Borosilicate fibers

The 3M Company manufactures a continuous polycrystalline alumina—silica—boria fiber (Nextel) by a sol process (17). Aluminum acetate is dissolved in water and mixed with an aqueous dispersion of colloidal silica and dimethylformamide. This mixture is concentrated in a Rotavapor flask and centrifuged. The viscous mixture is then extruded through spinnerettes at 100 kPa (1 atm) the filaments are collected on a conveyor and heat-treated at 870°C to convert them to metallic oxides. Further heating at 1000°C produces the 10-pm diameter aluminum borosilicate fibers, which are suitable for... 

Fibers made from borosilicate glass are also used in making cloth. Borosilicate fibers are blended with other synthetic fibers to make durable fabric for automobile seat covers and other long-wear applications. 

High silica fibers by leaching of borosilicate fibers... 

Ceramic materials are used in the manufacture of ceramic tiles for the surfaces of the Space Shuttle, to protect against overheating on reentry into Earth s atmosphere (Figure 12.25 4). The tiles are made of short, high-purity silica fibers reinforced with aluminum borosilicate fibers. The material is formed into blocks, sintered at over 1300°C, and then cut into tiles. The tiles have a density of only 0.2 g/cm, yet they are able to keep the shuttle s aluminum skin below 180°C while sustaining a surface temperature of up to 1250 C. 

The fibrous refiactory insulation tiles used on the body of the space shuttle containing alumina-borosilicate fibers in a silica ceramic matrix... 

Filament material Aluminum borosilicate glass fibers Membrane material Pd/Ag (23 wt.-%)... 

Barsoum, M. and Tung, F.C. (1991). Effect of oxidation on single fiber interfacial shear stresses in a SiC--borosilicate glass system. J. Am. Ceram. Soc. 74, 2693-2696. 

Disodium Tetraborate. In the United States, anhydrous borax finds most application in the glass industry for enamels, borosilicate glass, and fiber glass insulation. It is also used as an antifreeze additive and as an algicide in industrial water. 

Ulexite, NaCaB 09 8H20, and probertite, NaCaB509 5H20, have found application in the production of insulation fiber glass and borosilicate glass as well as in the manufacture of other borates. 

Therefore, glass fibers are favorable as filter medium because they give a lower pressure drop and are less liable to wetting or combustion. Modern fibrous filter systems are cylinders made from bonded borosilicate microfibers sheathed in reinforcing polypropylene mesh in which the layers increase in fineness and density from the center outward. This type of design can deliver over 3 m3/s of sterile air at 0.1 bar of pressure drop (Quesnel, 1987). 

For both type of microwave reactors, if the reactor is not supplied with a temperature sensor or more likely accurate temperature measurment is prerequisited during an experiment, the fiber-optic temperature sensor is directly applied to the reaction mixture. In order to secure the sensor from harsh chemicals, the sensor is inserted into a capillary that in turn is inserted into the reaction mixture. In such a case, it is strongly advocated to use capillaries that are made of quartz glass and are transparent to microwave irradiation. Any capillary that is made of glass or even borosilicate glass can always slightly absorb microwave energy, in particular, while the reaction mixture does not absorb microwaves efficiently, and in turn lead to failures of fiber-optic thermometer performance. 

Boccaccini, A.R., Janczak-Rusch, J., Pearce, D.H., Kern, H. (1999), Assessment of damage induced by thermal shock in SiC-fiber-reinforced borosilicate glass composites , Comp. Sci. Tech., 59, 105-112. 

Pleated These cartridge filters are typically used in higher-purity applications, such as pharmaceutical and microelectronics. The filters can have a multi-layered construction or be single layer. Typical materials of construction include polypropylene, polyethersulfone, and borosilicate glass fiber. 

The above discussion pertains to unidirectional composites that are initially free of matrix cracking examples would include Nicalon SiCf/CAS, Nicalon SiQ/1723 glass, Nicalon SiQ/LAS, and SCS-6 SiQ/HPSN. For composites such as Cf/borosilicate, where the thermal expansion coefficient of the matrix is substantially greater than that of the fiber, microcracks can develop in the matrix during fabrication. These composites do not exhibit a linear stress-strain response (Stage I), even for small applied loads. 

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