Non-Wood Lignocellulosic Composites

Author(s):  
Marius C. Barbu ◽  
Roman Reh ◽  
Ayfer Dönmez Çavdar

It would seem that with appropriate treatment almost any agricultural residue may be used as a suitable raw material for the wood-based panels like particle- and fiberboard production. The literature on wood-ligno-cellulose plant composite boards highlights steady interest for the design of new structures and technologies towards products for special applications with higher physical-mechanical properties at relatively low prices. Experimental studies have revealed particular aspects related to the structural composition of ligno-cellulose materials, such as the ratio between the different composing elements, their compatibility, and the types and characteristics of the used resins. Various technologies have been developed for designing and processing composite materials by pressing, extrusion, airflow forming, dry, half-dry, and wet processes, including thermal, chemical, thermo-chemical, thermo-chemo-mechanical treatments, etc. Researchers have undertaken to determine the manufacturing parameters and the physical-mechanical properties of the composite boards and to compare them with the standard PB, MDF, HB, SB made from single-raw material (wood). A great emphasis is placed on the processability of the ligno-cellulose composite boards by classical methods, by modified manufacturing processes, on the types of tools and processing equipment, the automation of the manufacturing technologies, the specific labor conditions, etc. The combinations of wood and plant fibers are successful, since there is obvious compatibility between the macro- and microscopic structures, their chemical composition, and the relatively low manufacturing costs and high performances, as compared to synthetic fiber-based composite materials.

Author(s):  
Marius C. Barbu ◽  
Roman Reh ◽  
Ayfer Dönmez Çavdar

It would seem that with appropriate treatment almost any agricultural residue may be used as a suitable raw material for the wood-based panels like particle- and fiberboard production. The literature on wood-ligno-cellulose plant composite boards highlights steady interest for the design of new structures and technologies towards products for special applications with higher physical-mechanical properties at relatively low prices. Experimental studies have revealed particular aspects related to the structural composition of ligno-cellulose materials, such as the ratio between the different composing elements, their compatibility, and the types and characteristics of the used resins. Various technologies have been developed for designing and processing composite materials by pressing, extrusion, airflow forming, dry, half-dry, and wet processes, including thermal, chemical, thermo-chemical, thermo-chemo-mechanical treatments, etc. Researchers have undertaken to determine the manufacturing parameters and the physical-mechanical properties of the composite boards and to compare them with the standard PB, MDF, HB, SB made from single-raw material (wood). A great emphasis is placed on the processability of the ligno-cellulose composite boards by classical methods, by modified manufacturing processes, on the types of tools and processing equipment, the automation of the manufacturing technologies, the specific labor conditions, etc. The combinations of wood and plant fibers are successful, since there is obvious compatibility between the macro- and microscopic structures, their chemical composition, and the relatively low manufacturing costs and high performances, as compared to synthetic fiber-based composite materials.


2021 ◽  
Vol 888 ◽  
pp. 15-21
Author(s):  
Ivelina Ivanova ◽  
Jules Assih ◽  
Dimitar Dontchev

This research aims at studying the mechanical properties of industrial hemp fibers and promoting their use as a reinforcing composite material for strengthening of civil engineering structures. Natural hemp fibers are of great interest due to the following advantages they have: low cost, high strength-to-weight ratio, low density and non-corrosive properties. The use of plant fiber composite materials has increased significantly in recent years because of the negative reduction impact on the environment. For example, the tendency to use renewable resources and their possibility for recycling. They cause fewer health and environmental problems than synthetic fibers. Natural fibers, in addition to environmental aspects, have advantages such as low densities, i.e. have low weight, interesting mechanical properties comparable to those of synthetic fiber materials, and last but not least, low cost. Composites based on natural plant fibers can be used to reinforce or repair reinforced concrete structures, as shown by research on flax fiber composites. These concretes specimens strengthened with biocomposite materials have very good resistance to bending and significantly increase the rigidity of the structure. The results show that the hemp fiber reinforcement has significant effects on the strengthening and increase in flexural strength from 8% to 35 %.


2021 ◽  
Vol 887 ◽  
pp. 110-115
Author(s):  
G.A. Sabirova ◽  
R.R. Safin ◽  
N.R. Galyavetdinov

This paper presents the findings of experimental studies of the physical and mechanical properties of wood-filled composites based on polylactide (PLA) and vegetable filler in the form of wood flour (WF) thermally modified at 200-240 °C. It also reveals the dependence of the tensile strength, impact strength, bending elastic modulus, and density of composites on the amount of wood filler and the temperature of its thermal pre-modification. We established that an increase in the concentration of the introduced filler and the degree of its heat treatment results in a decrease of the tensile strength, impact strength and density of composite materials, while with a lower binder content, thermal modification at 200 °C has a positive effect on bending elastic modulus. We also found that 40 % content of a wood filler heated to 200 °C is sufficient to maintain relatively high physical and mechanical properties of composite materials. With a higher content of a wood filler, the cost can be reduced but the quality of products made of this material may significantly deteriorate. However, depending on the application and the life cycle of this product, it is possible to develop a formulation that includes a high concentration of filler.


2015 ◽  
Vol 766-767 ◽  
pp. 167-172 ◽  
Author(s):  
R. Bhoopathi ◽  
C. Deepa ◽  
G. Sasikala ◽  
M. Ramesh

Due to desirable properties and its role of natural and manmade fibers reinforced composite materials are growing in a faster rate in the field of engineering and technology. Now-a-days the treated natural composites are serves better in terms of corrosive resistance, and other desirable properties when compared to the traditional materials. The main aim of this experimental study is to fabricate and investigate the mechanical properties such as tensile strengths, flexural strengths and impact strengths of NaOH treated and hemp-banana-glass fibers reinforced hybrid composites. From the experimental results, it has been noted that the treated hemp-banana-glass fibers reinforced hybrid epoxy composites exhibited superior properties and used as an alternate material for synthetic fiber reinforced composite materials. Morphological studies are carried out to analyze the interfacial characteristics, internal structures, fiber failure mode and fractured surfaces by using scanning electron microscopy (SEM) analysis.


2017 ◽  
Vol 380 ◽  
pp. 66-71 ◽  
Author(s):  
D. Gomes dos Santos ◽  
A.G. Barbosa de Lima ◽  
P. de Sousa Costa

Vegetable fibers have been used in most several applications, as raw material, for manufacturing of different products or directly as reinforcement in composite materials. Green fibers are wet, what requires its drying before their use.In this sense, the aim of this work is to study drying of the sisal fibers in oven. Drying experiments were carried out at different drying condition. It was evaluated the curves of moisture content, drying and heating rates and temperature, as well as the influence of the drying temperature on the mechanical properties of the fibers. It was found that the drying temperature (60 - 105°C) had no significant influence on the tensile mechanical properties, elongation at rupture and modulus of elasticity of the sisal fibers.


Author(s):  
Д.В. Чащилов ◽  
А.А. Генина

Для полимерных композиционных материалов (ПКМ) с армирующим наполнителем из натуральных волокон одними из проблем являются оценка качества подготовки волокон и определение динамики взаимодействия волокон и полимерной матрицы. Актуальность проблем обусловлена расширяющимся объёмом исследований ПКМ с растительными волокнами и разнообразными видами и глубиной предварительной обработки растительных волокон. Предметом исследования выступил стандартный метод определения смачиваемости целлюлозных материалов. Цель экспериментального исследования – предложить модифицированный метод определения смачиваемости, потенциально пригодный для оценки качества подготовки армирующих наполнителей ПКМ из растительных волокон. Использован стандартный по ГОСТ и модифицированный метод определения смачиваемости. В качестве пробного материала использовали целлюлозу древесную, полубелёную сульфитную из хвойной древесины в форме целлюлозной папки. Образцы целлюлозы механически разрыхляли до элементарных волокон и испытывали на смачиваемость. Использовали три схемы испытаний – взвешивание стаканчика с навеской, погруженного в воду (схема 1), взвешивание сосуда с водой (схема 2), стандартную методику по ГОСТ (схема 3). По схемам 1 и 2 измерения проводили в течение до 120 секунд, по схеме 3 – 30 секунд. Эксперименты проводили в трёхкратной повторности. Сущность модифицированного метода определения смачиваемости основана на постоянном контроле массы навески по мере сорбции водной влаги. Полученные закономерности кинетики процесса показали, что количество водной влаги, впитываемой образцами, нелинейно меняется во времени. Величины смачиваемости, определённых по различным схемам, с учётом отклонений, соответствуют друг другу. Определение смачиваемости по модифицированному методу предложено проводить в течение 120 секунд, периодически контролируя показания весов. Предложенный модифицированный метод может быть использован в исследовательских целях для изучения динамики впитывания воды и сравнения поведения различных целлюлозных материалов для ПКМ с матрице на основе гидрофильных полимеров. For polymer composite materials (PCM) with a reinforcing filler made of natural fibers, one of the problems is to assess the quality of fiber preparation and determine the dynamics of the interaction of fibers and a poly-dimensional matrix. The urgency of the problems is due to the expanding volume of research on PCM with plant fibers and various types and depth of pretreatment of plant fibers. The subject of the study was a standard method for determining the wettability of cellulose materials. The purpose of the experimental study is to propose a modified method for determining wettability, potentially suitable for assessing the quality of preparation of reinforcing fillers of PCM from plant fibers. The standard GOST and modified method for determining wettability were used. As a test material, wood cellulose, semi-green sulfite from coniferous wood in the form of a cellulose folder was used. Cellulose samples were mechanically loosened to elementary fibers and tested for wettability. Three test schemes were used – weighing a cup with a suspension immersed in water (scheme 1), weighing a vessel with water (scheme 2), standard procedure according to GOST (scheme 3). According to schemes 1 and 2, measurements were carried out for up to 120 seconds, according to scheme 3 – 30 seconds. The experiments were carried out in threefold repetition. The essence of the modified method for determining the permeability is based on the constant control of the weight of the suspension as the sorption of water moisture. The obtained laws of the kinetics of the process showed that the amount of water moisture absorbed by the samples varies non-linearly over time. The wettability values determined according to various schemes, taking into account deviations, correspond to each other. The determination of wettability by the modified method is proposed to be carried out within 120 seconds, periodically monitoring the readings of the scales. The proposed modified method can be used for research purposes to study the dynamics of water absorption and compare the behavior of various cellulose materials for PCM with a matrix based on hydrophilic polymers.


2021 ◽  
Vol 2 (01) ◽  
pp. 13-23
Author(s):  
Md. Maruf Billah ◽  
Md. Sanaul Rabbi ◽  
Afnan Hasan

From the last few decades, the study of natural fiber composite materials has been gaining strong attention among researchers, scientists, and engineers. Natural fiber composite materials are becoming good alternatives to conventional materials because of their lightweight, high specific strength, low thermal expansion, eco-friendly, low manufacturing cost, nonabrasive and bio-degradable characteristics. It is proven that natural fiber is a great alternative to synthetic fiber in the sector of automobiles, railway, and aerospace. Researchers are developing various types of natural fiber-reinforced composites by combining different types of natural fiber such as jute, sisal, coir, hemp, abaca, bamboo, sugar can, kenaf, banana, etc. with various polymers such as polypropylene, epoxy resin, etc. as matrix material. Based on the application and required mechanical and thermal properties, numerous natural fiber-based composite manufacturing processes are available such as injection molding, compression molding, resin transfer molding, hand lay-up, filament welding, pultrusion, autoclave molding, additive manufacturing, etc. The aim of the paper is to present the developments of various manufacturing processes of natural fiber-based composites and obtained mechanical properties.


2019 ◽  
Vol 12 (1) ◽  
pp. 37-44
Author(s):  
Jiankang Wang ◽  
Zhijian Li ◽  
Hongwei Lu

Background: With the improvement of environment protection awareness, human beings have gradually become aware of that the plastic products, waste are harmful to the human living environment. Therefore, research and application of biodegradable materials that do not rely on petroleum resources have become hot topics. Researchers have accelerated the development and promotion of plant fiber because they are good flexibility, relatively rough surface and biodegradable. Objective: The development of plant fiber composites is reviewed, including composition ratio, interfacial modification, processing technology, and the effects of these technologies on the properties of plant fiber composites. Methods: The paper reviews various patents and research developments about plant fiber composite materials. It also analyzes the advantages and disadvantages of various patents and technologies from the aspects of biodegradable ability, mechanical properties, dispersing performance, processing properties, cost, and so on. Results: The component proportion, interface modification, and processing technology of plant fiber composite materials are prospected to improve the quality and application of the plant fiber composite materials in the future development. Conclusion: The considerable attention has been paid on the technology of biodegradable plant fiber composite. The recent patents and technologies have shown us a wider application in biodegradable plant fiber composite. The problems how to improve the mechanical properties of plant fibers, the dispersion properties of plant fibers and resins, and the processing properties of composite materials, will need more and more methods and equipment to solve or simplify.


2020 ◽  
Vol 9 (1) ◽  
pp. 2304-2310

Little consume energy materials have recently received increased attention as an ecological and sustainable alternative. We propose to study a building approach with raw earth (adobe) combined with plant fibers. The latter used as reinforcement in composite materials have specific competitive mechanical properties compared to those of synthetic fibers (glass, carbon, ...) and are an environmentally friendly alternative to these fibers because of their low cost, low density, biodegradability and availability. We describe adobe stabilization and reinforcement process with treated rush fibers. We introduce our approach to formulate an earth mortar allowing the making of blocks of adobe, intended for the construction of works such as walls, arches and domes.


2020 ◽  
Vol 322 ◽  
pp. 01011
Author(s):  
Kinga Korniejenko ◽  
Krzysztof Miernik ◽  
Wei-Ting Lin ◽  
Arnaud Castel

The additive manufacturing technologies are fast-developing industrial sector and, potentially, a ground-breaking technology. They have many advantages such as the saving of resources and energy efficiency. However, the full exploitation of 3D printing technology for ceramic materials is currently limited; a lot of research is being conducted in this area. A promising solution seems to be geopolymers, but its application requires a better understanding of the behaviour this group of materials. This article analyses the influence of microstructure on mechanical properties whilst taking the production method into consideration. The paper is based on comparative analysis – the investigation is focused on the influence of material structure on the mechanical properties and fracture mechanism of these kinds of composites, including those reinforced with different kind of fibres. As a raw material for the matrix, fly ash from the Skawina coal power plant (located in: Skawina, Lesser Poland, Poland) was used. The investigation was made by SEM analysis. The results show that the microstructural analysis did not sufficiently explain the underlying reasons for the observed differences in the mechanical properties of the composites.


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