flexible spacer length in the backbones. Such poly(ester-amide-secondary amine)s (PEAsAs) show low glass transition temperatures (Tg ≤ 18.4 °C), highly ordered smectic liquid crystalline phases, and reversible photoresponsivity. Their uniaxially oriented fibers fabricated via the melt spinning method exhibit good mechanical strength and photoinduced reversible bending/unbending and large stress at room temperature, which are largely influenced by the flexible spacer length of the polymers. Importantly, all these fibers can be easily reprogrammed under strain at 25 °C into stable fiber springs capable of showing a totally different photomobile mode (i.e., unwinding/winding), mainly owing to the presence of low Tg and both dynamic hydrogen bonding and stable crystalline domains (induced by the uniaxial drawing during the fiber formation). They can also be recycled from a solution at 25 °C. This work not only presents the first azo LCPs with 3D shape reprogrammability, recyclability, and photomobility at room temperature, but also provides some important knowledge of their structure–property relationship, which is useful for designing more advanced photodeformable azo polymers.
16
Wang, Zhi Gang, Wen Hao Xi, Jing Bo Zhou, Jia Ming Xu e Guang Li. "Preparation and Properties of Recycled PET Fibers Filled Polyethylene Composites". Materials Science Forum 848 (marzo 2016): 89–93. http://dx.doi.org/10.4028/www.scientific.net/msf.848.89.
Abstract (sommario):
Responding to the resource waste and environmental damage, the recycled Polyethylene Terephthalate (PET) fibers were successfully obtained from waste PET textiles using a PFI mill. The high density polyethylene (HDPE)-based composites reinforced with recycled PET fibers were manufactured by melting blend. The mechanical properties of the composites were investigated by mechanical property test. The thermal stability and crystallinity were analyzed by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC), and their microstructures were characterized by Scanning Electron Microscopy (SEM). The mechanical properties of the composites indicated the significant improvements in tensile, flexural and impact properties by increasing the recycled PET fibers to 20wt%. The morphological and structural results showed that the recycled PET fibers dispersed well in HDPE matrix with the help of PE-g-MAH as a compatibilizer. The thermal analysis revealed that the degree of crystallinity and crystallizing rate tended to increase, while the thermal stability remained stable. In addition, using PFI mill in dealing with the waste textiles will help open new ways for recycling of waste textiles.
17
Ichim, Mariana, Ioan Filip, Lucia Stelea, Gabriela Lisa e Emil Ioan Muresan. "Recycling of Nonwoven Waste Resulting from the Manufacturing Process of Hemp Fiber-Reinforced Recycled Polypropylene Composites for Upholstered Furniture Products". Sustainability 15, n. 4 (16 febbraio 2023): 3635. http://dx.doi.org/10.3390/su15043635.
Abstract (sommario):
Waste recycling is a solution that reduces the environmental impact of waste landfilling or incineration. The aim of this paper is to investigate both the effect of incorporating recycled fibers obtained by defibrating 50/50 hemp/rPP nonwoven waste and the effect of the compatibilizer on the properties of composite materials. Composites incorporating 50% and 100% recycled fibers were treated with 2.5% and 5% maleated polypropylene (MAPP), respectively, and compared to both the untreated composites and the composite obtained by thermoforming from the nonwovens that generated the waste. The incorporation of 50% and 100% recycled fibers into composites decreased the tensile strength by 17.1–22.6%, the elongation at break by 12.4–20.1%, the flexural strength by 6.6–9%, and flexural modulus by 10.3–37%. The addition of 5% MAPP showed the greatest improvements in mechanical properties of composites containing 100% recycled fibers, as follows: 19.2% increase in tensile strength, 3.8% increase in flexural strength, and 14.8% increase in flexural modulus. Thermal analysis established that at temperatures ranging between 20 °C and 120 °C, the composites were thermally stable. SEM analysis revealed good coverage of the reinforcing fibers, and EDX analysis confirmed the presence of the compatibilizing agent in the structure of the composite material.
18
BEYİT, ALI, MUSTAFA SABRI ÖZEN e ERHAN SANCAK. "Electromagnetic shielding effectiveness of needle-punched composite nonwoven fabrics with stainless steel fibres". Industria Textila 75, n. 01 (27 febbraio 2024): 75–85. http://dx.doi.org/10.35530/it.075.01.202346.
Abstract (sommario):
In the study, electromagnetic shielding efficiency (EMSE) absorption and reflectivity properties of fabric produced from staple stainless-steel fibres and recycled staple polyester fibres by carding and needling technologies were investigated. The bi-component core/sheath polyester fibres at a fixed ratio of 20% in producing all nonwoven fabrics were used. The staple stainless-steel fibres and recycled staple polyester fibres were blended at 13 different ratios such as 1%, 2.5%, 5%, 7.5%, 10%, 12.5%, 15%, 17.5%, 20%, 22.5%, 25%, 27.5%, 30%. The fibre webs were formed at wool type carding machine and then the folded webs were bonded mechanically with needle punching machines. Half of the produced nonwoven composite fabrics were bonded by thermal bonding technology with oven and calender machines. As the conductive fibres were costly, the study aimed to obtain optimum shielding effectiveness with the usage of minimum conductive fibres. Electromagnetic shielding properties, absorption and reflection characteristics of needle-punched nonwoven fabrics with calendered or un-calendered were performed by coaxial transmission line method according to ASTM-D4935-10 in the frequency range of 15 MHz to 3000 MHz. It is a known fact that electromagnetic shielding effectiveness increases with the increase in the amount of conductive fibre. It was found that nonwoven fabric produced with a usage of 17.5% stainless steel fibre has at least 90% electromagnetic shielding percentage in general use with 15 dB at a frequency of 1800 MHz. Increased stainless steel fibre content in nonwoven fabrics resulted in decreased nonwoven fabric thickness and tensile strength. Such a nonwoven composite material with electromagnetic shielding property could be used for construction and building applications.
19
Rabehi, Rachid, Rabehi Mohamed e Omrane Mohammed. "Study of the durability of self-compacting concrete made from recycled gravel". Journal of Engineering and Exact Sciences 9, n. 4 (6 giugno 2023): 15927–01. http://dx.doi.org/10.18540/jcecvl9iss4pp15927-01e.
Abstract (sommario):
Research has been carried out in Japan recently with the aim of creating concrete formulations characterized by high workability while being stable in order to adapt concrete to structures with more complex and heavily reinforced sections. (Low segregation, compaction, and bleeding) with strong mechanical properties. The result of this research is self-compacting concrete (SCC), a new type of concrete that can fulfill the aforementioned properties. SCC is distinguished by a high paste volume, a high fines volume, the use of superplasticizers, and a low gravel volume. Due to the increasing demand for aggregates, crushed gravel may be replaced with recycled gravel in the interests of environmental conservation and sustainable development goals. Steel fibers are added to recycled concrete and gravel SCCs to improve their properties. The objective of this research is to examine the durability in the hardened state as well as the physico-mechanical characteristics of self-compacting concrete (SCC) made from recycled concrete gravel. According to the results, the best recycled concrete gravel contains 50%, and the addition of 0.5% fibers improves the properties of these SCCs.
20
Becker, Christian, Joachim Hausmann, Janna Krummenacker e Nicole Motsch-Eichmann. "First Conclusions on Damage Behaviour of Recycled Carbon Staple Fibre Yarn Using X-ray and Acoustic Emission Techniques". Materials 16, n. 13 (5 luglio 2023): 4842. http://dx.doi.org/10.3390/ma16134842.
Abstract (sommario):
This paper presents the first results on the characterisation of the damage behaviour of recycled carbon fibre (rCF) rovings manufactured into unidirectionally (UD) reinforced plates. In the first step, the mechanical properties of several material combinations were determined by mechanical tests (tensile, flexural, compression). This proves the usability of the material for load-bearing structures. For example, a tensile modulus of up to 80 GPa and a tensile strength of 800 MPa were measured. Subsequently, the fracture surface was analysed by scanning electron microscopy (SEM) to characterise the fibre–matrix adhesion and to obtain first indications of possible failure mechanisms. Despite the high mechanical properties, poor fibre–matrix adhesion was found for all matrix systems. In situ X-ray microscopy tests were then performed on smaller specimens under predefined load levels as transverse tensile and bending tests. The results provide further predictions of the failure behaviour and can be compared to the previous test results. The three-dimensional scan reconstruction results were used to visualise the failure behaviour of the staple fibres in order to detect fibre pull-out and fibre or inter-fibre failure and to draw initial conclusions about the damage behaviour in comparison to conventional fibre composites. In particular, a benign failure behaviour in the transverse tensile test was demonstrated with this procedure. In addition, first concepts and tests for the integration of AE analysis into the in situ setup of the X-ray microscope are presented.
21
Sharma, Shubham, P. Sudhakara, Jujhar Singh, Sanjay M. R. e S. Siengchin. "Fabrication of Novel Polymer Composites from Leather Waste Fibers and Recycled Poly(Ethylene-Vinyl-Acetate) for Value-Added Products". Sustainability 15, n. 5 (28 febbraio 2023): 4333. http://dx.doi.org/10.3390/su15054333.
Abstract (sommario):
This investigation was focused on evaluating the utilization of Leather-waste, i.e., “Leather Shavings”, to develop “Poly(ethylene-vinyl-acetate)” (EVA) based “polymer matrix composites”. Composites with the highest ratio of 1:1 were developed using a rolling-mill, which was then subjected to hot-press molding for value-added applications, notably in the “floor-covering”, “structural”, “footwear”, and “transportation domain”. The specimens were examined for evaluating the “physico-mechanical characteristics” such as, “Compressive and Tensile, strength, Abrasion-resistance, Density, tear-resistance, hardness, adhesion-strength, compression, and resilience, damping, and water absorption” as per standard advanced testing techniques. Raising the leather-fiber fraction in the composites culminated in considerable enhancement in “physico-mechanical characteristics” including “modulus”, and a decline in “tensile-strain” at “fracture-breakage”. The thermo-analytic methods, viz. TGA and DSC studies have evidenced that substantial enhancement of thermo-stability (up to 211.1–213.81 °C) has been observed in the newly developed PMCs. Additionally, the DSC study showed that solid leather fibers lose water at an endothermic transition temperature of around 100 °C, are thermo-stable at around 211 degrees centigrade, and begin to degrade at 332.56-degree centigrade for neat recycled EVA samples and begin to degrade collagen at 318.47-degree centigrade for “leather shavings/recycled EVA polymer composite samples”, respectively. Additionally, the “glass transition temperature” (Tg) of the manufactured composites was determined to be between −16 and 30 °C. Furthermore, SEM and EDAX analysis have been used to investigate the morphological characteristics of the developed composites. Micrograph outcomes have confirmed the excellent “uniformity, compatibility, stability and better-bonding” of leather-fibers within the base matrix. Additionally, the “Attenuated-total-reflection” (ATR-FTIR) was carried out to test the “physicochemical chemical-bonding”, “molecular-structure”, and “functional-groups” of the “base matrix”, and its “composites” further affirm the “recycled EVA matrix” contained additives remain within the polymeric-matrix. An “X-ray diffraction study” was also conducted to identify the “chemical-constituents” or “phases” involved throughout the “crystal-structures” of the base matrix and PMCs. Additionally, AFM analysis has also been utilized to explore the “interfacial adhesion properties” of mechanically tested specimens of fabricated polymeric composite surfaces, their “surface topography mapping”, and “phase-imaging analysis” of polymer composites that have leather-shavings fibers.
22
Rabehi, Rachid, Mohamed Rabehi e Mohammed Omrane. "Steel fiber's effects on the physical and mechanical characteristics of selfcompacting concrete (SCC) made of recycled gravel". International Conference on Scientific and Innovative Studies 1, n. 1 (14 aprile 2023): 295–301. http://dx.doi.org/10.59287/icsis.616.
Abstract (sommario):
In order to adapt the concrete to structures with more complex and highly reinforced sections,research has been carried out in recent years in Japan with the aim of developing concrete formulationscharacterized by high workability while being stable. (Low segregation, bleeding, and compaction), withgood mechanical characteristics and durability. The culmination of this research has given rise to a newtype of concrete that can satisfy the properties mentioned above, called self-compacting concrete (SCC).SCC is characterized by its high volume of paste, a large amount of fines, the use of superplasticizers, anda low volume of gravel. For the preservation of the environment and in the vision of sustainabledevelopment, due to the increasing demand for the use of aggregates, crushed gravel can be replaced byrecycled concrete gravel. To improve the properties of SCCs based on recycled concrete gravel, metal fibersare added. The objective of this work is to study the effect of the introduction of metal fibers in selfcompacting concretes based on recycled concrete gravel on the physico-mechanical properties of theseSCCs. The results obtained show that 50% recycled concrete gravel is the best, and the 1% fibers improvethe physico-mechanical characteristics of these SCCs.
23
Wei, Jin, Abdukeyum Abdurexit, Ruxangul Jamal, Tursun Abdiryim, Jiangan You, Zhiwei Li, Jin Shang e Qian Cheng. "Carbon Fiber Reinforced Recycled Polypropylene/Polyolefin Elastomer Composites with High Mechanical Properties". Polymers 16, n. 7 (3 aprile 2024): 972. http://dx.doi.org/10.3390/polym16070972.
Abstract (sommario):
The treatment of waste plastics has gradually become a hot topic in the current scientific community. In response to the needs for high-impact performance R-PP-based composites, carbon fiber (CF)-reinforced polyolefin elastomer (POE)/recycled polypropylene (R-PP) composite (CF/POE/R-PP) was prepared by the mechanical blending method, and its mechanical and thermal properties were systematically studied. It was found that the CF could effectively improve the bending and notch impact strength as well as enhance the thermal stability of POE/R-PP. Furthermore, a stable and dispersed composite interface formed by the combination of maleic anhydride-grafted polypropylene (PP-g-MAH) with the surface of CF and the fusion alkyl chains in R-PP and POE further enhanced the CF’s reinforcing effect. As a result, the addition of 9 wt.% CF successfully improved the heat resistance of the composite material, and the residual carbon content increased by 97.84% after sintering. The composite toughening of POE and CF effectively improved the impact strength of the composite material, with a maximum increase of over 1000%. This study ultimately resulted in a high-impact-resistant composite material.
24
Elmasri, Mabrooka A., Ahmed Abdulqadear Alaribe e Mustafa M. Amami. "Compressive Strength Improvement of Lightweight Concrete by Incorporation Waste Materials: An Experimental Investigation". مجلة علوم البحار والتقنيات البيئية 7, n. 2 (31 dicembre 2021): 97–104. http://dx.doi.org/10.59743/jmset.v7i2.21.
Abstract (sommario):
In the world of depletion of resources, using recycled materials is getting more and more interesting, since recycling generally reduces the need for extracting, refining, and processing raw materials. In this study, attempts to investigate the effect of two types of steel fibers (staples) on concrete compressive strength have been experimentally accomplished. The different fibers at constant fractions of 0.5%, 1%, 1.5%, and 2 % by the weight of cement are used as reinforced agents with different curing duration times of steel fibers-normal concrete samples. The results obtained by the compressive strength test showed a significant improvement in the concrete compressive strength up to 47.8 MPa could be on hand with such simple reinforcement.
25
Chuang, Bao, Lin, Lin e Lou. "Fabric Composites Reinforced with Thermally Bonded and Irregularly Aligned Filaments: Preparation and Puncture Resistant Performance". Polymers 11, n. 4 (17 aprile 2019): 706. http://dx.doi.org/10.3390/polym11040706.
Abstract (sommario):
This study proposes fabric composites with improved static and dynamic puncture via increasing a friction force to restrain the slide of filaments as well as the compression and abrasion between the fibers and the puncture probe. The the bi-layered shell layers of composite fabrics are composed of aramid staple fibers and nylon staple fibers and a layer of low-melting-point polyester (LPET). The nonwoven layer consisting of recycled aramid and nylon staple fibers provides a shear effect to dissipate part of the puncture energy. Reinforcing interlayers include a woven fabric and PET filaments that are circularly aggregated between the surface layers, providing isotropic filament reinforcement and strengthening the resistance against the tip of the puncture probe. The reinforcing filaments may slide after the employment of needle punching, and to compensate for this disadvantage, the LPET layers are used to thermal bond the composite fabrics and the total thickness is controlled at 2 mm. The thermally bonded fabric composites are evaluated in terms of puncture resistance, thereby examining the effects of fabric structure and thermal bonding. According to the test results, the optimal composite structure is the sample N/L/W/F/L/N, which was reinforced by the LPET adhesive layer and irregularly aligned filaments. The sample which used the LPET adhesive layer had a positive influence on static puncture resistance and dynamic puncture resistance, preventing the slide of filaments, but the poor interfacial combination only contributed to limited reinforcement.
26
Ye, Jiahao, Ping Jiang, Lejie Chen, Xuhui Zhou, Fei Rao e Xinyi Tang. "Strength and Deformation Characteristics of Fiber and Cement-Modified Waste Slurry". Polymers 15, n. 16 (17 agosto 2023): 3435. http://dx.doi.org/10.3390/polym15163435.
Abstract (sommario):
Using fiber and cement to modify waste slurry and apply it to roads is an effective way to recycle waste slurry. A new type of road material, fiber–cement-modified waste slurry (FRCS), was prepared in this study. The static and dynamic characteristics of the cement soil were studied using an unconfined compressive strength test and dynamic triaxial test. The results show that the optimum fiber content of FRCS is 0.75%. In the unconfined compressive strength test, under this fiber content, the unconfined compressive strength (UCS) of the FRCS is the largest, and the elastic modulus and modulus strength ratio are both the smallest, indicating that the tensile properties of the cement slurry have been enhanced. In the dynamic triaxial test, the hysteretic curve of the FRCS tends to be stable with the increase in the number of cycles, the dynamic elastic modulus of the FRCS decreases first and then increases with the increase in the dosage, while the damping ratio becomes stable after a rapid decline, and the fiber incorporation increases the cumulative strain of the soil–cement under low-stress cycles, indicating that the ductility of the FRCS is improved. In addition, a cumulative strain prediction model of the FRCS is established in this paper, which can provide a reference for the resource application of waste slurry in road engineering.
27
Mischo, Florian, Christian Goergen, Sebastian Schmeer e Peter Mitschang. "Use of recycled carbon staple fibers in an advanced thermoforming process and analysis of its crash performance". Advanced Manufacturing: Polymer & Composites Science 6, n. 1 (2 gennaio 2020): 48–56. http://dx.doi.org/10.1080/20550340.2020.1739402.
28
Hasan, Mir Mohammad Badrul, Anwar Abdkader, Tobias Georg Lang, Thomas Gereke e Chokri Cherif. "Tensile Properties of Different Yarn Structures Based on Recycled Carbon Fibre for Sustainable Thermoset Composites". Materials Science Forum 1117 (19 marzo 2024): 55–61. http://dx.doi.org/10.4028/p-xrj5ka.
Abstract (sommario):
The development of different hybrid yarn structures from recycled carbon fibre (rCF) (rCF content approx. 50% by weight) and thermoplastic fibres for thermoplastic composites has been reported earlier. However, manufacturing of yarns with high rCF content (>90%) required for thermoset composites is still not realizable due to high shortening (≥ 70%) in fibre length of rCF, which occurs during different processing steps of spinning. The reason lies in low shear strength, smooth fibre surface, small diameter and high brittleness of rCF. In addition to this, lack of crimp in rCF leads to drafting error during drawing and spinning process. Therefore, there is a high demand on rCF yarns for thermoset composites, as around 70% of composites are produced based on thermoset matrix. In this paper, yarns consisting of staple rCF with high rCF content (>90 weight%) are developed on DREF-friction spinning and wrap spinning technologies. For the production of yarns, slivers with different rCF content are produced using carding and drawing machine. The effect of different spinning parameters suction air pressure for DREF friction spun yarns and yarn twist for wrap spun yarns is investigated and their effect on tensile properties of yarn is analysed. The results show that the tensile properties of yarns can be adjusted to a wide range varying the yarn structure and spinning parameters.
29
Hengstermann, M., MMB Hasan, A. Abdkader e Ch Cherif. "Development of a new hybrid yarn construction from recycled carbon fibers (rCF) for high-performance composites. Part-II: Influence of yarn parameters on tensile properties of composites". Textile Research Journal 87, n. 13 (20 agosto 2016): 1655–64. http://dx.doi.org/10.1177/0040517516658511.
Abstract (sommario):
This article reports the successful manufacturing of hybrid yarns from virgin staple CF (40 or 60 mm) or recycled staple CF (rCF) by mixing with polyamide 6 (PA 6) fibers of defined length. The hybrid yarns are produced using an optimized process route of carding, drawing, and flyer machine. Furthermore, the influence of CF length, CF type (i.e. virgin or rCF), CF volume content, and twist of the yarn are also investigated regarding the tensile properties of unidirectionally laid (UD) thermoplastic composites. The results show that CF length, yarn twist, and CF content of composites play a big role on the tensile properties of thermoplastic composites. From the comparison of tensile strength of UD composites produced from 40 and 60 mm virgin staple CF, it can be seen that the increase of yarn twist decreases the tensile strength. However, the effect of twist on the tensile properties of UD composites manufactured from 40 mm virgin staple CF is insignificant. The tensile strength of UD thermoplastic composites manufactured from the hybrid yarn with 40 and 60 mm virgin staple CF and rCF is found to be 771 ± 100, 838 ± 81, and 801 ± 53.4 MPa, respectively, in the case of 87 T/m containing 50 volume% CF.
30
Fleury, Mateus Porto, Lucas Deroide do Nascimento, Clever Aparecido Valentin, Jefferson Lins da Silva e Marta Pereira da Luz. "Creep Behaviour of Recycled Poly(ethylene) Terephthalate Non-Woven Geotextiles". Polymers 13, n. 5 (28 febbraio 2021): 752. http://dx.doi.org/10.3390/polym13050752.
Abstract (sommario):
At the beginning of this century, due to well-established Brazilian recycling processes, geosynthetics’ manufacturers started to use recycled poly(ethylene) terephthalate (PET) yarns/filaments (from PET bottles) in geotextile production. Despite the fact that recycled products cannot act as reinforcement functions, geosynthetics are constantly under sustained tensile load and experiences evolutions of the axial strain (creep behaviour). Thus, this study aims to assess the influence of the structure of (needle-punched) non-woven geotextiles manufactured using recycled PET yarns on their creep behaviour. Two geotextiles with different fibre/filament production processes were investigated (short-staple fibres—GTXnwS—and continuous filaments—GTXnwC). Unconfined in-isolated conventional and accelerated (using the stepped isothermal method) creep tests were performed at 5%, 10%, 20%, 40% and 60% of geotextiles’ ultimate tensile strength. The geotextiles investigated provided similar creep behaviour to geotextiles manufactured with virgin PET material. The standard deviation of the axial strain tends to increase as the load level applied increase. The structure of the GTXnwS harms its tensile –strain behaviour, promoting axial deformation under sustained loads, at least 50% higher than GTXnwC for the same load level applied. The influence of the load level and geotextile structure in the initial axial strain is pointed out. Long-term predictions based on creep tests performed using the stepped isothermal method have proven to be conservative and they must be restricted for quality control of the investigated geotextiles.
31
Cestari, Sibele Piedade, Peter Martin, Paul Hanna, Mark Kearns e Luis Claudio Mendes. "Rotational-Moulded Building Blocks for the Circular Economy". Materials Science Forum 1042 (10 agosto 2021): 17–22. http://dx.doi.org/10.4028/www.scientific.net/msf.1042.17.
Abstract (sommario):
Throughout the combination of unique approaches on innovative polymer composites and rotational moulding plastics processing technique, we developed a building block using a mix of recycled and virgin plastic. This block was a technical case study from a multidisciplinary approach - comprising materials science, polymers processing and design - to reinsert recycled plastics in the Circular Economy. The aim was to produce a three-dimensional interlockable block, combining unique design and unconventional materials to create an emblematic building element. We investigated the composition and availability of local plastic waste, as well as other waste-stream materials – concrete waste, red mud, hemp fibre, sugarcane bagasse. We prepared a range of composites and blends to test their prospective aspect and processability. To simulate the end-result of a rotationally-moulded part, we prepared samples of the blends in an oven. The thermal analysis showed that all materials were thermally stable at the processing temperature of the virgin polymer in rotomoulding, around 200 °C. There were an evident LLDPE continuous-phase and a recyclate dispersed-phase. We also explored the aesthetic effect of scattering particles of colour in the mixes. The impact test showed better results for the polyethylene-based recyclates if compared to polypropylene and poly (ethylene terephthalate) ones. We concluded that waste materials could be revalued into something practical and reproducible, produced by rotational moulding plastics processing. And we developed a viable and innovative potential product for the Circular Economy, requiring minimal fixing and no further external finishing.
32
VAR, Cansu, e Sema PALAMUTCU. "İplik Teknolojileri ve Makinaları Konularında Türkiye'de Yazılmış Lisansüstü Tezlerin Nicel Olarak Değerlendirilmesi". Uludağ University Journal of The Faculty of Engineering 28, n. 3 (2 dicembre 2023): 791–808. http://dx.doi.org/10.17482/uumfd.1349139.
Abstract (sommario):
Yarn and spinning technology is a complex process that is a combination of raw materials, machinery, and automation technology where continuous improvements, researches and innovations run progressively. For the evolution of spinning technology, academic publications, postgraduate theses, and technological contributions of related shareholders must be considered as adherent supplements. Aim of this study is to examine the accomplished 236 postgraduate theses related to conventional and novel textile fibre types, staple spun/filament yarn technology and machinery, yarn types with structural and functional varieties, and modified spinning technologies in Turkish Universities. Moreover, it is aimed to reveal any trend in theses on yarn technology and the regional textile clusters in Türkiye. The methodology of the pursuit is a quantitative assessment where postgraduate level, thesis subject, year of thesis defence, and raw materials used in the theses are concerned. The findings showed that researchers focussed on conventional spinning systems and yarns in parallel with the spinning capacity and import potential of the country. Other extractions of the study are; classical ring system is mostly studied by the researchers, modern spinning technologies are included in many theses, reflections of global circumstances are distinguished in theses with keywords of manmade/recycled fibres, and blended yarns.
33
Ding, Cailing, Jianyong Yu e Weiguo Chen. "The structure and properties of wool treated with a reversed-phase microemulsion containing aqueous alkali". Textile Research Journal 88, n. 3 (13 novembre 2016): 254–60. http://dx.doi.org/10.1177/0040517516677229.
Abstract (sommario):
In order to limit modification to the surface of wool fibers and decrease pollution caused by conventional chemical treatments using chlorine, a water-in-oil-type reversed-phase microemulsion with decamethylcyclopentasiloxane as the external phase was prepared containing very small amounts of an aqueous solution of alkali. The edges of the wool cuticle scales were modified by the alkali in aqueous solution contained in the reversed-phase microemulsion. The external phase decamethylcyclopentasiloxane can be recycled after application. In this paper, the solubility of water in the reversed-phase microemulsion and its stability were first studied and then it was applied in the treatment of wool. The results showed that surfactant sodium alcohol ether sulfate/NaOH aqueous solution was quite stable. Felting shrinkage of treated wool was reduced and the initial dyeing speed was higher than that for untreated wool. The corroded scales of treated wool were observed by scanning electron microscopy and the bromine Allwörden reaction with bromine water was reduced or eliminated after treatment. This adsorbable organohalogen-free modification should be useful in improving the manufacturing properties of wool, such as hydrophilicity, and as a pretreatment for wool printing.
34
Gudeta, Bedane, Endale Gebre Kedisso, Donis Gurmessa, Dawit Tesfaye, Samuel Damtew, Workishet Taye, Arkebe Gebre-Egziabher et al. "Adaptability of Genetically Engineered Bt Cotton Varieties in Different Growing Regions of Ethiopia". Advances in Agriculture 2023 (8 maggio 2023): 1–16. http://dx.doi.org/10.1155/2023/8224053.
Abstract (sommario):
Cotton varieties that are high yielding and resistant to pests are required to improve production and productivity and to capitalize on the crop’s enormous potential and its critical role in Ethiopia’s expanding textile industry. Lack of improved cotton technology has forced farmers to recycle local varieties for ages which have become very susceptible to pests which are the major causes of very low productivity and quality of cotton in the country. Among major pests, bollworms (Helicoverpa armigera and Pectinophora gossypiella) account for 36–60% of yield losses. In the absence of genetically resistant or tolerant varieties, genetically engineered bollworm-resistant Bacillus thuringiensis (Bt) cotton has offered a great opportunity to reduce crop losses from bollworms. The objective of the study was to evaluate the efficacy of bollworm resistance and adaptability of Bt cotton varieties across cotton growing environments in Ethiopia and provide recommendations. Two Bt cotton hybrids (JKCH 1947 and JKCH 1050), one Bt OPV (Sudan), and three OPV conventional varieties (Weyito 07, Stam-59A, and Deltapine-90) were evaluated at seven different agro-ecologies using a randomized complete block design (RCBD) with three replications. Results showed significant differences among genotypes for yield and other traits. Hybrids JKCH 1947 and JKCH 1050 were the top high yielders under high and mild bollworm infestations, with mean seed cotton yield of 3.10 t·ha−1 each and lint yield of 1.20 and 1.19 t·ha−1, respectively, whereas the standard check Deltapine-90 (popular variety) recorded a mean seed cotton and lint yield of 2.3 t·ha−1 and 0.8 t·ha−1, respectively. Combined analysis showed that genotypes, environment, and the genotypes × environment interactions had a highly significant effect ( P < 0.05) on fiber quality. Weyito 07 and the two hybrids (JKCH 1947 and JKCH 1050) had upper half mean fiber lengths in the range of 27.78 to 32.11 mm. For fiber strength, genotypes Weyito 07, JKCH 1050, Stam-59A, and JKCH 1947 had 33.50 g/tex, 28.59 g/tex, 28.00 g/tex, and 27.75 g/tex, respectively. The fiber quality values of the hybrids were within acceptable limits, with staple lengths ranging from 27.78 to 28.44 mm and fiber strengths ranging from 27.75 to 28.59 g/tex. Results show potential adaptation of the hybrids under different cotton growing environments and their superior yield performance due also to added protection of yield losses from damage by bollworms. The contrast is bigger under high insect pressure conditions due to the genetically engineered Bt trait compared to the conventional varieties. The effective field resistance against bollworms in most locations shows that wider use of these hybrids can enhance cotton productivity and quality in Ethiopia.
35
Hardiani, Henggar, e Rina Masriani. "Potensi Sludge dari Industri Kertas Sebagai Bahan Baku Chipboard". Jurnal Riset Teknologi Industri 9, n. 1 (28 agosto 2016): 1–12. http://dx.doi.org/10.26578/jrti.v9i1.1635.
Abstract (sommario):
From the regulatory perspectives, pulp and paper mill sludge management as a environmental issue is significant. The restricted of imported recycle paper is a problem for the pulp and paper industry. Therefore a research was conducted to determine utilization potential of the WWTP sludge from paper industry in Indonesia as raw material for chipboard based on the characteristics of the sludge. The environmental aspects evaluation also has been cundected TCLP test and toxicology LD50 to determine whether the sludge waste category B3. The test results showed that the levels of alpha cellulose sludge is high (45-84%). Primary Sludge from virgin pulp contains high alpha cellulose (76-84%), ash content (3-14%), and the fines are quite low (30-34%). Potential of primary and final sludge to be used as raw material for chipboard. However, the primary sludge is generally recycled so that the final sludge are more preferable to be utilized. The results of FT-IR spectra analysis showed that the dominant chemical components in the sludge are cellulose. Fiber and fines content in line with the observation using SEM. Based on the results of the TCLP test and LD50, it is known that the sludge contains heavy metals, inorganic and organic are stable, so it is safe for the environment and can be utilized. Thus sludge has potential as a raw material for chipboard.ABSTRAKPengelolaan limbah sebagai isu lingkungan penting untuk dilakukan, terutama dari perspektif regulasi. Adanya larangan impor kertas daur ulang, merupakan masalah bagi industri pulp dan kertas. Oleh karena itu dilakukan penelitian untuk meneliti potensi pemanfaatan sludge IPAL dari industri kertas di Indonesia sebagai bahan baku pembuatan chipboard berdasarkan karakteristik sludge. Evaluasi terhadap aspek lingkungan berdasarkan uji karakteristik beracun TCLP dan uji toksikologi LD50 untuk mengetahui apakah sludge termasuk kategori limbah B3 juga dilakukan. Hasil uji menunjukkan bahwa kadar alfa selulosa sludge relatif cukup tinggi (45-84%). Sludge primer pulp virgin mengandung kadar alfa selulosa yang tinggi (76-84 %), kadar abu (3-14 %), dan kadar fines yang cukup rendah (30-34 %). Sludge primer maupun sludge final berpotensi untuk dimanfaatkan sebagai bahan baku pembuatan chipboard. Akan tetapi sludge primer pada umumnya didaur ulang sehingga sludge final lebih berpotensi untuk dimanfaatkan. Hasil analisa spektra FT-IR sludge menunjukkan bahwa komponen kimia yang dominan dalam sludge adalah selulosa. Data kandungan serat dan kandungan fines sejalan dengan pengamatan menggunakan SEM. Berdasarkan hasil uji TCLP dan LD50, diketahui bahwa sludge mengandung logam berat, inorganik dan organik yang bersifat stabil, sehingga aman terhadap lingkungan dan dapat dimanfaatkan. Dengan demikian sludge mempunyai potensi sebagai bahan baku pada industri karton chipboard. Kata kunci : Chipboard, industri kertas, LD50, sludge IPAL, TCLP
36
Hardiani, Henggar, e Rina Masriani. "Potensi Sludge dari Industri Kertas Sebagai Bahan Baku Chipboard". Jurnal Riset Teknologi Industri 9, n. 1 (16 agosto 2016): 1–12. http://dx.doi.org/10.26578/jrti.v9i1.1695.
Abstract (sommario):
From the regulatory perspectives, pulp and paper mill sludge management as a environmental issue is significant. The restricted of imported recycle paper is a problem for the pulp and paper industry. Therefore a research was conducted to determine utilization potential of the WWTP sludge from paper industry in Indonesia as raw material for chipboard based on the characteristics of the sludge. The environmental aspects evaluation also has been cundected TCLP test and toxicology LD50 to determine whether the sludge waste category B3. The test results showed that the levels of alpha cellulose sludge is high (45-84%). Primary Sludge from virgin pulp contains high alpha cellulose (76-84%), ash content (3-14%), and the fines are quite low (30-34%). Potential of primary and final sludge to be used as raw material for chipboard. However, the primary sludge is generally recycled so that the final sludge are more preferable to be utilized. The results of FT-IR spectra analysis showed that the dominant chemical components in the sludge are cellulose. Fiber and fines content in line with the observation using SEM. Based on the results of the TCLP test and LD50, it is known that the sludge contains heavy metals, inorganic and organic are stable, so it is safe for the environment and can be utilized. Thus sludge has potential as a raw material for chipboard.ABSTRAKPengelolaan limbah sebagai isu lingkungan penting untuk dilakukan, terutama dari perspektif regulasi. Adanya larangan impor kertas daur ulang, merupakan masalah bagi industri pulp dan kertas. Oleh karena itu dilakukan penelitian untuk meneliti potensi pemanfaatan sludge IPAL dari industri kertas di Indonesia sebagai bahan baku pembuatan chipboard berdasarkan karakteristik sludge. Evaluasi terhadap aspek lingkungan berdasarkan uji karakteristik beracun TCLP dan uji toksikologi LD50 untuk mengetahui apakah sludge termasuk kategori limbah B3 juga dilakukan. Hasil uji menunjukkan bahwa kadar alfa selulosa sludge relatif cukup tinggi (45-84%). Sludge primer pulp virgin mengandung kadar alfa selulosa yang tinggi (76-84 %), kadar abu (3-14 %), dan kadar fines yang cukup rendah (30-34 %). Sludge primer maupun sludge final berpotensi untuk dimanfaatkan sebagai bahan baku pembuatan chipboard. Akan tetapi sludge primer pada umumnya didaur ulang sehingga sludge final lebih berpotensi untuk dimanfaatkan. Hasil analisa spektra FT-IR sludge menunjukkan bahwa komponen kimia yang dominan dalam sludge adalah selulosa. Data kandungan serat dan kandungan fines sejalan dengan pengamatan menggunakan SEM. Berdasarkan hasil uji TCLP dan LD50, diketahui bahwa sludge mengandung logam berat, inorganik dan organik yang bersifat stabil, sehingga aman terhadap lingkungan dan dapat dimanfaatkan. Dengan demikian sludge mempunyai potensi sebagai bahan baku pada industri karton chipboard. Kata kunci : Chipboard, industri kertas, LD50, sludge IPAL, TCLP
37
Plazonić, Ivana, Irena Bates e Marina Vukoje. "Changes in Straw-Containing Laboratory Papers Caused by Accelerated Ageing". Heritage 5, n. 3 (25 luglio 2022): 1836–51. http://dx.doi.org/10.3390/heritage5030095.
Abstract (sommario):
Natural ageing has a major influence on the properties of paper, while light, heat, and humidity are the environmental influences that most disrupt the stability of paper. This research focuses on changes in straw-containing papers caused by accelerated ageing. The papers were made in the laboratory by mixing straw pulp with the pulp of recycled fibers in different weight ratios and were artificially aged by a dry-heat treatment (thermal oxidation) and UV radiation treatment (photo-oxidation) over a 24 h period to simulate natural ageing. The observed changes in the optical, surface, and chemical stability of papers were analyzed and are discussed in this paper. It is evident that, regardless of the origin of straw for pulp production, it forms papers that undergoes similar optical properties (photo-yellowing and brightness lose), while certain differences have been observed in surface and chemical stability. Based on all analyses performed as part of this research, it was found that paper produced with the addition of wheat pulp is the most stable of all laboratory straw-containing papers. However, it must be emphasized that, if lignin-containing straw pulp is used as the main constituent of paper, the brightness stability of such pulp must be improved, or the paper surface must be improved by surface finishing in order to obtain greater stability against ageing.
38
Kuru, D., A. Akpinar Borazan e M. Guru. "Effect of chicken feather and boron compounds as filler on mechanical and flame retardancy properties of polymer composite materials". Waste Management & Research: The Journal for a Sustainable Circular Economy 36, n. 11 (15 ottobre 2018): 1029–36. http://dx.doi.org/10.1177/0734242x18804041.
Abstract (sommario):
Sustainable utilisation of solid waste has been influenced by the increasing population of the world. Benefits of using solid waste based on natural fibre in polymer material are biodegradability and cost effectiveness. In poultry farms, chicken poultry, one of the slaughterhouse wastes is confronted with 30 106 kg of waste per year in Turkey. The evaluation of this waste, which is quite rich in keratin, is extremely important both for the solution of the waste problem and for maintaining a clean environment, bringing this valuable material to the economy. These fibres are stable, durable and biodegradable because they have a crystalline structure. However, this valuable waste will have a positive effect when used together with boron minerals, which both increase the mechanical properties, flame retardancy and biodegradation of composite material. In this study, it is the aim to manufacture superior polyester-based composite materials reinforced with three kinds of boron minerals, such as boron oxide, borax pentahydrate, borax decahydrate and fibres recycled from waste chicken feathers. The effect of different filling ratios of filling materials on the mechanical and physical properties of composite materials was examined. Flame retardancy properties of the composites with best mechanical results were investigated. After pouring by means of the pre-casting process, the water absorption and swelling thickness of final products, as well as density, bending strength, flexural modulus, limiting oxygen index, thermogravimetric analysis and scanning electron microscope analysis, was performed. Mixing prescriptions and conditions with the best properties were determined.
39
Totito, Thandiwe Crystal, Katri Laatikainen, Chris Bode-Aluko, Omoniyi Pereao e Leslie Petrik. "Fabrication and Characterization of Electrospun Waste Polyethylene Terephthalate Blended with Chitosan: A Potential Single-Use Material". Polymers 15, n. 2 (13 gennaio 2023): 442. http://dx.doi.org/10.3390/polym15020442.
Abstract (sommario):
Textile single-use products are dominantly used for hygiene and personal care, many of which are non-biodegradable and are frequently discarded into sewerage systems, thus causing blockages. Thus, there is a need to move towards water-soluble textiles. This research study focuses on transforming or repurposing biomass material and synthetic reusable waste plastic materials to improve waste. Chitosan (CS) nanofibers could be used in single-use nonwoven fabric or biodegradable tissues, as the water-soluble properties of chitosan nanofibers make them the perfect material for single-use applications. Furthermore, CS was blended with polyethylene terephthalate (PET) polymer and PET-based waste plastic (CS-WPET) to slow the CS nanofibers’ water degradability and strengthen the durability of the nanofiber which could be used as air filters. The CS-TFA and CS-TFA/DCM nanofiber diameters were 95.58 ± 39.28 nm or 907.94 ± 290.18 nm, respectively, as measured from the HRSEM images. The CS-PET and CS-WPET hybrid nanofibers had fiber diameters of 246.13 ± 96.36 or 58.99 ± 20.40 nm, respectively. The thermal durability of the nanofibers was tested by TGA, which showed that CS-TFA/DCM nanofibers had sufficient thermal stability up to 150 °C, making them suitable for filter or fabric use at moderate temperatures. The blended nanofibers (CS-PET and CS-WPET) were thermally stable up to 160 °C. In the aqueous medium stability test, CS-PET and CS-WPET hybrid nanofibers had a slower degradation rate and were easily dissolved, while the CS nanofibers were rapidly and completely dissolved in an aqueous medium. Blending waste PET with CS allows it to be recycled into a useful single-use, non-woven textile, with greater water solubility than unmodified PET nanofibers but more durability than CS nanofibers on their own.
40
Marín-Genescà, Marc, Jordi García-Amorós, Ramon Mujal-Rosas, Lluís Massagués e Xavier Colom. "Study and Characterization of the Dielectric Behavior of Low Linear Density Polyethylene Composites Mixed with Ground Tire Rubber Particles". Polymers 12, n. 5 (8 maggio 2020): 1075. http://dx.doi.org/10.3390/polym12051075.
Abstract (sommario):
The waste rubber vulcanizate, on account of its stable, cross-linked and three-dimensional structural arrangement, is difficult to biodegrade. Thus, the ever-increasing bulk of worn-out tires is a serious environmental issue and its safe disposal is still a challenging task reported widely by the scientific community. The rubber materials, once they end their useful life, may present difficulties to be reused or recycled. At present, only one tire recycling method is used, which involves grinding and separating steel and fibers from vulcanized rubber, and then using rubber for industrial applications, such as flooring, insulation, footwear. In this paper, a new compound material is presented from a base of reused tire powder (Ground Tire Rubber: GTR) as a mixer and linear low-density polyethylene (LLDPE) as a matrix. The reused tire powder, resulting from grinding industrial processes, is separated by sieving into just one category of particle size (<200 μm) and mixed with the LLDPE in different amounts (0%, 5%, 10%, 20%, 40%, 50% and 70% GTR). Due to the good electrical properties of the LLDPE, this study’s focus is settled on the electrical behavior of the obtained composites. The test of the dielectric behavior is carried out by means of DEA test (Dynamic Electric Analysis), undertaken at a range of temperatures varying from 30 to 120 °C, and with a range of frequencies from 1 to 102, to 3·106 Hz, from which permittivity, conductivity, dielectric constant and electric modulus have been obtained. From these experimental results and their analysis, it can be drawn that the additions of different quantities of GTR to LLDPE could be used as industrial applications, such as universal electrical cable joint, filler for electrical applications or cable tray systems and cable ladder system.
41
Shen, Yang, Erik Svensson Grape, Dag Noréus, Erika Widenkvist e Stina Starborg. "Upcycling of Spent NiMH Battery Material—Reconditioned Battery Alloys Show Faster Activation and Reaction Kinetics than Pristine Alloys". Molecules 25, n. 10 (17 maggio 2020): 2338. http://dx.doi.org/10.3390/molecules25102338.
Abstract (sommario):
During formation and cycling of nickel–metal hydride (NiMH cells), surface corrosion on the metal hydride particles forms a porous outer layer of needle-shaped rare-earth hydroxide crystals. Under this layer, a denser but thinner oxidized layer protects the inner metallic part of the MH electrode powder particles. Nano-sized nickel-containing clusters that are assumed to promote the charge and discharge reaction kinetics are also formed here. In this study, mechanical treatments are tested to recycle hydrogen storage alloys from spent NiMH batteries. This removes the outer corroded surface of the alloy particles, while maintaining the catalytic properties of the surface. Scanning electron microscopy images and powder X-ray diffraction measurements show that the corrosion layer can be partly removed by ball milling or sonication, combined with a simple washing procedure. The reconditioned alloy powders exhibit improved high rate properties and activate more quickly than the pristine alloy. This indicates that the protective interphase layer created on the alloy particle during their earlier cycling is rather stable. The larger active surface that is created by the mechanical impact on the surface by the treatments also improves the kinetic properties. Similarly, the mechanical strain during cycling cracks the alloy particles into finer fragments. However, some of these particles form agglomerates, reducing the accessibility for the electrolyte and rendering them inactive. The mechanical treatment also separates the agglomerates and thus further promotes reaction kinetics in the upcycled material. Altogether, this suggests that the MH electrode material can perform better in its second life in a new battery.
42
Overberg, Matthias, Muhammad Furqan Khurshid, Anwar Abdkader, Mir Mohammad Badrul Hasan e Chokri Cherif. "Development of a micro-scale hybridized yarn structure from recycled carbon, aramid and polyamide 6 staple fibers for thermoplastic composites with improved impact strength". Textile Research Journal, 9 dicembre 2023. http://dx.doi.org/10.1177/00405175231197652.
Abstract (sommario):
The aim of this research is to improve the impact strength of thermoplastic composites manufactured from recycled carbon fiber (rCF). For this purpose, the development of a novel multi-material, micro-scale hybridized and low-cost hybrid yarn by blending aramid fibers with rCF and polyamide 6 (PA 6) fibers through the processing route of carding, drawing and flyer spinning is reported in this paper. In addition, two other hybrid yarns were produced from rCF/PA 6 and aramid/PA 6 for comparison with the multi-material rCF/aramid/PA 6 hybrid yarn. Finally, the tensile, flexural and impact properties of composites based on the developed rCF/aramid/PA 6 multi-material hybrid yarn were compared with those of composites reinforced only with rCF and aramid fiber. The results of the Charpy impact test showed that the inclusion of 24 volume percentage aramid fiber increased the impact strength by 70% compared to the composite reinforced with rCF alone. The multi-material hybrid yarn consisting of rCF/aramid/PA 6 fibers shows good potential for designing a hybrid composite with tailored tensile, flexural and impact resistant properties.
43
Krzysik, Andrzej M., John A. Youngquist, James M. Muehl, Roger M. Rowell, Poo Chow e Steven R. Shook. "Dry-Process Hardboards from Recycled Newsprint Paper Fibers". MRS Proceedings 266 (1992). http://dx.doi.org/10.1557/proc-266-73.
Abstract (sommario):
AbstractDry-process hardboard represents a favorable option for recycling old newspaper fibers. However, dry-process boards tend to be less dimensionally stable than boards processed by other methods. Our objective was to determine the effects of various wood fiber (WF) to old newspaper (ONP) ratios (100:0, 50:50, and 0:100 WF/ONP) on the mechanical strength and water resistance of dry-process hardboards made from these fibers. Untreated and acetylated hardboards were made with 3 or 7 percent resin and 0.5 percent wax. Boards were tested for static bending and tensile strength properties and water resistance. As expected, increasing the resin level from 3 to 7 percent generally improved all measured properties. Acetylation substantially improved the water resistance of all boards; increasing the amount of ONP caused a corresponding deterioration in both mechanical properties and water resistance.
44
Bågenholm-Ruuth, Edvin, Miguel Sanchis-Sebastiá, Nadine Hollinger, Anita Teleman, Per Tomas Larsson e Ola Wallberg. "Transforming post-consumer cotton waste textiles into viscose staple fiber using hydrated zinc chloride". Cellulose, 23 dicembre 2023. http://dx.doi.org/10.1007/s10570-023-05646-2.
Abstract (sommario):
AbstractLarge amounts of cellulose-based waste textiles are generated every year, yet little is done to recycle this waste. Alternatives such as fiber-to-fiber recycling, where a significant part of the value of the waste textiles is recovered, are attractive possibilities. In this study, we have investigated the viability of using hydrated zinc chloride (ZnCl2·4H2O) as a solvent and swelling agent to convert cotton waste textiles (the most abundant cellulose-based waste textile) into a dissolving pulp that can be used as raw material for the production and spinning of viscose fibers. The solvent produced an accessible dissolving pulp and exhibited excellent recyclability, maintaining good dissolving power even after repeated recycling. The dissolving pulp was subsequently used to produce viscose dope, a spinning solution which was spun and cut into viscose staple fibers. The viscose dope exhibited good properties (moderate filter clogging value and gamma number), and the resulting staple fibers were strong and of good quality (high linear density, elongation, and tenacity). These results illustrate the potential of using hydrated zinc chloride for the production of viscose grade dissolving pulp from cotton waste textiles.
45
Liu, Lulu, Jinpeng Zhao, Xiaoyan Liu e Shixin Lv. "Dynamic characteristics and reinforcement mechanism of silty soil improved by regenerated fiber polymer". Scientific Reports 13, n. 1 (25 ottobre 2023). http://dx.doi.org/10.1038/s41598-023-45281-2.
Abstract (sommario):
AbstractThe development of economical and efficient roadbed silt reinforcement technology not only guides the proficient utilization of silt resources but also fosters the green development of geotechnical engineering construction. Ensuring the robust dynamic stability of the roadbed is pivotal for the safe operation of vehicular traffic. In this context, employing recycled polyester fibers and inorganic curing agents, this paper leverages dynamic triaxial testing and scanning electron microscopy (SEM) methods to scrutinize the dynamic characteristics and microscopic mechanisms of recycled fiber polymer modified roadbed silt. The findings indicate that: (1) with a fiber content of 0.2%, the fiber-modified soil sample exhibits minimal damage, maximal dynamic strength and dynamic elastic modulus, and optimum resilience to dynamic loads; (2) akin to fiber-reinforced sand, an elevation in confining pressure can induce the creation of a quasi-cohesive force in fiber-reinforced soil, equivalently enhancing the confining pressure and thereby amplifying its strength; and (3) the surfaces of microparticles in the enhanced soil structure are enveloped with cementitious substances, while smaller soil particles coalesce to form aggregates that fill inter-particle pores, cultivating a denser and more stable improved soil structure and augmenting the dynamic characteristics of the improvement investment.
46
Wu, Jianqiao, Ying Pan, Ziyi Ruan, Ziji Zhao, Jing Ai, Jinghai Ban e Xianghai Jing. "Carbon fiber-reinforced epoxy with 100% fiber recycling by transesterification reactions". Frontiers in Materials 9 (24 novembre 2022). http://dx.doi.org/10.3389/fmats.2022.1045372.
Abstract (sommario):
Carbon fiber (CF)-reinforced epoxy is the most commonly used advanced composite with high performance. However, these composites usually face intractable disposal problems in their lifecycles, due to the stable cross-linked network structures of epoxy. To address this dilemma, this work proposes a facile yet efficient strategy for recycling carbon fibers from traditional carbon fiber-reinforced epoxy composites using epoxy–anhydride systems as a matrix. Diglycidyl ester of aliphatic cyclo (DGEAC) and methylhexahydrophthalic anhydride (MHHPA) were used as matrix, while T300 woven carbon fiber was used as reinforcement, to construct the composites CF/DGEAC/MHHPA. The epoxy matrix exhibited a high glass transition temperature (Tg = 126°C), high decomposition temperature (Td5 = 300°C), and good solvent resistance. By using 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as a catalyst, the DGEAC/MHHPA networks could be degraded completely in ethylene glycol (EG) at 180°C within 6 h because of transesterification reactions between EG and the networks. Taking advantage of this result, a fiber recycling process was developed for carbon fiber composites, where the cross-linked networks of epoxy could be degraded with 100% carbon fiber recycling. Furthermore, the recycled carbon fiber maintained nearly 100% similarity in surface microscopic morphology and chemical structure compared with virgin carbon fiber. This work proposes a simple and efficient strategy for recycling carbon fiber from traditional high-performance composites, offering a convenient concept for the cyclic utilization of advanced composites.
47
Malhotra, Girisha, e Shilpa S. Chapadgaonkar. "Thermo-alkali stable bacterial xylanase for deinking of copier paper". Journal of Genetic Engineering and Biotechnology 21, n. 1 (25 ottobre 2023). http://dx.doi.org/10.1186/s43141-023-00563-0.
Abstract (sommario):
Abstract Background The bleach-boosting capability of xylanases is well-known. The use of xylanase pre-treatment before the application of chemical bleach has multiple advantages including (i) lesser use of polluting chemicals of the traditional bleaching process; (ii) less damage to the cellulosic fibers, therefore better recyclability; and (iii) better brightness of chemical bleach. The major impediment in the application is the availability of commercial enzymes that are active at the elevated temperature and pH that exist during the industrial pulping process. In the present paper, xylanase having suitability for application in deinking is reported. Results The xylanase used showed high deinking potential. Optimal deinking was obtained at the xylanase dosing of 20U/g of the dried pulp at 60℃ for a treatment time of 1h. It could bring about a 50% reduction in the usage of chemical bleach that was applied after xylanase pre-treatment. The comparison of FTIR spectra showed changes in intensity without significant changes in the functional group signatures implying that there is negligible damage to the fiber strength in the xylanase pre-treatment process as compared to the chemical bleach process. Conclusion The xylanase used in this study was effective in deinking paper pulp and can be used for bio-bleaching of recycled paper.
48
Zhang, Hualei, Nihua Zheng, Tong Xing, Guozhu Zhang, Dong Cao, Yuyong Bai, Shixin Wang et al. "Study on the characteristics of glass fiber‐reinforced polymers from recycled wind turbine blades as reinforcement in particleboard". Polymer Composites, 9 maggio 2024. http://dx.doi.org/10.1002/pc.28514.
Abstract (sommario):
AbstractGlass fiber‐reinforced polymer (GFRP), extensively employed in diverse industries, generates considerable waste, especially from decommissioned wind turbine blades. Our research group has developed a new method of mechanical recovery for GFRP from wind turbine blades. In this study, waste GFRP was processed into a mixed particle size of 0.9–6 mm using a crusher and a screening machine, and then added as reinforcement materials to particleboards. The effects of different levels of four factors (GFRP addition, hot pressing temperature, hot pressing time, and binder dosage) on the properties of GFRP particleboards were evaluated by orthogonal experiments. The study results showed that the particleboards with 30 wt% GFRP improved modulus of rupture (MOR), modulus of elasticity (MOE), and internal bonding strength (IB) by 74.94%, 42.28%, and 92.05%, respectively, compared to pure poplar particleboards. Moreover, GFRP particleboards demonstrated better water resistance and dimensional stability than commercial particleboards and excelled in thermal stability. Recycling GFRP waste from decommissioned wind turbine blades and incorporating it into particleboard production can reduce environmental pollution, increase the resource recovery utilization rate, and contribute to sustainable manufacturing practices.Highlights Low‐cost and efficient methods of recycling wind turbine blades were proposed. Recycled GFRP from wind turbine blades can be used as reinforcement for particleboard. The prepared particleboards have excellent physical and mechanical properties and are thermally stable. Determination of the optimal glass fiber‐reinforced polymer addition level in particleboard at 30 wt%.
49
Cuiffo, Michael, Hye Jung Jung, Asta Skocir, Theanne Schiros, Emily Evans, Elizabeth Orlando, Yu-Chung Lin et al. "Thermochemical degradation of cotton fabric under mild conditions". Fashion and Textiles 8, n. 1 (5 agosto 2021). http://dx.doi.org/10.1186/s40691-021-00263-8.
Abstract (sommario):
AbstractTextile waste presents a major burden on the environment, contributing to climate change and chemical pollution as toxic dyes and finishing chemicals enter the environment through landfill leachate. Moreover, the majority of textile waste reaching landfills is discarded clothing, which could be reused or recycled. Here we investigate environmentally benign morphology changing of cotton textiles as a precursor for reintegration into a circular materials economy. At 50 °C using low concentrations of acids and bases, the interfiber structures of woven cotton were successfully degraded when treated with the following sequence of chemical treatment: citric acid, urea, sodium hydroxide, ammonium hydroxide, and sodium nitrate. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) reveal separation of the constituent fibers without depolymerization of the cellulose structure, and streaming potential measurements indicate that surface charge effects play a key role in facilitating degradation. The proposed reaction procedures show feasibility of effective waste-fabric recycling processes without chemically intensive processes, in which staple fibers are recovered and can be re-spun into new textiles.
50
Liu, Shang‐Hao, Chen‐Feng Kuan, Cing‐Yu Ke, Ming‐Yuan Shen e Chin‐Lung Chiang. "Preparation of thermally stable and flame‐retardant sugarcane bagasse‐ammonium dihydrogen phosphate/epoxy composites and their performance". Journal of Applied Polymer Science, 26 gennaio 2024. http://dx.doi.org/10.1002/app.55201.
Abstract (sommario):
AbstractEpoxy resin was often applied in fiber‐reinforced composite materials, adhesives, and encapsulation materials. However, epoxy was easily flammable and limited its usage in certain applications. The study recycled and reused agricultural waste sugarcane bagasse to prepare a halogen‐free bio‐based intumescent flame retardant and then mixed with epoxy resin to prepare a composite containing polymer with improved thermal properties and flame retardancy of the materials. The work followed the concept of circular economy and sustainability. Bagasse‐ammonium dihydrogen phosphate (ADP) flame retardant was added to an epoxy resin to prepare epoxy/bagasse‐ADP composites, an effective flame‐retarding composite material through hydrothermal method. Adding bagasse‐ADP increased the thermal stability and flame retardancy of the composite materials compared with that of pure epoxy. For the material with 30 wt% added bagasse‐ADP, the char yield was 32.3 wt%, which was 18.2 wt% higher than that of pure epoxy (14.1 wt%) through thermogravimetric analysis. In addition, the limiting oxygen index increased from 21% to 30%, and the UL‐94 classification improved from “Fail” to “V‐0.” This performance was attributed to the nitrogen, phosphorus, and silicon content of the flame retardant.