Fiberglass reinforcing, material

Volume resistivity is the ratio of the DC potential applied to electrodes embedded in a material to the current between them, typically expressed in megohm-centimeters. The measured current flows between electrodes 1 and 3, while stray current flows between electrodes 2 and 3, as shown in Fig. 8.15. Table 8.8 shows the volume resistivity values of some common fiberglass-reinforced material types. 

Dry chlorine has a great affinity for absorbing moisture, and wet chlorine is extremely corrosive, attacking most common materials except HasteUoy C, titanium, and tantalum. These metals are protected from attack by the acids formed by chlorine hydrolysis because of surface oxide films on the metal. Tantalum is the preferred constmction material for service with wet and dry chlorine. Wet chlorine gas is handled under pressure using fiberglass-reinforced plastics. Rubber-lined steel is suitable for wet chlorine gas handling up to 100°C. At low pressures and low temperatures PVC, chlorinated PVC, and reinforced polyester resins are also used. Polytetrafluoroethylene (PTFE), poly(vinyhdene fluoride) (PVDE), and... 

Typical stress-strain curves are shown for the commonly used fiber-reinforced materials fiberglass-epoxy, boron-epoxy, and a representative graphite-epoxy. These curves are not accurate enough for design use ... 

H = History if a plant has used material successfully for many years, and the staff members know its strengths and limitations, how to weld it, etc., hesitate before making a change. For example, a fiberglass-reinforced plastic had given excellent service for many years when another composite from the same company, with the same name but a different number, was used instead, it failed overnight. 

For facilities susceptible to the contamination of nitroglycerin liquids and vapors, basic construction materials of wood framing, reinforced concrete, fiberglass reinforced plastic, and sandwich panels were chosen for development of architectural details incorporating lead conductive floor lining, equipment doors, personnel escape chutes and doors, ceiling and wall interfaces, interior finishes, joint sealing, door and wall louvers, wall vents, wall penetrations, and fixed windows. 

Note that glazing is acrylic plastic to comply with the AMC Safety Manual requirements. Screws for attachment of wood door frames and vision panel stops are countersunk and caulked. Joints not taped are sealed with caulking. It should be noted here that Sunflower AAP has had major problems with exterior wood doors exposed to the weather. A recurring problem has been the delamination of wood door materials. This may require a change to a more weather-resistant door material such as fiberglass reinforced plastic. Details for doors of this material are included in the standard architectural details. 

In the course of curing, the viscosity vanes from thin to syrupy liquids. This is convenient for impregnating reinforcing materials, such as fiberglass scrim, used in making wiring or circuit boards for electronics applications. 

Bathtubs, showers and sinks account for significant consumption of unsaturated polyester resins. Fiberglass-reinforced bathtubs and shower stalls account for as much as 90% of the unsaturated polyester used in construction. Unsaturated polyesters have significantly replaced cast-iron bathtubs as a lower-cost material. Similarly, highly filled cast unsaturated polyesters have replaced ceramics and steel in bathroom sinks and countertops. 

Materials acceptable for underground piping use include ductile iron, fiberglass-reinforced epoxy plastic, polyethylene, polyvinyl chloride, reinforced concrete, and carbon steel. Plastic pipes are not acceptable in areas subject to solvent exposure. 

Photooxidation Diffusion Chemical changes due to photochemical reactions Introduction of contaminants from man-made materials, such as solvents from polyvinyl chloride (PVC) materials and PVC cement, plasticizers, and phthalates from polyethylene and polypropylene materials Protection from exposure to light, use of amber glass bottles Use of inert materials (PTFE, fiberglass-reinforced epoxy materials) steam-cleaning of groundwater well components prior to installation... 

High density charring ablators such as carbon-phenolic contain high density reinforcements to improve shear resistance. In contrast, lower density charring ablators as a rule are used for low shear environments. Hie Apollo mission reentry conditions are typical of a relatively low shear environment, so low density ablators consisting of epoxy—novolac resin containing phenolic microballoons and silica fiber reinforcement have been used. In order to improve the shear resistance and safety factor of the material for this mission, the ablator was injected into the cavities of a fiberglass -reinforced phenolic honeycomb that was bonded to the substructure of the craft (48). 

Federal environment regulations, 75-78 Feed-tray location in distillation towers, lo Fiberglass reinforced plastics (FRP), 436-437 Fibonacci search, 407 Fifo method for materials accounting, 148... 

The membrane material used in the past, if a membrane were used at all, was lead. Today membrane materials include rubber, urethanes, fiberglass reinforced thermoset resins, and aggregate filled thermoset resins. The fiberglass reinforced and aggregate filled resins have also found use as linings without brick or tile. 

---