Presentation on theme: "Glass Kulinich Ekaterina, Ph"— Presentation transcript:
1Glass Kulinich Ekaterina, Ph Glass Kulinich Ekaterina, Ph.D, Chair of Silicate Technology and Nanotechnology
2Glass is a type of non-crystalline or amorphous solid Glass is a type of non-crystalline or amorphous solid. Glass generally refers to hard, brittle, transparent material. Examples of such materials include, but are not limited to:soda-lime glassborosilicate glassacrylic glasssugar glass
3In the technical sense, glass is an inorganic product of fusion which has been cooled to a rigid condition without crystallizing
4Glass in the common sense contains silica as the main component and glass former, but silica-free glasses also existThe amorphous structure of glassy Silica (SiO2). Long range order is not present, but we can see short-range order with tetrahedral arrangement of Oxygen (O) atoms around the Silicon (Si) atoms.
5In the scientific sense the term glass is often extended to all amorphous solids (and melts that easily form amorphous solids), including plastics, resins, or other silica-free amorphous solidsIn addition, besides traditional melting techniques, any other means of preparation are considered, such as:ion implantation, and the sol-gel method. However, glass science commonly includes only inorganic amorphous solids, while plastics and similar organics are covered by polymer science, biology and further scientific disciplines
6Glass plays an essential role in science and industry The optical and physical properties of glassmake it suitable for applications such asflat glass,container glass,optics and optoelectronics material,laboratory equipment,thermal insulator (glass wool),reinforcement fiber (glass-reinforced plastic, glass fiber reinforced concrete),art
7The term glass developed in the late Roman Empire The term glass developed in the late Roman Empire. It was in the Roman glassmaking center at Trier, Germany. Probably, the late-Latin term glesum originated Germanic word Glas for a transparent, lustrous substances.Roman glass found at Begram, Afghanistan, then part of the Greco-Bactrian KingdomRoman glass from the 2nd century
8Pure silica (SiO2) has a "glass melting point"— at a viscosity of 10 Pa·s - of over 2300 °C. While pure silica can be made into glass for special applications, other substances are added to common glass to simplify processingSamples of fused silica
9Sodium carbonate (Na2CO3) lowers the melting point to about 1500 °C in soda-lime glass However, the soda makes the glass water soluble, which is usually unnecessary, solime (calcium oxide (CaO)magnesium oxide (MgO) andaluminium oxide (Al2O3)are added to provide for a better chemical stability of glassThe resulting glass contains about 70 to 74 percent silica by weight and is called a soda-lime glass. Soda-lime glasses account for about 90 percent of manufactured glass.
10As well as soda and lime, most common glass has other ingredients added to change its properties Lead glass (lead crystal, flint glass) is more 'brilliant' because the litharge (PbO2) increases glass shineBoron may be added to change the thermal and electrical properties (Pyrex - borosilicate glass)Adding barium increases the refractive indexThorium oxide or lanthanum oxide gives glass a high refractive index and low dispersion. Such glass is used in production of high-quality lenses
11Large amounts of iron are used in glass for infrared energy absorption (absorbing filters) Cerium(IV) oxide can be used for glass that absorbs UV wavesFining agents such as sodium sulfate, sodium chloride, or antimony oxide are added to reduce the bubble content in the glass
12Borosilicate glass is a type of glass with the main glass-forming components silica and boron oxide Borosilicate glasses are most well known for having very low coefficient of thermal expansion (~5 × 10-6 /°C at 20°C). Borosilicate glass is very resistant to thermal shock, much more than any other common glassBorosilicate glass was first developed by German glassmaker Otto Schott in the late 19th century. After Corning Glass Works introduced Pyrex in 1915, it became a synonym for borosilicate glass in the English-speaking world
13In addition to the quartz, sodium carbonate, and calcium carbonate traditionally used in glassmaking, boron is used in the manufacture of borosilicate glassTypically, the resulting glass composition is about 70% silica, 10% boron oxide, 8% sodium oxide, 8% potassium oxide, and 1% calcium oxide (lime)Borosilicate glass is use inchemical laboratory equipment,cookware, lighting, and incertain cases, windows
14Glass container factories Modern glass container factories are broadly divided into three parts:-Batch house-Hot end-Cold end
15The batch house is concerned with raw materials. In the hot end are situated furnaces, machines that produce the containers (forming machines) and annealing ovens.In the cold end – the aria for inspection and packaging equipment.
16Batch houseThe batch house holds the raw materials for glass, primarily sand, soda ash, limestone, feldsparThese materials are received (typically by truck or rail transport) and elevated into storage silos. From the silos they areweighed outinto a batch (charge) of several tonnes, using common glass batch calculation procedures. The batch is mixed and sent to silos over the furnaceQuartz sand (silica) as main raw material for commercial glass production
17Hot endFurnaceThe hot end of a glassworks is where the molten glass is formed into containers. Batch is fed at a slow controlled rate into the furnace. The natural gas or fuel oil fired and operate at temperatures up to 1675°C. The temperature is limited by the quality of the furnace and by the glass composition
18Forming processThere are currently two primary methods of making a glass container –the blow and blow methodthe press and blow method.In both cases a stream of molten glass at its plastic temperature (1050°C-1200°C) is cut by a shearing blade to form a cylinder of glass called a gob.Both of the processes start whan gob is falling into the blank moulds. In the blow and blow process, the glass first is blown into the blank moulds to create a pre-container. This is flipped into a final mould, where a final blow make the final container shape.In the case of press and blow, the pre-container is formed by a metal plunger which pushes the glass out into the blank mould.
19Forming machinesThe most widely used forming machine arrangement is the individual section machine (or IS machine). This machine has a bank of identical sections. The sections are in a row, and the gobs feed into each section via a moving chute, called the gob distributor. Sections make one, two, three or four containers simultaneously and the gobs fall into the blank moulds in parallel.
20Annealing As glass cools it shrinks and solidifies. Uneven cooling causes weak glass due to stress. Even cooling is achieved by annealing.An annealing oven heats the container to about 580°C then cools it, depending on the glass thickness, over a 20 – 6000 minutes.
21Cold endThe role of the cold end is to inspect the containers for defects, package the containers and label the containers
22Inspection equipmentGlass containers are 100% inspected; automatic machines, or sometimes persons, inspect every container for a variety faults.Typical faults include:Small cracks in the glass called checksForeign inclusions called stones (pieces of the refractory brick fallen into the molten glass)Other defects include bubbles in the glass called blisters and too thin walls
23Lifecycle impactGlass containers are wholly recyclable and the industry in many countries have a policy of a high price on cullet to ensure high return rates.In Sweden, Norway, Denmark and Finland return rates is about 95 %. Return rates of less than 50 % are usual in other countries.
24ColorsColors in glass may be obtained by addition of coloring ions and by precipitation of finely dispersed colloides.
25Iron(II) oxide give bluish-green tint and such glass is used for a beer bottles. Together with chromium it gives a more dark green color, used for wine bottles.
26Sulphur together with carbon and iron salts produces amber glass from yellowish to almost black. In borosilicate glasses sulphur imparts a blue color. With calcium it provides a deep yellow color
27Manganese can be added in small amounts to remove the green tint given by iron, or in higher concentrations to give glass an amethyst color. Manganese is one of the oldest glass additives, and purple manganese glass was used since early Egypt history
28Black Manganese dioxide is used to remove the green color from the glass; in a very slow process this is converted to sodium permanganate, a dark purple compound. In New England some houses built more than 300 years ago have window glass which is light violet tint because of this chemical change
29Selenium, like manganese, can be used in small concentrations to decolorize glass, or in higher concentrations to provide a reddish color, caused by selenium atoms dispersed in glass. It is a very important agent to make pink and red glass. When used together with cadmium sulfide, it yields a brilliant red color known as "Selenium Ruby"
30Small concentrations of cobalt (0. 025 to 0. 1%) yield blue glass Small concentrations of cobalt (0.025 to 0.1%) yield blue glass. The best results are achieved when using glass containing potash. Very small amounts can be used for decolorizing.
31Tin oxide, antimony oxide and arsenic oxide produce an opaque white glass, firstly used in Venice to produce an porcelain imitation
32Pure metallic copper produces a very dark red opaque glass, which is sometimes used as a substitute for gold in the production of ruby-colored glass
33Nickel, depending on the concentration, produces blue, or violet, or even black glass. Lead crystal with added nickel have purple color. Nickel together with small amount of cobalt was used for decolorizing of lead glass
34Chromium is a very powerful colorizing agent, yielding dark green or in higher concentrations even black color. Together with tin oxide and arsenic it yields emerald green glass.
35Cadmium together with sulphur results in deep yellow color, often used in glazes. However, cadmium is toxic.
36Titanium produces yellowish-brown glass Titanium produces yellowish-brown glass. Titanium is often used to intensification of other colorizing additives
37Metallic gold, in very small concentrations (around 0 Metallic gold, in very small concentrations (around 0.001%), produces a rich ruby-colored glass ("Ruby Gold"), while lower concentrations produces a less intense red, often named as "cranberry". The color is caused by the size and dispersion of gold particles. Ruby gold glass is usually made of lead glass with added tin.
38Uranium (0.1 to 2%) can be added to give glass a fluorescent yellow or green color. Uranium glass is typically not radioactive enough to be dangerous, but if ground into a powder and inhaled, it can be carcinogenic. When used with lead glass with very high proportion of lead, produces a deep red color
39Silver compounds (notably silver nitrate) can produce a range of colors from orange-red to yellow. The way the glass is heated and cooled can significantly affect the colors produced by these compounds. The chemistry involved is complex and not well understood
40Main components of glass Container glass production cycle Color glass Definition of glassTypes of glassMain components of glassContainer glass production cycleColor glass