Оцінка теплопровідності вовняних текстильних наповнювачів для ковдр

Now-a-days, the natural fibers and fillers from renewable natural resources offer the potential to act as a reinforcing material for polymer composite material alternative to the use of synthetic fiber like as; glass, carbon and other man-made fibers. Among various natural fibers and fillers like banana, wheat straw, rice husk, wood powder, sisal, jute, hemp etc. are the most widely used natural fibers and fillers due to its advantages like easy availability, low density, low production cost and reasonable physical and mechanical properties This research work presents the effect of natural fillers loading with 5%, 10% and 15% on mechanical behavior of polyester based hybrid composites. The result of test depicted that hybrid composite has far better properties than single fibre glass reinforced composite under impact and flexural loads. However it is found that the hybrid composite have better strength as compared to single glass fibre composites.

Epoxy resins as important organic matrices, thanks to their chemical structure and the possibility of modification, have unique properties, which contribute to the fact that these materials have been used in many composite industries for many years. Epoxy resins are repeatedly used in exacting applications due to their exquisite mechanical properties, thermal stability, scratch resistance, and chemical resistance. Moreover, epoxy materials also have really strong resistance to solvents, chemical attacks, and climatic aging. The presented features confirm the fact that there is a constant interest of scientists in the modification of resins and understanding its mechanisms, as well as in the development of these materials to obtain systems with the required properties. Most of the recent studies in the literature are focused on green fillers such as post-agricultural waste powder (cashew nuts powder, coconut shell powder, rice husks, date seed), grass fiber (bamboo fibers), bast/leaf fiber (hemp fibers, banana bark fibers, pineapple leaf), and other natural fibers (waste tea fibers, palm ash) as reinforcement for epoxy resins rather than traditional non-biodegradable fillers due to their sustainability, low cost, wide availability, and the use of waste, which is environmentally friendly. Furthermore, the advantages of natural fillers over traditional fillers are acceptable specific strength and modulus, lightweight, and good biodegradability, which is very desirable nowadays. Therefore, the development and progress of “green products” based on epoxy resin and natural fillers as reinforcements have been increasing. Many uses of natural plant-derived fillers include many plant wastes, such as banana bark, coconut shell, and waste peanut shell, can be found in the literature. Partially biodegradable polymers obtained by using natural fillers and epoxy polymers can successfully reduce the undesirable epoxy and synthetic fiber waste. Additionally, partially biopolymers based on epoxy resins, which will be presented in the paper, are more useful than commercial polymers due to the low cost and improved good thermomechanical properties.

Environmental concerns and cost reduction have encouraged the use of natural fillers as reinforcement in polymer composites. Currently, a wide variety of reinforcement, such as natural fibers and nanocellulose, are used for this purpose. Composite materials with natural fillers have not only met the environmental appeal, but also contribute to developing low-density materials with improved properties. The production of natural fillers is unlimited around the world, and many species are still to be discovered. Their processing is considered beneficial since the natural fillers do not cause corrosion or great wear of the equipment. For these reasons, polymer reinforced with natural fillers has been considered a good alternative for obtaining ecofriendly materials for several applications, including the automotive industry. This review explores the use of natural fillers (natural fibers, cellulose nanocrystals, and nanofibrillated cellulose) as reinforcement in polymer composites for the automotive industry.

The need of biodegradable bio-composite materials has significantly increased in recent years for its uses including packaging, agriculture, medicine, sportswear, insulation, paint, etc. Both the environmental and the economical benefits are achieved from the use of natural fibers and natural fillers. Aeronautical and automotive industries use newly identified lightweight biodegradable composite materials because they are strong, light, and consume less energy. They are recognized for having exceptional properties, such as a high strength to weight ratio, a high stiffness to weight ratio, resistance to corrosion, resistance to water absorption, and high hardness. More and more natural fibers and filler materials are being employed in composite materials to lessen the need for the polymer matrix and enhance their chemical, physical, mechanical and thermal properties and so on. This current analysis is carried out experimentally on the impact of adding natural nicker nut shell powder as filler and epoxy resin as matrix on the fabricated biodegradable composites with different volume percentages (5, 10, 15, 20, 25, 30 and 35% so on). On the created biodegradable composites, the impacts of particle size and filler volume percentages on mechanical parameters like tensile strength, flexural strength, and impact strength have been experimentally assessed. Following the standard of American Society for Testing and materials, the specimens were prepared and tested. The mixture of 25% Nicker nut shell powder and 75% epoxy resin produced the highest tensile strength, which measured as 22.05 N/mm2. The blend of 75% epoxy resin and 25% nicker nut shell powder was discovered to have the maximum flexural strength, measuring 46.9 N/mm2. It has been shown that better interfacial adhesion between the filler and matrix allows for the storage of the largest amount of impact energy, 16.29 KJ/mm2, when the filler and matrix are 25% nicker nut shell powder and 75% matrix, respectively. SEM analysis was conducted to analyze the interfacial bonding between the matrix and filler particles with defects in the composites. SEM images are evidence to attribute better mechanical behavior of bio-composites.

Nowadays, the use of recyclable, eco-friendly materials in automotive industries are growing due to the environmental concerns in place of synthetic polymers. Natural filler materials are increasingly used to reduce the usage of the polymer matrix and to improve the mechanical, thermal properties of the composite materials. Natural fiber and filler incorporated hybrid composite materials are used in places where the load requirements are low. This study focuses on the use of Almond shell as a particulate reinforcement in the Aquilaria agallocha Roxb reinforced Epoxy composite with different volume fractions. The specimens were fabricated using hand layup process and the mechanical properties were investigated. The results had shown that the composite with 20% v/v Almond shell particulate reinforced composite had shown better mechanical properties. While the Visco elastic properties had shown minor improvement due to the incorporation of natural filler in the hybrid composite material.

The objective of this work is to enhance the thermal conductivity and electrical properties of polymer hybrid composites through a systematic novel grey relation grade analysis (GRGA) optimization approach. This involves reinforcing the hybrid composites with hexagonal boron nitride (hBN) and various kinds of natural fibers or fillers. The development of a unique technology to produce multiphase composites using 2% of natural fibers or fillers such as coir fiber, rice husk filler, wood filler (WF), banana fiber (BF) and sugarcane fiber along with hBN (1, 3, 5 wt.%) particulates as reinforcements in epoxy matrix. The Taguchi L15 matrix array is utilized to fabricate interlaced composite samples via hand layup molding. Ultrasonic waves are used to ensure the uniform distribution of hBN filler into the matrix. Analysis of variance and GRGA reveal the significant results. It shows that the multiphase hybrid composites exhibit good thermal conductivity when higher content of hBN (5 wt.%) particulate for all the micro particulate polymer (MPP) composites. Multi-response optimization shows that the micro BF (2 wt.%) interlaces with hBN (5 wt.%) composite exhibits the higher thermal conductivity and electrical resistance compared to all other natural fiber interlaced composites. The aforementioned MPP composite has thermal conductivity of 1.03 W (m·K)−1 and electrical resistance of 279.88 Giga Ohms. Besides, the WF interlaced hBN (5 wt.%) composite shows the minimum dielectric constant compared to all other natural fiber composites. This desirable result is caused by the proper dispersion of hBN with the matrix which encourages interlocking with the fiber and the matrix. Maximum electrical resistance is observed for composite containing 5 wt.% of h-BN and 2 wt.% of BF. The developed MPP composite could be used in heat shields, electrical insulation components, and interior automotive components like dashboards, luggage compartments and interior walls.

Natural fillers as reinforcement for closed-molded polyurethane foam plaques: Mechanical, morphological, and thermal properties

Background and Objective: The use of biopolyesters and natural fibres or fillers for production of biobased composites has attracted interest of various application sectors ranging from packaging to automotive components and other high value applications in agreement with a bioeconomy approach. In the present paper biobased composites were produced by using compostable polymers degradable even in soil and marine water such as polyhydroxyalkanoates with natural fibres or fillers derived by food wastes (legumes by-products) and by wood industry. Material and Methods: Polyhydroxyalkanoates were processed with a biobased, biodegradable plasticizer such as acetyltributylcitrate and calcium carbonate as inorganic filler. The selected polymeric matrix was used for the production of composites with variable amounts of natural fibres. Green composites were manufactured by extrusion and injection moulding. Thermal, rheological, mechanical and morphological characterizations of the developed composites were performed. Results and Conclusion: The bio composites properties match the requirements for production of rigid food packaging or other single use items where the market is looking for more sustainable solutions versus the products actually used and hardly recyclable, opening a route for valorization of food residue. Pukanzsky’s model predicts with good accuracy the tensile behavior of the composites showing a medium intensity adhesion between fibres and polymer matrix in both cases analyzed. Conflict of interest: The authors declare no conflict of interest.

The urge to build a more environmentally friendly future has motivated researchers to examine composites outside of synthetic fiber and continue to consider natural fibre polymer composite. This present research, the hybrid bio composite was developed by bio fillers and natural fibres. The preliminary investigation was done to examine the possibility of using natural fillers (palm and coconut shell) in natural fibre (hemp and basalt) reinforced polymer (NFRP) composite for manufacturing application. In that way initially mechanical (tensile and flexural) properties testing were done on four different combinations of NFRP by using palm and coconut shell particles, to their influence on mechanical properties (tensile stress 278 MPa and flexural stress 330 MPa). It was found that 5% wt. palm + coco shell fillers combination hybrid composite presented good results in mechanical properties. Then 5% wt. palm + coco fillers was added in the matrix phase of NFRP composite was developed and study the machinability properties by using Abrasive Water Jet Machining (AWJM). NFRP machining in the relationships of material removal rate (MRR), kerf angle and surface roughness has been experimentally examined for various process parameters (nozzle pressure, distance stand and transverse speed). The research values for quality properties (MRR, Kt and Ra) were analysis-based on the trimming factors by developing the Taguchi method. The influence of optimized input process parameters on quality features were examined by utilizing experiential models. From this study, it is noticeable that, filler material in natural fiber composites reduces the kerf angle and the low and very high traverse speed leads the wide disparity in kerf inclination. For obtaining the good surface roughness and material removal rate medium traverse speed and medium stand of distance is the significant parameter respectively and moreover impact of jet pressure on surface finish is 3 times lower than the impact supplied to the surface finish by traverse speed

The performance of polymer-based nano iron composites reinforced with natural fibers and nanoparticles is investigated in this work with the aim of enhancing their mechanical electrical and water-absorbing properties for a variety of applications. System 1 (PLA with nano iron particles) System 2 (PLA with natural fillers) and System 3 (PLA with both natural fillers and nano iron particles) are the three composite systems that were developed. Mechanical performance assessment tests including tensile compression and bending tests as well as electrical conductivity and water absorption morphological analysis using SEM and EDAX were all conducted. According to the results System 3 which combines natural fillers with nano iron showed superior tensile and flexural strength because of improved filler dispersion and improved filler-matrix bonding. The creation of a conductive network by nano iron was responsible for System 2s highest electrical conductivity (340 µS/cm). Compression testing showed that Systems 2 and 3 were stronger because there were fewer voids and cracks spreading. System 2 did however exhibit a high water absorption rate of 20% which may indicate durability problems. According to this study adding natural fibers and nanoparticles to PLA composites may produce lightweight incredibly durable multifunctional materials with exciting potential uses in the electronics automotive and construction sectors.

An investigation has been carried out to study the effect of spindle speed and feed rate on thrust force generated in drilling glass fiber-reinforced plastics with natural fillers. An effort has been made to use abundantly available natural fibers, namely coconut coir, rice husk, and wheat husk as fillers along with synthetic glass fibers. The drilling experiments have been extensively conducted at six different levels of feed rate and spindle speed using carbide twist drills of 4 mm. Predictive model has been developed using Levenberg–Marquardt algorithm to predict the thrust force with material, spindle speed, and feed rate being the input parameters and thrust force being the output parameter. The results of the predictive model are in close agreement with the actual values. Coefficient of correlation between predicted and experimental values for training and testing data sets is 0.995 and 0.9849, respectively. The mean percentage error in training and testing is found to be 3.175 % and 5.31 %.

A comparison study on mechanical properties of E-glass fiber and areca sheath fiber hybrid composites

Injection molded composites are becoming more widespread in recent years because of their high quality and low cost. However, compared to synthetic fiber composites, it is difficult to maintain a constant fiber volume fraction and uniform distribution for natural fiber composites during the direct injection process. This is mainly because natural fibers are more easily twisted during feeding into the injection machine, owing to their rough surfaces. These feeding difficulties are particularly due to the low bulk densities of natural fibers, especially natural fillers. Additional challenges to the injection process include the concentration and, especially for natural filler reinforced composite. To address these problems, the current study investigates the mechanical properties and morphologies of polypropylene (PP) reinforced by wood powder. Two pre-molding processes, dry-blending and compounding, were compared, and the effects of an additive (crystalline polyalpha olefin (CPAO)) on the mechanical properties of the wood/PP composites were investigated. This investigation is based on tensile, three point bending, and Izod impact tests, and scanning electron microscope (SEM) observation of the fracture surfaces. Results indicated that the composites molded through compounding exhibited better mechanical properties than the samples molded through the direct dry-blending process. In addition, the tensile and bending properties of the composites produced through compounding were found to increase with the addition of CPAO content, because of improved wood powder distribution in the PP matrix.

Chapter 8 - Fused deposition modeling of polymer-matrix composites with natural fibers

17 - Tribological property enhancement of polymeric composites using bio-fillers