Windshields

Beryllium is used as an alloying agent in producing beryllium copper, which is extensively used for springs, electrical contacts, spot-welding electrodes, and non-sparking tools. It is applied as a structural material for high-speed aircraft, missiles, spacecraft, and communication satellites. Other uses include windshield frame, brake discs, support beams, and other structural components of the space shuttle. 

This is going to supply the cold water that courses through the condenser whether that condenser is set up for reflux or is part of a distillation configuration. The pump need not be very strong. In fact, the perfect example is one of those little, submergible fish tank pumps that one can find at any pet store for about 10. All the chemist does is attach a hose to the outlet, chunks the little pump into a bucket of ice water, attaches the hose to the condenser and there it is. An alternative source is that little pump that s attached to the windshield washing fluid reservoir of any car in a junk yard. The chemist removes the reservoir (pump still attached), applies an adapted power source to the pump and uses the plastic reservoir to hold the ice water. 

Arcraft structures Arcraft windshields Ar drying Ar electrode Arex Ar filters Arfocon Ar fresheners Ar hydrocarbons Air-jet spinning Aliens... 

Safety glass Safety helmets Safety match Safety regulations Safety shields Safety windshields Safflorite Safflower... 

The rate of spray is deterrnined by propellant concentration, the solvent used, and valve and vapor pressure. The pressure must be high enough to dehver the product at the desired rate under the required operating conditions. For example, a windshield ice remover that is likely to be used around 0°C must be formulated to provide an adequate pressure at that temperature. Spray dryness or wetness and droplet size depend upon propellant concentration. 

Small ultrasonic motors such as the rotary actuator shown in Figure 10 have also been made and can be used for automobile windows, seats, and windshield wipers. Many small industrial motors could make use of the high torque, low speed, and precise stepping character of these actuators. 

Nonreactive additive flame retardants dominate the flexible urethane foam field. However, auto seating appHcations exist, particularly in Europe, for a reactive polyol for flexible foams, Hoechst-Celanese ExoHt 413, a polyol mixture containing 13% P and 19.5% Cl. The patent beHeved to describe it (114) shows a reaction of ethylene oxide and a prereacted product of tris(2-chloroethyl) phosphate and polyphosphoric acid. An advantage of the reactive flame retardant is avoidance of windshield fogging, which can be caused by vapors from the more volatile additive flame retardants. 

Aliphatic isocyanates have a small but growing market application in thermoplastic polyurethanes (TPU). Medical appflcafions include wound dressings, catheters, implant devices, and blood bags. A security glass system using light-stable TPU as an inner layer is under evaluation for shatterproof automotive windshield appflcafions. 

Laminated windshields, as opposed to tempered glass windshields, are gaining in market share outside of North America. From 37% of the non-North American market of 1976, they were estimated to have reached 75% by 1982 (13). In addition to North America, Belgium, Italy, and the Scandinavian countries permit only laminated windshields, and other nations are increasing use by customer option. The trend toward laminated windshields is expected to continue and nonlaminated windshields will likely be obsolete by the year 2000 (14). 

Subsequent to processing, an inspection is made for incomplete bonding, inside dirt, and glass quaUty. In the case of windshields, rigid optical standards must be met, and these must be evaluated for the completed windshield. Extensive test requirements are described in the appropriate codes (11,12,15,18—24), and they include light stabiUty, resistance to optical distortion, humidity, boil test, abrasion resistance, and assorted impact tests. 

The ASA (now ANSI) performance code for Safety Glazing Materials was revised in 1966 to incorporate these improvements in windshield constmction. The addition of test no. 26 requiring support of a 2.3-kg ball dropped from 3.7 m defined this level of improvement. It was based on a correlation estabUshed between 10-kg, instmmented, head-form impacts on windshields, on 0.6 x 0.9-m flat laminates, and the standard 0.3 x 0.3-m laminate with the 2.3-kg ball (28). Crash cases involving the two windshield interlayer types were matched for car impact speeds and were compared (29). The improved design produced fewer, less extensive, and less severe facial lacerations than those produced in the pre-1966 models. 

Additional improvements have been incorporated since 1966 with the availabihty of thinner float glass. Glass thickness and interlayer thickness have been studied to optimize the product for occupant retention, occupant injury, and damage to the windshield from external sources (30,31). The thinner float glass windshields are more resistant to stone impacts than the early plate glass windshields. The majority of laminated windshields are made of two pieces of 2—2.5 mm aimealed glass and 0.76 mm of controlled adhesion interlayer. 

Fig. 7. Cross section of Sierracin windshield used on Boeing 747 (32) A, 2.2-mm chemically strengthened glass B, Sierracote 3 conductive coating C, 1.9-mm PVB D, 23-mm stretched acryflc E, 1.3-mm PVB F, laminated cloth spacer ring G, 23-mm stretched acryflc H, 0.6-mm PVB and I, 3.0-mm...

Fig. 8. Sierracin lightweight, birdproof F-111 windshield cross section (43). A, 3.0-mm as-cast acryflc face ply B, S-100 silicone interlayer C, fiberglass retainer D, 6.4-mm polycarbonate stmctural ply E, S-120 polyurethane interlayer E, stainless steel bearing strip and G, stainless steel bushing.

The constmction of the E-111 windshield shown in Eigure 8 replaced a glass—silicone laminate previously used. The all-plastic windshield has improved impact resistance so that it is birdproof to 250 m/s (33). In this instance, the scratch resistance of glass was waived to obtain the impact performance at the allowed weight. 

J. C. Widman, Recent Developments in Penetration Resistance of Windshield Glass, SAE 650474, SAE, 1965. 

D. E. Huelke, W. G. Grabb, and R. O. E)m. cn.2ia, Automobile Occupant Infuriesfrom Striking the Windshield, Report No. Bio-5, Highway Safety Research Institute, Ann Arbor, Mich., 1967. 

Malonates can also be used as blocking agents in the formulation of one-part urethanes. These systems, curable by moisture, are used, for example, for automotive windshield gla2ing (53) (see Urethane polymers). 

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