Browsing by Author "Smrček, Antonín"
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- ItemEvolution of the compositions of commercial glasses 1830 to 1990. Part I. Flat glass(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Smrček, AntonínMore than 500 analyses of flat glasses made sinee 1830 in seventeen eountries have been analysed statistieally. They inelude samples made by all the eommonly used proeesses. The purpose of the analysis was to investigate differenees related to type of process, region of manufacture, and the passage of time. Changes in the use of the various important constituents are demonstrated and commented on. In the early years of the twentieth Century only sulphate was used as refining agent and high SO3 contents were found until around 1960. Other constituents, such as BaO and B2O3, were tried but did not gain acceptance. As time went by variations within any company decreased and compositions of all flat glasses converged. Differences in flat glass compositions produced by different processes were rather random as were differences between various countries.
- ItemEvolution of the compositions of commercial glasses 1830 to 1990. Part II. Container glass(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Smrček, AntonínThis paper treats container glasses in the same way as an earlier paper reviewed flat glass compositions. Data for more than 970 analyses of container glasses manufactured during 150 years in 37 countries have been collected and analysed. The data obviously include containers made by hand as well as by machine from green, white and amber glasses. Compositions developed along two lines, one being green and brown glasses coloured by manganese; such glasses were characterized by low alkali content compensated by increased RO and higher AI2O3 contents. The other, younger, line includes white glasses historically descended from old "forest glasses" and closely related amber glasses. The compositions of both lines converged gradually, so that from about 1970 all container glasses have fallen within a narrow range of compositions, differing in little but their colouring oxides. Differences between particular producers and countries have decreased a great deal.
- ItemEvolution of the compositions of commercial glasses 1830 to 1990. Part III. Pressed glass(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2005) Smrček, AntonínThis paper considers the evolution of glasses used for pressed wares in the way already used for flat and container glass. About 160 samples of common pressed soda-lime-silica glass used for utilitarian and technical purposes are considered. The composition of pressed glass is related to flint container glass, it differs mainly in higher alkali content, low iron content and, from time to time, in addidons of K2O and BaO. Development of the compositions of flat, container, and pressed glasses is then compared and notable features such as the introductions of magnesia and alumina discussed, as is the use of high-alumina low-alkali container glasses. How future constraints may affect further developments is also considered.