A modified resistance to compression (RtC) test for evaluation of natural fiber softness

Comfort is a key feature of any clothing that relates significantly to softness of the fiber, yarn and fabric from which is it constructed. A known softness assessment method for fibers is the resistance to compression test. This traditional test only provides a single force value for the resistance of a loose fiber sample using a fixed mass under compression. In this research, a modified resistance to compression test was introduced to show the effects of repeated compression, providing more information about the softness and resilience of selected fibers. Three different natural fiber types, including wool, cotton and alpaca were compared using this new approach. The results showed compression profiles were quite different for different fiber types as well as for the same fibers with different diameters. While the diameters of the wool and alpaca samples were similar (18.5 μm), the modified resistance to compression values were significantly higher for wool (with a peak value at 9.5 kPa compared to 2.1 kPa for alpaca). Cotton was different from wool and alpaca but showed a similar modified resistance to compression value (10.4 kPa) to wool. During cycles of compression, modified resistance to compression peak values decreased slightly and then tended to be constant. Even though the structures of wool, cotton and alpaca were quite different, there was no significant difference in the magnitude of decline in modified resistance to compression peak values. This means that the modified resistance to compression test is able to provide additional information on the resilience characteristics of different natural fibers, and can reveal the resistance behavior of fiber samples during cyclic compression.

General practices to enhance bast fiber composite properties for state of art applications – a review

Composite materials are revolutionizing to realize the demanding needs of aeronautical, automobile, construction, chemical, and biomedical applications. The natural fiber composite is chosen as one of the best choices among composites due to its sustainable goods like eco-friendly nature, better properties and Greenhouse gas (GHG) balance. Furthermore, the bast fiber composites are identified as promising industrial composites based on the availability, strength-to-weight ratio, manufacturing ease, and economics for commercialization. However, product quality and production volume significantly influence commercial adoption of the bast fiber composites. Especially the product quality primarily suffer due to climatic conditions, damage while harvesting, extraction method, retting issues, and extraction location. Consequently, this review aims to provide an overview of the bast fibers & their composites, properties enhancement techniques, overall mechanical behaviours and thermal stability with suitable applications.

A Review on Synthesis and Characterization of Activated Carbon from Natural Fibers for Supercapacitor Application

Supercapacitors have gained much attention in recent years due to their promising characteristics, such as high specific capacitance, high power density, long cycle life, and environment-friendly nature. Usage of natural sources for activated carbon synthesis is a major focus by many researchers worldwide for discovering a replacement of existing supercapacitors. This review summarizes the methods used to synthesize activated carbon (AC) from various natural fiber, their physical and electrochemical characteristics, and the improvement of supercapacitor electrode performance. Previous research studies indicate the practicability of activated carbon derived from various natural fibers with superior electrochemical properties. The effect of activating reagents and temperature on the electrochemical performance for supercapacitor applications are also highlighted in this paper. Since the nature of activated carbon from fibers and its synthesizing methods would result in different properties, the Cyclic Voltammetry (CV) study is also thoroughly discussed on the specific capacitance together with charge/discharge test to observe the capacitance retention after several cycles. Finally, a detailed approach of converting biowaste materials to activated carbon for energy storage applications with environmental concerns is explored.

Manufacture of Banana-Based Paper

The paper is one of the most used elements in modern society, despite the fact that its invention dates back to ancient times. The paper is used for different domestic, labor and industrial purposes. Its manufacture is made from cellulose pulp and vegetable fibers, which have had a significant environmental impact in recent years. This work proposes the analysis of the production of paper from the use of residues of the banana plant, which could offer a better use of natural resources and a lower impact on nature. In addition, the natural fiber of bananas is resistant and is easily obtained in Latin American countries such as Ecuador, which has a high production of it. The results found show that it is possible to make paper with fiber from banana residues and that it is possible to commercialize and make good use of resources. Keywords: Organic paper, banana waste, environmental protection. References [1]A. Herrera, «ELABORACIÓN DEL PAPEL ORGÁNICO A BASE DE PSEUDOTALLO DE BANANO, CANTÓN SANTA ROSA, PROVINCIA DE EL ORO, ECUADOR,» Guayaquil, 2019. [2]R. d. León, «Fabrican papel con desechos de plátano,» CIENCIAMX, 1 julio 2016. [En línea]. Available: http://www.cienciamx.com/index.php/tecnologia/biotecnologia/8476-generacion-de-celulosa-a-partir-de-desechos-de-la-planta-del-platano. [3]A. Cortéz, «ELABORACIÓN DE PAPEL A BASE DE RESIDUOS DE BANANO,» Guayaquil, 2014. [4]M. Dávalos and S. Zurita, «Organic paper, banana waste, environmental protection,» Universidad Politécnica del Litoral, Chile, 2004. [5]G. Castillo-Tumaille and W. Espinoza- Espinoza, «Análisis de aceptación del papel a base de pinzote de banano como alternativa de,» Ingeniería Industrial. Actualidad y Nuevas Tendencias, vol. V, nº 18, pp. 59-70, 2017. [6]M. Mazzeo, L. León, L. Mejía, L. Guerrero and J. Botero, «APROVECHAMIENTO INDUSTRIAL DE RESIDUOS DE COSECHA Y POSCOSECHA DEL PLÁTANO EN EL DEPARTAMENTO DE CALDAS,» Educación en Ingeniería, vol. junio de 2010, nº 9, pp. 128-139, 2010. [7]M. Arzola and A. Mejías, «Modelo conceptual para gestionar la innovación en las empresas del sector servicios,» Revista Venezolana de Gerencia, vol. 12, nº 37, pp. 80-98, 2007. [8]I. Azman and S. Yusrizal, «Service quality as a predictor of satisfaction and customer loyalty.,» Scientific Journal of Logistics. , vol. 12, nº 4, pp. 269-283, 2016.

Valorization of Vegetal Fibers in Anti-Fissuration Screed Mortar Formulation

This work, which is part of the FIBRABETON project, aims to anti-fissuration screed formulations proposition based on natural fibers and comparing these formulations to a synthetic fiber-screed formulation. Different natural fiber (hemp, flax, miscanthus and bamboo) with contents rangingfrom 0.4% to 0.8% were tested. The spread (slump), the shrinkage and mechanical strength (flexural and compressive) studies were carried out. SEM images of natural fibers and natural fibers screed formulation were analyzed. Overall, it is found that all natural fibers screed formulations tested, have shown better behaviour than the synthetic fibers screed formulation in point of view workability, shrinkage and mechanical properties. The lowest shrinkage value is found in the case of the H5 (5 mm long hemp fibers) screed formulation. Generally speaking, the mechanical strength values (flexural and compressive) are more or less similar between natural soft fibers (hemp and flax) and rigid fibers (miscanthus and bamboo). Taking in account slump, shrinkage and mechanical behavior, the proposed good compromise in this work is the H5 screed formulation.

Natural Fibers vs. Synthetic Fibers Reinforcement: Effect on Resistance of Mortars to Impact Loads

Given their specific properties, their natural and renewable sources and their low environmental impact in production, natural fibers offer an opportunity for the development of eco-friendly cement-based composites. The main objective of this experimental work is to evaluate the resistance to the impact load of mortars incorporating natural fibers or polypropylene fibers at 28 days. The assessment was carried out according to an experimental protocol developed in our laboratory. The method consists in dropping a metallic ball on a square shaped specimen of 30x30x2 cm3 to determine the energy supported by each sample. For each specimen, the number of blows required for the first crack initiation and for the total collapse of specimen are detected using a device allowing to measure the speed of ultrasonic waves. The device was fixed on the specimen itself. In order to fulfill the mechanical identity card of the composites, flexural and compression tests were also carried out at 28 days. In this experimental protocol, the pozzolanic binder was considered with different fiber percentages of polypropylene (0.25% and 0.5% by mass of binder) and of natural fibers (0.5% and 1% by mass of binder). All fibers have a length of 12 mm. Results show that natural fiber reinforcement could be considered as an ecological alternative to polypropylene fiber one to improve the resistance of mortars to impact loads.

Effect of Natural and Polypropylene Fibers on early Age Cracking of Mortars

Throughout time, the use of lignocellulosic resources has been implemented in the development of building materials. Among these resources, natural fibers are used as mineral binders reinforcement due to their specific mechanical properties. This experimental investigation focused on effect of flax and hemp fiber reinforcement on the resistance of pozzolanic-based mortars to cracking due to restrained plastic shrinkage. Results were compared with polypropylene fiber reinforcement and with control mortar without fibers. The quantity of fibers added to the mortar mix were respectively 0.25% - 0.5% by mass of binder for polypropylene fibers and 0.5% - 1% by mass of binder for flax and hemp fibers. All fibers have a similar length of 12 mm. The cracking sensitivity was evaluated based on two different methods: the first consists in casting the mortar in a metal mold with stress risers whose criteria are inspired by the ASTM standards. The second consists in pouring the mortar on a brick support. In order to assess the effect of fibers on cracking due to restrained plastic shrinkage, the number of cracks, total crack area and maximum crack width within the first 6 hours after casting were determined using digital image correlation (DIC). Results showed that the flax and hemp fibers were more effective in controlling restrained plastic shrinkage cracking compared to polypropylene fibers. With a natural fiber of 1% by mass of binder, maximum crack width was reduced by at least 70% relative to control mortar based specimens. Natural fibers show great ability to propensity for cracking due to restrained plastic shrinkage; so that, they could be an alternative and ecological solution for polypropylene fibers.