Inorganic insulation materials

Fire properties of insulation materials range from the highest to the lowest, from non-combustible to flammable with toxic fume emission. Generally, inorganic materials tend to be non-combustible while organic (or oil-based) materials are combustible, but many have surface treatments to improve their fire-safety rating. 

Depth profiling may be conducted on insulating materials, and XPS can perform thickness measurements on organic films such a lubricants on magnetic media. It is capable of measuring surface contamination by both inorganic and organic materials on a wide variety of substrates. 

These large electrical waste appliances consist mainly of iron, copper, aluminum, and insulation materials. The insulation materials are mostly inorganic. The electronic controllers contained in the appliances are classified as electronic scrap. They may contain particularly hazardous components (accumulators, batteries, condensers, mercury switches, etc.). 

The choice of sensor material determines range, sensitivity, and stability. By considering the latter factors, it is found that inorganic insulating compounds, such as most lamp phosphors and many solid state laser materials, are the most suitable materials for thermometric applications. Indeed, these materials are most commonly used in the existing commercial fluorescence thermometer schemes. 

Asbestos fibers are found worldwide in many products as reinforcement in cement water pipes and the inert and durable mesh material used in filtration processes of chemicals and petroleum, for example. However, asbestos is not the only inorganic fiber in use today. Synthetic inorganic fibers abound. Glass fibers have replaced copper wire in some intercontinental telephone cables. Fiberglas (a trade name) has become the insulation material of choice in construction. Carbon and graphite fiber composites are favored materials for tennis racket frames and golf clubs. Fibrous inorganic materials have become commonplace in our everyday lives. 

Nonmetallic Inorganic Solids. This category includes many items of forensic importance ceramic and glasses naturally occurring substances such as building and insulation materials and soil components additives to papers, paints, explosives, drugs and many other materials. In contrast to metals, even the task of basic material identification often requires considerably more than the overall chemical analysis for these substances. 

However, when such insulation mats are exposed to moisture, the bonding strength is reduced, which can affect the quality of the insulation material. To prevent this problem, on the one hand, a hydrophobic agent is added to make the mineral wool more water repellent, and on the other hand silane is included in the binder mixture to enhance the bond between the inorganic fibers and the organic binder. 

Filled Isocyanurate Foams. The addition of specific inorganic powders, such as graphite and talc, to urethane-modified isocyanurate foams, has been jH oven to jH oduce high temperature- and flame-retardant insulation materials (59). 

Other inorganic materials are also used, which are considered in other sections of this book glass (see Section 5.1.1) and sound and thermal Insulation materials (see Section 5.2.3). 

Some of the problems seen with the commercially available polyimides such as limited shelf life,gelation and high ionic contamination are traceable to the raw materials themselves. A zone refining technique has been perfected for use with organic materials and these precursors have been used to synthesize ultrapure polyamic acids for IC device applications. The key feature of the synthesis is the use of solid ingots of the dianhydrides. Materials prepared by this technique show low metallic impurities and have been shown to be excellent film formers for a variety of applications. In particular a polyimide derived from PMDA-ODA has been used to passivate magnetic bubble devices. IR techniques coupled with electrical measurements have been used to optimize the cure conditions and a simple resist process has been defined to passivate these devices. Device performance compares well with conventional inorganic insulators. 

---