Glass-ceramic#Cooktops
Ceran is the brand name for glass ceramic hobs Schott AG in Mainz ( to 30 June 2004 Schott glass works ). Schott produced since 1973 the first German manufacturer Hobs from the glass-ceramic material in series. In 1971 the product was manufactured ceramic in a small series and presented as a prototype at the show Domotechnica. Because of its favorable properties, the ceramic product developed since the 1980s, the world market leader in the field of glass-ceramic hotplates.
Prehistory
Already on November 6, 1962 ceramic was registered as a word mark of Scotland at the German Patent and Trademark Office. The brand name ceramic thus stood for future products. The product idea for ceramic hobs was created only in 1969. Both an employee of Schott glass works as well as the Managing Director of Imperial works had observed the American market for glass ceramic hobs. It was recognized by Schott that for the production of high quality ceramic glass cooktops, especially in comparison to the American models, still had to be developed first a sophisticated heating system. A hand formed the basis for the start of production in 1971 in the Schott glass works, the existing technical production requirements. Schott presented in separate furnaces already glass-ceramic for use in space ago. On the other hand, the test was targeted by the company based in Mainz taken the heat output of ceramic and like its competitors, such as the American pyroceram hotplate made of ceramic glass and the traditional cast-steel plates to improve.
In coordination with various manufacturers of electric cookers on cooperation the Application Technology Laboratory was established on 1 October 1971. The first electric cooker with ceramic hob was presented at the fair Domotechnica 1971. It was a prototype that had the characteristic features of later ceramic hobs: a flat, black surface under the shine through the coils in the on-state red. In addition, the heating zone could be heated to a maximum of 700 ° C, at the same time the surrounding zones heated to about 100 ° C. The problem at that time was the low quantity of produced glass-ceramic cooktops. On 7 July 1972, the future series production was officially declared the project. In August 1972, the project management was transferred to Dipl. Ing Herwig Scheidler. Scheidler was Head of Application Technology Laboratory. Considered together with Prof. Dr. Jürgen Petzoldt, the inventor of the glass ceramic and Hans Arno Roth, who negotiated intensively with equipment manufacturers, as one of the three fathers of ceramic.
Start of series production and first economic successes
On 29 January 1973, production of the first ceramic plates ran in series. In this phase, the optimization of the product ceramic stood in relation to the most important features of boiling time, energy consumption and the adjustability of the stock temperature in the foreground. In the second production phase, which began on January 2, 1974, the number of air inclusions was reduced in the glass ceramic and significantly improves product quality. Nevertheless, remained the actual sales for the financial year 1973/74, which ended on September 30, 1974, with 7000 sold ceramic cooking surfaces up to expectations. As a reason for this, declining by the oil crisis willingness to buy is seen. At the request of the stove industry Schott developed the marking of ceramic cooking zones on. Had they been initially highlighted in the sandblasting process, we sought to create colorful accents on the decoration for an opportunity. Finally, a ceramizing together with the company Leipold in Fuerth was developed. Ceramic decorations should meet in addition to the optical two more practical functions: the heated zone should be recognized so as to avoid an energy loss during the cooking process. Some equipment manufacturers, such as Bauknecht, Electrolux and AEG put on an individual decor of ceramic cooking surfaces to stand out from other suppliers. With the willingness ceramic hobs constantly develop, the Schott glass works were not only a component supplier for equipment manufacturers. The development of a ceramic system included that as of August 1975 in the ceramic post a montage friendly frame bonding was carried out as standard. As a result of improvements in sales of ceramic rose to 18,000 in the financial year 1974/75. In fiscal year 1975/76, as sales had grown to 48,000 ceramic plates, the turnover achieved with ceramic was the first time about the costs.
Marketing of ceramic system
To be able to compete with ceramic permanent on the market, Schott sat on building a ceramic cooking system. After its entry into the consumer and trade marketing in 1976, the company used the insights gained there for the marketing of ceramic cooking surfaces and the development of complementary products. In Consumer ceramic was perceived as a product that is easy to maintain and aesthetically beautiful, but also fragile. They also created a danger of combustion to still switched plates. This was counteracted by the incorporation of a neon lamp which indicates the residual heat. With the development of " Ceraquick " scraper and the creation of a care instructions for ceramic hobs you underlined the ease of use when cleaning.
Ceramic as a world leader
Schott sold on February 28, 1980, the millionth ceramic cooking surface and had thus become the market leader in the field of glass -ceramic cooktops in Europe. The development of the North American market began in 1985. For this one presented at the International Appliance Technical Conference already successfully marketed in Europe Ceran -top system before. In response to the reputation and lost sales since the late 1970s, Corning 's main rival, draws, Schott AG, in 1983 the market for glass ceramic cooktops back. Schott takes henceforth a monopoly.
International manufacturing sites
Ceramic is produced at three production sites: Mainz, Vincennes (Indiana ) (USA) and Suzhou ( China).
In 1991, with the ceramic post in Vincennes started as a joint venture between Schott and AFG GEMTRON, which the company Schott Hometech North America started. 1993 has started with the production in Jena and now ended. 2002, the post-processing in China was recorded.
Awards
The Schott glass works in 1984 awarded the awarded annually by the German Marketing Prize. At the award ceremony presented itself as a product innovator and acknowledged Ceran an essential position within the company strategy. In -house publications ceramic as the main product of Schott was henceforth officially called. 2010 received the Schott AG for the development of their arsenic and antimony produced ceramic cooktops the German Innovation Award. The Schott AG was the first who did not need to use during the purification process. For its eco-friendly manufacturing process Ceran was nominated for the 2011 German Sustainability Award, making it one of three finalists for the category Germany's most sustainable products / services. In November 2012 Ceramic was awarded by the German publishing standards editions titled Brand of the century.
Technical Features
Glass-ceramic plates have a high transmittance for radiation of heat ( that is, glass-ceramic, such as glass having a low attenuation constant for part of the infrared spectrum ), and virtually no thermal expansion. They have a smooth, non-porous surface. Therefore, the majority of the heat transfer occurs in glass ceramic hobs heat radiation instead of heat conduction (as in steel or iron hobs). The thermal conductivity is 1.46 W / ( m · K ) is very low, resulting in that the region is adjacent to the cold hob. The other hand, steel or iron hobs use for the heat transport only their high thermal conductivity. Ceramic glass is a semi-crystalline material, the appropriate glasses produced by incomplete crystallization ( " ceramicization "). Result in the production in the glass matrix of areas with an ordered crystal structure. This glass-ceramic is at the appropriate chemical composition and the preceding partial neutralization crystal has a negative coefficient of thermal expansion, so will contract when heated. If the ratio of glass to crystal phase properly adjusted, creating a material that expands as good as not upon heating. Main constituents of the glass-ceramic for ceramic cooktops are lithium, aluminum and silicon oxide ( so-called " LAS glass- ceramics "). Such glass ceramic can withstand sudden temperature shocks undamaged to 750 K.
Applications
The most widely used has found the glass ceramic cooking surface in conjunction with the electric radiant heating. Here arranged below the glass ceramic heating resistor is heated up to red heat. The radiation emitted by the heating element passes through the infrared heat radiation very infrared transmissive ceramic glass therethrough, so that it can heat up the bottom of the pot or the pan. The cooking surface can be almost no heat loss from the heating energy to the cooking vessel, and heat is hardly discharged to the sides. This results in the possibility of hobs into multiple, individually switchable to divide zones, which allows to change the active hob the size of the pot bottom.
Besides the classic ceramic glass ceramic cooking surface that can be produced in different sizes, shapes and colors, there are now also other versions of the product, for example, grill equipment from ceramic or glass ceramic cooktops to accommodate a wok. Often the front windows of stoves made of glass ceramics.
Originally, the ceramic glass (trade name Zerodur ) by Schott was developed for mirror support of astronomical telescopes and is there in use for decades, for example in the Keck telescopes or the Gran Telescopio Canarias.