Glass Fiber Research Articles

Effect of Displacement Rate on Delamination Growth Rate in Unidirectional Glass Fiber Composites in Both Bridging and Non-Bridging Scenarios

Effect of Displacement Rate on Delamination Growth Rate in Unidirectional Glass Fiber Composites in Both Bridging and Non-Bridging Scenarios

Factors Influencing the Bond Strength between FRP Bars and Concrete and the Calculation Methods for Anchorage Length

Since the 21st century, developed countries such as Japan, the United States, and Europe have designated Fiber Reinforced Polymer (FRP) as a key industry for development. Currently, FRP sheets, represented by carbon fiber fabric, have become an important material for structural reinforcement and are widely used in the renovation and reinforcement of various civil and industrial buildings. For example, in the early 1960s, the American company Marshall-Vega produced Glass Fiber Reinforced Polymer (GFRP) bars to address the issue of salt corrosion in reinforced concrete structures in coastal and cold regions. In the design of the ArtScience Museum in Singapore, to ensure the integrity and smoothness of the architectural form, facilitate prefabrication and assembly of components, and meet structural, fire safety, and security requirements, the designers evaluated various materials and ultimately selected polyethylene resin-based GFRP panels. This paper employs a literature review methodology, first analyzing the factors that affect the bond strength between FRP bars and concrete, then reviewing standards to understand the calculation methods for anchorage length in different countries, collecting relevant experimental data, and finally analyzing the advantages and disadvantages of various anchorage length calculation methods.

Analysis Method of 131I Activity in Carbon Cartridge and Internal Dose Assessment for Nuclear Medicine Workers.

Inhalation of 131I is the main route for internal doses to nuclear medicine workers. This study aimed to establish a simple analysis method for determining 131I activity in carbon cartridges, explore the activity concentration of 131I in nuclear medicine departments, and evaluate the internal dose of workers. A total of 21 nuclear medicine departments in the hospital conducted air sampling using a high-volume air sampler equipped with carbon cartridges and glass fiber filters to collect gaseous 131I and aerosol 131I, respectively. Furthermore, a mathematical model was developed to analyze the 131I activity with inhomogeneous distribution in cartridges. Based on the 131I activity measured by the HPGe γ spectrometer, the personal annual inhalation effective dose was estimated. The results showed that there is a significant difference in the activity of gaseous 131I and aerosol 131I, with the activity ranging from 1.5±0.08 Bq m-1 to 3,944.23±197.21 Bq m-3 and ND (not detectable) to 842.11±42.11 Bq m-3, respectively. The activity of aerosol 131I is about 1% to 7% of that of gaseous 131I. The annual committed effective dose caused by inhalation of 131I for workers is 3.6 μSv to 8.23 mSv, which is lower than the dose limit of 20 mSv y-1. In general, the 131I contamination in the nuclear medicine department cannot be ignored, and the concentration of 131I should be regularly monitored to prevent and control the internal radiation to which workers may be exposed.

An Experimental Research Into the Bonding Strength of GFRP Bars in Concrete Under Elevated Temperatures

This study investigates the bond strength of Glass Fiber Reinforced Polymer (GFRP) bars in concrete at high temperatures. Twenty-four specimens were tested at 600°C to replicate fire conditions and analyze performance consequences in structural applications, with variables such as bar diameter and position within the concrete taken into account. The results show a considerable drop in binding strength, notably in edge-positioned bars with thinner covers, which is related to thermal degradation of the epoxy resin. The stress-slip relationship revealed significant increases in slippage, particularly for bigger diameter bars, as well as the vulnerability of GFRP bars to high temperatures. Failure modes shifted mostly to splitting following exposure, emphasizing the importance of design concerns in fire-prone structures. These findings improve our understanding of GFRP performance in harsh situations, influencing material selection for greater fire resilience.

Polymer Materials for U-Shaped Optic Fiber Sensors: A Review

Fiber optic sensors have gained popularity over the last few decades. This is due to their numerous advantages, such as good metrological parameters, biocompatibility and resistance to magnetic and electric fields and environmental pollution. However, those built from glass fiber have one main disadvantage—they are fragile, meaning they can be easily damaged, even by the presence of vibration. Due to the great progress made by material research recently, it is possible to build such a sensor with polymer fibers instead. Although those fibers have worse transmission parameters compared to telecommunication fibers, they provide the possibility to realize flexible fiber optic sensors. Taking into consideration other advantages of such fibers, including biocompatibility, electromagnetic resistance and even, biodegradation characteristics, as well as there being a variety of materials we can use, it can be seen that those materials are beneficial to produce fiber optic sensors. This paper aims to provide researchers with guidelines on the factors to consider when choosing a material for bent fiber optic sensors, depending on the application.

Low Shrinkage and Robust Polyimide/Ultrafine Glass Fiber Aerogel for Efficient Heat Resistance and Oil/Water Separation

Low Shrinkage and Robust Polyimide/Ultrafine Glass Fiber Aerogel for Efficient Heat Resistance and Oil/Water Separation

Fracture resistance and behavior of endodontically treated maxillary premolars with varying ferrule heights and post numbers: A laboratory study.

To investigate how varying ferrule heights and the number of glass fiber posts affect fracture resistance and behavior of endodontically treated maxillary first premolars with substantial loss of tooth structure. Twenty-four extracted endodontically treated human maxillary first premolars were divided into three groups (n=8) based on ferrule height and post number. The groups were as follows: premolars of 2mm ferrule height that were restored with single posts (control group), premolars of 0.5mm ferrule height that were restored with single posts in palatal canals (single-post group), and premolars of 0.5mm ferrule height that were restored with double posts in palatal and buccal canals (double-post group). All groups were then restored with composite core and metal-ceramic crowns cemented with zinc phosphate cement. All specimens were subjected to 10,000 thermal cycles at temperatures of 5°C and 55°C, as well as 1.2 million cyclic loadings of 49N load at 1.2Hz using a chewing simulator. The specimens were loaded to fracture in a universal testing machine and fracture behavior was examined under stereomicroscope and divided into restorable and unrestorable fracture modes. Fracture loads and modes were analyzed by one-way ANOVA, Tukey's post hoc test, and Fisher's exact probability test (p≤0.05). The control group showed the highest mean fracture load (1127±172) of all groups (p<0.001). The specimens in the single-post group showed numerically higher mean fracture load (522±171) but with no significant difference compared to the ones in the double-post group (518±157; p>0.967). In the control group, 75% of specimens showed unrestorable fractures compared to 50% and 12.5% in single-post and double-post groups. The specimens in the control group had similar unrestorable fractures, starting from the coronal part and extending obliquely to the cervical third of the root below resin level. Two specimens in the control group showed unrestorable fractures in the middle third of the root. No middle-third root fractures were observed in single-post and double-post groups, and unrestorable fractures in both groups were similar to those of the control group. The single-post group had two specimens with core-post crown complex restorable fractures, while the control and double-post groups had one specimen each. The remaining specimens showed cervical-third root restorable fractures above resin level. The ferrule height significantly influences the fracture resistance of endodontically treated premolars compared to the number of placed posts. Nonetheless, more restorable fractures are seen in endodontically treated premolars restored with double posts than single posts regardless of ferrule height.

A Study of Reinforced Cement Paste Properties with Woven Fabrics from Poly(ethylene Terephthalate) Bottle Yarn.

This study investigates the reinforcement of cement paste with woven fabrics made from recycled poly(ethylene terephthalate) (PET) bottle yarn, aiming to enhance its mechanical properties while addressing PET waste. PET bottles were transformed into yarn with a denier of 3,593.8, strength of 91.2 N, and 25.6% elongation before breaking. The yarns were woven into plain weave, twill weave, and basket weave fabrics, with the basket weave exhibiting the highest yarn density at 10 threads per inch and fabric weight of 277.08 g per square meter. Mechanical testing of cement paste samples, unreinforced, reinforced with PET fabrics, and reinforced with standard fiberglass fabric, demonstrated that the basket weave fabric reinforced samples exhibited superior compressive and flexural strengths of 31.99 and 1.53 N per square millimeter, respectively. This study highlights the potential of using PET bottle yarn woven fabrics, especially the basket weave pattern, as an effective and sustainable reinforcement material in cement paste. The findings offer a promising approach for PET waste valorization and the development of construction materials with improved performance. Environmental and economic assessments indicate that this approach can reduce CO2 emissions by approximately 11% and achieve cost savings of 6.4% compared to traditional glass fiber reinforcement. These results demonstrate the potential for sustainable engineering solutions that combine environmental benefits with economic viability.

Study on Cut‐Resistance Properties of Composite Yarn Based Knitted UHMWPE Textiles: Influence of Reinforcement, Radiant Heat Exposure, Outdoor Environment, and Cutting Angles

ABSTRACTThe safety of workers in hazardous environments depends on personal protective clothing capable of withstanding various real‐world challenges, especially in automotive, glass, aerospace, mining, construction, and food industries where cut hazards are prevalent. Ultra‐high‐molecular‐weight‐polyethylene (UHMWPE) is widely utilized in cut‐protective textiles for its exceptional strength and durability. This study investigates the cut‐performance of stainless‐steel and glass fibers reinforced UHMWPE knitted fabrics under real‐world industrial conditions, focusing on the influence of varying cutting angles, outdoor environments, and thermal exposure on their cut‐protective efficacy. Reinforcement significantly improved cut‐performance, with stainless‐steel reinforced UHMWPE fabric (13SU) exhibited the highest tear strength (lengthwise‐313.1 N, widthwise‐405.8 N) and abrasion resistance (withstanding up to 800 rubbing cycles), providing best cut‐protection with cutting force of 32.43 N at 90° cutting angle. Differential scanning calorimetry (DSC) and scanning electron microscope (SEM) characterizations revealed UHMWPE's sensitivity to thermal effects, with a significant decrease in crystallinity after exposure to radiant heat flux of 20 kW/m2 at fabric surface, leading to diminished cut‐performance. Environmental durability assessments indicated a reduction in cut‐resistance properties due to changes in the chemical composition of UHMWPE polymer structure, such as the presence of ketone (CO) and hydroxy (OH) polar groups, as confirmed by Fourier‐transform infrared (FTIR) spectroscopy.

Mechanical Properties and Numerical Modelling for Prosthetic Foot

This study uses laminated composite materials made of hybrid glass and carbon fibers to determine the mechanical characteristics of the foot. Tensile, bending, and fatigue of composite material were evaluated and applied to the ANSYS model. The volume fraction for carbon and glass fibers was 22.5% and 10.04%, respectively. The mechanical property results: σy = 40 MPa, σult = 150 MPa, and E = 1.2 GPa. The patient is a 30-year-old male with a left amputation side, 1.60 meters tall, and weighs 74 kg. The analysis was carried out for the two scenarios (toe-off and heel contact) as boundary conditions. The overall deformation, equivalent stresses, and foot safety factor have been calculated using ANSYS17.2 software. In the end, it appears that the foot is secure based on equivalent stress calculations and the Von-Mises hypothesis. The computed safety factor for the foot is constructed of a chosen composite material with the subsequent layers. When the heel (stance phase) is fixed at 1.3449, and the metatarsal (toe off) is fixed at 1.259, the safety factor for a force of 860 N is reached. The foot is secure, according to the Von-Mises hypothesis.

Tough and circular glass fiber composites via a tailored dynamic boronic ester interface.

Glass fiber reinforced polymer (GFRP) composites are valued for their strength and cost-effectiveness. However, traditional GFRPs often face challenges for end-of-life recycling due to their non-depolymerizable thermoset matrices, and long-term performance due to inadequate interfacial adhesion, which can lead to fiber-matrix delamination. Here, we have designed dynamic fiber-matrix interfaces to allow tough and closed-loop recyclable GFRPs by utilizing a vitrimer, derived from upcycled polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) with boronic ester (S-Bpin) and amine-based diol crosslinker. The boronic ester groups in S-Bpin form dynamic covalent bonds with the naturally present hydroxyl groups on the unsized GF surface, which eliminates the need for fiber sizing and enables facile closed-loop recyclability of both the fibers and the vitrimer matrix. The resulting strong fiber-matrix interface, depicted by the Raman mapping, leads to a 552% increase in-plane shear toughness (6.2 ± 0.3 MJ m-3) and 27% ultimate tensile strength (361 ± 89.2 MPa) compared to those of the conventional epoxy-based matrix (0.95 ± 0.05 MJ m-3 and 264 ± 59.7 MPa, respectively). The network rearrangement through dynamic boronic ester exchange enables fast thermoformability and repairability of micro-cracks at elevated temperatures. Additionally, both the matrix and composite demonstrate strong adhesion to various surfaces including steel and glasses exhibiting ≥6 MPa lap shear strength, which expands their suitability for diverse industrial applications. The readily created dynamic interface between boronic ester functionalized vitrimer and neat GFs presents a promising strategy for developing closed-loop recyclable, multifunctional structural materials, offering a sustainable alternative to non-recyclable thermoset GFRPs and contributes to a circular economy in composite materials.

A multicomponent donor–π–acceptor covalent organic framework as a nanoporous cation-selective separator for durable aqueous zinc ion batteries

A multicomponent covalent organic framework with donor–π–acceptor structure is designed and composited with glass fiber as the separator for zinc-ion batteries. The ordered zinc-ion channel regulates zinc-ion transport, ensuring battery durability.

The effect of travertine waste on the strength and insulation properties of foam concrete

Abstract Incorporating waste additives into foam concrete mixtures is a promising route to develop environmentally-friendly concrete production with tailored thermos-mechanical properties. In this paper, the effects of various fabrication parameters of foam concrete, including the type of waste additive, water/binder ratio, density of mixture, and incorporation of glass fibers were investigated. Foam concrete samples were fabricated using fly ash and travertine wastes, and the variations in their flexural strength, compressive strength, and thermal conductivity using various concrete mixture designs were measured. The obtained results show that foam concrete with fly ash additive tends to have higher compressive strength and thermal conductivity than foam concrete with travertine waste. However, the latter exhibits better thermal insulation properties, which tend to improve by adding glass fibers. This work defines the outlines for exploring the use of harmful wastes in fabricating foam concrete. It offers guidelines for developing improved foam concrete mixtures with tailored thermos-mechanical properties.

Impact of fibre reinforcement on cryogenic performance of novel epoxy composites for cryogenic applications

Due to the dynamic development of technology and science, there is an increasing demand for materials combining high mechanical resistance to extreme temperature conditions and suitable thermal properties. Especially the knowledge of heat transfers by conduction and thermal radiation is crucial for the successful design of devices operating at cryogenic temperatures, such as Dewars, cryostats, or space probes. This study aimed to assess important thermal and mechanical properties at cryogenic temperatures for three composite materials made of identical epoxy resin reinforced by carbon, basalt or glass fibres. Apart from loading/unloading cyclic tensile tests conducted at room temperature and in cryogenic environments at 77 K, thermal conductivity and total hemispherical emissivity were obtained in wide temperature ranges from 5 K up to 300 K. The results highlighted the importance of the fibre material and have potential to help with optimal material selection. We found that the initial stiffness of the laminates increased at low temperatures, and the glass composite exhibited the best mechanical properties. On the other hand, the carbon composite showed the lowest but steeply increasing thermal conductivity with increasing temperature. This, together with the lowest emissivity, makes the carbon composite a more favourable option for the lowest temperatures.

Enhancing Syagrus romanzoffiana lignocellulosic fibers' properties by ecological treatment with sodium bicarbonate for applications in sustainable lightweight biocomposites.

Investigating the fascinating world of natural fibers, where Syagrus romanzoffiana fibers (SrFs) are promising substitutes for glass and synthetic fibers in composite materials, is more than interesting. The improvement of SrFs through an environmentally friendly treatment employing sodium bicarbonate (NaHCO₃) at different concentrations (5%, 10%, 20%, and 30% by weight) over various durations (24, 72, and 168h) is the subject of this study. The objective is to provide a sustainable and economical approach to enhancing fiber characteristics. Comparisons were made between treated and untreated fibers and fibers from semi-arid and humid regions to evaluate geographical influences. Key findings include considerable enhancements in tensile properties: a 58% rise in Young's modulus and a 69% rise in traction stress for fibers treated with 20% NaHCO₃ for 72h. The stretching at fracture of these treated fibers was measured at 1.04±4.49%. The treated fibers also showed an increased crystallinity index of 71.61% and a crystal size of 2.38nm. Fourier-transform infrared spectroscopy revealed the chemical modifications from the treatment. Thermogravimetric analysis (TGA) indicated thermal stability up to 327°C and a kinetic activation energy of 53.84kJ/mol, compared to 62.72kJ/mol for untreated fibers. The study highlights an environmentally friendly approach to material development by showcasing the potential of treated SrFs in lightweight biocomposite applications. This study provides valuable information on the TGA/pyrolysis of SrFs at 10°C/min for potential bioenergy production, including assessing environmental impact, opportunities concerning sustainable resource management, and integration with other renewable energy systems.

Efficacy of Canal Disinfectants Temoporfin, Carbon Nanoparticles, and Er: YAG Laser on Martens Hardness, Smear Layer Removal, and Bond Strength of Glass Fiber Posts to Canal Dentin.

To investigate the effectiveness of unconventional post space disinfection techniques, specifically Er:YAG laser, Temoporfin, and Carbon Nanoparticles (CNPs), in improving Martens hardness (MH), eliminating the smear layer (SL), and enhancing the push-out bond strength (PBS) of glass fiber posts in canal dentin. An in vitro study was conducted utilizing 80 single-rooted extracted human teeth, which were decoronated and subjected to standardized root canal preparation. The teeth were equally distributed into four experimental groups: Group 1 (NaOCl + EDTA), Group 2 (Er: YAG laser + EDTA), Group 3 (Temoporfin + EDTA), and Group 4 (CNPs + EDTA). Each group underwent disinfection protocols followed by assessment of Martens hardness (MH) using nanoindentation testing, SL evaluation via scanning electron microscopy, and bond strength testing using a universal testing machine (UTM). Statistical analysis was performed using one-way ANOVA followed by Tukey's post hoc test to determine the level of significance among the groups. A significant level of p<0.05 was established. Group 4 (CNPs+17% EDTA) showed a high MH value of (0.25 ± 0.02 GPa), significantly outperforming Groups 1 (0.13 ± 0.02 GPa) and 3 (0.10 ± 0.03 GPa). Group 2 (Er: YAG laser + 17% EDTA) demonstrated superior smear layer removal across all sections, particularly in the apical third (1.94 ± 0.38). Push-out bond strength was highest in Group 2 (9.98 ± 0.14 MPa at the cervical level) and Group 4 (10.08 ± 0.21 MPa), while Group 1 showed a decrease in apical bond strength of (5.11 ± 0.19 MPa) CONCLUSION: CNPs and Er:YAG laser treatments, in comparison to Temoporfin and NaOCl, significantly increase dentin hardness and bond strength while reducing SL. This finding suggests that the incorporation of these innovative disinfection methods into endodontic procedures may enhance the durability and success of glass fiber post restorations.

Mechanical Behavior and Microscopic Mechanisms of Glass Fiber–Modified Loess in Seasonally Frozen Regions

Mechanical Behavior and Microscopic Mechanisms of Glass Fiber–Modified Loess in Seasonally Frozen Regions

Confinement of Concrete Cylinders Using Dry Glass Fiber Hoops: Experimental Investigation and Analytical Modeling

Confinement of Concrete Cylinders Using Dry Glass Fiber Hoops: Experimental Investigation and Analytical Modeling

Effects of Cutting Parameters on Delamination in Machining for S 2 Glass Fiber Reinforced Polymer Composites

Effects of Cutting Parameters on Delamination in Machining for S 2 Glass Fiber Reinforced Polymer Composites

Study on properties of high-performance glass fiber fabrics and composites using different surface treatment

Study on properties of high-performance glass fiber fabrics and composites using different surface treatment