Float Glass Production
玻璃英文名
1、浮法玻璃（Float Glass）颜色：透明；茶色；绿色；蓝色。
Color: clear; bronze; jade green; dark blue厚度：3mm—19mm(透明)Thickness: 3mm—19mm(clear)2、平板玻璃（Sheet Glass）:颜色：透明；茶色。
Color: clear; bronze厚度：1.8mm—5mm(透明)Thickness: 1.8mm—5mm(clear)3、安全玻璃（Safety Glass）:钢化玻璃(toughened/tempered glass)夹层玻璃(laminated glass)汽车玻璃(vehicle glass)中空玻璃(insulated/hollow glass)防弹玻璃(anti-shooting glass)防火玻璃(fire blocking glass)4、加工玻璃（Processed Glass）各种磨边、钻孔、刻花、异形玻璃等。
Edged polished glass, glass grooving, hole boring,Irregular shaped glass, etc.喷砂玻璃、磨沙玻璃、防眩玻璃、蒙砂玻璃等。
Sand blasted glass, obscured glass, non-glare glass, Misty glass, etc..5、镀膜玻璃(Coated Glass)在线镀膜、离线镀膜、ITO膜、LCD玻璃、LED玻璃等。
Hard coating, soft coating, ITO coating, LCD glass, LED glass6、镜片(Mirror)平板铝镜、浮法铝镜、镀银镜、汽车倒视镜。
Sheet glass mirror, float glass mirror, silvered mirror and car mirrors.7、其他玻璃产品( Other Glass Products)压花玻璃、冰花玻璃、玻璃砖、玻璃球。
调整超白浮法玻璃板下沾锡的生产实践
调整超白浮法玻璃板下沾锡的生产实践潘弘I郝元涛彳王涛I田华彳孙钢I（1.金晶科技股份有限公司淄博255086；2.滕州金晶玻璃有限公司滕州277500）摘要浮法玻璃生产中沾锡现象普遍存在，表现为锡及其氧化物对玻璃板下表面的污染、沾附，呈片（点）状或条状，是影响玻璃质量的一个重要因素，直接造成生产中无效作业时间的增加。
特别是近几年，随着人们对生活品质、环保节能意识的提高，离线镀膜、深加工企业对浮法玻璃原片下表面质量提岀更高的要求。
通过对生产高档浮法玻璃中岀现的板面下表面沾锡缺陷形成原因的分析，找岀解决措施。
关键词锡缺陷；渗锡；保护气氛；治理措施中图分类号：TQ171文献标识码：A文章编号：1003-1987（2021）03-0034-05Adjust the Tin Pick Up for the Ultra Clear GlassPAN Hong1,HAO Yuantao2,WANG Tao1,TIAN Hua2,SUN Gang1(1.Jinjing Technology Co.,Ltd.,Zibo255086,China；2.Tengzhou.Jinjing glass Co.,Ltd.,Tengzhou277500,China)Abstract:Tin pick up is a common phenomeon in float glass production,which is shown as the contamination and adhension of tin and its oxides to the bottom of the glass ribbon,in the form of the sheet or strip.Which is an important factor affecting the quality of glass and directly causes the increase of invalid operation time in the production.Especially in the recent years,with the imporvement of people5sawareness of life quality,environmental protection and energy saving,offline coating and deep porcessing enterprises have put forward higher requirements for the surface quality of float glass.Based on the analysis of the cause of the tin pick up defect on the bottom surface ofthe gall in the production ofhigh qualit float glass,the contermeasures are found out.Key Words:tin defect,permeability of tin,proctecing the atmosphere,control measures0引言浮法玻璃的生产在锡槽内完成成形作业，在成形过程中由于浮托介质锡液受到污染而使玻璃产生了与锡有关的缺陷，俗称锡缺陷。
玻璃种类的特性和用途
玻璃种类的特性和用途玻璃是一种无机非晶体材料，由石英砂、硼砂、石灰石和纯碱等原料经过高温熔化后，再经冷却而得。
它具有硬度高、透明、无色、耐高温、抗酸碱腐蚀、电绝缘性好等特点，因此在各个领域都有广泛的应用。
根据其成分和用途，玻璃可以分为多种不同类型。
下面简要介绍几种常见的玻璃种类及其特点和用途：1.平板玻璃（Float Glass）：平板玻璃是最常见的一种玻璃，以其表面光滑平整，透明度高等特点在建筑和家居装饰领域广泛应用。
平板玻璃还可以通过加工处理，如热弯、热割、冷弯、打孔、磨剪等工艺，以满足不同的设计需求。
2.透明玻璃（Transparent Glass）：透明玻璃具有较高的可见光透过率，可广泛应用于窗户、镜片、玻璃器皿等领域。
透明玻璃的制备主要通过控制原料和生产工艺，减小杂质含量来实现。
3.防弹玻璃（Bulletproof Glass）：防弹玻璃是一种特殊的玻璃，经过复合处理和强化改性后，具有较高的抗弹性能。
它能够阻挡子弹、爆炸和碎片，广泛应用于银行、政府建筑、机场、车辆等安保领域。
4.夹层玻璃（Laminated Glass）：夹层玻璃是由两层外层玻璃中间夹一层聚合物薄膜而形成的，它具有较好的抗冲击性和防火性能。
夹层玻璃不会破碎成尖锐的碎片，被广泛应用于汽车、建筑物的门窗、室内隔断等领域。
5.钢化玻璃（Tempered Glass）：钢化玻璃是通过热处理使玻璃表面形成压缩应力，从而提高其强度和抗冲击性能。
钢化玻璃破碎时会变成较小的无尖锐角的颗粒，从而减少了对人体的伤害。
因此，在建筑、家电、汽车等领域广泛使用。
6.隔热玻璃（Insulated Glass）：隔热玻璃是由两层或多层玻璃之间加入空气或真空层而形成的，以提高保温性能。
隔热玻璃可以降低室内与室外的热传导和空气对流，实现节能的效果，被广泛应用于建筑领域。
7.特种玻璃：特种玻璃是指经过特殊处理的玻璃种类，如荧光玻璃、光纤玻璃、耐高温玻璃等。
浮法玻璃气泡的产生与控制
２６１ 气泡的形状直径在０．３￣２ｍｍ的气泡，肉眼很容易看到，在偏光显微镜下观察泡壁上或泡内有的油花状的小液滴，有的泡壁周围有微粒杂质，有的泡内不清亮，如图１￣４所示。
浮法玻璃气泡的产生与控制解丽丽张艳华（德州晶华集团振华有限公司德州市２５３００７）摘要关键词中图分类号：ＴＱ１７１文献标识码：Ａ文章编号：１００３－１９８７（２０１１）１０－００－０气泡是浮法玻璃的主要缺陷之一，在浮法玻璃生产中，除退火以外，其他任何一个小环节的不稳定，都有可能产生气泡。
总结气泡规律，利用岩相分析准确快速判断气泡来源，采取措施，尽快提高玻璃产量质量，成为生产过程中的一个重要课题。
气泡成因措施２６４图１图２图３图４根据形成部位的不同，温度高一些的部位生成的气泡，进入玻璃液可能深一些，温度低一些的部位进入玻璃液浅一些，一般在玻璃板１／３靠上的位２７置。
从形状上看，受生产玻璃厚度的影响也有所不同，玻璃越厚，越接近圆形，反之，椭圆的直径越长。
也就是生产薄板时大部分被拉成长长的椭圆形。
以上气泡，如图３、图４无可争议均认为是芒硝泡，对图１和图２，目前，业内人士尚无统一的概念。
有人称此类气泡为Ｓ泡，还有人称其为挥发滴落物气泡，还有称其为过还原泡，也有人统称芒硝泡，但无论名称如何，以采取措施将气泡得到彻底有效控制为主。
根据资料显示，浮法玻璃配合料中，气体比为１５％～２０％。
气体比过大，熔制时形成过多的泡沫，不仅延长澄清时间，气泡也难以消除。
但气体比过小则气泡对玻璃液的翻动无力，气泡也难消除。
因此要严格控制各种原料的粒度，避免超细粉太多，控制配合料的水分。
碎玻璃的加入，有助于熔化和澄清。
随着浮法玻璃生产技术水平的不断提高，成品率大大提高，回头的碎玻璃量比较少，因此外购碎玻璃的加入量也在逐渐增多。
对熔化质量要求高的厂家，碎玻璃比例一般在１８％￣２０％。
这就给碎玻璃的质量提出了更高的要求，挑拣质量有时就制约着浮法玻璃质量的稳定与提高。
碎玻璃液中混入木块、锯末、纸团、橡胶、生活垃圾类等污染物或细粉过多，则碎玻璃会导致配合料氧化还原势的改变，容易产生气泡。
浮法玻璃生产成套装备通用技术要求
ICS91.110Q 93中华人民共和国国家标准GB/T XXXXX—XXXX浮法玻璃生产成套装备通用技术要求General technical requirement for complete set of float glass production equipment添加与国际标准一致性程度的标识（征求意见稿）在提交反馈意见时，请将您知道的相关专利连同支持性文件一并附上XXXX-XX-XX发布XXXX-XX-XX实施前言本标准按照GB/T 1.1—2009给出的规则起草。
请注意本标准的某些内容有可能涉及专利，本标准的发布机构不承担识别这些专利的责任。
本标准由中国建筑材料联合会提出。
本标准由全国建材装备标准化技术委员会（SAC/TC465）归口。
本标准负责起草单位：中国建材国际工程集团有限公司、本标准主要起草人：浮法玻璃生产成套装备通用技术要求1 范围本标准规定了浮法玻璃生产成套装备的构成、技术要求、安全环保要求、安装和试车、性能测试及交货文件。
本标准适用于浮法玻璃生产成套装备的技术要求。
2 规范性引用文件下列文件对于本文件的应用是必不可少的。
凡是注日期的引用文件，仅所注日期的版本适用于本文件。
凡是不注日期的引用文件，其最新版本（包括所有的修改单）适用于本文件。
GB/T 1234-2012 高电阻电热合金GB 2894 安全标志及其使用导则GB 5083 生产设备安全卫生设计总则GB/T 7932 气动对系统及其元件的一般规则和安全要求GB/T 8196 机械设备防护罩安全标准GB/T 10595 带式输送机GB 11614-2009 平板玻璃GB/T 14048.1 低压开关设备和控制设备第1部分：总则的要求GB 16754 机械安全急停设计原则GB/T 17888.2-2008 机械安全进入机器和工业设备的固定设施第2部分:工作平台和通道GB 18613-2012 中小型三相异步电动机能效限定值及能效等GB/T 18831 机械安全与护装置相关的联锁装置设计和选择原则GB/T 19670 机械安全防止意外启动GB/T 20641 低压成套开关设备和控制设备空壳体的一般要求GB/T 25295 电气设备安全设计导则GB/T 26336 工业通信网络工业环境中的通信网络安装GB/T 35076 机械安全生产设备安全通则GB/T 36054 浮法玻璃拉边机GB/T 50087 工业企业噪声控制设计规范GB 50435-2016 平板玻璃工厂设计规范GB 50559 平板玻璃工厂环境保护设施设计标准GB/T 50561-2010 建材工业设备安装工程施工及验收规范JB/T 3926 垂直斗式提升机JB/T 7679 螺旋输送机JC/T 532 建材机械钢焊接件通用技术条件JC/T 604 浮法玻璃退火窑3 浮法玻璃生产成套装备构成浮法玻璃生产成套装备由原料系统设备、熔化系统设备、成形系统设备、退火系统设备、冷端系统设备等构成。
浮法玻璃生产中流道处产生气泡原因及应对措施
浮法玻璃生产中流道处产生气泡原因及应对措施田文龙胡会民崔裕栋（海南中航特玻材料有限公司海口571924）摘要在浮法玻璃生产中，气泡类的缺陷占比很高，影响玻璃产品质量和成品率。
随着窑龄的增长，耐火材料的侵蚀加重，类似的气泡类缺陷逐渐突出，特别是在流道附近产生的气泡尤为突出。
结合某公司实际生产状况，简要分析了流道处气泡产生的原因，给出了应对解决方法。
关键词浮法玻璃；流道；气泡；缺陷中图分类号：TQ171文献标识码：A文章编号：1003-1987（2021）03-0039-05Causes and Countermeasures of Bubble from Spout in Float Glass ProductionTIAN Wenlong,HU Huimin,CUI Yudong(AVIC Hainan Special Glass Material Co.,Ltd.,Haikou571924,China)Abstract:In float glass production process,the proportion of bubble type defect is very high,which affects the quality and yield of glass products.With the increase of the furnace service life,the erosion of refractory material is aggravated,and the bubble defects are gradually prominent,especially the bubbles occurred near the bined with the actual production states of a company,the causes of bubbles in the spout are briefly analyzed,and the solutions are recommended.Key Words:float glass,spout,bubble,defect0引言在浮法玻璃生产线上，流道是连接熔窑与锡槽的重要部位，由流道底砖，流道垫砖，流道侧壁砖组成，见图1。
浮法玻璃气泡的产生与控制
Ｇｅｎｅｒａｔｉｏｎ ａｎｄ Ｃｏｎｔｒｏｌ ｏｆ Ｂｕｂｂｌｅ ｉｎ Ｆｌｏａｔ Ｇｌａｓｓ
Ｘｉｅ Ｌｉｌｉ Ｚｈａｎｇ Ｙａｎｈｕａ
Ｚｈｅｎｈｕａ Ｃｏ．，Ｌｔｄ ｏｆ Ｓｈａｎｄｏｎｇ Ｄｅｚｈｏｕ Ｊｉｎｇｈｕａ Ｇｒｏｕｐ Ｄｅｚｈｏｕ Ｓｈａｎｄｏｎｇ ２５３００７
玻璃工艺学 中讲 的气氛包括两个方面 ，即配合 气 氛 和熔制 气 氛 。前 者是 在 配方设计 时需要 考量 的 因素 ，如氧 化剂 或还 原剂 的引 入 ，目的是 为 了完成 熔 制时配合料内部的氧化 一还原过程 ；后者是在熔制 过程 中通 过相关 参数 （一次 风 、二 次风 及炉 压等 ）改 善 火焰 燃烧 状态 来实 现熔 制气 氛 的调整 ， 目的是通 过 炉气 完成 高温 熔体 表 面的还 原过 程 。这两类 气 氛 在 熔 制 过 程 中进 行 ，即可 大 大 降低 硝 水 产 生 的 几 率。但是 ，过度的还原性熔制不但会产生色道 ，还会 导致硫 化 物 内部 反应 产生 气 泡等新 的熔 体缺 陷 。
４．２考量 熔 制气氛 的调 整
温度越高 、时间越长 ，硫酸盐分解就越彻底 ，硝水产 生的几率就越低。但在制定熔制制度时 ，要充分考 虑 窑炉性 能 、成 形 工艺 及配 方设计 时辅 助 原料 的使 用 方案 等 因素 ，确 保制 定 出的熔 制工 艺能 符合 预期 要求 一无 硝水 泡 的高 品质熔 体 。
配合料 内部 在熔 化时 的还 原过程 、还原性 气氛 从 熔体 表 面的作 用及熔 化 温度 三者 的有机 结合 和完 美进行 ，也可以使高含率的硫酸盐配合料熔制出无 硝 水 的优质 熔体 。
ｉ０
嘲嗣■·····—·■·－ ２０１１．￣ｌｌｌ ５，ቤተ መጻሕፍቲ ባይዱ
浮法玻璃float glass
From Wikipedia, the free encyclopediaFloat GlassFloat glass is a sheet of glass made by floating molten glass on a bed of molten metal, typically tin, although lead and various low melting point alloys were used in the past. This method gives the sheet uniform thickness and very flat surfaces. Modern windows are made from float glass. Most float glass is soda-lime glass, but relatively minor quantities of specialty borosilicate[1] and flat panel display glass are also produced using the float glass process.[2] The float glass process is also known as the Pilkington process, named after the British glass manufacturer Pilkington, which pioneered the technique (invented by Sir Alastair Pilkington) in the 1950s./**/History Until the 16th century, window glass or flat glass was generally cut from large discs (or rondels) of crown glass(冕牌玻璃). Larger sheets of glass were made by blowing large cylinders which were cut open and flattened, then cut into panes. Most window glass in the early 19th century was made using the cylinder method(柱状法). The 'cylinders' were 6 to 8 feet (1.8 to 2.4 m) long and 10 to 14 inches (250 to 360 mm) in diameter, limiting the width that panes of glass could be cut, and resulting in windows divided by transoms(横梁) into rectangular panels(矩形面板).The first advances in automating glass manufacturing were patented in1848 by Henry Bessemer, an English engineer. His system produced a continuous ribbon(带) of flat glass by forming the ribbon between rollers. This was an expensive process, as the surfaces of the glass needed polishing. If the glass could be set on a perfectly smooth body this would reduce costs considerably. Attempts were made to form flat glass on a molten tin bath, notably in the US. Several patents were granted, but this process was unworkable.Before the development of float glass, larger sheets of plate glass were made by casting a large puddle of glass on an iron surface, and then polishing both sides, a costly process. From the early 1920s, a continuous ribbon of plate glass was passed through a lengthy series of inline grinders(联机磨床) and polishers, reducing glass losses and cost.Glass of lower quality, sheet glass, was made by drawing upwards from a pool of molten glass a thin sheet, held at the edges by rollers. As it cooled the rising sheet stiffened and could then be cut. The two surfaces were not as smooth or uniform, and of lower quality than those of float glass. This process continued in use for many years after the development of float glass.Between 1953 and 1957, Sir Alastair Pilkington and Kenneth Bickerstaff of the UK's Pilkington Brothers developed the first successful commercial application for forming a continuous ribbon of glass using a molten tin bath on which the molten glass flows unhindered under theinfluence of gravity.[3]The success of this process lay in the careful balance of the volume of glass fed onto the bath, where it was flattened by its own weight.[4]Full scale profitable sales of float glass were first achieved in 1960.Manufacture Float glass uses common glass-making raw materials, typically consisting of sand, soda ash (sodium carbonate), dolomite, limestone, and salt cake (sodium sulfate) etc. Other materials may be used as colourants, refining agents(澄清剂) or to adjust the physical and chemical properties of the glass. The raw materials are 【A】mixed in a batch mixing process, then fed together with suitable cullet (waste glass), in a controlled ratio, 【B】into a furnace where it is heated to approximately 1500°C. Common flat glass furnaces are 9 m wide, 45 m long, and contain more than 1200 tons of glass. Once molten, the temperature of the glass is stabilised to approximately 1200°C to ensure a homogeneous specific gravity.【C】The molten glass is fed into a "tin bath", a bath of molten tin (about 3–4 m wide, 50 m long, 6 cm deep), from a delivery canal and is poured into the tin bath by a ceramic lip known as the spout lip（喷口）.[5] The amount of glass allowed to pour onto the molten tin is controlled by a gate called a Tweel（流道控制闸门）.Tin is suitable for the float glass process because【1】it has a high specific gravity, 【2】is cohesive, and 【3】immiscible（不相溶的）into the molten glass. Tin, however, oxidises in a natural atmosphere to form Tin dioxide (SnO2). Known in the production process as dross（结瘤）, the tin dioxide adheres to the glass. To prevent oxidation, the tin bath is provided with a positive pressure protective atmosphere consisting of a mixture of nitrogen and hydrogen.The glass flows onto the tin surface forming a floating ribbon with perfectly smooth surfaces on both sides and an even thickness. As the glass flows along the tin bath, the temperature is gradually reduced from 1100°C until【D】the sheet can be lifted from the tin onto rollers （辊筒）at approximately 600°C. The glass ribbon is pulled off the bath by rollers at a controlled speed. Variation in the flow speed and roller speed enables glass sheets of varying thickness to be formed. Top rollers positioned above the molten tin may be used to control both the thickness and the width of the glass ribbon.Once off the bath, 【E】the glass sheet passes through a lehr kiln（退火炉）for approximately 100 m, where it is further cooled gradually so that it anneals without strain and does not crack from the change in temperature. On exiting the "cold end" of the kiln, 【F】the glass is cut by machines.Market As of 2009, the world float glass market, not including China and Russia, is dominated by the four companies: Asahi Glass（旭硝子,日本）, NSG（核供应国）/Pilkington, Saint-Gobain（神戈班）, and GuardianIndustries（守护者）. Other companies include Sise Cam AS, PPG, Central Glass, Hankuk, Zeledyne, and Cardinal Glass Industries.[6]Glass batch calculationGlass batch calculation(玻璃配料计算) or glass batching is used to determine the correct mix of raw materials (batch) for a glass melt. Principle The raw materials mixture for glass melting is termed "batch". The batch must be measured properly to achieve a given, desired glass formulation. This batch calculation is based on the common linear regression equation:with N B and N G being the molarities 1-column matrices（摩尔分数单列矩阵）of the batch and glass components respectively, and B being the batching matrix.[1][2][3] The symbol "T" stands for the matrix transpose operation, "-1" indicates matrix inversion, and the sign "·" means the scalar product（数积）. From the molarities matrices N, percentages by weight (wt%) can easily be derived using the appropriate molar masses.Example calculation An example batch calculation may be demonstrated here. The desired glass composition in wt% is: 67 SiO2, 12 Na2O, 10 CaO, 5 Al2O3, 1 K2O, 2 MgO, 3 B2O3, and as raw materials are used sand, trona（天然碱）, lime, albite（钠长石）, orthoclase（正长石）,dolomite（白云石）, and borax. The formulas and molar masses of the glass and batch components are listed in the following table:The batching matrix B indicates the relation of the molarity in the batch (columns，列) and in the glass (rows，行). For example, the batch component SiO2 adds 1 mol SiO2 to the glass, therefore, the intersection of the first column and row shows "1". Trona adds 1.5 mol Na2O to the glass; albite adds 6 mol SiO2, 1 mol Na2O, and 1 mol Al2O3, and so on. For the example given above, the complete batching matrix is listed below. The molarity matrix N G of the glass is simply determined by dividing the desired wt% concentrations by the appropriate molar masses, e.g., for SiO2 67/60.0843 = 1.1151.The resulting molarity matrix of the batch, N B, is given here. After multiplication（乘法）with the appropriate molar masses of the batch ingredients one obtains the batch mass fraction matrix M B:orThe matrix M B, normalized（归一化）to sum up to 100% as seen above, contains the final batch composition in wt%: 39.216 sand, 16.012 trona, 10.242 lime, 16.022 albite, 4.699 orthoclase, 7.276 dolomite, 6.533 borax. If this batch is melted to a glass, the desired composition given above is obtained.[4] During glass melting, carbon dioxide (from trona, lime, dolomite) and water (from trona, borax) evaporate.Another simple glass batch calculation can be found at the website of the University of Washington.[5]Advanced batch calculation by optimization If the number of glass and batch components is not equal, if it is impossible to exactly obtain the desired glass composition using the selected batch ingredients, or if the matrix equation is not soluble for other reasons (e.g., correlation), the batch composition must be determined by optimization techniques.Calculation of glass propertiesThe calculation of glass properties allows "fine-tuning"（微调）of desired material characteristics, e.g., the refractive index.[1]The calculation of glass properties (glass modeling) is used to predict glass properties of interest or glass behavior under certain conditions (e.g., during production) without experimental investigation, based on past data and experience, with the intention to save time, material, financial, and environmental resources, or to gain scientific insight. It was first practised at the end of the 19th century by A. Winkelmann and O. Schott. The combination of several glass models together with other relevant functions can be used for optimization and six sigma procedures. In the form of statistical analysis（统计分析）glass modeling can aid withaccreditation（鉴定）of new data, experimental procedures, and measurement institutions (glass laboratories).History Historically, the calculation of glass properties is directly related to the founding of glass science. At the end of the 19th century the physicist Ernst Abbe developed equations that allow calculating the design of optimized optical microscopes in Jena, Germany, stimulated by co-operation with the optical workshop of Carl Zeiss. Before ErnstAbbe's time the building of microscopes was mainly a work of art and experienced craftsmanship, resulting in very expensive optical microscopes with variable quality. Now Ernst Abbe knew exactly how to construct an excellent microscope, but unfortunately, the required lenses （透镜）and prisms（棱镜）with specific ratios of refractive index and dispersion（色散）did not exist. Ernst Abbe was not able to find answers to his needs from glass artists and engineers; glass making was not based on science at this time.[2]In 1879 the young glass engineer Otto Schott sent Abbe glass samples with a special composition (lithium silicate glass) that he had prepared himself and that he hoped to show special optical properties. Following measurements by Ernst Abbe, Schott's glass samples did not have the desired properties, and they were also not as homogeneous as desired. Nevertheless, Ernst Abbe invited Otto Schott to work on the problemfurther and to evaluate all possible glass components systematically. Finally, Schott succeeded in producing homogeneous glass samples, and he invented borosilicate glass with the optical properties Abbe needed.[2] These inventions gave rise to the well-known companies Zeiss and Schott Glass (see also Timeline of microscope technology).Systematic glass research was born. In 1908, Eugene Sullivan founded glass research also in the United States (Corning, New York).[3]At the beginning of glass research it was most important to know the relation between the glass composition and its properties. For this purpose Otto Schott introduced the additivity principle in several publications for calculation of glass properties.[4][5][6] This principle implies that the relation between the glass composition and a specific property is linear to all glass component concentrations, assuming an ideal mixture, with C i and b i representing specific glass component concentrations and related coefficients respectively in the equation below. 【#1】The additivity principle is a simplification and only valid （有效的）within narrow composition ranges as seen in the displayed diagrams for the refractive index and the viscosity. Nevertheless, the application of the additivity principle lead the way to many of Schott’s inventions, including optical glasses, glasses with low thermal expansion for cooking and laboratory ware (Duran), and glasses with reduced freezing point depression for mercury thermometers. Subsequently,English[7] and Gehlhoff et al.[8] published similar additive glass property calculation models.【#2】Schott’s additivity principle is still widely in use today in glass research and technology.[9][10]Additivity Principle(加和原理):Global modelsThe mixed-alkali effect（混合碱效应）: If a glass contains more than one alkali oxide, some properties show non-additive behavior. The image shows, that the viscosity of a glass is significantly decreased.[11]Decreasing accuracy (精度)of modern glass literature data for the density at 20 °C in the binary system SiO2-Na2O.[12]Schott and many scientists and engineers afterwards applied the additivity principle to experimental data measured in their own laboratory within sufficiently narrow composition ranges (local glass models). This is most convenient because disagreements between laboratories andnon-linear glass component interactions do not need to be considered. In the course of several decades of systematic glass research thousands of glass compositions were studied, resulting in millions of published glass properties, collected in glass databases. This huge pool of experimental data was not investigated as a whole, until Bottinga,[13], Kucuk[14], Priven[15], Choudhary[16], Mazurin[17], and Fluegel[18][19] published their global glass models, using various approaches.【#3】In contrast to themodels by Schott the global models consider many independent datasources, making the model estimates more reliable. In addition,【#4】global models can reveal and quantify non-additive influences of certain glass component combinations on the properties, such as the mixed-alkali effect as seen in the diagram above, or the boron anomaly. 【#5】Global models also reflect interesting developments of glass property measurement accuracy, e.g., a decreasing accuracy of experimental data in modern scientific literature for some glass properties, shown in the diagram. They can be used for accreditation of new data, experimental procedures, and measurement institutions (glass laboratories). In the following sections (except melting enthalpy) empirical modeling techniques are presented, which seem to be a successful way for handling huge amounts of experimental data. The resulting models are applied in contemporary engineering and research for the calculation of glass properties.Non-empirical (deductive) glass models exist.[20] They are often not created to obtain reliable glass property predictions in the first place (except melting enthalpy), but to establish relations among several properties (e.g. atomic radius, atomic mass, chemical bond strength and angles, chemical valency, heat capacity) to gain scientific insight. In future, the investigation of property relations in deductive（演绎）models may ultimately lead to reliable predictions for all desired properties,provided the property relations are well understood and all required experimental data are available.Methods Glass properties and glass behavior during production can be calculated through statistical analysis of glass databases such asGE-SYSTEM[21] SciGlass[22] and Interglad,[23] sometimes combined with the finite element method. For estimating the melting enthalpy thermodynamic databases are used.Linear regression（线性回归）Refractive index in the system SiO2-Na2O. Dummy variables（虚变数）can be used to quantify systematic differences of whole dataseries from one investigator.[12]If the desired glass property is not related to crystallization (e.g., liquidus (液相线)temperature) or phase separation（相分离）, linear regression canbe applied using common polynomial functions（多项式函数）up to the third degree. Below is an example equation of the second degree. TheC-values are the glass component concentrations like Na2O or CaO in percent or other fractions, the b-values are coefficients, and n is the total number of glass components. The glass main component silica (SiO2) is excluded in the equation below because of over-parametrization due to the constraint that all components sum up to 100%. Many terms in the equation below can be neglected based on correlation and significance analysis. Systematic errors such as seen in the picture are quantified by dummy variables（虚变数）. Further details and examples are available in an online tutorial by Fluegel.[24]Non-linear regressionLiquidus surface in the system SiO2-Na2O-CaO using disconnected peak functions based on 237 experimental data from 28 investigators. Error = 15 °C.[25]The liquidus temperature has been modeled by non-linear regression using neural networks[26]（神经网络）and disconnected peak functions.[25]The disconnected peak functions approach（离散峰函数法）is based on the observation that within one primary crystalline phase field linear regression can be applied[27] and at eutectic points（低共熔点）sudden changes occur.Glass melting enthalpy（玻璃熔融焓）The glass melting enthalpy reflects the amount of energy needed to convert the mix of raw materials (batch) to a melt glass. It depends on the batch and glass compositions, on the efficiency of the furnace and heat regeneration systems, the average residence time of the glass in the furnace, and many other factors. A pioneering article about the subject was written by Carl Kröger in 1953.[28]Finite element method（有限元法）For modeling of the glass flow in a glass melting furnace the finite element method is applied commercially,[29][30] based on data or models for viscosity, density, thermal conductivity, heat capacity, absorption spectra, and other relevantproperties of the glass melt. The finite element method may also be applied to glass forming processes.Optimization It is often required to optimize several glass properties simultaneously, including production costs. GE-SYSTEM[21][31] This can be performed, e.g., by simplex search(单一研究), or in a spreadsheet(试算表) as follows:1.Listing of the desired properties;2.Entering of models for the reliable calculation of properties basedon the glass composition, including a formula for estimating theproduction costs;3.Calculation of the squares of the differences (errors) betweendesired and calculated properties;4.Reduction of the sum of square errors using the Solver option[32] inMicrosoft Excel with the glass components as variables. Othersoftware (e.g. Microcal Origin) can also be used to perform these optimizations.It is possible to weight the desired properties differently. Basic information about the principle can be found in an article by Huff et al.[33] The combination of several glass models together with further relevant technological and financial functions can be used in six sigma optimization(六标准差优化).。
1.玻璃知识培训(综合部分)
第一章、浮法玻璃一、浮法玻璃（Float glass）的生产目前平板玻璃的成型工艺主要有浮法、垂直引上法、压延法等，采用各种成型方法生产出来的玻璃统称为平板玻璃，资料表明我国生产的平板玻璃中浮法玻璃占据比率为83%以上，其中优质浮法玻璃约为10%，浮法玻璃已成为平板玻璃中最主要的部分。
浮法玻璃成型工艺在1959年由英国皮尔金顿爵士发明，因玻璃在金属锡液上漂浮（Float）成型而得名。
该工艺为目前国际上最先进的平板玻璃成型工艺，采用浮法工艺生产的玻璃具有平整度好、光学变形小、杂质缺陷少、板宽可控、生产周期长、生产率高等特点。
1.浮法玻璃的生产流程浮法玻璃和普通平板玻璃一样，都是Na-Ca-Si系玻璃，化学成分主要为SiO2O等（71.5—72.5%）、CaO（8.0—9.0%）、Na21）浮法玻璃原材料包括生料与熟料。
生料：硅砂、长石、石灰石、白云石、纯碱、澄清剂（芒硝）、还原剂（碳粉）、着色剂等；熟料：碎玻璃。
绿色、蓝色等着色玻璃颜色主要因为在玻璃原材料中加入着色剂而形成，着色剂一般为铁粉（绿色）、钴粉、氧化铜、氧化铬等。
2）浮法玻璃的生产：将配料完毕的原材料在熔窑中熔化为玻璃液后，玻璃液流入锡槽中并在自身重力和表面张力的作用下，摊开成为向前缓慢移动的双面平整和平行的连续玻璃带，降到一定温度后，在拉边机的作用下形成一定的板宽和厚度，该玻璃带经拉引辊进入退火窑进行退火，退火完毕后便成了浮法玻璃。
2.我司浮法玻璃的生产优势1.设备情况：我司现共有六条浮法玻璃生产线投入生产（深圳两条，广州两条，成都2条），设备分别从法国、德国、比利时、芬兰和美国引进，生产厚度为0.55-22mm 优质浮法玻璃，年总产量约100万吨，其中0.55-1.1mm超薄浮法玻璃填补了国内空白，使我国跻身于当今世界能够生产超薄浮法玻璃为数不多的几个国家之列。
1）高度自动化的生产过程控制采用德国西门子提供的DCS控制系统，将三大热工设备的生产过程连成整体。
浮法玻璃在线阳光镀膜生产中针孔缺陷产生原因分析及解决措施
0引言阳光控制镀膜玻璃是指对波长范围在350-1 800 nm 的太阳光具有一定控制作用的镀膜玻 璃。
硅质在线阳光镀膜玻璃采用CVD 方法，是在 浮法玻璃生产过程中采用硅烷、乙烯等镀膜气体，通过氮气携载与热玻璃表面发生反应产生一层约20~50 nm 厚的硅质膜层。
浮法玻璃在线阳光镀膜生产中 针孔缺陷产生原因分析及解决措施李清华1刘卫东2孙立群彳(1.中国耀华玻璃集团有限公司 秦皇岛066000；2•河北省镀膜玻璃技术创新中心 秦皇岛066000；3.秦皇岛耀华玻璃技术开发公司 秦皇岛066000)摘要分析了导致在线阳光镀膜玻璃产生针孔的原因。
其中锡槽污染是最主要的原因，要通过多种方式减少硫化亚锡和氧化亚锡的产生；此外，镀膜工艺及设备也是产生针孔的主要原因之一。
要严格按操作规程执行，以提高镀膜质量。
关键词 浮法玻璃；锡槽；在线；阳光镀膜玻璃；针孔中图分类号：TQ171.72 文献标识码：A 文章编号：1003-1987(2020)12-0051-04Analysis on Causes and Solutions of Pinhole Defects in the On-line Solar-control Coating Production on Float Glass SurfaceLI Qinghua 1, LIU Weidong 2, SUN Liqun 3(1. China Yaohua glass group Co., Ltd., Qinhuangdao 066000, China ；2. Hebeiprovince coating glass technology innovation center Qinhuangdao 066000, China ；3. Qinhuangdao Yaohua Glass Technology Development Co., Ltd., Qinhuangdao 066000, China )Abstract: The causes of pinholes in the online solar-control coated glass were analyzed, among which the pollution in tin bath was the main reason. Reducing formation of stannous sulfide and stannous oxide can be achieved in a number of ways. In addition, the coating process and equipment are also one of the maincauses of pinhole defects. The operation procedures must be strictly followed so as to improve the coated qualityKey Words: float glass, tin bath, on-line, coated glass for solar control, pinhole在镀膜生产中，针孔是一种常见的缺陷，一直难以根除。
浮法玻璃一窑两线工艺流程
浮法玻璃一窑两线工艺流程英文回答：The float glass process is a widely used method for manufacturing flat glass sheets. It involves two production lines running simultaneously in a single glass furnace. Let me explain the process in detail.First, the raw materials, such as silica sand, soda ash, limestone, and dolomite, are mixed together and melted in the furnace at a temperature of around 1600°C. This molten glass is then poured onto a bath of molten tin, which acts as a liquid mirror. The glass floats on top of the tin, hence the name "float glass."As the glass floats on the tin bath, it spreads out and forms a continuous ribbon. The thickness of the glass is controlled by the speed at which it is pulled out of the furnace. The glass ribbon then goes through a series of rollers to ensure its smoothness and uniform thickness.Once the glass ribbon has solidified, it is transferred to the annealing lehr, where it is slowly cooled to relieve any internal stresses. This process is crucial to ensure the glass's strength and durability.After annealing, the glass ribbon is cut intoindividual sheets of desired sizes. These sheets are then inspected for any defects or imperfections. Any defective sheets are rejected, while the good ones move on to the next stage.The next stage involves further processing of the glass sheets, such as grinding, polishing, and coating. These processes are carried out to meet specific requirements for different applications, such as architectural glass, automotive glass, or solar panels.Once the sheets are processed, they are packed and prepared for shipment to customers. The finished glass products are then used in various industries, including construction, automotive, electronics, and solar energy.中文回答：浮法玻璃是一种广泛使用的制造平板玻璃板的方法。
浮法玻璃生产线在线阳光镀膜玻璃废气排放问题探讨
节能与环保浮法玻璃生产线在线阳光镀膜玻璃废气排放问题探讨王国华'刘卫东2孙立群2（1.中国建材检验认证集团秦皇岛有限公司秦皇岛066004；2.秦皇岛耀华玻璃技术开发有限公司秦皇岛066000）摘要对浮法玻璃生产线在线阳光镀膜玻璃废气排放状况进行了简要的描述，介绍了国内外废气排放的发展与现状及最新信息，针对目前存在的问题提岀合理解决方案。
关键词阳光镀膜；硅烷；废气排放中图分类号：TQ171文献标识码：A文章编号：1003-1987（2020）08-0059-03The Suggestion of the Exhaust Emissions Problemof the Sun-coated Glass On-line of Float Glass Production LineWANG Guohua1,LIU Weidong2,SUN Liqun2（1.China Building Material Test&Certification group Qinhuangdao Co.,Ltd.,Qinhuangdao066004,China；2.Qinhuangdao Yaohua Glass Technology Development Co.,Ltd.,Qinhuangdao066000,China）Abstract:Briefly described the status of the exhaust gas of the sun-coated Glass on-line of float glass production line,and introduces the development and status quo of the ground exhaust gas at home and abroad,as well as the latest information,and put forward the reasonable solution to the existing problem. Key Words:sunlight coating,silane,exhaust emissi0引言镀膜玻璃的生产方法有多种，按类划分可以分为在线和离线两大类。
浮法玻璃一窑两线工艺流程
浮法玻璃一窑两线工艺流程The process flow of one furnace with two lines for float glass production involves multiple intricate steps that are carefully orchestrated to achieve high-quality glass products. Initially, the raw materials, primarily silica sand, soda ash, limestone, and dolomite, are meticulously mixed and pulverized to ensure homogeneity. This blended mixture is then fed into the furnace, where it undergoes a controlled melting process at high temperatures.浮法玻璃一窑两线生产工艺流程涉及多个复杂的步骤，这些步骤需要精心协调，以生产出高质量的玻璃产品。
首先，原料主要是硅砂、苏打灰、石灰石和白云石，经过精心混合和粉碎，以确保其均匀性。
然后，这种混合物料被送入窑炉中，在高温下进行受控熔化。
Within the furnace, the molten glass flows through a refining zone, where bubbles and impurities are removed to enhance clarity. Subsequently, the refined glass is fed onto the floating bath, a pool of molten tin that acts as a support surface. As the glass floats on the tin bath, it assumes a flat and level surface due to the surface tension of the molten tin.在窑炉内，熔融玻璃流经精炼区，通过精炼去除气泡和杂质，提高清晰度。
浮法玻璃熔化工艺流程
浮法玻璃熔化工艺流程英文回答：The float glass melting process is a crucial step inthe production of float glass, which is a type of high-quality flat glass widely used in the construction and automotive industries. The process involves melting raw materials and forming a continuous ribbon of molten glasson a bath of molten tin. Here is a detailed description of the float glass melting process:1. Raw Material Preparation: The main ingredients for float glass production are silica sand, soda ash, limestone, and dolomite. These raw materials are carefully selectedand mixed in the right proportions to achieve the desired glass composition. The mixture is then crushed and ground into a fine powder.2. Batch House: The powdered mixture, known as batch,is stored in silos and transported to the batch house. Inthe batch house, the batch is weighed and mixed with cullet, which is recycled glass, to promote melting and reduce energy consumption. The mixed batch is then conveyed to the melting furnace.3. Melting Furnace: The melting furnace is a large refractory-lined chamber where the batch is heated to high temperatures, typically around 1600°C (2912°F). The heatis generated by burners that use natural gas or fuel oil. The batch gradually melts and forms a pool of molten glass.4. Refining: The molten glass undergoes a refining process to remove any impurities and homogenize the composition. This is achieved by stirring the glass with mechanical devices or by injecting gases, such as chlorineor nitrogen, to remove bubbles and other defects.5. Tin Bath: The molten glass is then fed onto a bathof molten tin, which is maintained at a temperature around 1000°C (1832°F). The tin bath serves as a support for the glass and provides a smooth surface. The glass spreads out and forms a continuous ribbon on the tin bath.6. Annealing Lehr: The ribbon of glass is slowly cooled and solidified as it travels through an annealing lehr, which is a long chamber with a controlled temperature gradient. The annealing process relieves internal stresses in the glass and improves its strength and durability.7. Cutting and Inspection: After leaving the annealing lehr, the solidified glass ribbon is cut into individual sheets of the desired size. These sheets undergo a thorough inspection to ensure they meet quality standards in terms of thickness, flatness, and optical clarity.中文回答：浮法玻璃熔化工艺是浮法玻璃生产中的关键步骤，浮法玻璃是一种广泛应用于建筑和汽车工业的高质量平板玻璃。
延长浮法玻璃熔窑卡脖深层水包使用寿命的改进措施及方法
技术讲座431 前言浮法玻璃卡脖深层水包置于熔化澄清部与冷却部之间，是玻璃熔窑玻璃液的分割设备，是一对浸入卡脖玻璃液中的水包冷却器，它根据卡脖内宽可以分为水平放入和垂直放入。
通常情况下卡脖内宽超过2200mm 采用水平式卡脖深层水包，其深度为300～600mm，水包上表面露出玻璃液面10～20mm 以上，呈“Ｖ”形对插（接近“一”字形）。
其作用一是减慢熔化部出口端前进流的速度，使玻璃液在热区停留较长的时间，从而获得良好的澄清；二是有助于冷却部玻璃液的温度调节，满足冷却部及流道处的温度参数要求；三是减少了玻璃液由冷却部向熔化部的回流量，即减少了二次加热，并使澄清部的温度提高；四是阻挡熔化部的浮渣进入冷却部，取自池深方向最优质的玻璃液进入冷却部，提高玻璃的产量和质量。
各个玻璃窑炉根据卡脖宽度选择适合自己的深层水包，满足使用要求，使水包的各项作用（包括节能、熔化效果、玻璃液回流、澄清、均化、阻挡浮渣等）充分发挥出来，为玻璃生产提供最优质的服务。
兰州某公司1000t/d 浮法玻璃生产线，熔窑卡脖宽度为4300mm、卡脖长度为7500mm、池深为1100mm，使用吊挂式水平对插式深层水包，水包升降采用手轮配合蜗轮蜗杆及丝杠结构、水平对插移动采用手轮配合单梁小车结构，该机构对深层水包的水平和垂直方向的控制比较灵敏和精准，对水包在玻璃液内的横向和纵向稳固起到了很好的控制作用。
2 深层水包在运行过程中出现的问题延长浮法玻璃熔窑卡脖深层水包使用寿命的改进措施及方法白瑞军兰州蓝天浮法玻璃股份有限公司 甘肃 兰州 730060摘 要：本文结合兰州某公司1000t/d 浮法玻璃生产线熔窑卡脖深层水包投产后固定部位频繁渗漏水的实际情况，对其产生的原因进行解刨分析，介绍了可行的改进措施并予以实施,从而达到了延长水包使用寿命的目的。
实践证明，该改进措施行之有效，解决了生产中水包频繁渗漏水产生气泡对生产造成的影响。
关键词：卡脖深层水包；渗漏水；频繁；延长寿命Improvement Measures and Methods for Prolonging Service Life of DeepNeck Cooler in Melting Furnace of Float GlassBai RuijunLanzhou Blue Sky Float Glass Co., Ltd. Lanzhou Gansu 730060Abstract: Abstract: In view of the actual conditions of frequent water leakage after production in the fixed position of the deep neck cooler in melting furnace of 1000t/d float glass production line in a company of Lanzhou, this paper analyzes the causes of water leakage, introduces the feasible improvement measures and puts them into practice, so as to extend the service life of the neck cooler. It has been proven that the improved measures are effective and solve bubbles problems due to frequent leakage in neck cooler during production.Key words: Deep neck cooler; Water leakage; Frequence; Service Life extension技术讲座44兰州某公司1000t/d浮法玻璃生产线投产后，在半年时间里卡脖深层水包（南北两侧）共计发生4次渗水和漏水事故，期间间隔时间较短，最短的一次为15天，该水包渗漏水位置相对固定，而且发生渗漏后该点位的无缝钢管损坏速度较快，造成在玻璃板上产生大量的气泡，对生产造成了一定的影响。
浅析浮法玻璃成型质量的影响因素
2016 NO.09SCIENCE & TECHNOLOGY INFORMATION工 业 技 术64科技资讯 SCIENCE & TECHNOLOGY INFORMATION浮法玻璃技术是目前平板玻璃的主要生产技术,广泛应用于建筑、汽车等领域,已经成为一种基本的生产资料。
我国浮法玻璃在近几十年里工业技术水平迅速提高,使用范围已经扩展到了建筑、制镜、镀膜、钢化、夹层等深加工行业,有些已出口到了国外。
但是许多高档玻璃仍需要进口或使用合资企业的产品,由于质量很不稳定,玻璃品种也还不够齐全,国产浮法玻璃在高档深加工中的占有率还相当低,这就影响了它的使用范围。
因此,提高浮法玻璃质量是亟待解决的问题。
1 成型质量的影响因素浮法玻璃成型需要多方面的配合,任何一方面出现问题均会造成玻璃质量的下降,严重者可导致停产,其中影响成型质量的因素主要包括锡槽温度制度、气氛制度、压力制度以及来自熔窑方面的影响。
1.1 锡槽温度制度对成型质量的影响锡槽温度制度是指沿锡槽长度方向的温度分布,是锡槽成型作业的基础,对玻璃液的摊平、抛光、冷却、固型都起着重要作用,对玻璃带的拉引速度、锡液的对流状态、玻璃的品种、规格及产量、质量等都有一定的影响。
合理控制锡槽温度制度,通过在锡槽设计上的改进和生产中的调整、控制,建立适合浮法玻璃工艺的合理的锡槽温度制度并不断地加以优化,在生产中会取得预期的效果。
(1)流道温度。
流道是玻璃液从熔窑流入锡槽的通道,流道的温度是成型作业最主要的温度指标,必须严格遵循温度制度,且在相应位置应设置热电偶或红外温度计测温点。
流道温度过高时,玻璃液粘度降低,进入锡槽后摊平面积变大,造成玻璃带过薄、过宽,这样容易引起沾边、满槽等事故,而且在拉边机处,会感到成型困难。
流道温度过低时,玻璃液粘度增大,摊平和抛光的条件不充分,玻璃表面质量会受到影响,并容易引起脱边、断板等事故,同时存在成型时不易拉薄或积厚的困难。
玻璃工艺英语
玻璃工艺英语
玻璃工艺英语涵盖了许多与玻璃相关的词汇和短语，包括玻璃制造的不同过程、不同类型和形状的玻璃、玻璃的特性和用途等等。
以下是一些常见的玻璃工艺英语词汇和短语：
1. 玻璃种类：float glass（浮法玻璃）、tempered glass（钢化玻璃）、laminated glass（夹层玻璃）、insulated glass（双层玻璃）、decorative glass（装饰玻璃）等等。
2. 玻璃制造过程：blowing（吹制）、casting（铸造）、rolling （轧制）、drawing（拉制）、cutting（切割）等等。
3. 玻璃特性：transparency（透明度）、refraction（折射）、reflection（反射）、durability（耐久性）、heat resistance（耐热性）等等。
4. 玻璃用途：windows（窗户）、doors（门）、shower enclosures （淋浴房）、mirrors（镜子）、greenhouses（温室）等等。
在玻璃工艺领域，英语是一种重要的交流语言。
掌握玻璃工艺英语词汇和短语，能够帮助玻璃工程师和技术人员更有效地与国际同行合作，提高工作效率和质量。
- 1 -。
浮法玻璃生产介绍
At processed level €50 billion
4
NSG and Pilkington combined
•A global glass leader – the pure play in Flat Glass •Combined annual sales c. £4 billion •Equal to Asahi Glass in scale, most profitable in Flat Glass •Ownership/interests in 46 float lines •6.4 million tonnes annual output •Widened Automotive customer base •36,000 employees worldwide •Manufacturing operations in 26 countries •Sales in 130+ countries
24
Chemical Vapour Deposition
25
Chemical Vapour Deposition
Main gas flow region Gas Phase Reactions
• + MgO Glass stays as a super-cooled liquid in bath, no crystallisation
• + Al2O3 Adds durability • + Fe2O3 Adds required level of ‘green’ colour for customer
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
Float Glass ProductionIntroductionFloat glass is produced by floating a continuous stream of molten glass onto a bath of molten tin. The molten glass spreads onto the surface of the metal and produces a high quality, consistently level sheet of glass that is later heat polished. The glass has no wave or distortion and is now the standard method for glass production and over 90% of the world production of flat glass is float glass.The float glass process was developed by Sir Alastair Pilkington and patented by Pilkington in 1959 and the detailed history of the development is process is described by Sir Alastair Pilkington in his review lecture to the Royal Society of London in 1969 (Pilkington, L.A.B. Proc. Roy. Soc. London 1969, A314, 1-25).The float glass processThe basic scienceIf molten glass is poured onto a bath of clean molten tin, the glass will spread out in the same way that oil will spread out if poured onto a bath of water. In this situation, gravity and surface tension will result in the top and bottom surfaces of the glass becoming approximately flat and parallel.The molten glass does not spread out indefinitely over the surface of the molten tin. Despite the influence of gravity, it is restrained by surface tension effects between the glass and the tin. The resulting equilibrium between the gravity and the surface tensions defines the equilibrium thickness of the molten glass (T).The resulting pool of molten glass has the shape shown below:The equilibrium thickness (T) is given by the relation:where S g, S gt, and S t are the values of surface tension at the three interfaces shown in the diagram.For standard soda-lime-silica glass under a protective atmosphere and on clean tin the equilibrium thickness is approximately 7 mm.The best detailed explanation of the physics involved in the float glass process is describedby Charnock (Charnock, H. Physics Bulletin 1970, 21, 153-156).The raw materialsThe basic raw material composition for standard soda-lime-silica float glass are:The production processThis basic science was developed over a long period by Pilkington into the full scale continuous process that is illustrated below:The batch of raw materials is automatically weighed and mixed and then continuously added to the melting furnace where it is taken to around 1050oC using gas fired burners. The mix then flows over a ‘dam’ where th e continuous stream of molten glass flows onto the bath of molten tin. The stream of glass is pulled along the top of the molten tin by haul-off conveyors at the end of the float area which transport the glass into the annealing lehr.At the start of the float area the molten glass spreads outwards with flat top and bottom surfaces and the thickness decreases towards the equilibrium thickness (T). The thicknesscan then be further controlled by the stretching effect of the conveyors as it cools until it reaches 600oC when it exits the float area and enters the annealing lehr.Whilst the equilibrium thickness is approximately 7 mm the process has been developed to allow the thickness to be controlled between 0.4 mm and 25 mm.For thin sheets, the exit conveyor speed can be increased to draw the glass down to thinner thicknesses. This drawing down will also result in a decrease in the sheet width and to prevent unacceptable sheet width decreases edge rolls are used. Edge rolls grip the outer top edge of the glass and not only reduce decrease in width but also help to reduce the thicknesseven further.For thick sheets, the spread of the molten glass is limited by using non-wetted longitudinal guides. The glass temperature allows the spread to remain uniform and is reduced until the ribbon can leave the guides without changing dimensions Low-e coatingsMuch of the architectural glass produced is now coated with low-e (for low emissivity) coatings to enable the production of more energy efficient windows. As with any advanced technology, there are several different production methods and the products have differentproperties.The two basic methods of producing low-e coatings are sputtering and pyrolytic deposition: Sputtering - Soft coat and off-line coatingSputtering uses a vacuum chamber to put several layers of coating on the basic glass and the total thickness of the coatings is around ten thousand times thinner than a human hair. Sputtered coatings are referred to as 'soft coats' and must be protected from humidity and contact. The sputtered coatings are very soft but inside a sealed unit, they will easily last forthe life of the unit.These sputtered 'soft coat' products can have emissivities ranging from 0.05 to 0.1 compared to uncoated glass that has a typical emissivity of 0.89. This means that 'soft coat' products will reflect between 95 and 90% of the long-wavelength radiant energy from the surface where uncoated glass will only reflect 11% of the radiant energy received by the surface. Pyrolytic Deposition - Hard coat and on-line coatingPyrolytic coating deposits a metallic oxide directly onto the glass surface whilst it is still hot. The low-e coating is effectively 'baked-on' to the surface and the resulting low-e coating is very hard and durable. The pyrolytic coatings are often referred to as 'hard coats'. Pyrolytic coatings can be up to 20 times thicker than sputtered coatings (they are still 500 times thinner than a human hair) and the baking process makes them much harder and resistant to wear.Pyrolytic 'hard coats' have a low emissivity but this is higher than those achieved for soft coats. Hard coat products have emissivities ranging from 0.15 to 0.2.The ability to apply 'hard coats' whilst the glass is still hot means that hard coated productsare cheaper than soft coated products.。