Presence Of Glass Fibers Research Articles

Investigation on the damage mechanisms using acoustic emission method and damping characteristics of hybrid flax‐glass composites

AbstractFiber‐reinforced polymers (FRP) feature high strength‐to‐weight ratio amongst the emerging class of natural composites. This paper presents the impact of the glass fiber on the tensile strength of the flax epoxy laminate. The mechanical behavior and damping characteristics of flax fiber reinforced polymer (FFRP) and the hybrid flax‐glass fiber reinforced polymer (HFRP) are experimentally investigated. Both the flax and hybrid FRPs are made using vacuum infusion process. The specimens without and with holes of 4, 5, and 6 mm in diameter are subjected to tensile test using acoustic emission monitoring and free vibration test. In the former testing, HFRP resulted in higher peak frequencies and cumulative counts. Also, the natural frequency and damping factor of HFRP vary proportionately with the hole size, as identified in the latter tests. Different damage mechanisms during the tensile test revealed that the presence of glass fibers in HFRP increased resistance for certain damage mechanisms.Highlights Adding glass fiber to flax fiber reinforced polymer (FFRP) creates a hybrid FRP (HFRP) with increased resistance to damage and improved damping characteristics. HFRP exhibits a distinction in failure mechanisms compared to FFRP. The study utilizes acoustic emission (AE) to identify various damage mechanisms in the material, providing a more detailed information. The addition of glass fibers in HFRP leads to a more pronounced increase in damping factors.

Study on the effect of EPS particles and glass fiber on the properties of phosphogypsum

Polystyrene (EPS) particles have the properties of light weight, low cost, smooth and small density. The presence of glass fiber (GF) can significantly improve the toughness and fracture resistance of the material. By adding EPS particles and glass fiber into phosphogypsum, the influence of EPS particle content and glass fiber content on the properties of phosphogypsum was studied, and the phosphogypsum composite with light weight and strong toughness was prepared.

Flax-Glass Fiber Reinforced Hybrid Composites Exposed to a Salt-Fog/Dry Cycle: A Simplified Approach to Predict Their Performance Recovery.

Despite natural fibers gaining significant attention in recent decades, their limited performance and poor durability under humid environments cannot allow them to fully replace their synthetic counterparts as reinforcement for structural composites. In such a context, this paper aims to investigate how exposure to a humid/dry cycle affects the mechanical response of epoxy laminates reinforced with flax and glass fibers. In particular, the main goal is to assess the performance evolution of a glass-flax hybridized stacking sequence in comparison with the full glass and flax fiber reinforced composites. To this end, the investigated composites were first exposed to salt-fog for 15 or 30 days and then to dry conditions (i.e., 50% R.H. and 23 °C) for up to 21 days. The presence of glass fibers in the stacking sequence significantly stabilizes the mechanical performance of composites during the humid/dry cycle. Indeed, hybridization of inner flax laminae with outer glass ones, acting as a protective shield, hinders the composite degradation due to the humid phase also promoting performance recovery during the dry phase. Hence, this work showed that a tailored hybridization of natural fibers with glass fibers represents a suitable approach to extend the service-life of natural fiber reinforced composites exposed to discontinuous humid conditions, thus allowing their employment in practical indoor and outdoor applications. Finally, a simplified theoretical pseudo-second-order model that aimed to forecast the performance recovery shown by composites was proposed and experimentally validated, highlighting good agreement with the experimental data.

Study on the Flexural Strength of Glass Fiber Reinforced M20 Grade Self-Compacting Bacterial Concrete

Aim: The goal of this research is to determine the effect of glass fibre on the flexural strength of M20 grade self-healing concrete utilising a unique approach called microbial induced calcite precipitation.. Materials and methods: For data collection, two groups of 18 samples each were produced. The first group is formed without the presence of glass fibre, whereas the second group is formed with the presence of glass fibre. Bacillus subtilis bacteria were cultured in the bioinformatics laboratory using a strain obtained from Hi media laboratories. Results: SPSS statistical software was used to analyse the data. The mean flexural strength of bacterial concrete without fibre was 7.944 N/ mm2, while Glass fibre reinforced concrete had a mean flexural strength of 8.666 N/mm2. The events had a significance of 0.00 (p<0.05). Conclusion: The flexural strength of glass fibre reinforced M20 grade self-healing concrete was higher than that of conventional M20 grade self-healing concrete prepared utilising a unique process of microbial induced calcite precipitation. The strength of Glass fibre reinforced M20 grade self-healing concrete increased by 9 percent.

Development of polyurethane/polyethylene terephthalate/fiber glass polymeric composite from internal auto parts waste

The use of polymers in the automotive industry has been growing significantly, the recycling of these materials is a major challenge nowadays, since most polymer parts comprises of different types of polymers, and they are joined by chemical adhesives due to their lack of good compatibility. This characteristic hampers the recycling of such polymers, and makes separation economically unfeasible, as a consequence, their final destination has ended up in landfills. In this sense, the present research developed a technique to verify the recyclability of the manufacturing waste polymer auto parts from industry processes, through the polymer layup process to obtain a composite (fiberglass, polyester fiber, polyurethane) in the form of flat panel. To achieve the objectives, the polymers were individually analyzed by differential scanning calorimetry to assist in the definition of the overlap of joined polymers, in which differentiates from the conventional method of polymer blend by extrusion. The preformed polymer was consolidated by a hot press. The polymer composites were evaluated by three-point bending test and their structure was analyzed using scanning electron microscopy (SEM). The results in flexural properties indicate a suitable consolidation strategy when compared with results in literature, which is explained by the presence of glass fiber and PET in the final composition. Through the SEM images, it enabled to observe a good interface between the glass fiber and the polyester-based polymer matrix of the wastes, directly influencing the mechanical results of the material.

Mechanical characteristics and hydrophobicity of alkyl ketene dimer compatibilized hybrid biopolymer composites

AbstractIn this study, the effect of alkyl ketene dimer (AKD) on the mechanical and physical properties of natural fiber (NF) and glass fiber (GF) reinforced poly(lactic acid) (PLA) composites were investigated in detail. The hybrid PLA composites were manufactured by extrusion method followed by hot press molding. AKD was used to improve the hydrophobicity of hybrid PLA composites and compatibility of NF and PLA in the polymer matrix. The tensile and flexural tests, thickness swelling, water absorption, and contact angle measurements were accomplished for determining the performance of the hybrid PLA composites. The surface morphology of the hybrid PLA composites was also performed by scanning electron microscopy. The incorporation of AKD and NF into PLA matrix improved the mechanical strengths by 40% and above compared to those of samples without AKD. But, tensile and flexural moduli decreased as 7% and 14% of the samples with NF and AKD, respectively. Contact angle was higher for the hybrid PLA composites with AKD compared with the composites without AKD. However, the results revealed that in the presence of GF, AKD had no significant effect on overall properties of the hybrid PLA composites. In the light of the findings, AKD may have a potential usage as coupling agent in the NF filled PLA composites.

Dripping and decomposition under fire: Melamine cyanurate vs. glass fibres in polyamide 6

Manipulating the melt dripping of thermoplastics makes a fire scenario more or less dangerous. Yet, a detailed understanding of this phenomenon has remained a question mark in studies of the flammability of plastics. In this work, the individual and collective impacts of additives on the dripping behaviour of polyamide 6 (PA6) were studied. A set of materials compounded with melamine cyanurate (MCA) and glass fibre (GF) was investigated. Under UL 94 vertical test conditions, the dripping during first and second ignition was quantified and investigated in detail. The number, size and temperature of the drops were addressed, and the materials and their drops evaluated with respect to such aspects as their averaged molecular weight, thermal decomposition and rheological properties. PA6 with V-2 classification improved to V-0 with the addition of MCA, and achieved HB in the presence of GF. PA6/GF/MCA achieved V-2. Non-flaming drops of PA6/MCA consisted of oligomeric fragments. Flaming drops of PA6/GF showed a more pronounced decomposition of PA6 and an increased GF content. The dripping behaviour of PA6/GF/MCA can be understood as a combination of the influence of both additives. The results showed nicely that dripping under fire is neither a straightforward material property nor a simple additive influence, but the complex response of the material influenced by the interaction and competition of different phenomena.

Full control of polymer properties during the two‐stage on‐demand free‐radical photopolymerization of fiber‐reinforced polymers

ABSTRACTThe effect of a two‐step free‐radical photopolymerization of an acrylate resin on the polymer properties in the presence of glass fibers is studied. It is found that a first irradiation leading to a partial conversion is effective for the fabrication of a preimpregnated glass‐fiber composite, which can be further processed and fully polymerized through a second irradiation. DMA analysis evidences the formation of a first relatively soft polymer embedding unreacted double bonds during the preirradiation. Further process allows the completion of the photopolymerization together with a reinforcement of the polymer network. This obviously affects the final mechanical properties of the photocomposite. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1440–1447

Enhancemenet of Mechanical and Vibrational Properties of Plywood for Packaging and Container Applications

Abstract Commercially available plywood has been used in doors, windows, interior decorations of hose and commercial complexes, containers for transportation of goods. Moisture absorbs by the plywood (W) and deteriorates its physical and mechanical properties leads to degradation of its durability and reliability of the laminates. Therefore, hybridization with synthetic glass (G) fiber is one of the solutions to avoid water absorption and improves its mechanical strength of the hybrid composites in hygrothermal environment. Therefore, the present investigation emphasizes the effect of glass fiber position in the hybrid composites on its mechanical and vibrational responses as compared to plain plywood laminates. There were three types of hybrid composites were considered for this investigation. It was observed that maximum impact strength of 5.325 J/m2 was found to be in GWG2WG type hybrid composite, maximum flexural strength and modulus was found to be in G2WG2 type of hybrid composite and maximum natural frequency of 52.515 Hz was found to be in WG4W hybrid composite. However, the overall mechanical and vibrational properties were improved for G2WG2 type hybrid composites as compared to others. Therefore, the presence of glass fiber in the outer surface of the hybrid composites is the better position to achieve desirable mechanical and vibrational properties of the hybrid composites as compared to other positions. This hybrid composite may be used as alternative materials for containers in goods transport sectors.

Synthesis, characterization and properties of porous micro/nanostructures obtained by oxidizing aluminum nanoparticles with water in the presence of glass fibers

The formation of glass fibers/AlOOH micro/nanostructures during the oxidation of aluninum nanoparticles with water has been studied. Analysis of the reaction intermediates showed that a porous coating of boehmite nanosheets on the glass fibers surface is formed due to dissolution of aluminum nanoparticles and subsequent boehmite deposition. Hydrothermal treatment of glass fibers/AlOOH composite at 200 °C for 3 h results in the glass fibers dissolution to form hollow fibers consisting of boehmite nanosheets. Also, under these conditions, silicon dioxide is deposited on the surface of boehmite nanosheets, which results in the nanostructures acquiring negative charge. The differences in the sorption properties of both glass fibers/AlOOH and hollow fibers SiO2/AlOOH using organic dyes have been shown.

Polypropylene/short glass fiber/nanosilica hybrid composites: evaluation of morphology, mechanical, thermal, and transport properties

In this work, the effect of incorporation of glass fiber and nanosilica separately and in combination in a thermoplastic matrix is investigated. Individual micro, nano, and hybrid multiphase composites based on polypropylene were prepared via twin screw extrusion followed by injection molding. The glass fiber content was maintained at 10 wt% and nanosilica level was fixed at 4 wt%. The microstructure of the hybrid composite indicated the presence of nanosilica surrounding the glass fibers. Higher tensile strength and modulus was reported for hybrid composite, followed by micro and nanocomposite. The differential scanning calorimetry studies suggested that the presence of glass fibers could hasten the crystallization of PP in comparison with nanosilica. The thermal degradation studies for hybrid composite exhibited a prominent thermal stability. The delayed diffusion of solvent in hybrid composite was observed due to the confinement regions generated by the combination of micro and nanofillers.

Pengaruh bahan pengisi serat kaca terhadap sifat fisik dan kristalinitas polipaduan PC/ABS

This research aimed to determine the effects of the addition of glass fibers on the physical and crystallinity properties of PC/ABS polyblends. The ratio of PC/ABS used in this research was 75/25, while the addition of glass fibers ranged from 0; 5; 10; to 15 phr (based on the weight of PC/ABS). Polyblends of PC/ABS/glass fibers were prepared in a twin screw extruder. The test results showed that density and tensile strength of PC/ABS polyblends increased with an increase in the glass fiber content. The presence of glass fibers decreased MFI and impact strength of these PC/ABS polyblends. The functional groups were determined by the fourier transform infrared (FTIR) spectrophotometer while crystallinity was examined using X-ray diffractometer (XRD). Keywords: PC/ABS polyblend, glass fiber, physical properties, crystallinity.

Structural, thermal, morphological and dynamic mechanical characteristics of waste‐reinforced polypropylene composites: A novel approach for recycling electronic waste

ABSTRACTAn in‐depth investigation has been carried toward utilizing polymer‐rich nonmetallic fraction of printed circuit boards (PCBs) as reinforcing fillers in polypropylene (PP) composites. The influence of waste additions (up to 25 wt %) on structural, thermal, morphological, and dynamic mechanical behavior of PP composites was investigated using a range of analytical techniques. The incorporation of PCB waste was found to affect the crystalline morphology resulting in the formation of smaller spherulites. The presence of glass fibers in PCB waste promoted the formation of β‐crystal enhancing the mechanical properties of composites. Thermal analysis showed a maximum increase of ∼15 °C in the crystallization onset temperature (Tco) suggesting the nucleating effect of the filler, a feature also supported by structural investigations. Polarized microscopy revealed a reduction in the spherulite size after 5 wt % PCB waste loading owing to the presence of large number of nucleation sites. The incorporation of waste also increased the thermal stability of composites increasing the final degradation temperature by up to 14 °C. Dynamic mechanical properties of PP/PCB waste composites were determined in the temperature range −20 to 155 °C; a significant increase in the storage modulus further confirmed the reinforcing effect of waste additives. This investigation has shown that the nonmetallic fraction of PCB waste could be used as a cost‐effective reinforcing filler for PP, providing an environmental friendly route to utilize electronic waste in value‐added products. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43389.

The effect of nanoparticles in single-lap composite joints studied by experimental and numerical analyses

This study aimed to investigate the effect of nanoparticles on the strength of single-lap nanocomposite joints. Three different types of specimens were studied, each of which contained 1 wt% of carbon nanotube in the adhesive. The adherends included three different percentages of nanoclays, namely 0, 5 and 7 wt%. The material used here was glass fibers/epoxy, with epoxy as the matrix. After fabrication of the laminates, they were stuck together by epoxy resin containing 1 wt% of carbon nanotube. Different tests were also conducted to analyze the specimens. These tests included X-ray diffraction (XRD), scanning electron microscope (SEM) and tensile test. In the XRD test, the presence of glass fiber, epoxy resin and nanoclays was verified and in the SEM test, the distribution of nanoclays into the laminates was investigated and finally the strength of the joints with different nanoparticles was examined by tensile test. In addition, a finite element (FE) analysis was also incorporated and the results of this method were verified by the experimental results. To perform the FE analysis, Young’s modulus of the laminates and the adhesive were both required. Therefore, a tensile test was conducted to obtain the Young’s modulus of the adherends and the elastic modulus of adhesive was obtained from the data existing in the literature. Finally, the results from FE analysis and the experimental tests were compared with each other and a good agreement was observed. It was finally concluded that the specimen comprised of 5 wt% nanoclays had the best performance among the three.

The influence of glass fibers on the morphology of β-nucleated isotactic polypropylene evaluated by differential scanning calorimetry

The presence of fillers/fibers can significantly affect the polymorphic behavior of semi-crystalline polymers. The influence of glass fibers on morphology of ?-nucleated iPP during isothermal and nonisothermal crystallization was analyzed in detail by DSC, and the kinetics and thermodynamic parameters were determined for the systems containing 10-60 % glass fibers. The presence of glass fibers in model composites with ?-iPP has insignificant effect on the morphology of the polymer. Thermodynamic and kinetics parameters of crystallization of iPP in model composites are close to those obtained for the nucleated polymer. The relative content of ?-crystalline phase is slightly affected by increasing glass fiber?s content from 10 % mas to 60 % mas, due to appearance of ?-crystallites. However, the stability of ?-crystalline phase is decreased by the increasing glass fibers content and there appeared certain amount of ?1 and ?2 phases which are known as disposed to recrystallization.

Mechanical Properties, Heat Resistance and Flame Retardancy of Glass Fiber-Reinforced PLA-PC Alloys Based on Aluminum Hypophosphite

Poly(lactic acid) (PLA) and polycarbonate (PC) alloy (the wt. ratio of PLA and PC was 70/30) was modified by blending with glass fiber (GF), and then aluminum hypophosphite (AP) was applied to improve the flame retardancy of GF-reinforced PLA-PC alloys. The mechanical properties of the alloys were investigated by tensile, flexural and impact tests. The heat resistance was surveyed via HDT test. The flame retardancy, combustion and thermal behavior of the alloys were evaluated by LOI and UL-94 tests, cone calorimeter and thermogravimetric analyzer, respectively. The results showed that the addition of GF enhanced the mechanical properties and heat resistance of PLA-PC alloy significantly; and the flame retardancy of GF-reinforced alloys could be improved obviously through adding AP, resulting in UL-94 V-0 rating (1.6 mm). Interestingly, the PLA-PC/AP alloys could reach the UL-94 V-0 rating at a lower loading of AP in the presence of GF. Meanwhile, the mechanical properties still retained in a high level, and were higher than 77% of the corresponding alloys filled only by GF. The thermogravimetric analysis and cone calorimetric test results revealed that AP could slow down the decomposition rate of PLA-PC matrix and increase its melt viscosity; meanwhile, it was found that GF played several roles on the flame retardancy, mainly including stabilizing the char residue formed during the combustion process, insulating heat and mass, and improving the compactness of the char residue via increasing the residual mass.

Optimized Injection Molding of Unfilled and Glass Filled PA6 Gears

Shrinkage behavior is a crucial problem in manufacturing plastic molded gear. This is because it negatively affects the dimensional stability and accuracy of the involute profile, as well as the concentricity, roundness, tooth spacing uniformity, and size of the gear. By integrating the Taguchi robust design, Grey relational analysis, and principal component analysis, we investigated the dimensional stability related to the shrinkage of tooth thickness, addendum circle, and dedendum circle of molded gear via the optimization of processing parameters and glass fiber reinforcement. The results revealed that the optimal combination of the processing parameters of the molded gear to achieve minimum shrinkage is melt temperature of 260°C, packing pressure of 60%, packing time of 5 s, and cooling time of 30 s. The melt temperature showed the highest comparability sequence among the four key process parameters examined, followed by packing pressure, cooling time, and packing time. Meanwhile, the presence of glass fibers induced higher deviations of tooth thickness, addendum circle, and dedendum circle than those of the unfilled polyamide 6 gears.

Flexural properties of epoxy syntactic foams reinforced by fiberglass mesh and/or short glass fiber

Epoxy syntactic foams containing 15wt.% hollow glass microballoon were reinforced by fiberglass mesh and/or short glass fiber, and the flexural behavior of these foams were investigated. Flexural tests results showed that the presence of glass fiber or fiberglass mesh led to increased values of strength and modulus in syntactic foams compared with unreinforced syntactic foams. And fiberglass mesh was found to be much more efficient. By adding two-layer fiberglass mesh to the glass fiber reinforced syntactic foams, the flexural strength and modulus further increased almost 2.5 and 2times, respectively, while the density of the reinforced foam only increased by 9.3%. In addition, it was found that the position and layers of fiberglass mesh had significant influence of the flexural properties. The failure modes and mechanisms of different reinforced syntactic foams are examined and the underlying differences are discussed.

EXPERIMENTAL STUDIES ON MECHANICAL, FRICTION AND WEAR OF NON ASBESTOS ORGANIC BRAKE LININGS FOR LIGHT MOTOR VEHICLE

In this study, flyash based non asbestos organic brake lining composition of more than 14 ingredients was investigated to study the effect of ingredients on various behavior of friction properties. Two types of friction materials with different combinations were developed: i) fly ash range (10 %to 60%) and ii) without fly ash based friction materials were investigated to study the effect of ingredients on the friction characteristics and wear. The main focus on the average normal coefficient of friction, hot coefficient of friction (Fade and recovery), wear loss, mechanical, as the function of the relative amount of the ingredient. The results also showed that the friction coefficient of fly ash based friction material was better in the range of 0.35 to 0.48 when compared barites based brake linings in the range of 0.46 to 0.58. The materials such as potassium titanate(terraces), wollastonite, friction dust powder have strongly influence on friction coefficient. The wear résistance of the brake linings was strongly affected by the presence of rock wool calcium hydroxide and zircon silicate. The presence of glass fiber, twaron fiber, glass fiber has increased the strength of the friction material. All these samples were tested on chase type friction tester at automobile ancillary unit.

EFFECT OF GLASS FIBER ON THE PROPERTIES OF ELECTRICALLY CONDUCTIVE POLYOXYMETHYLENE COMPOSITES

Polyoxymehtylene(POM)/multiwalled carbon nanotubes(MWCNTs)/glass fiber(GF) and POM/carbon black(CB)/GF composites were prepared by melt mixing in a rotational rheometer.The effects of GF on the electrical conductivity,crystallization behavior and dynamic mechanical properties of the composite materials were investigated.The morphology of the composites was observed by field emission scanning electron microscopy(FESEM),showing that GF does not significantly affect the dispersion state of MWCNTs and CB.Although GF is electrically inert,its presence can increase the effective concentration of the conductive filler by holding up some space,therefore the conductivity of the material increases.The electrical resistivity/effective concentration data points are all around the electrical resistivity/conductive filler concentration curve of POM/MWCNTs and POM/CB composites,proving that the concept of effective volume concentration can be used to explain the decrease in the electrical resistivity with the incorporation of GF.The crystalline behavior of POM in the composites was investigated by differential scanning calorimetry(DSC).The crystallization temperature,melting temperature and degree of crystallinity have no significant change by incorporation of GF,revealing that GF does not have obvious influence on the crystalline behavior of POM.The storage modulus,as measured by dynamic mechanical analysis(DMA),increases significantly by the presence of GF,showing a strong reinforcing effect.Therefore,GF-filled POM/MWCNTs and GF-filled POM/CB are promising materials having both good electrical conductivity and good mechanical properties.