【摘要】 玄武岩纤维制备中,出丝漏嘴长度直接关乎纤维能否成型以及拉丝过程稳定性。为探讨制备玄武岩纤维的熔融出丝漏嘴长度对纤维成型的影响,专门设计了漏嘴长度为2 mm、3 mm、4 mm、5 mm、6 mm的五孔坩埚,采用同一玄武岩熔体原料及实验环境条件。拉丝实验显示,所用样品在1 450℃成纤效果最好,3 mm长度的漏嘴最容易稳定成纤,2 mm和4 mm长度的漏嘴可成纤但不稳定,5 mm和6 mm长度的漏嘴成纤较难。基于熔融实验,利用COMSOL Multiphysics建立模型,选择1 450℃进行过程数据模拟分析,模拟结果与实验中呈现的不同漏嘴长度的成纤效果是吻合的;漏嘴长度与熔体流速负相关,3 mm漏嘴出口处熔体流动性好,而2 mm漏嘴的过高流速会降低拉丝稳定性;漏嘴长度与熔体温度负相关,3 mm的漏嘴熔体纵向温度变化较小,易成纤,而4 mm、5 mm、6 mm的漏嘴因散热增强末端温差达14.7～29.6℃,不利于成纤;漏嘴长度与熔体黏度正相关,3 mm漏嘴末端熔体黏度差为3.2 Pa·s,成纤稳定;随着漏嘴长度增加,黏度梯度逐渐增加,成纤稳定性降低;玄武岩熔体黏度与温度负相关。当漏嘴出口处熔体温度为1 379.9℃、流速为1.08×10^-3 m/s、黏度为48.5 Pa·s时,漏嘴长度为3 mm条件下的成纤效果最优。所提出的方法对于玄武岩熔融出丝漏嘴长度参数的优化以及纤维产业化生产工艺参数的调整具有重要参考价值。更多还原

【Abstract】 The successful formation of basalt fibers and the stability of the fiber drawing process are directly governed by the length parameter of the spinneret nozzle.The influence of spinneret nozzle length on basalt fiber formation was systematically investigated through the design of a quintuple-orifice crucible with precisely controlled nozzle dimensions of 2 mm,3 mm,4 mm,5 mm,and 6 mm.Under standardized experimental conditions with consistent basalt melt composition and thermal environment,optimal fiber formation was achieved at 1 450 ℃,wherein the 3 mm nozzle exhibited superior process stability.While continuous filaments were obtainable with 2 mm and 4 mm nozzles,notable process fluctuations were observed.The 5 mm and 6 mm configurations demonstrated compromised fiber-forming capability under equivalent process parameters.The quantitative correlation between spinneret nozzle geometries and fiber formation efficiency was systematically validated through COMSOL Multi physics simulations conducted at 1 450 ℃ melt temperature.Computational results demonstrated precise consistency with experimental observations regarding filament continuity and process stability across varying nozzle lengths.The inverse correlation between nozzle length and melt flow velocity was quantitatively established,wherein optimal fluidity characteristics were attained at the 3 mm configuration,whereas excessive velocity gradients induced by the 2 mm nozzle were identified as detrimental to fiber drawing stability.Concurrently,longitudinal thermal gradients within the melt were demonstrated to be inversely governed by nozzle length,with the 3 mm variant exhibiting minimal temperature variation along the flow path,thus enabling continuous fiber formation.By contrast,terminal temperature differentials ranging from 14.7 ℃ to 29.6 ℃ were recorded in 4—6 mm nozzles due to intensified convective heat dissipation,resulting in compromised fiber-forming continuity.A positive correlation between spinneret nozzle length and melt viscosity was established through characterization,with the 3 mm configuration exhibiting an optimal terminal viscosity differential of 3.2 Pa·s that ensured stable fiber formation.Progressive destabilization of the fiberization process was observed as the nozzle length increased,attributable to amplified viscosity gradient magnitudes within the melt flow field.An inverse correlation between basaltic melt viscosity and temperature was established.Optimal fiber formation efficiency was demonstrated under standardized conditions of 1 379.9 ℃ melt temperature,1.08×10^-3 m/s flow velocity,and 48.5 Pa·s viscosity at the spinneret orifice,achieving superior process stability with the 3 mm nozzle configuration.The established methodology was validated as providing a critical optimization framework for spinneret nozzle length parameters and industrial fiber production process adjustments in basaltic melt fiberization systems.更多还原