Description of the life cycle stages

Numerous raw materials are used in the manufacture of displays. In the following, the essential production steps and raw materials utilized for each of the display technologies considered are described and summarized. Detailed illustrations can be found in the chapter on life cycle stages. Production of a CRT monitor includes manufacture of the two main components, the panel glass and the glass bell the glass contains a fair amount of lead. The individual luminescent phosphors are then applied...

Chromating

Until recently, chromate treatment of aluminum was indispensable for the adhesion of a surface coating. With aluminum in particular, exposure to the oxygen in the air quickly causes a thin aluminum oxide coating to form. In order to make possible the adhesion of the surface coating to this oxide layer, the metal parts have always been treated with chromic acid. This reduces the thickness of the existing oxide layer, eliminates other metallic particles, and causes the formation of a new mixed...

Environmental profile assessments

Building on this characterization of nanotechnology, the concurrent ongoing assessment approach to the prospective TA is followed by an ascertainment of sustainability effects using specific application examples in comparison to existing products and processes, whereby, in accordance with the life cycle assessment method, the focus is on the substance and energy flows and their associated ecological opportunities and risks. The involvement of current fields of application means that the time...

Greenhouse effect

The energy in the sunlight that strikes the surface of the earth in the course of the day is stored as thermal energy and then released at night as infrared radiation. A part of this infrared radiation is absorbed by trace gases in the troposphere (0-10 km) and reflected back to earth. This natural greenhouse effect is essential, otherwise the earth's surface would cool to inhospitable below-zero temperatures. The greenhouse effect we speak of as an environmental problem refers to the...

Nanocoat system

The manufacture of a nanocoating varies not so much in the processes, but rather in the binder that is utilized. As a rule, the binders used in industrial coatings have an organic structure. But inorganic binders are also utilized in certain applications. Their advantage is in their hardness and chemical durability. But because of their serious drawbacks, including difficult ap plication and brittleness after hardening, these coating materials do not have an extensive field of application. In...

Raw material procurement and production

A great number of raw materials are used in the production of light sources. In the following, the essential production steps for three of the light sources are shown, with special reference to the production of LEDs. The manufacture of incandescent lamps consists of four major production steps Production of the glass envelope, production of the tungsten filament and its support structure, production of several small components, and final assembly of all components. Sintering of compacted...

Eutrophication

Eutrophication describes the spread of chemical nutrients into water bodies. The anthropological contributions of nitrogen compounds (e.g. nitrates) from excessive applications of fertilizers as well as phosphorus compounds (e.g. phosphates) from detergents or agricultural runoff lead to overfertilization of waters. In addition to these two groups of compounds, the COD (chemical oxygen demand) is enlisted as a measure for calculating organic pollutants. A consequence of the excessive nutrient...

Phosphating

Phosphating is commonly used as a pretreatment for steel and iron. But it is an alternative to chromate for the pretreatment of aluminum as well. Treating aluminum with a dilute phosphoric acid solution produces a thin film of aluminum phosphate. Compared to chromating and anodizing, phosphating is certainly more expensive and more complicated, but it results in a more corrosion-resistant surface, which ensures a better bond for surface coatings. Phosphate coatings solutions for aluminum...

Disposal

There are no legal regulations governing the disposal of incandescent lamps, as the environmental impact of almost all substances they contain is negligible due to their nature and the amounts involved. Therefore almost all incandescent lamps are disposed of in the household waste. The disposal of compact fluorescents, however, is regulated. In 1996, the German Waste Avoidance, Recycling and Disposal Act came into effect. It places discharge-type lamps in the case of disposal and recycling into...

Styrene Economic impact and market data

Worldwide demand for styrene is estimated to be more than 20 million tons and growing by 5 annually Rohden 2001 . In 20 the styrene industry did face a 1.8 lapse in demand, but by the following year demand had again increased by 5.1 Childre 2003 . An overview of the development of styrene production is provided in Table 21 and Table 22. Table 21. Production data and capacity in Western Europe67 Styrene Production and Capacity in Western Europe 1000 tons Capacity Production Table 22. Styrene...

Variant 5 Nanoparticle clearcoat from the firm NTC

The newly developed nanoparticle coating differs in many respects from conventional coatings. The process is fundamentally different. Like traditional liquid clearcoats it consists of a binder, a liquid carrier, fillers, and additives. The binder, however, does not have the usual organic structure, but is instead a so-called inorganic-organic hybrid polymer. The nanopar-ticle coating is manufactured by means of the sol-gel process. The sol-gel process has been in existence for a long time,...

Life cycle inventory analysis

In the life cycle inventory analysis, the material and energy relationships between the display technology being studied and the environment are recorded, i.e., the input flows from the environment and the output flows that are returned to the environment are noted. The goal of the life cycle inventory analysis is to establish a data inventory based on functional equivalents for the selected variants. Complete quantitative life cycle inventory data are available for the CRT and LCD. On this...

Life cycle analysis of nanomaterials

As already remarked, possible harm by nanoparticles may occur especially in environmentally open applications. A look at the life cycle of nanomate-rials reveals several points where such a release may take place 1. Nanomaterials production processes vary greatly. Industrially manufactured nanomaterials are not generally produced by combustion processes with the exception of CVD DVD and flame-assisted deposition , but mainly in liquid or closed gas-phase reactors. Therefore, direct exposure to...