降低浮法玻璃下表面渗锡量的体会

浮法玻璃在锡槽复杂的气液固多相系统中成形,不可避免受到锡的污染,若玻璃下表面渗锡超标,在热处理会时因晶格膨胀而产生钢化虹彩,本文分析、列举了一些针对性措施,以减少锡液污染和锡离子的扩散,从而降低了玻璃下表渗锡量。     

锗对浮法玻璃下表面离子扩散影响的研究

利用浮法玻璃锡槽模拟装置,研究在锡槽中添加锗元素对玻璃下表面离子扩散的影响.通过X射线能谱仪(EDS)、X射线光电子能谱(XPS)测试手段对所得玻璃样品表面进行分析.结果表明:当锡液中添加0.02％锗元素时,玻璃样品下表面渗锡量与纯锡液上所得到的玻璃样品的渗锡量相比,降低3.74％.同时发现,渗入玻璃表面的锗主要以Ge4+为主.     

二氧化硫气体在浮法线中的应用研究

对浮法玻璃样品进行了在高温SO2气氛下的实际现场条件实验,采用X射线荧光光谱仪(XRF)和微区X射线能谱仪(SEM-EDS)分别测量了浮法玻璃下表面的渗锡量及沿深度方向上的渗锡分布.还对锡槽窗口沉积物进行了X射线衍射(XRD)分析,研究表明:浮法玻璃在二氧化硫的气氛中保持不同时间以后,下表面锡含量没有明显的变化:锡槽内已被二氧化硫气体污染.     

浮法玻璃下表面渗锡分布特点成因及渗锡量测量探讨

我国浮法玻璃的外观质量已与国外先进水平相接近,浮法玻璃下表面渗锡引起的深加工玻璃产品的“虹彩”缺陷是我国几家主要浮法玻璃生产厂产品的最突出的缺陷。本文简要介绍了运用SEM、EDS和我院自行研制的FS-100型渗锡测定仪等手段对国内外浮法玻璃样品的渗锡分布分析、渗锡量的测试及结果,讨论了由于各浮法玻璃厂生产工艺上的差别引起的渗锡分布不同以及某些工况条件对渗锡量的影响。     

浮法玻璃渗锡问题分析及相应措施

浮法玻璃渗锡问题严重限制了我国浮法玻璃在玻璃深加工领域中的应用和发展。通过分析热加工虹彩现象和离子强化玻璃翘曲现象及浮法生产工艺中渗锡影响因素和测试方法,提出了监控锡槽内气体和锡槽密封性的必要性以及准确及时有效测试渗锡量和渗锡分布的重要性。     

渗锡量的定性检测及降低玻璃表面渗锡量的措施研究

浮法工艺生产平板玻璃,由于玻璃在锡槽内成形,玻璃下表面必然会引入一定的渗锡量,当渗锡量达到一定程度时,如果玻璃进行钢化加工,就会出现钢化彩虹,从而影响到玻璃的外观质量.分析了浮法玻璃钢化彩虹的形成与渗锡量的关系,提出了浮法玻璃生产中渗锡量的定性快速检测方法,可以避免玻璃在后续加工中造成损失;论述了降低玻璃渗锡量的措施,可用于指导浮法玻璃生产.     

锡对超薄浮法玻璃热膨胀系数和黏度的影响研究

渗锡会造成浮法玻璃锡面和空气面成分、硬度等结构以及物理或化学性质有所区别.通过模拟实测浮法玻璃表面成分差异,熔制不同渗锡量的浮法玻璃样品,并对其进行高温热膨胀系数及黏度的测试分析,结果表明:渗锡对浮法玻璃的高温热膨胀系数及高温黏度会有所影响,并且随着SnO2含量的增加,浮法玻璃的热膨胀系数变小,其绝对膨胀量也变小,其黏度则变大.     

边界锡浓度的计算方法

说明了浮法玻璃在钢化过程中是否出现虹彩取决于涉锡面上边界锡浓度的达到大小,介绍了边界锡浓度与单位涉锡面上总含锡量的函数关系,解决了从化验室测得的单位涉锡面上总锡量直接换算成边界锡浓度的问题,使判断抗虹彩特性的依据成为可能.     

热处理对浮法玻璃和Low-E玻璃表面组成的影响

采用X射线光电子能谱(XPS)研究了不同热处理后浮法玻璃和单银Low-E玻璃的表面化学组成.结果表明,钢化、真空退火、钢化+真空退火都能增加浮法玻璃中Na+向表面的扩散,真空退火能使表面富集的Na+挥发;热处理能使未镀膜面的Na+挥发到膜面.真空退火和先钢化再真空退火处理样品表面锡的相对含量高于钢化处理样品.热处理使Low-E镀膜玻璃的表面层Si和SiNx复合膜层氧化,形成SiNx Oy/SiOx复合膜层,能提高Low-E玻璃的可见光透过率.     

平板玻璃表面渗锡量测试方法的研究

浮法玻璃表面渗锡含量的高低,直接影响玻璃的再加工质量,本文通过对浮法玻璃表面渗锡量测试技术的分析、研究,确定了渗锡量的两种测试方法。     

降温速率对浮法硼硅酸盐玻璃下表面渗锡的影响

研究锡槽中降温速率对浮法硼硅酸盐玻璃下表面渗锡的影响.采用不同降温速率制备浮法硼硅酸盐玻璃,用电子探针测试浮法硼硅酸盐玻璃在1 250～650℃温度范围内不同降温速率情况下表面渗锡分布情况.研究结果表明:浮法成形过程中硼硅酸盐玻璃渗锡的深度可达到40.0μm左右,并且在1 050℃以上的高温段锡离子以深度方向扩散为主,在1 050℃以下的低温阶段锡离子主要在玻璃的近表面富集.随着时间的延长浮法硼硅酸盐玻璃近表面的渗锡量增加,而深度大于7.0μm以上的内部的渗锡量不会由于时间的延长而累加,只与温度有关.在浮法成形过程中渗锡曲线会在1 050℃左右,距玻璃表面15.0μm处出现卫星峰,但最终在低温时该卫星峰会由于逆扩散而消失.     

锡槽中的化学反应及其对浮法玻璃质量的影响

在锡槽内,玻璃液、锡液和保护气体构成一个多相体系,各相界面都进行着复杂的氧化、还原反应.在浮法工艺条件下,钠钙硅玻璃熔体和纯锡液接触时,会产生多相反应.溶解在锡液中的钠和氧在锡液/耐火材料界面处析出Na2O,进而与槽底砖反应而使槽底砖破坏.氧化锡、氧化亚锡、硫化亚锡等锡的化合物是对玻璃质量产生影响的几种主要化合物.浮法玻璃所特有的几种缺陷-"钢化彩虹"、"沾锡"、"斑点"和"小波纹"都是锡及锡化合物参与反应的结果.     

Biaxial Flexure Strength and Dynamic Fatigue of Soda–Lime–Silica Float Glass

The strength and dynamic fatigue behavior of float glass was investigated using biaxial flexure tests. The samples were tested using the ring-on-ring (ROR) biaxial flexure test geometry, and the data analyzed using a conventional two-parameter Weibull distribution. The as-received samples revealed that the air side exhibits a higher characteristic strength (243 MPa) compared with the tin side (114 MPa); fractographic analysis confirmed the presence of significantly larger flaws on the tin side of the specimens, presumably due to contact damage by the rollers in the float glass process. Dynamic fatigue results for as-received and indented samples were performed to assess whether differences in the stress corrosion behavior of float glass exist because of tin penetration. No statistical difference in the stress corrosion exponent was found between the air ( n = 21.7) and tin ( n = 21.6) sides of the float glass. This indicates either that the tin penetration (which extends ∼25 μm) plays no role in altering the stress corrosion susceptibility of float glasses because the native flaw size is larger than the tin penetration depth or that the tests do not have the required sensitivity to distinguish the effect of the tin. Alternative test methods for direct observation of slow crack growth in tin-doped bulk glasses are planned to investigate this in the future.     

Al2O3含量对无碱铝硼硅玻璃网络结构的影响

采用高温熔融法制备了不同氧化铝含量的SiO_2-Al_2O_3-B_2O_3-MO(M=Mg²⁺、Ca²⁺、Sr²⁺)系统无碱铝硼硅酸盐玻璃。通过X光电子能谱(XPS)和红外光谱(FTIR)对玻璃样品进行了结构分析,并对其性能进行检测。结果表明,在铝硼硅酸盐玻璃中,随着氧化铝含量的增加,更多的铝离子与游离氧参与组成玻璃网络结构的形成,与此同时,碱土金属离子进入玻璃网络空隙,导致玻璃的介电性能和密度改变,介电常数在氧化铝含量(摩尔分数)为11.4%附近出现极大值。玻璃中的游离氧或是形成[AlO_4]进入玻璃网络或是与铝离子形成[AlO_6],数量不断减少。随着氧化铝含量的增加,密度和硬度的变化趋势为先增大后减小,且均在氧化铝含量(摩尔分数)11.6%和12.2%时出现了极大值。     

Control of the near-surface OH concentration of float glass by anodic proton injection

Controlling the OH concentration near the float glass surface was investigated via anodic proton injection into a glass melt under conditions simulating the float glass process. A DC voltage of 1-4 V was applied to the glass at 1000°C between the molten tin as an anode and graphite placed on the glass as a cathode. Although the OH concentration of the glass near the glass/tin interface was controlled to the same level as that in the interior of the glass when a DC voltage of 3 V was applied, the decrease in Na concentration, one order of magnitude greater than the amount of injected protons, was observed around the glass/tin interface. Therefore, the OH concentration by dehydration cannot be restored using anodic proton injection without substantial composition change. Tin was observed to be electrochemically injected into the glass when a DC voltage of >4 V was applied, and majority of the injected protons were released from the glass under the experimental conditions. Finally, the conditions that achieved an OH concentration near the glass/tin interface matching with that in the interior of the glass without substantial composition change around the anode are discussed and proposed.     

Effect of Enameling on the Strength and Dynamic Fatigue of Soda–Lime–Silica Float Glass

The effect of a glass enamel coating on the strength and fatigue behavior of float glass was investigated. Commercially available enamel that was comprised of Cu₂Cr₂O₄ pigment particles in a bismuth-zinc borosilicate glass matrix was applied to a soda–lime–silica float glass via screen printing, followed by fusion at elevated temperature. Strengths of the enameled specimens were evaluated in biaxial flexure using a ring-on-ring (ROR) test geometry, and the data were analyzed using a conventional two-parameter Weibull distribution. Enameling was found to significantly degrade the strength of the float glass. There was no statistical difference in the characteristic strengths of samples enameled on the air side (66 MPa) compared with samples enameled on the tin side (61 MPa) of the float glass. Fractographic analysis revealed that the failures in the enameled float glass samples initiated at pores and pigment aggregates in the enamel, whereas failures in float glass samples initiated solely from surface flaws. Dynamic fatigue tests were performed on enameled float glass and indented float glass samples to determine the effect of the enamel on the stress corrosion behavior of the enameled components. There was no statistically significant difference between the stress corrosion exponents for the float glass and enameled float glass specimens.     

浮法锡槽入口段玻璃液流动过程模拟分析

针对浮法玻璃成形过程,提出了锡槽入口段简化稳态多相模型,并采用Ansys Fluent 2019 R3软件,模拟研究了500 t/d锡槽入口段玻璃液的流动与成形过程,分析了拉引量、玻璃液黏度对唇砖与八字砖区玻璃液流动与液层厚度分布的影响。结果表明,拉引量过小或黏度过低时液层出现不连续,拉引量过大或黏度过高时液层横向厚度均匀性变差,案例锡槽实现浮法玻璃均匀稳定成形的工艺操作范围是拉引量400~550 t/d,黏度400~600 Pa·s。