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Abrasion : The technique of using abrasive wheels to cut shallow decorative areas in glass. It also refers to the process of using hard particles in various ways to cut or matt the glass surface or to shape glass items.
Abrasive wheels : Wheels for grinding and cutting glass.
Acid etching Graver à l'acide Травлениекислотой : This process for the decoration of glass involves the application of hydrofluoric acid to the glass surface. Hydrofluoric acid vapours or baths of hydrofluoric acid salts may be used to give glass a matt, frosted appearance (similar to that obtained by surface sandblasting). Acid-etched decoration is produced by covering the glass with an acid-resistant substance such as wax, through which the design is scratched.
Acid polishing Polir à l'acide Zuurpolijsten Кислотная полировка : A process of making a glossy, polished surface, used in the production of cut crystal to remove the opacity of etched surfaces where decoration has been applied. Items to be polished are immersed in a mixture of de-mineralized water, sulphuric acid and hydrofluoric acid, and then rinsed.
Acid stamping : The use of a stamp to produce a logo or trademark on glass using an etching acid.
Agate glass : Glass marbled with brown, blue, green, and yellow swirls in imitation of banded semiprecious stones like agate or chalcedony.
Alabaster Albast : CaSO4.2H2O, calcium sulphate or gypsum.
Alabaster glass : A type of translucent slightly grey or white glass, similar to opal glass.
Albite Albiet Albit Albita : NaAlSi3O8, a feldspar mineral.
Alexandrit glass, alexandrite glass : Glass which produces the dichroic effect exhibited by the mineral alexandrite. It results from the addition of about 4% neodymium oxide to the batch.
Alumina Alumine, oxyde d'alumine Aluminiumoxide Оксид алюминия : Al2O3; aluminium oxide.
Amber glass Braunglas Bruin glas Verre brun, Verre jaune Янтарное стекло : Amber coloured glass, used particularly for container glass. Amber glass offers excellent protection from ultraviolet radiation; amber glass extends the shelf life of light sensitive products..
Ampoul, Ampoule, Ampul Ampulle Ампула : A relatively small glass container designed to be filled and sealed by fusion of the glass neck.
Anatase Anataas : TiO2, titanium dioxide.
Andalusite Andalousite Andalusiet Andalusit Andalúzit Andaluzita Andaluzyt : Al2SiO5, Aluminium silicate mineral.
Anhydrite Anhidrit Anhydriet Anhydrit Anhydrita Anidrita : CaSO4, mineral.
Anisotropy Anisotropie : Term used in the façade industry to describe the manifestation, under certain light and viewing conditions, of patterns and colourful areas in heat-treated glass.
Annealing Recocido Recuisson Ricottura Uitgloeien : Under natural conditions, the surface of molten glass will cool more rapidly than the centre. This results in internal stresses which may cause the glass sheet or object to crack, shatter or even explode some time later. The annealing process is designed to eliminate or limit such stresses using a strictly controlled cooling in a special oven known as a "lehr".
Annealing lehr, Lehr Arca de recocido Arche de recuisson Kühlofen, Kühltunnel печь отжига : A long belt-fed, tunnel shaped oven used for continuous annealing to remove any residual thermal stresses in the glass.
Annealing point Hoge ontspanningstemperatuur Oberer Kühlpunkt Point supérieur de recuit : Temperature at which 'stress is relieved' in a few minutes; the viscosity at the annealing point is 1012Pa.S..
Annealing range Интервал отжига : Range of glass temperature in which stress in glass can be relieved at a practical rate. The annealing range corresponds with the temperature difference between the annealing point and the strain point.
Anorthite Anorthiet : CaO.Al2O3.2SiO2, lime feldspar mineral.
Anorthoclase Anorthoklaas : NaKO.Al2O3.6SiO2, feldspar mineral.
Applied ceramic labelling, ACL : Coloured lettering or design of a ceramic nature fused onto glass containers. After printing, the design is heated in a lehr and becomes permanently fused.
Arcanite Arkaniet : K2SO4, potassium sulphate mineral.
Aurene : A type of glass with an iridescent surface made by spraying the glass with lead chloride or stannous chloride and reheating it under controlled atmospheric conditions.
Aventurine : Translucent glass with sparkling inclusions of gold, copper, or chromic oxide.
AZS refractories AZS vuurvasten : Refractory blocks or tiles in varying proportions of alumina-zirconia-silica; initially used for areas where corrosion resistance was important but now used in most parts of the furnace.
Back wall : Section of wall above the soldier blocks at the furnace charging end.
Baddeleyite Baddeleyiet Baddeleyit Baddeleyita Βαδδελεΐτης бадделеит : ZrO2zirconium oxide mineral.
Baffle Voorvormbodem : Mould part, on top of the blank, used to close the delivery or baffle hole in a blank mould.
Baffle mark : Mark or seam at the bottom of the glass container, resulting from a mould joint between blank mould and baffle.
Baryte, barite Bariet Barita, Baritina Barite Baryt Baryte, Barytine Βαρύτης : BaSO4, mineral consisting of barium sulphate.
Batch Composition Gemeng Gemenge Шихта : A term used to refer to the raw materials required to produce the desired type of glass once they have been weighted and mixed, and are ready for melting. Silica, soda and lime are often the major ingredients (for soda lime glass). Cullet as well as minor ingredients like colorants can be added to the batch
Batch charger Cargadora Einlegemachine Enfourneuse Загрузчик шихты : Mechanical device for introducing the batch into the furnace.
Batch house Atelier de composition Gemengehaus : Part of the glass plant where batch materials are received, handled, weighted and mixed for delivery to the melting furnaces.
Bent finish : Container glass defect: a finish which has a bent appearance.
Bent neck : Container glass defect: a neck where the finish is tilted to one side.
Binder : Resin soluble adhesive that secures the random glass fibres in chopped strand mat or continuous strand roving.
Bird swing, bird cage Affenschaukel Balançoire, Trapèze Trapecio Vogelkooitje : A string of glass across the inside of a glass container. Bird swings are classified as critical defects.
Bit : Gob; A mass of molten glass, usually small and freshly gathered from the furnace.
Blank Voorvorm : Refers to a glass parison or preliminary shape that is formed during the first step of the glass forming process (container glass).
Blank mould Moule ébaucheur Voorvorm Vorform Черновая форма : Container glass: the mould that first shapes the glass during the hollow ware manufacturing process i.e. the mould in which the parison is formed.
Blister Blasen Blazen, bellen Bolle Bouillons Burbujas : Relatively large (>2mm) gaseous inclusion in glass.
Blobbing : A technique of decorating hot glass by dropping coloured blobs of molten glass onto the surface.
Blow and blow process Blas-Blas-Verfahren Procédé souffler souffler, Soufflé-soufflé : A machine-made bottle forming process where the parison is blown in both the parison mould and blow mould.
Blow mould, Finishing mould Blasform, Fertigform Moule finisseur Navorm Чистовая форма : Container glass: the mould within which the parison (gob of glass) is expanded into the final shape.
Blowpipe Blaaspijp Canne, Canne à souffler Glasmacherpfeife : An iron or steel tube, usually about four to five feet long, for blowing glass. Blowpipes have a mouthpiece at one end and are usually fitted at the other end with a metal ring that helps to retain a gather.
Body check : Container glass defect: a crack through the wall thickness in the body of the container.
Borax Borac Borace Bóra : Na2B4O7.10H2O; a hydrated borate mineral used for boron containing glasses.
Bore : The opening from which the glass container content is accessed.
Borosilicate glass Borosilicaatglas Borosilikatglas Verre borosilicate Vetro al borosilicato Vidrio borosilicatado, Vidrio de borosilicato Vidro borossilicato Боросиликатное стекло ホウケイ酸ガラス : A high silicate glass that has at least 5% boron oxide. Such glass is highly resistant to chemical corrosion and thermal shock and is particularly suitable for laboratory ware, domestic cooking ware, high-power lamps and other technical glass ware. It is also used when glass has to be bonded to metal and low expansion is a key characteristic.
Boosting : An auxiliary method of adding energy to the glass melt by passing electric current through the molten glass.
Borax : Na2B4O7·10H2O; mineral and important boron compound.
Bottle spacer : An equipment to create a space between glass containers on a conveyor to avoid bottle to bottle contact.
Bottom plate : Part of the mould which contains the heel (base) radius and the push up of the glass container to be formed.
Bridge wall Brugwand Schattenwand : Part of a glass melting furnace between melter and furnace.
Brightness Helderheid Helligkeit Luminance : Describes the average transmission across the entire visible spectrum of a glass colour according the CIE colour system. The brightness ranges from 0% to 100%. In the CIE colour diagram the brightness is not shown, it is in fact the third dimension perpendicular to the X-Y surface of the CIE colour diagram. The darker a glass colour, the lower the brightness.
Brush marks : Container glass defect: fine vertical lines on the side or neck of a bottle.
Bubble Bouillon Пузырь : A pocket of gas trapped in glass during the melting or forming process. Very small bubbles are known as seeds.
Bulged finish : Finish defect; a finish blown out of shape.
Burner block Branderblok Brennerstein, Düsenstein Горелочный блок : Refractory block through which fuel is admitted to the furnace.
Burnt lime Gebrannter Kalk : CaO; calcined limestone, calcium oxide
Bushings Filières : Platinum alloy electrically-heated boxes with numerous nozzles in their bases used as furnaces for the forming of continuous glass fibre. Glass can be fed into the heated bushing either in its molten state from a forehearth (direct melt) or, alternatively, as marbles to be melted (re-melt process).
Calcedonio : Glass marbled with brown, blue, green, and yellow swirls in imitation of chalcedony or other banded semiprecious stones.
Calcite Calciet Calcit Calcita Kalcit Canxit Kalsit 方解石 : CaCO3, mineral.
Calcium oxide, quicklime, burnt lime Calciumoxide Chaux окись кальция : CaO; chemical compound; basic compound of soda lime glass.
Calumite Calumiet : Blast furnace slag used as a batch raw material; often used as an alternative to feldspar and nepheline syenite.
Came : A grooved strip of lead used to join separate parts of glass windows.
Cassiterite Cassiteriet : SnO2, tin oxide mineral.
Cat scratch : glass defect: surface irregularities on glass resembling the marks of a cat's claws.
Cathedral glass : a form of rolled, translucent glass, often with a highly textured surface.
Celsian Celsiaan Celsiana Celsiane Celsjan : BaAl2Si2O8, a barium feldspar. The mineral is too rare to be used as a source of barium for glassmaking.
Ceramic labeling : A process of labeling glass containers with a label composed of coloured glass that is fused to the container.
Ceramic welding : Glass furnace hot repair technique, i.e. a repair whilst the furnace is still in operation; the process consists of projecting a dry mixture or refractory powder and finely divided metals carried by a current of oxygen onto the hot face of the refractory zone to be repaired. The refractory powder is raised to its melting temperature and bonds to the repair zone substrate.
Chamotte : a ceramic raw material having a high percentage of silica and alumina. It can be produced by firing selected fire clays to high temperature.
Charging : The process of loading batch into a furnace.
Checker bricks Briques d'empilage Kammerstein : Firebricks alternating with openings in the chambers of a regenerative furnace.
Checks Glaçures Risse : Glass surface cracks.
Chipped finish : Container glass defect: piece(s) broken out of the top edge of the finish.
Choked bore : Container glass defect: excess of glass has been distributed to the inside of the finish or opening.
Choked neck Col bouché Cuello obstruido Verengter Hals Stophals : A container glass defect: an obstruction of the neck of a bottle.
Chopped strand mat, CSM : Fiberglass: short strands of fiber arranged in a random pattern and held together with a binder.
Chromite Chromiet Chromit Cromit Cromita хромит Χρωμίτης : FeCr2O4,iron chromium oxide mineral.
Chromium oxide Chromoxid Chroomoxide Ossido di cromo : Inorganic compound of the formula Cr2O3.
Coated glass : Glass obtained by applying one or more coatings of inorganic materials to alter its physical properties like solar factor, emissivity, colour, light transmission, light reflection etc.
Cobalt oxide Kobaltoxide : CoO, CoO2, Co2O3 or Co3O4; a very powerful colouring oxide. It produces a very strong, intense blue. The colour changes towards mauve in the presence of magnesium and towards turquoise with titanium.
Cold end Bout froid холодный участок линии : The stage in glass production involving processing when the container glass is cold. Cold end processes include quality inspection, grinding, engraving, cutting, etc..
Cold end coating : A container glass coating, typically polyethylene applied immediately after annealing via a water based emulsion. This coating makes the glass slippery, improving conveyor transport and protecting the glass container from scratching.
Colemanite Colemaniet Colemanit Colemanita Colémanite Kolemanit Колеманит : Ca3B6O11.5H2O; borocalcite, a hydrated borate mineral used for boron containing glasses.
Conditioning zone : The part of the forehearth after the cooling zone(s) where the glass is brought to the required working temperature.
Container glass Behälterglas Verpakkingsglas Verre d'emballage Тарное стекло : A type of glass for the production of glass containers such as bottles and jars.
Cooling curve : Curves shown by plotting the temperature against time in an annealing cycle.
Cooling zone Koelzone : The part of a forehearth adjacent to the refiner or distributor/working end and before the conditioning zone.
Copper oxide Koperoxide Kupferoxide : CuO, Cu2O; strong colouring oxide. In an alkaline glass they produce a turquoise blue and in a lead glass, green.
Copper wheel engraving : A form of engraving carried out by holding the glass against a small copper wheel which is running in a lathe and fed with a mixture of oil and abrasive powder.
Cords Cordes Koorden, Slieren Schlieren : A glass defect: part of the glass that differs in composition from the surrounding matrix. This different chemical composition produces a change in the refractive index so that the cord is visible as a streak.
Corkage tear : Container glass defect: a vertical surface crack at the inside of the finish.
Corundum Corindon Corindón Korund Κορούνδιο : Al2O3;a mineral valued as an abrasive and, if transparent as a gemstone, called ruby if red and padparadscha if pink-orange. All other colors are called sapphire. The name "corundum" is derived from the Tamil word Kuruvindam or Sanskrit word Kuruvinda meaning ruby.
Cristobalite Cristobaliet Cristobalit Cridtobalita Krystobalit : SiO2; a high-temperature polymorph of silica.
Critical defects Défauts critiques Defectos críticos Kritischer Fehler Критические дефекты : Defects that affect the safety or health of the consumer and people involved in the supply chain, or defects that result in non-conformity with legislation and legal requirements.
Crizzle, Striae Посечки : An imperfection consisting of a multitude of fine surface fractures, cracks.
Crizzled finish : Container glass defect: a finish with many fine surface fractures, mainly across the top.
Crooked finish : Container glass defect: a finish which has a crooked appearance.
Cross-fired furnace Dwarsgestookte oven Four à brûleur transversal Печь с поперечным направлением пламени : Regenerative furnace in which the flames pass across the width of the furnace.
Crown Bóveda Gewelf, Kap Gewölbe Voûte : Top or roof of a glass furnace. It is usually a free-standing arch built of high quality silica bricks.
Crystal, Crystal glass Cristallo, Vetro cristallo Cristal, Verre cristal Kristal, Kristalglas Kristallglas Хрустальное стекло : Lead glass which has a high refractive index and consequently is very brilliant.
Cullet стекольный бой Glasgruis, Scherven Groisil, Calcin Polvere di Vetro Scherben : Scrap glass intended for recycling.
Cycle : The complete repeating sequence of the operation in a specific process in moulding containers.
Cycle time : The elapsed time between a specified point in one cycle and the same point in the next. During the cycle the independent production section will manufacture a single container for each mould loaded into that section.
Cylinder glass Cilinderglas : A technique for producing window glass dating from the 11th century. By blowing a hollow glass sphere and swinging it vertically, gravity pulls the glass into a cylindrical "pod" measuring up to 3 metres long, with a width of up to 45 cm. While still hot, the ends of the pod are cut off and the resulting cylinder cut lengthways and laid flat.
Danner process Danner proces : A widely used method for the production of glass tubing. The process was developed by Edward Danner in 1912. In the Danner process, the glass flow falls onto a rotating, slightly downward pointing mandrel. Air is blown down a shaft through the middle of the mandrel, thus creating a hollow space in the glass as it is drawn off the end of the mandrel by a tractor mechanism. The diameter and thickness of the glass tubing can be controlled by regulating the strength of the air flow through the mandrel and the speed of the drawing machine.
Danny neck, tear on the neck : Container glass defect: a small surface section of glass torn from the neck of the bottle.
Day tank Dagwan, Dagwanoven Tageswanne : A small glass furnace, refilled with batch daily, with melting usually done at night and glass production the following day. Used for producing larger quantities of glass than is possible with pot furnaces (see "pot"). The type of glass to be melted can be changed at short notice.
Dead plate : A stationary plate receiving a glass article awaiting transfer (automatic production of moulded glass)
Decolourising Décoloration Ontkleuring : The process of introducing minerals into the batch which neutralise the colouring effect of other materials in glass e.g. selenium and cobalt are often used to counter the colour produced by iron oxide, often occurring sand and other raw materials
Devitrification Desvitrificación Dévitrification Entglasung Ontglazing Расстекловывание : The crystallisation of a glass melt, which can occur when the melt is held too long at a temperature just below the liquidus temperature.
Devitrite Devitriet Devitrit : Na2O.3CaO.6SiO2 devitrification crystals.
Dichroic : Term to describe glasses that have been coated with one or more ultra-thin crystalline layers of transparent metal oxides to enhance reflections at specific wavelengths of light. The process occurs in a vacuum chamber at elevated temperatures. The resulting effects are striking and brilliant colour reflections at varying angles of incidence.
Diopside Diopsid Diopsiet : MgCaSi2O6, a monoclinic pyroxene mineral.
Direct-fired furnace : A melting furnace having neither a recuperator nor regenerator.
Disthene Distheen Disthène : Al2O3.SiO2; silicate mineral.
Distributor : Section of the furnace to which glass is delivered from the throat and then directed to the forehearths.
Doghouse Einlegeraum, Einlegevorbau Hondenhok, Inleghuis Засыпочный карман : The batch feeding compartment within the furnace.
Dolomite Dolomie Dolomiet Dolomit Dolomita : CaMg(CO3)2; a raw material compound of calcium and magnesium carbonate.
Domestic ware : The collective term for glass containers used in the home (oven dishes, bowls, jars, etc.).
Dominant wavelength Bunttongleiche Wellenlänge Dominante golflengte Longueur d'onde dominante : Describes the hue of a the colour of a glass article according the CIE colour system. On the CIE colour diagram, the dominant wavelength values are indicated on the diagram border.
Double gob : The process of manufacturing a glass container in which each independent production section of the glass forming machine produces two containers in each cycle.
Drag marks : Container glass defect: fine vertical laps near the shoulder or neck of the glass container.
Drawn glass Getrokken glas Verre étiré Vetro tirato : A process for making sheet glass by drawing the molten glass as a sheet directly from the furnace. The thickness of the glass is determined by the drawing rate.
E-glass Стекло Е E-glas Verre de type E : Most common glass formulation used in fiber glass reinforcements, originally formulated for use in electric circuitry as the electrical conductivity is low.
Embossing : Raised lettering, designs or graphics on the surface of a bottle that are formed by incising on the mould surface.
Enamel Email Smalto : A vitreous substance made of finely powdered glass coloured with metallic oxide and suspended in an oily medium for ease of application with a brush. The medium burns away during firing in a low-temperature muffle kiln (about 500-700°C).
End-fired furnace Four à boucle Stirnbrennerofen, U-Flammenofen U-vlamoven Печь с подковообразным пламенем : A furnace in which the flames travel lengthwise through ports in the end wall.
End-port furnace : A furnace with ports for fuel and air in the end wall.
Engraving Graver Graveren : The production of a design in glass by cutting into the glass surface. Engraving methods include rotating copper wheel engraving, diamond or tungsten point engraving, acid etching and sand blasting.
Eskolaite : Cr2O3; chromic oxide. A glass defect that usually consists of thin green hexagonal plates, often in clusters.
Extrusion : A process for the production of continuous strips or rods of material such as glass and also the butyl used in the sealing of insulating glass units. The material, molten in the case of glass, is forced through a die and cut to the required length.
Feeder Speiser питателя : A mechanical device mounted on the casing of the forehearth which delivers the glass in gobs to the forming process. The rate of flow of the molten glass is regulated by the use of different sized orifices in the feeder spout and by a plunger which pushes the glass through the orifice.
Feldspar Feldspat Feldspath Feldespato Veldspaat полевой шпат : Aluminium silicates of potassium, sodium, or calcium; used in the batch as a means of adding alumina to the molten glass.
Fibre glass, fiberglass Fibra de vidrio Glasvezel : Very fine strands of glass (usually with a high boric oxide content) used in the form of glass wool for insulation, glass fibre for matting, etc., and for the reinforcement of plastics. The principal production process involves blowing jets of steam or air onto molten glass as it emerges from a tank furnace through very small diameter nozzles.
Filament : Container glass defect: a hair-like string inside the bottle.
Fining Affinage Läuterung Louteren : The process by which gaseous inclusions are removed from the glass melt. Fining agents induce the formation of large bubbles which collect smaller bubbles as they rise to the surface.
Finish Bague Kop, Mond Mündung : Part of a bottle above the distinctive upper terminus of the neck. It refers to the combination of the lip (upper part) and collar (lower part) of a finish.
Finish tear : Container glass defect: a finish which has a light surface crack in the threads or in the middle.
Fire clay Vuurklei : Clay capable of being subjected to high temperatures without fusing. So, fire clay crucibles are suitable for glass batch melting.
Fire polishing Feuerpolieren Vuurpolijsten : Reheating of a glass object to melt the surface and eliminate superficial irregularities or dullness.
Flange : Container glass defect: a small ring of glass which is pressed out between the guide and neck ring.
Flanged bottom : Container glass defect: a rim of glass around the bottom at the parting line.
Flat glass Flachglas Verre plat Vetro piano Vlakglas : All types of glass (rolled, float, plate, etc.) produced in a flat form, regardless of the method of production.
Flint glass Blank glas Verre blanc Vetro flint Weiβglas, Flintglas флинт-стекло : Clear or colourless glass.
Float process Procesos de flotación : A method for the production of high-quality sheet glass whereby a ribbon of molten glass is fed across a bath of heated liquid, usually molten tin, in a carefully controlled atmosphere. The process was developed by the UK firm Pilkington Brothers.
Fluorspar, fluorite Fluβspat Fluorit Fluorita Fluorite Fluoryt Spath fluor Vloeispaat плавикового шпата : CaF2,Calcium fluoride or fluorite.
Flux-line : Level of molten glass in the furnace
Foam glass Mousse de verre Schaumglas Schuimglas Пеностекло : Glass with a high bubble content, produced by adding additional gases or gas forming substances to the glass melt. The resulting glass has a very low density but a high compressive strength and dimensional stability, making it particularly suitable for thermally and acoustically insulation of construction materials.
Forehearth Avant-corps Voorhaard Канал питателя : A channel along which molten glass flows from the furnace to the forming machines.
Forsterite Forsteriet : Mg2,SiO4, magnesium silicate.
Fourcault process Fourcault-Prozess, Fourcault-Verfahren : A process for manufacturing sheet glass, invented by a Belgian engineer in 1905, by which sheet glass is drawn directly from the melting tank. The slower the draw, the thicker the glass.
Freaks : Container glass defect: odd shapes and conditions that render the glass container unusable e.g. bent or cocked necks.
Frit : Batch material that is melted with other materials and then ground into powder form before being added to the batch.
Fulgurite Fulguriet, Bliksembuis Фульгурит : Natural hollow glass tube formed in quartz sand or soil by lightning strikes. Fulgurites are formed when lightning with a temperature of at least 1800°C instantaneously melts silica on a conductive surface and fuses grains together; the fulgurite tube is the cooled product. They are sometimes referred to as petrified lightning.
Fused cast refractories Smeltgegoten vuurvast : Refractories which are made by melting the component materials in an electric furnace, and then pouring the molten refractory materials into moulds.
Glass Cam Скло Cтакло тъклo Стекла De sticlă Glas Gler Gotë Kaca Klaas Kioo Ly Sklo Szkło Şüşə Üveg Verre Vetro Vidrio Vidro Ħġieġ Шкла Γυαλί कांच 유리 ガラス กระจก الزجاج 玻璃 : Glass is an inorganic product of fusion that has cooled to a rigid condition without crystallisation.
Glass-ceramics Glaskeramiek Glaskeramik : material consisting of an amorphous phase (glass) and crystalline phases (ceramics). Glass-ceramics are produced by a controlled crystallization after the glass manufacturing process. Glass-ceramics have interesting properties like high strength, toughness, translucency or opacity, low or even negative thermal expansion, high temperature stability and high chemical durability. Glass ceramics are e.g. used for cooktops and cookware as well as for astronomical telescopes using the interesting thermo-mechanical properties of glass-ceramics.
Glass container : General term for glass bottles and jars.
Glass wool Glaswol Glaswolle Laine de verre Lana di vetro Lano de vidrio : An insulating material made from fiberglass, arranged into a texture similar to wool.
Glory hole : A high-temperature chamber or hole in the side of a furnace used for reheating and reshaping glass either on a rod or blow pipe.
Gob Glasdruppel Goutte de verre, Paraison Tropfen : A portion of the molten glass which is to be expanded into a glass item.
Gob feeder капельный питатель : A machine mounted at the end of the forehearth that dispenses gobs of molten glass of consistent size and weight for forming into glass containers.
Gold pink : Common name for pink coloured glasses that require gold oxide as a coloring agent.
Gold ruby : Deep red glass, coloured by the addition of gold chloride to the batch.
Grisaille : A decorative painting in monochrome gray on stained glass windows.
Gypsum Alçi Gesso Gips Gipsita Gipsz Gypse Yeso Γύψος : CaSO4.2H2O, mineral.
Hackle marks : Fine ridges on the fracture surface of glass parallel to the direction of propagation of the fracture.
Haematite Hematiet Hématite : Fe2O3, mineral.
Hard glass Hard glas Hartglas : A glass with high softening point or high viscosity.
Head space Kopfraum Kopruimte : Unfilled space in a glass container.
Heat resistant glass : Glass which has a low coefficient of expansion and which is therefore less liable to thermal shock. Borosilicate glass is the most common type of heat resistant glass.
Heel Hiel : The lowest portion of a bottle where the body begins to curve into the base.
Heel check : A container glass defect: a vertical check located at the heel of the container.
Heel tap : A container glass defect where excess glass has been distributed into the heel.
Hollow ware, Hollow glass ware Hohlglas Holglas Verre creux полые стеклоизделия : A term used to refer to a wide variety of containers and receptacles: container glass (bottles, jars, medical and packaging glass), tableware (drinking glasses, bowls, etc.), construction hollow ware (glass building blocks, etc.), medico-technical glassware (laboratory equipment, tubing, etc.) and lighting glass (lamps, bulbs, etc.).
Hot end Bout chaud горячийучасток линии : The area of a glass manufacturing plant where molten glass is processed.
Hot end coating : Container glass coating consisting (usually) of a very thin layer of tin oxide applied immediately before annealing. The coating renders the surface of the glass more adhesive to the cold end coating.
Hot spot Point chaud : The area inside a furnace, on the surface of the melt, which has reached the maximum temperature.
Hydrofluoric acid Acide fluorhydrique Acido fluorhídrico Acido fluoridrico : HF, a highly corrosive acid that attacks glass. Hydrofluoric acid is used for acid etching.
Ice glass : A decorative effect hat causes the glass surface to resemble cracked ice. By repeatedly plunging a parison of hot glass into cold water and withdrawing it quickly, the thermal shock creates fissures in the surface. These fissures impart a frosted appearance after the parison has been reheated to continue the forming process.
Iridescence : The rainbowlike effect that changes according to the angle from which it is viewed or the angle of incidence of the source of light.
Iridescent : Surface treatment in which a layer of metallic oxide is bonded to the hot glass surface just after sheet-forming, resulting in a colourful, rainbowlike, shimmering effect.
I.S. Machine I.S. Maschine Machine I.S. : Individual section container forming machines; made up of individual but identical sections placed side by side in line. Each section comprises an arrangement of mechanisms with gears enabling the sections to be started or stopped independently of the others, making the I.S. machine more flexible than continuous- or intermittent-motion rotary machines.
Jar Bokaal, Pot Pot : Rigid (glass) container with a wide mouth or opening.
Kaolinite Kaoliniet : Al2Si2O5(OH)4, a clay mineral. Rocks that are rich in kaolinite are known as kaolin or china clay. Kaolin is named after the hill in China (Kao-ling) from which it was mined for centuries.
Knockout : Container glass defect: a small glass protrusion caused by a small chip in the mould seam.
Knot Knobbel Knoten : A glass defect: inhomogeneity in the form of a vitreous lump.
Kyanite Kyaniet : Al2O3.SiO2; silicate mineral. It occurs as a natural contaminant of sands.
Laminated glass Cristal laminado Многослойное стекло Verre feuilleté Vetro stratificato, vetro laminato Vidro laminado : Glass consisting of two or more sheets of glass with one or more viscous plastic layers "sandwiched" between the glass panes. The solid joining of the glasses takes place in an autoclave. When laminated safety glass breaks, the pieces remain attached to the internal plastic layer and the glass remains transparent.
Lead crystal Bleikristall, Bleikristallglas Cristal au plomb Loodkristal : Type of glass with a high lead oxide (PbO) content. Such glass has a high refractive index and is particularly suited for decoration by cutting.
Lehr : Oven used for annealing glassware.
Leopard spots : Term used in the façade industry to describe the manifestation, under certain light and viewing conditions, of patterns and colourful areas in heat-treated glass due to its anisotropic characteristics.
Letter checks : Container glass defect: small cracks or fissures in any lettering or embossing.
Leucite Leuciet Leucit : K2O.Al2O3.4SiO2, mineral composed of potassium and aluminium tectosilicate.
Limestone Calcaire Caliza Kalksteen, Kalk Kalkstein, Kalk : CaCO3; a sedimentary rock composed mainly of calcium carbonate which is added to the batch to provide calcium oxide.
Line over finish, LOF, Line over Mündungsfalte : A container glass defect: line across the sealing surface of a glass container that can cause a bottle leak after filling.
Liquidus temperature Liquidustemperatur Liquidustemperatuur Температура ликвидуса : The maximum temperature at which an equilibrium exists between the molten glass and its primary crystalline phase.
Littleton softening point Point de Littleton Verwekingstemperatuur : The temperature at which glass will deform under its own weight; the corresponding viscosity is 106.6Pa.S.
Loading marks : A glass container defect: surface marks in the upper region of the bottle, often with a fine line of blisters along these marks.
Low emissivity glass, low-E glass Laag-emissiviteitsglas Verre à basse émissivité Vetro basso emissivo : Glass having a special thin-film metallic or oxide coating which allows the passage of short-wave solar energy but prevents long-wave energy produced by heating systems and lighting from escaping outside. Low-E glass thus allows light to enter while also providing thermal insulation.
Magnesia, magnesium oxide Magnésie Magnesiumoxide : MgO2; a white mineral that occurs naturally as periclase
Magnesite Magnesiet Magnesit Magnésite Magnezit : MgCO3; magnesium carbonate
Major defects Défauts majeurs Defectos mayores Hoofdfouten : Major (container glass) defects are defects that are not critical (see critical defects) but that make the product unsuitable for the purpose it was intended for and/or cause disturbance during handling in the supply chain.
Mantle block : A refractory block fitting in the gap between forehearth zones.
Marangoni effect : The Marangoni effect takes place when there is a gradient of surface tension at the interface between two phases e.g. a liquid-gas interface. The Marangoni effect is the mass transfer along this interface. Due to the Marangoni effect, there is a severe corrosion of the refractory blocks at the glass melt surface line.
Metal line Fluxlijn, Glaslijn : The surface line of a glass (or metal) melt in a furnace or pot.
Microcline Microklien : KAlSi3O8, a potassium-rich alkali feldspar.
Milk glass Молочное стекло : An opaque or translucent, milky white or coloured glass, blown or pressed into a wide variety of shapes.
Minor defects Défauts mineurs Defectos menores Kleine fouten : Minor (container glass) defects are small defects which are not critical defects (see 'critical defects') or major defects (see 'major defects') but which influence the (visual) appearance of a glass container in a negative way.
Moldavite Moldaviet Молдавит : An olive-green or dull greenish vitreous substance possibly formed by a meteorite impact.
Molybdenum Molybdän Molybdeen : Mo, a metallic transition element commonly used for electrodes in glass furnaces (electric melting).
Mould Form Moule Vorm форма : A form, normally made of metal (or wood), used for shaping and/or decorating molten glass. Some moulds (e.g., dip moulds impart a pattern to the parison, which is then withdrawn, and blown and tooled to the desired shape and size; other moulds are used to give the object its final form, with or without decoration.
Mould seam шов формы : Raised lines on a glass article that are formed where the edges of different mould parts came together.
Mullite Mulliet Mullit Mullita Муллит : 2SiO23Al2O3; an alumino-silicate e.g. used in furnace refractory blocks.
Narrow-neck ware, Narrow neck glass containers Enghalsbehälter узкогорлая стеклотара : Glass containers, such as bottles, whose opening is tapered and of smaller diameter than the body of the vessel.
Neck Col Hals : Part of a bottle that lies above the shoulder and below the finish.
Neck-ring Moule de bague Mündungsform, Mündungsring, Mündungsrand Nekring : In the production of glass containers, the tool coupled with the blank mould (parison) which gives the shape to the neck (finish) of the container. During the shaping process in the IS machine, the neck ring transports the glass container into the blow mould (or finishing mould).
Neck-ring parting line : Seam where the blank mould and the neck ring join (container glass).
Neck ring seam : Container glass defect: a seam of glass lying across the top or the side of the finish.
Nepheline Nefelien Nefelin Nefelina Nephelin Néphéline Нефелин : (Na,K)2O.Al2O3.2SiO2; a rock forming mineral, common in nepheline syenite; feldspathoid; silica-under saturated aluminosilicate. The name comes from the Greek 'νεφος' for 'cloud' since it turns cloudy when treated with strong acid.
Nephelinesyenite Nefelina sienito Nefelien syeniet 霞石閃長岩 : a plutonic rock consisting of nepheline and alkali feldspar.
Nickel sulphide Nikkelsulfide : Inorganic compound with the formula NiS.Occurs as a spherical or sometimes ellipsoidal inclusion with metallic appearance. A glass defect that causes spontaneous breakage by volumetric expansion especially in heat-strengthened and temepered glass.
NNPB PSEO : Narrow neck press-blow; the process of manufacturing narrow-neck glass containers through the press-blow process.
Nosean Noseaan : Na8Al6Si6O24(SO4),a mineral of the feldspathoid group.
Obsidian Đá vỏ chai Obsidiaan Obsidiana Obsidienne Obsidyen Ossidiana обсидианы : A natural (usually) black volcanic siliceous glass.
Overpress finish Überpresste Mündung : A critical container glass defect: a finish which has excessive glass projecting upward from the inside edge of the finish
Opal glass Opaalglas Verre opale Opalglas Vetro opalino Vidrio opalino опаловое стекло : Glass that resembles an opal, being translucent and (usually) milky white
Optical glass Cristal óptico, Vidrio óptico Optisches Glas Optisch glas Verre optique Vetro ottico Оптическое стекло : High quality glass having closely specified optical properties used for optical systems.
Orifice : A circular opening in the bottom of the forehearth through which glass flows; in a feeder: an opening in the bottom of the spout formed by the orifice ring.
Orifice ring Ausflussring, Speiserring, Tropfring : A ring forming a hole through which glass flows (feeder process).
Orthoclase Orthoclas Orthoklas Ortoklas Ortoclasa Ορθόκλαστο : KAlSi3O8, feldspar mineral.
Overflow capacity : The volume measurement of a container at the point of overflow.
Overpress Surpressées : Glass defect; projecting excess glass resulting from imperfect closing of mould joints; a small ridge of glass on the sealing surface of the finish of a glass container.
Parison Paraison : Preliminary shape or blank from which a glass article is to be formed.
Parison mould Moule ébaucheur Voorvorm : Blank mould, a preliminary bottle forming mould where the parison is formed.
Parting line Разделительная линия : Line or seam on glass articles resulting from the joint of the two mould parts.
Pelletising : The preparation of materials, e.g. batch ingredients, in pellet form.
Phonolite Fonoliet, klanksteen : An extrusive volcanic rock; a fine-grained equivalent of nepheline syenite.
Pilkington process : Float glass process, invented by Pilkington and Bickerstaff: a method of high quality flat glass production by floating molten glass over a bath of molten tin.
Pincers : A glassworker's tool used for decorating glass items by pinching the glass while it is hot.
Pinhole : Container glass defect: any opening causing leakage, most often occurring in bottles with pointed corners.
Plagioclase Plagioclasa Plagioclasio Plagioklaas Plagioklazy : Na(AlSi3O8) - Ca(AlSi2O8), feldspar mineral
Plate glass : High quality flat glass made by the casting or rolling of molten glass which is then mechanically ground and polished to produce a smooth and transparent sheet.
Plunger Plunjer Preβstempel : A tool used in the production of glass containers during the first stage of shape forming in the IS machine. The task of the plunger is to help give the glass container its final shape inside the parison (or blank mould).
Portlandite Portlandiet : Ca(OH)2, calcium hydroxide mineral.
Pot furnace Four à pot, Four à creuset Potoven Горшковая печь : A furnace designed and built to hold one or more pots for melting glass.
Press and blow process Pers-blaas proces Preβ-Blas-Verfahren Procédé presser souffler Прессо-выдувной способ : A (container) glass manufacturing process: the finish and parison are pressed and the parison is subsequently blown to form the final shape.
Pressed glass Persglas Pressglas Verre pressé : Glassware formed by pressing a gob between a mould and a plunger.
Prince Rupert's drop Prins Ruperts druppel : Toughened glass beads created by dripping molten glass into cold water, which causes it to solidify into a droplet with a long, thin tail. These droplets are characterized by very high internal residual stresses, which give rise to a very high strength on the bulbous end without breaking, while exhibiting explosive disintegration due to the internal stress release if the tail end is even slightly damaged.
Push-up Bodeneinstich Piqûre Ziel : A steep rise or pushed-up portion of the base of a bottle (particularly of a wine bottle).
Pull : Quantity or weight of glass delivered by a furnace in a given time, usually 24 hours.
Pyrex : A type of borosilicate glass.
Pyrite Pirit Pirita Pirite Piryt Pyriet Pyrit : FeS2, an iron sulphide mineral.
Quartz Kwarts Quarz кварца : SiO2, An abundant mineral in the earth's continental crust. It is made of a continuous framework of SiO4silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2
Quartz glass Kwartsglas Quarzglas Verre de quartz Vetro di quarzo Vidrio de cuarzo : Quartz glass (fused quartz) is a type of glass containing primarily silica (SiO2) in amorphous form.
Ream : Similar to cords, but reams occur in layers rather than threads (more common in flat glass where the layers are be drawn out).
Reboil Sekundäre Blasenbildung : The formation of bubbles at refining temperatures which can lead to blisters in the glass.
Recuperative furnace Horno recuperador Pекуперативная печь Recuperatieve oven Recuperativofen : A furnace having a recuperator.
Recuperator Récupérateur : A continuous heat exchanger in which the combustion air is heated by the flue gasses.
Redox : The abbreviated form of reduction-oxidation. The term redox equilibria is used to refer to the balance between reduction and oxidation in the glass furnace.
Refiner Affineur Werkwan : A compartment of a glass tank furnace for the purpose of conditioning the glass.
Refining Affinage Läuterung Loutering : Refining ensures that a homogeneous glass is produced during founding by eliminating bubbles (see also "bubbles"). Refining is achieved through the action of certain chemicals (refining agents) added to the batch recipe and also by keeping the glass above the liquidus temperature so that the bubbles rise to the surface.
Refractive index Brechungsindex Brekingsindex Indice de réfraction Indice di rifrazione : A standard of measurement used particularly to establish the qualities of optical glass. The index is the ratio of the sine of the angle of incidence of a ray of light to the sine of the angle of refraction (the change in direction when a ray of light passes from one medium to another) by the glass. The second medium normally used to establish the index is a vacuum.
Refractories Feuerfestmaterial Réfractaires Vuurvast materiaal : Material capable of withstanding extremely high temperatures and thus used in furnaces for industries such as glass and steel where raw materials have to be heated to a molten form.
Regenerative furnace Horno regenerador Регенеративная печь Regeneratieve oven Regenerativofen : A furnace having a regenerator.
Regenerator Régénérateur : A cyclic heat interchanger alternatively receiving heat from exhaust gasses and transferring heat to air or gas before combustion.
Regenerator Chambers Cámaras de regeneración Chambres de régénération Regenerativkammern Regeneratorkamers камера регенератора : Cyclic heat interchanging chambers of a regenerative furnace, alternatively receiving heat from exhaust gasses and transferring heat to air or gas before combustion.
Ribbon machine : A machine with two continuous tracks, one above the other. Glass is fed between the tracks, the upper one carries blow moulds. The gobs of glass hang down from the continuous ribbon are blown into articles e.g. lamp bulbs.
Rim : The extreme upper surface of the finish of a glass container where the bore begins.
Ring mould Кольцевая форма : The neck forming and holding portion of a parison mould.
Rocker, Rocker bottom : Container glass defect: centre of bottom protrudes beyond the plane of the outer rim allowing the glass container to rock.
Rods : Cylindrical sticks of glass used primarily in flameworking and glass bead making. They are available in a wide colour range and many expansion coefficients.
Rolled glass Прокатное стекло : Rolled (or cast) glass is a translucent glass. It is used where transparency of the glass sheet is not important or not desired. To produce rolled glass, molten glass pours from the melting tank over a refractory barrier and onto the machine slab where it flows under a refractory gate, which regulates the volume of glass, and then between two water-cooled rollers. The distance between the rollers determines the thickness of the glass.
Roving : A collection of bundles of continuous filaments in untwisted strands.
Rutile Rutiel Rutil Rutilo Rutyl Рутил : TiO2, mineral.
Saddle finish : A glass container defect: a gradual saddle like slope or dip in the finish.
Safety glass Veiligheidsglas Vetrata di securezza, vetro antirapina Vidrio de seguridad Vitrage de sécurité Безопасное стекло : Glass which does not disintegrate into sharp and potentially dangerous splinters when it is broken. Safety glass may be produced by laminating or by tempering.
Sanbornite Sanborniet : A BaSi2O5, a barium phyllosilicate mineral.
Sand Arena Sabbia Sable Zand песка बालू رمللزجاج : The most common form of silica (SiO2) used in making glass. It is collected from the seashore or, preferably, from deposits that have fewer impurities. For most present-day glass making, sand must have a low iron content.
Sandblasting Sabbiatura Sandstrahlen Zandstralen пескоструйная очистка : High-pressured air with sand applied to the surface of a glass object to carve texture.
Sanidine Sanidin Sanidina Sanidino Sanidyn Санидин サニディン : (K,Na)(Si,Al)4O8, mineral, a high temperature form of (potassium) feldspar.
Screen printing : A process for the decoration of glass whereby coloured ink is forced by a flexible "squeegee" through a fine-mesh screen, or "mask", (traditionally made of silk, now also made of nylon, polyester and stainless steel) onto the glass surface. A separate mask is used for the application of each colour.
Seam Couture Naad : Mark on glass surface resulting from joint of matching mould parts.
Seeds Gispen Puces : Relatively small bubbles (0.2 - 2mm) of gas in the glass matrix.
Selenium Selenio : A chemical element with symbol Se and atomic number 34. Selenium has found wide application in decolorizing flint glasses.
Senarmontite Senarmontiet : Sb2O3, mineral; cubic form. Orthorombic form below 606°C is called valentinite.
Shadow wall Schattenwand : An open lattice structure built on top of the bridge wall or suspended from the crown to limit the heat flow from the melter to the refiner or working end.
Shear marks Marques de ciseaux Messerschnittmarkierungen, Scherenschnittmarkierung след от отреза ножниц : A glass container defect: a scar from the shearing operation (gob cutting) usually a slightly curved shape with a feathery appearance. Shear marks may run over the sealing surface and/or occur on the bottom of the glass container.
Sheet glass Flachglas Vidrio plano Vlakglas : Flat glass made by continuous drawing.
Shoulder Schouder Schulter : Part of a glass container: extends from the base of the neck to the straight part of the body.
Shoulder tear : Container glass defect: surface cracks on the shoulder of the glass container, usually wavy in appearance.
Sidewall : The side of a glass container extending from the heel upwards to the shoulder. The label panel usually appears in the sidewall of the container.
Silica Kieselerde Silice кремнезёма : SiO2, Silicon dioxide, a mixture that is the main ingredient of glass. The most common form of silica used in glass-making has always been sand.
Silicon sphere : Si sphere; glass defect, sphere consisting of elemental silicon. The defect is usually caused by aluminium that causes a reduction of SiO2.
Sill block : Refractory block above the melting end soldier or sidewall block supporting the burner block assembly.
Sillimanite Sillimaniet Sillimanit : Al2O3.SiO2,an alumino-silicate mineral.
Skimmer block : A refractory block that holds back glass surface impurities, positioned at the forehearth entry and adjacent to the refiner or distributor.
Soda ash Carbonatode sodio Carbonate de sódio Carbonato di sodio, soda Natri Cacbonat Natriumcarbonat, Soda Natriumkarbonat Soda Soda, natriumcarbonaat Sodyum Karbonat кальцинированная сода : Sodium carbonate (Na2CO3); the main source of sodium oxide (Na2O), or 'soda'. This anhydrous, white powder is added to the glass batch, with sodium oxide becoming part of the glass and carbon dioxide being released.
Soda-lime glass Natronkalkglas Kalknatronglas, Kalk-Natron-Glass, Soda-Kalkglas Verre sodocalcique известково-натриевое стекло ソーダ石灰ガラス : The most common type of industrially produced glass. A typical soda-lime glass is composed of silica (70-75%), soda (11-16%) and lime (8-15%), plus small amounts of other materials to provide particular properties such as colour.
Sodium nitrate, soda niter Natriumnitraat Nitrate de soude : NaNO3; chemical compound, used as an oxidising agent in glass melting.
Sodium sulphate сернокислый натрий Natriumsulfaat Natriumsulfat Sulfate de sodium Sulfato de sodio : Na2SO4; commonly used as a fining agent in glass production.
Softening point Erweichungspunkt Точка размягчения Verwekingstemperatuur : The temperature at which glass will deform under its own weight; the corresponding viscosity is 106.6Pa.S.
Spectral purity Pureté Sättigung Verzadigingsgraad : Describes the concentration of a specific hue of a glass article according the CIE colour system. The spectral purity ranges from 0% to 100%. In the CIE colour diagram, this purity indicates the relative distance of the plotted colour from the centre of the diagram compared to the distance of the centre point to the border of the diagram drawing a straight line through the measured value.
Spike Picot : A critical glass defect; upward pointing protrusions on the base of a glass container.
Spinel Espinela Spinell Spinelle : MgAl2O4, mineral.
Spiticule : Container glass defect: bead or string of glass that is adhered to the inside surface.
Split, split finish : Container glass defect: an open crack starting at the top of the finish and extending downward.
Spodumene Espodumena Spodumeen Spodumen Spodumène : LiO2.Al2O3.2SiO2, a lithium aluminium inosilicate, a source of lithium in glass production.
Spout : End part of a feeder carrying orifice and tube.
Sputtering : The process in which, by passing an electric current through an ionised gas and thus bombarding the surface of a metal cathode with ions, atoms of the desired metal are vaporised and then deposited in a thin film on the glass surface.
Squeeze tester : Container glass quality inspection equipment: each bottle is passed between discs that exert a force to the body of a glass container. Any weakness or crack in the bottle will cause it to fail.
Stem : The narrow part of drinking glasses separating the bowl and the foot.
Stem-ware Стеклоизделие на ножке Stielglas : The collective term given to drinking glasses whose body is connected to the base by a thinner column of glass.
Strain : Residual thermal stress, visible in polarised light.
Strain point Lage ontspanningstemperatuur Unterer Kühlpunkt : Temperature at which 'stress is relieved' in several hours. Below the strain point, at a viscosity of 1013.6Pa.S, glass is essentially an elastic solid.
Stria : Cord of low intensity
Striking : The process of reheating glass after it has cooled in order to develop a colour that only appears within a limited range of temperatures.
Stuck plunger, stuck plug : Glass defect, a small piece of glass, usually sharp, projecting inwards just inside the bore of the bottle.
Sunken shoulder : Container glass defect: a shoulder which is not fully blown up.
Sunken side : Container glass defect: the side of a container is not fully blown up or may have sunk after release from the blow mould.
Sulphate gall : Na2SO4 or K2SO4, sodium or potassium sulphate mineral. Glass defect commonly occurring as ellipsoidal inclusions consisting of bubbles completely filled with translucent crystalline deposits.
Superstructure Верхнее строение Bovenbouw Oberofen, Oberbau : Parts of a glass tank above the sidewall tank blocks.
Tableware Tafelglas : dishes or dishware used for setting a table, serving food and for dining. Tableware includes cutlery and glassware.
Tap : Process of draining a glass furnace under controlled conditions.
Tear : Container glass defect similar to a check; a tear will however not break when tapped.
Tears under finish : Container glass defect: surface cracks which occur on or near the parting line between the neck and the finish.
Temper : The degree of residual stress in annealed glass as measured using a polariscope.
Tempered glass Gehard glas Verre trempé Vetro temprato Vidrio templado Vidro temperado : Glass that has been subjected to a thermal treatment characterized by rapid cooling to produce a compressively stressed surface layer. Tempering puts the outer surfaces into compression and the inner surfaces into tension. Such stresses cause the glass, when broken, to crumble into small granular chunks instead of splintering into jagged shards as plate glass creates. The granular chunks are less likely to cause injury. As a result of its safety and strength, toughened glass is used in a variety of demanding applications, including vehicle windows, shower doors, glass doors and tables, refrigerator trays, mobile screen protectors, as a component of bulletproof glass, for diving masks, and various types of plates and cookware.
Tempering Temperen Tempern : see toughening.
Thenardite Thenardiet : Na2SO4,an anhydrous sodium sulphate mineral.
Thermal conductivity Conductividad térmica Conductivité thermique Conduttività termica Теплопроводность : The passage of heat through a material. Insulation materials are defined as having 'low' thermal conductivity whereas metallic materials generally have 'high' thermal conductivity.
Thermal shock Choc thermique Choque térmico Shock termico Термический удар Thermische schok Thermoschock : The effects of rapid temperature change on a material. In glass, the shock may derive from the external surface of glass expanding or contracting more rapidly than the interior surface as a result of heating or cooling. Any such difference may lead to cracking or shattering.
Thermal shock testing Abschreckprüfung, Wärmeschockprüfung испытание на термический уда : Assessing the effects of rapid temperature change on a material. In glass, the shock may derive from the external surface of glass expanding or contracting more rapidly than the interior surface as a result of heating or cooling. Any such difference may lead to cracking or shattering.
Thermocouple Thermokoppel : A pair of different metals in contact at a point, generating a thermoelectric voltage which can serve as a measure of temperature. The wires are encased in a protective sheath that can be introduced as a probe into the glass furnace or kiln.
Throat Garganta Gorge Keel : The submerged passage between melter and working end (final conditioning zones and feeders).
Toughened glass : see tempered glass.
Toughening Harden : Process in order to make glass particularly resistant to breakage. The process may be physical (thermal) or chemical. In the physical process, the glass sheet is heated to a temperature just below its softening point and then immediately cooled by cold-air in order to produce a compressively stressed surface layer resulting in a stronger glass item which, upon breakage, shatters into tiny pieces with blunt edges (e.g. used for automotive glass). The chemical process is based on the so-called ion-stuffing technique e.g. glass containing sodium is cooled slowly in a salt bath of molten potassium: the sodium ions will migrate from the glass to the salt, while the potassium ions will move to the surface of the glass where they create a denser and therefore stronger surface layer. Glass sheets which have been chemically tempered are more than five times stronger than those which have not undergone any tempering process.
Tridymite Tridimita Tridymiet Tridymit Trydymit Тридимит : SiO2; a high temperature polymorph of quartz.
Tuckstone : A block above the soldier (or side wall) blocks and beneath the breast walls of the melting end and refiner or distributor/working end.
Type I glass Type I glas Verre type I : Highly resistant borosilicate glass, commonly used for pharmaceutical or fine chemical products that are sensitive to pH changes.
Type II glass Type II glas Verre type II : Type II glass containers are made from soda lime glass that has been de-alkalised to obtain an improved chemical resistance.
Type III glass Type III glas Verre type III : Glass containers made of untreated soda-lime glass, having an average chemical resistance.
Ulexite Uleksyt Ulexiet Ulexit Ulexita Uléxite Ουλεξίτης : NaCaB2O9.8H2O; a hydrated borate mineral used for boron containing glasses.
Unfilled finish Bord non fini : Container glass defect: a finish which is incompletely filled in top, bead or thread.
Unit melter : A glass furnace type with burners along both sides and (usually) with a recuperator.
Uranium glass Ouraline Uraniumglas : Glass coloured with uranium oxide or diuranate.
Valentinite Valentiniet Valentinit Βαλεντινίτης : Sb2O3, mineral, orthorombic form below 606°C, cubic form is senarmontite.
Vello process Способ Велло Vello-proces : A drawing process used for the production of glass tubing: glass from the furnace forehearth flows down through an orifice (ring) within which is a rotating conical-ended shaft (or mandrel) over and around which the glass flows. The tube-shaped glass is pulled from the end of the shaft by a tractor machine and turned through 90° into a horizontal position ready for cutting.
Vial : A small cylindrical glass vessel especially for holding liquid medicines.
Viscosity Вязкость Viscosidad Viscosidade Viscosità Viscosité Viscositeit Viskosität Viskositeit Viskositet Viszkozitás Вязкость Độ nhớt श्यानता لزوجة : A measure of the resistance of a fluid (e.g. a glass melt) which is being deformed by either shear stress or tensile stress. Viscosity is the 'thickness' of a fluid. SI unit of dynamic viscosity: Pa.S.
Vitroceramic : Glass-ceramics; see glass-ceramics.
Washboard Стиральная доска : Container glass defect: horizontal waves, ripples on the surface of glassware.
Water glass Silicato di sodio Verre soluble Wasserglas Waterglas Жидкое стекло : Sodium silicate glass that is soluble in water.
Water hammer : A pressure surge or wave resulting when a fluid in motion is forced to stop or change direction suddenly (momentum change). E.g. the water hammer phenomenon occurs when a filled glass container drops suddenly during transportation and/or when it is vibrated. The liquid content remains at the same position for a short period of time due to the inertia which generates cavitation in the liquid. After that, the liquid starts dropping and then strongly hits the inside glass surface of the bottle (bottom), which can lead to the breakage of the glass container.
Weathering Verwitterung : Changes on a glass surface caused by chemical reaction with the environment. Weathering usually involves the leaching of alkali from the glass by water.
Wire edge : Container glass finish defect: a finish which has excessive glass projecting upwards from the inside edge of the finish; contrary to an overpress, the glass does not extend above the sealing surface.
Wired glass : Flat rolled glass reinforced with wire mesh and used especially for glass doors and roofing to prevent objects from smashing through the glass and also to hold pieces of broken glass together. By holding the glass together, it can also protect against break-in and the spreading of fire. Wired glass is produced by continuously feeding wire mesh from a roller into the molten glass ribbon just before it undergoes cooling.
Wollastonite Wollastoniet Wollastonit Wollastonita Волластонит : CaO.SiO2; a calcium inosilicate mineral.
Working end Arbeitsende : Compartment of a glass tank where glass is delivered for forming.
Working point Point de travail Verarbeitungspunkt Werktemperatuur, Verwerkingspunt : Temperature at which the molten glass can be deformed/manipulated: the viscous glass mass is deformed into its final shape at a viscosity of 103Pa.S
Working range Palier de travail Verarbeitungsbereich : Temperature range where the viscosity is between 103 and 106.6Pa.S. If there is a wide working range, we have a 'long glass'. If the working range is narrow, we have a 'short glass'. If the working range is situated at higher temperatures, we have so called 'hard glass'. A 'soft glass' has its working range at lower temperatures.
X-ray diffraction, XRD Diffraction des rayons X Röntgendiffractie : X-ray diffraction is an analysis technique used for determining the atomic and molecular structure of crystalline material, in which the atoms cause a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, the crystalline material and its three-dimensional crystal structure can be identified and analysed.
X-ray fluorescence, XRF Fluorescence X Röntgenfluorescentie : X-ray fluorescence (XRF) is the emission of characteristic secondary (or fluorescent) X-rays from a material that has been excited by bombarding with high-energy X-rays or gamma rays. X-ray fluorescence is as a powerful and precise technique to analyse the oxide types and content in glass products.
Yarn : Twisted strands of roving, used to weave textile reinforcements.
ZAC : Abbreviation for zircon-alumina electrocast refractories.
Zircon Cyrkon Zircão Zircón Zirkoon Zirkon Ζιρκόνιο Циркон : ZrO2.SiO2, zirconium silicate e.g. used as refractory.
Zirconia, zirconium dioxide Cirkónium-dioxid Dióxido de zircónio Ossido di zirconio Zirkondioxid Zirkonyum dioksit Zirkoonoxide двуокись циркони دیاکسید زیرکونیوم : ZrO2, Its most naturally occurring form, with a monoclinic crystalline structure, is the rare mineral baddeleyite. ZrO2 is often used for refractories because of the high melting point, chemical inertness and low thermal conductivity.