Effect of Nozzle Diameter on Basalt Continuous Fiber Properties

Jang K.

To enhance the mechanical, thermal, and electrical properties and economic profits, polycarbonates (PCs) have been blended with various inorganic additives for the past few decades. Herein, we fabricated basalt fiber (BF)-infiltrated PC composites as a promising candidate for a myriad of PC applications. Mechanical robustness and rheology were examined via the precise control of BF contents (up to 12.5 phr). The incorporation of BF gradually enhanced the mechanical properties of the composites such as moduli and strengths, as determined by flexural and tensile tests. The Izod impact strength was reduced as a function of BF concentration, representing the ductile-to-brittle transition. The heat deflection temperature of the PC/BF composites was increased from 131.2 °C to 138.9 °C, which was in good agreement with the thermomechanical results. By contrast, the glass transition temperature measured by differential scanning calorimetry remained unchanged at ca. 143 °C. The incorporation of BF in PCs enhanced the dimensional stability. The visual observation for PC/BF composites was examined via scanning electron microscopy. The rheological investigation was systematically performed by utilizing the melt flow index, and capillary and torsional rheometry with a variety of experimental conditions. These PC/BF hybrid composites with tunable mechanical and rheological properties will be employed for various applications by tailoring the PC/BF ratios.

Liu J., Yang J., Chen M., Lei L., Wu Z.

In this paper, high temperature resistance of basalt fibers with different SiO2 and Al2O3 contents was studied. The thermal expansion coefficient, crystallization performance and high temperature viscosity of basalt glasses was analyzed by TMA (thermomechanical analyzer), STA (synchronous thermal analyzer) and high temperature viscometer. The results showed that the monofilament strength, monofilament strength retention and high temperature viscosity of the basalt fibers increased with the increasing content of SiO2 and Al2O3, and the thermal expansion coefficient of basalt glass reduced and the thermal stability of the basalt fiber was improved. However, when the total content of SiO2 and Al2O3 was more than 78%, the melting temperature of basalt ore became higher, which will reduce the service life of platinum bushing and refractory material.

Zhang Y., Vulfson Y., Zheng Q., Luo J., Kim S.H., Yue Y.

The physical properties of the glass fibers and their woven and non-woven products are affected by many factors, such as glass composition, thermal history, melting conditions, and fiberizing method. In this work, we have investigated the impact of fiberizing method on dynamic properties and relaxation behavior of the glass wool fibers, and inferred its effect on the mechanical properties of the filtration mats consisting of glass wool fibers. We have fabricated the glass wool fibers using the rotary (R) and flame (F) attenuation processes, which are denominated as R- and F- fibers, respectively. Both fibers have the same chemical composition and hence similar structural features, surface quality, glass transition temperature (Tg), and sub-Tg enthalpy relaxation behaviors. However, two fibers show striking differences in the surface hydroxyl (OH) content, fictive temperature (Tf) and cooling rate (qc). F-fibers have weakly hydrogen-bonded surface hydroxy (OH) groups, while R-fibers have free OH groups and strongly hydrogen-bonded OH groups. F-fibers have higher Tf and qc than R-fibers. We argue that the higher tensile strength of the F-fiber mat (compared to the R-fiber mat) could be attributed to both the weaker hydrogen-bonded surface OH groups, and the higher Tf and qc values that may increase the tensile strength of fiber itself. This work gives guidance for designing the fiber mat products with high tensile strength.

Kuzmin K.L., Gutnikov S.I., Zhukovskaya E.S., Lazoryak B.I.

In the present research the dependence of compositional variations on the basaltic glass fibers mechanical properties was explored. Addition of 15 mol % MgO or 5 mol % ZnO led to enhanced for tensile strength up to 43% and 47% and for modulus up to 13% and 25% respectively. The structure of basaltic glass fibers with varying MgO and ZnO contents was investigated by solid-state 29 Si and 27 Al nuclear magnetic resonance with magic angle spinning (MAS-NMR) and infrared (IR) spectroscopy. It was indicated that the increase of MgO and ZnO contents slightly decreased the degree of network polymerization. 27 Al MAS NMR exhibit a peak consistent with tetrahedral aluminum units AlO 4 . The noticeable fraction peaks of narrow octahedral aluminum units AlO 6 are observed. Presence of aluminum cations in coordination 4 and 6 was confirmed by IR spectroscopy. In order to study their crystallization ability the glasses were heated at various temperatures for various time periods with following self-cooling. The crystalline phases were identified by X-ray diffraction analysis. Obtained results have shown the possibility to increase mechanical properties of continuous fibers and composites on their base by 50–60%.

Persikov E.S., Bukhtiyarov P.G., Sokol A.G.

Abstract New experimental data on the temperature and pressure dependences of the viscosity of synthetic hydrous kimberlite melts (82 wt.% silicate + 18 wt.% carbonate; degree of depolymerization: 100·NBO/T = 313 for anhydrous melts and 100·NBO/T = 247 for melts with 3 wt.% H2O) were obtained at a water pressure of 100 MPa and at lithostatic pressures of 5.5 and 7.5 GPa in the temperature range 1300–1950 °C. The temperature dependence of the viscosity of these melts follows the exponential Arrhenius–Frenkel–Eyring equation in the investigated range of temperatures and pressures. The activation energies of viscous flow for hydrous kimberlite melts were first shown to increase linearly with increasing pressure. Under isothermal conditions (T = 1800 °C), the viscosity of hydrous kimberlite melts increases exponentially by about an order of magnitude as the pressure increases from 100 MPa to 7.5 GPa. The new experimental data on the viscosity of hydrous kimberlite melts (error ±30 rel.%) are compared with forecast viscosity data for anhydrous kimberlite and basaltic melts (100·NBO/T = 51.5) and for hydrous basaltic melts (100·NBO/T = 80). It is shown that at comparable temperatures, the viscosity of hydrous kimberlite melts at a moderate pressure (100 MPa) is about an order of magnitude lower than the viscosity of hydrous basaltic melts, whereas at a high pressure (7.5 GPa) it is more than twice higher. It is first established that water dissolution in kimberlite melts does not affect seriously their viscosity (within the measurement error) at both moderate (100 MPa) and high (7.5 GPa) pressures, whereas the viscosity of basaltic melts considerably decreases with water dissolution at moderate pressures (100 MPa) and remains unchanged at high pressures (P > 3.5 GPa).

Yue Y., Zheng Q.

Fiber spinnability is the ability of a glass-forming melt to be steadily stretched and spun into defect-free fiber filaments. However, its quantification has not been well established owing to many controlling factors such as melt fragility, melt strength, surface tension, liquidus temperature, liquidus viscosity, and crystallization. To understand and quantify the fiber spinnability of a glass melt, we consider two key aspects: fiberizing viscosity window and melt stability. The fiberizing viscosity window is defined by the upper and lower viscosity limits. Fibers rupture above the upper viscosity limit, whereas a stable melt stream cannot form below the lower limit (ηlow). We introduce a simple parameter to quantify fiber spinnability, namely, Kfib=ηL/ηlow, where ηL is the viscosity at liquidus temperature (TL). A fiber can only form if Kfib>1. To quantify melt stability we propose the parameter of S=(TL-TC)/(TL-Tg), where TL and TC are the liquidus temperature, and the onset temperature of melt crystallization during cooling, respectively. Both parameters (Kfib and S) are important for a rational design of glass fiber compositions, and fiberizing process. We use two basalt melts as examples of this study to demonstrate the high sensitivity of fiber spinnability to a minor variation in chemical composition of melts.

Kuzmin K.L., Timoshkin I.A., Gutnikov S.I., Zhukovskaya E.S., Lipatov Y.V., Lazoryak B.I.

Abstract The present study explains the role of surface modification of constituent materials on composite material performance. The influence of silane and nano-hybrid coatings on mechanical properties of basalt fibers and composite materials on their base was investigated. Infrared spectroscopy indicated that modification of basalt fiber surface and nano-SiO2 was successfully applied. The surface modification leads to the significant increase in the tensile strength of basalt fibers compared to the non-coated fibers. The tensile strength of silane-treated fibers was established 23% higher than the non-coated fibers, indicating that silane plays a critical role in the strength retention of basalt fibers. Also it was pointed out that silane coupling agents can be used for the preparation of the nano-hybrid coating. Addition of SiO2 nanoparticles into the fiber surface was incorporated to enhance the interfacial bonding of basalt fiber reinforced epoxy composite.

Elgabbas F., Vincent P., Ahmed E.A., Benmokrane B.

The advances in fiber-reinforced-polymer (FRP) technology have spurred interest in introducing new fibers, such as basalt, in addition to the commonly used glass, carbon, and aramid. Recently, new basalt-FRP (BFRP) bars have been developed, but research is needed to characterize and understand how BFRP bars would behave in concrete members. This paper presents an experimental study aimed at determining the bond-dependent coefficient (kb) and investigating the structural performance of newly developed BFRPs in concrete beams. A total of six concrete beams reinforced with BFRP bars were built and tested up to failure. The test beams measured 200 mm wide, 300 mm high, and 3100 mm long. Ten, 12, and 16 mm BFRP bars with sand-coated surfaces over helical wrapping were used. The beam specimens were designed in accordance with Annex S of CSA S806-12 and tested under four-point bending over a clear span of 2700 mm until failure. The beam test results are introduced and discussed in terms of cracking behavior, deflection, and failure modes. The test results yielded an average kb of 0.76, which is in agreement with the CSA S6-14 recommendation of 0.8 for sand-coated bars. Moreover, comparing the results to code provisions showed that CSA S806-12 may yield reasonable yet conservative deflection predictions at service load for the beams reinforced with BFRP bars.

Dhand V., Mittal G., Rhee K.Y., Park S., Hui D.

A recent increase in the use of ecofriendly, natural fibers as reinforcement for the fabrication of lightweight, low cost polymer composites can be seen globally. One such material of interest currently being extensively used is basalt fiber, which is cost-effective and offers exceptional properties over glass fibers. The prominent advantages of these composites include high specific mechano-physico-chemical properties, biodegradability, and non-abrasive qualities to name a few. This article presents a short review on basalt fibers used as a reinforcement material for composites and discusses them as an alternative to the use of glass fibers. The paper also discusses the basics of basalt chemistry and its classification. Apart from this, an attempt to showcase the increasing trend in research publications and activity in the area of basalt fibers is also covered. Further sections discuss the improvement in mechanical, thermal and chemical resistant properties achieved for applications in specific industries.

Manylov M.S., Gutnikov S.I., Pokholok K.V., Lazoryak B.I., Lipatov Y.V.

As found by differential thermal analysis, X-ray diffraction and Mossbauer spectroscopy, the heat treatment of basalt glass fibers in air leads to complete iron oxidation and the bulk growth of superparamagnetic magnesioferrite particles which act as nucleation sites for pyroxene crystallization.

Kim J.S., Lim J.H., Huh Y.

In this study, we introduce a new melt-spinning technology for producing basalt fibers on a laboratory scale and provide a dynamic model describing the basalt-fiber spinning process with the thermal effect in terms of an Arrhenius equation. The new trial system for basalt melt-spinning was established, while a microwave furnace was used to melt the quarried basalt rocks. And a susceptor, i.e., silicon carbide (SiC) was applied. A crucible with a one-hole bushing took the role of the spinning block, which was placed in the heating zone. A take-up device controlled by a PC was installed and the take-up speed was varied in order to investigate the fiber drawing effect on the thickness produced. Experimental results demonstrated that this new system is feasible for producing basalt fibers. The theoretical estimate of the fiber diameter profile with the Arrhenius viscosity description along the spinning line agreed well with the measurement. The diameter profile of the basalt fibers decreased with a funnel-shaped profile along the spinning line, while it changed very rapidly near the bushing hole up to the position 15 mm downwards, and then the fiber diameter decreased further up to the position 30 mm. In the remaining spinning zone the diameter reduction was very small. The gravitational effect of the molten basalt in the crucible on the fiber diameter was negligible.

Gutnikov S.I., Manylov M.S., Lipatov Y.V., Lazoryak B.I., Pokholok K.V.

Basalt continuous fibers were treated in H 2 /Ar atmosphere at 650 °С and 700 °C. The 57 Fe Mössbauer spectroscopy indicated that after the treatment at 650 °C all ferric cations reduced to ferrous. Reduction at higher temperature leads to metallic iron formation. DSC and XRD data indicated that crystallization process in reduced basalt fibers carried slower. Glass transition temperature decreases after the reduction due to the increase of amount of ferrous cations, that act as modifiers. Due to Fe 2 + /Fe 3 + ratio changing spinel-like phase crystallization ability decreases. Crystallization in reduced basalt fibers starts at lower temperature. The tensile strength of reduced fibers is higher than the tensile strength of basalt continuous fibers that were annealed at the same condition in air. • Basalt continuous fibers were reduced in H 2 atmosphere. • Due to Fe 2 + /Fe 3 + ratio changing crystallization mechanism changes. • Crystallization process in the reduced basalt fibers carries slower. • The tensile strength loss of the reduced fibers is 40.4%.

Lipatov Y.V., Gutnikov S.I., Manylov M.S., Lazoryak B.I.

We have studied the effect of zirconia additions on the properties of basalt glasses and fibers. The solubility limit of ZrO2 in basalt glasses is determined to be 7.1 wt %. Fibers produced from modified basalt glass contain both tetragonal and monoclinic zirconia. The highest ZrO2 concentration in basalt fibers is 3.1 wt %. We have determined the fiber drawing temperature ranges and assessed the tensile strength and alkali resistance of the fibers. With increasing ZrO2 content, the tensile strength of the fibers (d = 11−12 μm) decreases from 1.8 to 0.6 GPa. The addition of less than 3.1 wt % ZrO2 increases the alkali resistance of the basalt fibers by 37%. The addition of more than 3.1 wt % ZrO2 to the glass batch reduces the alkali resistance and tensilestrength of the basalt fibers.

Zhang Y., Yu C., Chu P.K., Lv F., Zhang C., Ji J., Zhang R., Wang H.

a b s t r a c t Basalt fiber (BF) reinforced poly(butylene succinate) (PBS) composites have been fabricated with different fiber contents by a injection molding method and their tensile, flexural and impact properties, as well as thermal stability have been investigated. The tensile and flexural properties of the PBS matrix resin are improved markedly by increasing the fiber contents in the composites. The values are relatively higher than the natural fiber/PP systems reported earlier by other research groups. The heat deflection temperature (HDT) and Vicat softening temperature (VST) of the composites are significantly higher than those of the neat PBS resin. Scanning electron microscopy (SEM) conducted on the fracture surfaces of the composites reveals superior interfacial linkage between the basalt fibers and PBS matrix. The results suggest that the BF/PBS composites may be a potential candidate of PP or PP composites to manufacturing some daily commodities to solve the white pollution in environmental management.

Ivanitskii S.G., Gorbachev G.F.

Methods for determining the rheological and crystallization properties of basalt melts are considered. The physical properties of basalt melts suitable for the production of continuous fibers are compared with those of E-glass melts. It is established that the shape of the melt stream characterizes the fiber-forming area and depends on the production parameters and melt properties. A mathematical model is proposed to describe heat exchange during slow flow of basalt melt through a short nozzle into air and during its cooling. The longitudinal temperature distribution in both the melt and nozzle wall is calculated for various structural and processing parameters. It is shown that the melt is cooled to the greatest extent at low flow velocities (high viscosity) in longer nozzles with large internal diameter (small wall thickness). The results may be used to calculate temperature of the melt in a free stream flowing out of a nozzle and to optimize the continuous basal fiber technology.

Dou H., Wang Y., Bai J., Kong L., Bai Z., Li H., Guo Z., Li W.

Dou H., Bai J., Lu H., Zhang T., Kong L., Bai Z., Li W.

The low alkali resistance of basalt fiber limits its utilization in the strong alkaline environment such as cement and concrete as the reinforcing material. Adding additive in the basalt rocks is the feasible method to enhance the alkali resistance. However, it is necessary to develop the efficient additive for basalt fiber. In this work, the effect of TiO2 on the preparation condition, alkali resistance and mechanical properties of basalt fiber was investigated. The preparation conditions were studied by DSC, XRD and high-temperature rotational viscometer. Then the corrosion behavior of TiO2-basalt fibers in NaOH solution was studied via SEM/EDX, FIB/SEM and FTIR. The results indicated that the viscosity of basalt melt decreased significantly with the increasing TiO2 content from 0% to 2%, but the crystallization tendency was not changed with TiO2 below 2%, the upper limit for TiO2 addition. The tensile strength increased by 20–60% because Ti4+ promoted Al3+ into the network structure and intensify the polymerization by entering the network structure as network precursor in the form of [TiO4]. Meanwhile, TiO2 in the basalt fibers formed insoluble titanium hydroxide, so the weight loss of TiO2-basalt fibers in NaOH solution was reduced up to 50%. Through FIB/SEM/EDX, the corrosion of basalt fiber in alkali condition is controlled by ion diffusion. The outward diffusion of Fe, Mg and Ti to the surface of fiber formed the insoluble layer, so the rate of substitution reaction between the OH− and basalt fibers was slowed down, but it also leaded to the non-uniform corrosion.

Si J., Wang Z., Li J., Zuo C., Zhang P., Wei C., Wang J., Li W., Miao S.

• Continuous basalt fibers (CBFs) were produced from basalt mixtures. • The dosage of CaO inhibits the crystallization of spinel. • CaO promotes the crystallization of pyroxene and plagioclase. • The spinnability (capability of being spun) was improved. • The tensile strength of CBF was enhanced grealy. The influence of CaO on spinnability (the capability of being spun) of continuous basalt fibers (CBF) and strength property were investigated. The addition of CaO in raw basalts was found to eliminate spinel crystals (magnesioferrite), and to reduce frequency of fiber breaks during the fiber-drawing. The tensile strength of CBF was enhanced by 13% after addition 3% wt. of CaO to the starting materials. Excessive addition of CaO (>5.0%) would result in less spinnability and inferior mechanical strength. The structure of basaltic glass fibers with varying CaO contents was studied by various characterizations. Doping of CaO reduced the degree of fiber polymerization and increased the amount of non-bridging oxygen. Results showed that increase of CaO changes the crystallization behavior of fibers, inhibits the crystallization of spinel, and promotes the crystallization of pyroxene and plagioclase.

Gutnikov S.I., Popov S.S., Efremov V.A., Ma P., Lazoryak B.I.

This paper presents a study of the influence of basalt rocks’ phase composition, acidity modulus, and structural parameter NBO/T on the tensile strength and elastic modulus of basalt continuous fibers (BCFs) derived from them. A series of BCF samples based on 14 different basalt deposits was obtained under equal conditions. The tensile strength and elastic modulus of the BCFs from different deposits vary in the ranges of 1495–3380 MPa and 58.2–78.7 GPa, respectively. Using the original method of quantitative phase analysis based on the Rietveld method, the phase compositions of the 14 deposits were defined. All deposits can be used to obtain BCFs. In the studied natural rocks, the main component is tectosilicates; the mass content of framework aluminosilicates is in the range of 16.5–3.3 mass percent. The second main component is inosilicates; the mass content of chain aluminosilicates is in the range of 6.0–58.0 mass percent. The correlations among phase composition, acidity modulus, ratio of non-bridging oxygens to tetrahedral cations, tensile strength, and elastic modulus of the BCFs from the 14 different basalt deposits were calculated. There were strong positive correlation between tectosilicate minerals mass content and elastic modulus [Pearson correlation coefficient (PCC) of 0.7] and strong negative correlation between content of chain and layered aluminosilicates and elastic modulus (PCC of − 0.74).