CARBON FIBRE ALIGNMENT FOR REINFORCED COMPOSITES USING EMBROIDERY TECHNOLOGY

<p>Geopolymers have been suggested in the literature as matrix materials for fibre reinforced composites due to a unique combination of low-temperature synthesis and high temperature stability. This study investigated several key aspects of fibre reinforced geopolymer matrix composites in order to improve the basic knowledge of these materials. It was demonstrated that geopolymer matrix composites show great potential as fire-resistant materials for near room temperature applications. In particular, basalt fibre composites were of great interest due to their comparatively low cost and good mechanical performance. Microstructural investigations indicated that basalt fibres can potentially be used in geopolymer matrices up to 600°C. However, the success of the application of geopolymer matrix composites at higher temperatures is seen as critical and depends on further development of suitable matrices. Several compositions within a sodium-metahalloysite model matrix system were evaluated in order to identify a suitable formulation for composite fabrication. An average compressive strength of ~ 79 MPa and flexural strength and modulus of ~ 10 MPa and 8.5 GPa, respectively, were achieved for the best batch of the main matrix composition. By optimising the matrix composition, the mechanical properties could be significantly improved, achieving an extremely high maximum compressive strength value of 145 MPa. Issues with reproducibility and the influence of various aspects of the fabrication process are discussed. The room temperature flexural properties of unidirectional fibre reinforced composite bars with basalt, carbon and alumina fibres were investigated. Besides the fibre type, the effects of several other parameters including fibre sizing, matrix strength, span-to-depth ratio and specimen dimensions on the flexural properties and the failure behaviour of the composites were studied. Significant improvements to the mechanical properties were achieved with all fibre types. However, the mechanical behaviour was highly influenced by the elastic modulus of the fibre. Furthermore, it was shown that the composite properties were affected by the overall sample dimensions, the testing span and the mixing time of the geopolymer binder. The alumina fibre composites achieved the highest flexural stress with a maximum value of 470 MPa and a fibre content of ~ 30 vol.-%. Basalt and carbon fibre composites showed maximum flexural strength values around 200 MPa. Although all composite types displayed considerable post-fracture strength, only the basalt composites failed in tensile mode. The applicability of the weak matrix composites (WMC) concept to describe the mechanical behaviour of geopolymer matrix composites was discussed. The fibre-matrix interactions were analysed between room temperature and 1000°C by means of electron microscopy, EDS and x-ray diffraction. All fibres were found to be chemically stable under the highly alkaline conditions of the geopolymer synthesis and showed no significant reaction with the geopolymer matrix at room temperature. The results indicate that basalt fibre composites may be used up to 600°C without significant degradation of the fibre. The heating of the carbon fibre composites to 600°C had drastic effect on the strength and integrity of the composite, in particular, when using sized carbon fibres. The alumina fibres showed good wetting and bonding behaviour but otherwise little reaction with the matrix even after heating to 1000°C.</p>

Disposal of organic wastes with no reduction in intensity produces greenhouse gas, which affects the environment and its climatic conditions. Because of the increasing urge to save the environment and to add value for the waste, these can be converted into a value-added product. The development of biochar-based polymer composites from such wastes could be an effective and efficient one for various applications. This work focuses on new development of composite reinforced with biochar, prepared from cashew nutshell waste (CNSL) by the pyrolysis process. The CNSL waste is closely packed in an airtight container and heated at the temperature of 500° C for 1 h in a stir casting furnace. This CNSL biochar is used as reinforcement in unsaturated polyester resin for composite fabrication. The composites are prepared by the solution dispersion method at different weight percentages of 5, 10, and 15. The prepared specimens are subjected to tensile flexural and impact strength studies. Compared to unfilled composite 10% biochar filled composite shows maximum tensile, flexural, impact and hardness strength and their improvement percentages are 21, 41 & 37 respectively.Interestingly, the maximum flexural strength is noticed at 15% filled composites with a 40% improvement in strength.

Modeling for predicting and optimizing of the flexural and hardness properties of jute/kenaf/glass fiber nano-composite through RSM

Fiber-reinforced composites are essentially axial particulates embedded in fitting matrices. The primary objective of fiber-reinforced composites it to obtain materials with high strength in conjunction with higher elastic modulus. The strength elevation is however affected with applied load transiting from matrix to fibers, interfacial bonding between fiber-matrix, their relative alignment and nature of fiber scheming the overall material behaviors. The alignment of fibers may however be continuous or random depending on the end applications. The choice of the fiber reinforcement and its fitting matrix also depends on application requirements. In recent years, the advent of composite technology has led to the development of different fiber reinforced composite systems via varying manufacturing methodologies to obtain advanced material behaviors. Herein, we present a comparative account on various kinds of synthetic fibers and their significance as potential reinforcements with special emphasis on carbon fibers.

Effect of glass fiber and nylon fiber reinforcement on the mechanical and thermal properties of styrene butadiene rubber mixed PMMA denture base material

The most popular methodologies employed to manufacture composite components still lack sufficient rate to meet demand. Furthermore, the state of the art in automated processes imposes restrictions on component geometrical complexity. Many of these restrictions arise directly as a result of the use of continuous fibre reinforcements. Processing and use of highly-aligned discontinuous fibres may avoid many of the manufacturing defects induced in continuous fibre architectures, which are a result of design decisions and manipulations during processing operations, while theoretically allowing for similar mechanical properties if alignment and orientation are tightly controlled. An overview of the history of aligned short fibre composites has been presented, with the focus upon process and application of highly aligned advanced composites with properties near to that of continuous fibre composites. When continuous carbon fibres were first developed, there remained an interest to create aligned discontinuous fibre composites in order to form more complex components. This interest has reappeared in recent years with methods divided into those which align short fibres and those which introduce discontinuities into aligned fibres. It is clear that discontinuous material systems have their uses and applications, but greater development is still required in order to better quantify and categorise the materials and their associated properties and processes. doi:10.12783/issn.2168-4286/2/3/4/Such

The creation of biomaterials with aligned fibers offers broad applications in tissue regeneration, guiding cell organization and physiological cues, and providing appropriate mechanical properties for many biomedical applications. Herein, for the first time, highly aligned electrospun membranes are designed and developed using glycopolymers. The membranes retain the strong mechanical properties of polycaprolactone, and fiber alignment facilitates the creation of anisotropic mechanical properties, enabling failure stress to be manipulated by an order of magnitude relative to randomly ordered fibers. Biocompatibility and cell attachment in these materials are characterized using tenocytes as a cell model. Both random and aligned fiber glycopolymers show promising biocompatibility, but aligned glycopolymer fibers additionally offer patterning to guide cell organization. These materials potentially provide a novel platform for tissue regeneration studies, demonstrating that the sugar-lectin interaction can produce materials capable of managing cell guidance.

The bulk of the paper deals with a comparison of the flexural performance of 102-mm (4-in.)-square standard molded specimens with corresponding specimens of the same size produced either by sawing the bottom (tension) surface of a 102 by 152-mm (4 by 6-in.) cross section or by sawing the bottom and sides of a 152 by 152 mm (6 by 6-in.) cross section. The performance of plain concrete is discussed in terms of its flexural strength under third-point loading [ASTM Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading) (C 78)]. The conclusion is that sawing need not adversely affect the measured strength when done carefully with proper equipment. The performance of fiber-reinforced concrete is discussed in terms of changes in first-crack strength and toughness parameters defined according to ASTM Test Method for Flexural Toughness and First-Crack Strength of Fiber-Reinforced Concrete (Using Beam with Third Point Loading) (C 1018). The majority of the results deal with changes in those parameters that are associated with differences in fiber alignment between the molded and sawed specimens. The results of two other small studies involving differences in fiber alignment are also included. In the first, alignment is varied by inserting steel plates in the freshly mixed concrete during consolidation, and in the second by using the same length of fiber in 102-mm (4-in.) and 152-mm (6-in.) cross sections. The conclusion is that preferential fiber alignment by the mold surfaces can increase first-crack strength and toughness indices. To avoid undue influence of fiber alignment in small specimens on flexural test data determined in accordance with Method C 1018, the ratio of minimum specimen cross section to fiber length should not be less than 3.0, except perhaps when strict compliance with this criterion means using specimens larger than 152 mm (6 in.) square.

It was tried to prepare a carbon fiber reinforced carbon (CFRC) plate by the lamination of high performance carbon fiber (CF) paper.A carbon fiber reinforced plastics (CFRP) plate was prepared by laminating 80 sheets of the CF paper which was coated with phenol resin containing some amount of graphite powder, and carbonizing it into CFRC plate (3.5mm in thickness) at a temperature up to 1000°C under nitrogen (Fig.1).The CFRC plate underwent the densification, high temperature and hot-press treatments to improve its mechanical strength. The densification treatment did not improve the mechanical strength of the CFRC plate (Table 1).While, by the high temperature treatment (1500°C, 2200°C, and 2500°C), the flexural and shear strength of the CFRC plate remarkably increased and the modulus slightly decreased.The maximum flexural strength was obtained at 2200°C of HTT (Table 2).The thickness of CFRC plate decreased from 3.5mm to 3.2mm with the increase of the treatment temperature from 1000°C to 2500°C (Fig.4).The X-ray diffraction profiles of the CFRC indicated the growth of graphitic structure at the temperature over 2200°C (Fig.7).It suggests that the shrinkage of CFRC plate was due to the structural change of the matrix and CF by stress graphitization.By hot-press treatment (2200°C, 140kg/cm2), the thickness of CFRC plate decreased from 3.5mm to 2.5mm, the bulk density increased to 1.78, the porosity decreased to 12%, and the cross section texture became more homogeneous than that before the treatment.The mechanical properties of this CFRC plate was 150MPa in flexural strength, 39GPa in flexural modulus, and 200MPa in compressive strength, and these values obtained show narrower scatter than that in other cases (Table 2).On the bases of the best properties previously obtained on UD-CFRC samples and of the results in this work, it was assumed that the maximum value of quasi-isotropic CFRC plate is 150-200MPa in flexural strength.

Effect of random/aligned nylon-6/MWCNT fibers on dental resin composite reinforcement

In this study, a facile hybridization of sisal/coconut palm reinforced epoxy composite, is presented. The fabrication method involved the use of hand lay‐up techniques. The results of the fabricated composites were investigated by using the universal testing machine, hardness testing machine, scanning electron microscope, and an impact testing machine. In order to obtain optimize results for the tensile, flexural, and impact strengths of the fabricated samples, the fabrication procedures involved varying the volume fractions of sisal and coconut palm hybrid with different compositions. The maximum tensile, flexural, and impact strengths measured for the fabricated fiber/polymer composite, are: 45 MPa, 90 MPa, and 38.9 kJ/m2. The scanning electron microscopy (SEM) and energy dispersive x‐ray spectrometry (EDS) of the composites showed that the composites with equal volume fractions of sisal and coconut palm fiber exhibited better performance and better mechanical properties. Furthermore, the improved mechanical properties such as hardness, tensile strength, flexural strength and impact strength were obtained with fibers of longer length. By considering the excellent mechanical properties of the fabricated composite, it is envisaged that the composite be suitable for the manufacturing of helmet, automobile and train coach interiors.

Fiber-reinforced plastics (FRP) are a type of composite material consisting of a reinforcing structure and a plastic matrix. When compared to traditional construction materials, FRP has higher strength and stiffness due to the high mechanical properties of reinforcing fibers such as carbon or glass. However, the properties of FRP are dependent on the alignment of fibers within the composite, with deviations leading to reduced strength and stiffness. Eddy current testing is a non-destructive technique used to visualize carbon fibers in the composite and assess the impact of local fiber orientation on the structural properties of FRP. This study aims to understand the influence of local fiber orientation on tensile strength and elastic modulus by producing composites with defined fiber orientations, analyzing them with eddy current testing, and assessing their mechanical properties through tensile tests. The measured fiber orientations are then used to validate a finite element model, in which the actual, measured fiber orientation is applied to the simulation and correlated with the mechanical properties. In contrast to previous published studies measured fiber orientation is used, which as shown in this work, differs from the theoretically implemented fiber orientation.

Tensile properties and fiber alignment of human supraspinatus tendon in the transverse direction demonstrate inhomogeneity, nonlinearity, and regional isotropy

[ID] Concrete is a very popular building material used in the world of construction services, consisting of a mixture of Portland Cement (PC) or other hydraulic cement, fine aggregates, coarse aggregates and water, with or without using additional materials. The quality of materials such as cement also greatly affects the strength of the concrete after hardening, so the selection of cement quality must be in accordance with the concrete planning regulations in order to obtain optimal results. In Indonesia there are many new cement factories that produce to meet the needs of the community, one of which is the Conch brand cement. So in connection with the above, Conch cement can be examined to compare the value of compressive strength and flexural strength with old cement, namely cement Padang, Tiga Roda, Holcim and Bosowa which are generally always used in concrete planning at this time.The purpose of this study was to determine the comparison of compressive strength and flexural strength of the concrete and the multiplier between cement Padang, Three Wheels and Conch at 28 days of age. In this study using the method SNI 03-2834-2000. With cylindrical test specimens (150 mm x 300 mm) and size beams (150 mm x 150 mm x 600 mm) three specimens were made for each cement.The maximum concrete compressive strength is found in Padang cement with a compressive strength of 45.86 Mpa, for the minimum compressive strength found in Tiga Roda cement with compressive strength value of 40.19 Mpa and for the compressive strength of cement Conch there is a second with compressive strength value 42.84 Mpa. From the explanation above, the results of 28 days of concrete compressive strength with each cement brand still not reached the planned concrete compressive strength of 38 MPa. The maximum concrete flexural strength is found in Padang cement with a flexural strength value of 5.03 Mpa, for a minimum flexural strength value found in Tiga Roda cement with a flexural strength value of 3.96 Mpa and for the value of Conch cement compressive strength there is a second with flexural strength 4.43 Mpa. From the explanation above, the results of 28 days of concrete flexural strength with each cement brand that has not reached the 4.4 Mpa plan, namely the three-wheeled cement brand.
 [EN] Concrete is a very popular building material used in the world of construction services, consisting of a mixture of Portland Cement (PC) or other hydraulic cement, fine aggregates, coarse aggregates and water, with or without using additional materials. The quality of materials such as cement also greatly affects the strength of the concrete after hardening, so the selection of cement quality must be in accordance with the concrete planning regulations in order to obtain optimal results. In Indonesia there are many new cement factories that produce to meet the needs of the community, one of which is the Conch brand cement. So in connection with the above, Conch cement can be examined to compare the value of compressive strength and flexural strength with old cement, namely cement Padang, Tiga Roda, Holcim and Bosowa which are generally always used in concrete planning at this time.The purpose of this study was to determine the comparison of compressive strength and flexural strength of the concrete and the multiplier between cement Padang, Three Wheels and Conch at 28 days of age. In this study using the method SNI 03-2834-2000. With cylindrical test specimens (150 mm x 300 mm) and size beams (150 mm x 150 mm x 600 mm) three specimens were made for each cement.The maximum concrete compressive strength is found in Padang cement with a compressive strength of 45.86 Mpa, for the minimum compressive strength found in Tiga Roda cement with compressive strength value of 40.19 Mpa and for the compressive strength of cement Conch there is a second with compressive strength value 42.84 Mpa. From the explanation above, the results of 28 days of concrete compressive strength with each cement brand still not reached the planned concrete compressive strength of 38 MPa. The maximum concrete flexural strength is found in Padang cement with a flexural strength value of 5.03 Mpa, for a minimum flexural strength value found in Tiga Roda cement with a flexural strength value of 3.96 Mpa and for the value of Conch cement compressive strength there is a second with flexural strength 4.43 Mpa. From the explanation above, the results of 28 days of concrete flexural strength with each cement brand that has not reached the 4.4 Mpa plan, namely the three-wheeled cement brand.

Polymer-based composite materials resulted from a combination of a variety of raw materials to form a new composite material. The use of a type of polymer-based composite material, known as the Glass Fibre Reinforced Polymer (GFRP) has been on the increase today. GFRP Industrialised Building System (IBS) has been developed in the form of prefabricated structural beams, slabs, walls, staircases, and trusses for applications in buildings and bridges. For applications of the IBS system especially in areas that are often vulnerable to flooding, special attention needs to be paid to the water/flood-resistant properties of such a system. Most of the existing materials adopted for building construction are not intended to be used in flood environments, as they have a high percentage of water absorption. High water absorption of GFRP will result in the reduction of its mechanical properties. Therefore, the objective of this study is to obtain and improve the GFRP composite properties for use as a flood-resistant structure. The experiments involved materials such as woven fibreglass matrix, polyester resin, fly ash and calcium carbonate. The fly ash and calcium carbonate are introduced as filler materials to study their influence on the mechanical and water absorption properties of the GFRP composite. In total, 21 samples were tested for tensile, compressive and flexural strengths, and also water absorption. The results obtained from tensile tests found that the maximum tensile strength is 172.8 MPa for the composition of 10% of both fly ash and calcium carbonate. Through compression and three-point bending tests, the maximum compressive and flexural strengths are 169.2 MPa and 327.3 MPa, respectively for the composition of 5% fly ash and 15% calcium carbonate. The composition of 5% calcium carbonate and 15% fly ash yielded the lowest water absorption at 0.45%. It was discovered that compared to the conventional concrete, the percentage water absorption of the RHA concrete cured with 5% NaCl absorbs less water with increase in replacement proportions of RHA [9]. In conclusion, calcium carbonate improves mechanical strength while fly ash reduces water absorption.KeywordsGFRPCalcium carbonateFly ashMechanical propertiesWater absorption