Читать книгу Encyclopedia of Glass Science, Technology, History, and Culture - Группа авторов - Страница 44

From a technical point of view, glasses are classified in terms of applications rather than chemical composition. The following list presents the most important groups of industrial products under this aspect.

Glass hollowware
Container glass	Bottles (flint, green, amber)
	Preserving jars
	Flaconnage
Tableware	Stemware, kitchenware, vases
Flat glass
Architectural glass
Glass for personal security and property protection
Glass for photovoltaic application
Fire‐resistant glass
Automotive glass
Decorative interior glass and mirrors
Fiber glass
Continuous fibers (textile; reinforcement)	Multi‐purpose (E)
Acid resistant (A, C, E‐CR)
Alkali resistant (AR)
High strength (R, S)
Dielectric (D)
Fibers for thermal and acoustic insulation	Glasswool, stonewool
Other glass, comprising specialty glass
Soluble glass (water glass)	For chemicals and detergents
Foam glass	For thermal insulation
Laboratory and industry	Lab ware glasses
Glasses for process plants
Electrode glasses
Artificial lighting	Incandescent lamps
	Gas‐discharge lamps
	Semiconductor light sources
	Reflectors
Pharmaceutics and medicine	Ampoules and vials
Antibacterial glasses
Bioactive glasses
Optics	Eyeglasses
	Cameras, microscopes, telescopes
	Fiber optics and endoscopy
	Telecommunication fibers
	Laser glasses
Electronics and energy generation	Electronic tubes
Sealing glasses
Soldering and passivation glasses
	Substrate glasses and display glasses
	Glasses for thermal power generation
Radiation protection	Radiation shielding windows
High‐energy radiation detection windows
Silica (“quartz”) glass	For high‐T processing
For silicon crystal growth
For silicon‐wafer handling
	For optical fibers

The pie chart in Figure 2 provides a rough overview of the shares of these categories by amounts of worldwide production. The figures given are estimates based on an evaluation of multiple sources for the time span 2003–2008. By absolute amounts, the 2005 world production reached about 124 million metric tons (31 in the European Union, 8 in Germany). Since then, an average annual increase of about 3.5% is observed. Whereas the production is more or less leveling off in most industrialized countries, the PR of China is among the main driving markets for this increase as its 2005 output of flat glass already accounted for more than 50% of the world production (cf. Chapter 9.6).

For each type of glass products listed above, a typical chemical composition range has been adopted worldwide. The compositions of container and flat glass have never been developed by a scientific approach. Rather, they have remained pretty the same ever since the beginnings of glass makings (Chapter 10.2). Compositions have thus been very early constrained by the availability of affordable raw materials, the need to prevent water corrosion, and the highest temperatures reached in furnaces.

A systematic scientific approach to glass compositions did not begin before the nineteenth century, chiefly promoted by the work of individuals such as Fraunhofer, Faraday, Harcourt, Abbé, or Schott (Chapter 10.11). Since then, this scientific approach has remained the basis for designing not only the compositions of most specialty glasses but also to improve those of existing products. For example, there is a quest among the producers of continuous fibers for completely new compositions with outstanding mechanical or chemical properties such as high modulus for lightweight construction composites or extreme alkali resistance for concrete reinforcement. In other cases, the driving force for development stems from environmental or health concerns and legislation. As examples, lead and arsenic oxides are being replaced in the formulae of optical glasses, solder and sealant glasses, and even in crystal tableware, whereas insulation‐fiber compositions have been reformulated to avoid any confusion with asbestos fibers whose cancerogenic potency is well known. The typical composition ranges of current glass products are summarized in Table 1.

Figure 2 Glass production by branches; figures in % in the sequence world/United States/Europe.

Table 1 Typical compositions of industrial glasses comprising main oxides only (no colorants or impurities); compositional ranges from multiple sources (e.g. [13]) or typical individual examples (wt %).

Oxide	Container glass	Float glass	Crystal glass	Display glass	E fiber glass	Glass wool	Stonewool	Low‐α glass	Soluble glass
SiO2	66–75	70–74	66.0	65.0	52–60	56–66	35–48	70–81	66–77
TiO2			1.0				0–3
Al2O3	1–3	0.5–1.5	2.0	18.0	12–16	0–6	12–28	2.5–5
Fe2O3							3–12
B2O3				1.0	0–9	3–9		10–15
MgO	0–4	0–4	4.0	7.0	0.5–4.5	1–5	2–11	1.0
CaO	8–12	7–10	6.0	6.0	16–24	5–11	10–28	1.0
BaO			2.0	3.0
ZnO			3.0
Li2O	0–1							0–1
Na2O	11–15	12–14	8.0		0–2	13–17	1–6	4–8	23–34
K2O	0–2	0–1				0–2	1–6	0–3