Steering wheels

Water-borne adhesives are preferred because of restrictions on the use of solvents. Low viscosity prepolymers are emulsified in water, followed by chain extension with water-soluble glycols or diamines. As cross-linker PMDI can be used, which has a shelf life of 5 to 6 h in water. Water-borne polyurethane coatings are used for vacuum forming of PVC sheeting to ABS shells in automotive interior door panels, for the lamination of ABS/PVC film to treated polypropylene foam for use in automotive instmment panels, as metal primers for steering wheels, in flexible packaging lamination, as shoe sole adhesive, and as tie coats for polyurethane-coated fabrics. PMDI is also used as a binder for reconstituted wood products and as a foundry core binder. 

The methacrylic polymer remains a useful glazing material. In aircraft applications it is used extensively on aircraft which fly at speeds less than Mach 1.0. They form the familar bubble body of many helicopters. On land, acrylic sheet is useful for coach roof lights, motor cycle windscreens and in do-it yourself cabins for tractors and earth-moving equipment. Injection mouldings are frequently used for plaques on the centre of steering wheels and on some fascia panelling. 

Cellulose acetate-propionate (Tenite Propionate-Kodak) is similar to cellulose propionate. With the shorter side chains, cellulose propionate and cellulose acetate propionate tend to be harder, stiffer and of higher tensile strength than CAB. Like CAB they are easy to vacuum form and also tend to be used for similar applications such as steering wheels, tool handles, safety goggles and blister packs. 

Products intermediate to the flexible and rigid foams may be obtained from castor oil (a trihydroxyl molecule), synthetic triols of moderate molecular weight and polyesters with a moderate amount of trifunctional hydroxyl compound in the strueture. Current practice, however, is to use tipped polyols of the type used for flexible foams with MDI. Semi-rigid foams are used for such purposes as crash pads, car steering wheels and packaging equipment. 

If butyric or propionic acids are included in the esterifying mixture, acetate butyrates and acetate propionates are formed. These, requiring less plasticizer, are tougher and more moisture resistant material for making automobile steering wheels. 

Molded urethanes are used in items such as bumpers, steering wheels, instrument panels, and body panels. Elastomers from polyurethanes are characterized by toughness and resistance to oils, oxidation, and abrasion. They are produced using short-chain polyols such as polytetram-ethylene glycol from 1,4-butanediol. Polyurethanes are also used to produce fibers. Spandex (trade name) is a copolymer of polyurethane (85%) and polyesters. 

Figure 9.7 Assigning configuration to a chirality center. When the molecule is oriented so that the group of lowest priority (4) is toward the rear, the remaining three groups radiate toward the viewer like the spokes of a steering wheel. If the direction of travel 1 -> 2 3 is...

The solution to these problems is to develop "smart" airbag systems that can sense the severity of a collision, the size and weight of the driver, and how far his or her head is from the steering wheel. 

Injection molding is a common process that we use to convert polymer granules to solid objects. Unlike the products made by continuous extrusion processes, discussed in Chapter 11, products made by injection molding are discrete objects, produced in individual mold cavities. We encounter injection molded products of all sorts in our daily lives, ranging from combs, bottle caps, and ballpoint pens to car steering wheels, camera bodies, and the keys on our computers. 

Mil Portable Decontamination Apparatus A device containing DS-2 used to decontaminate small areas, such as the steering wheel of other equipment that military troops must touch. It is filled with one and one-third quarts of DS-2. 

In GM s Hy-wire hydrogen powered concept vehicle, there is a fuel cell for the power source and electronics replace mechanical parts in the steering and braking systems. The driver looks through a large, sloped windshield that covers space usually taken up by an engine. There is no dashboard, instrument panel, steering wheel or pedals, only a set of adjustable footrests. 

In 1996 GM would launch the EV1. Almost every part of the EV1 is designed for energy efficiency. The steering wheel and seat frames are made of low-weight magnesium. The radio antenna is part of the roof... 

Cars are now equipped with several airbags to ensure safety when a crash occurs but there are some drawbacks such as the cost, the volume, which dictates the steering wheel design and limits the capacity of other storage boxes, and the weight. 

Injection molding (containers, lids, bottles, toys, plastic chairs, luggage, steering wheels, battery cases, fan shrouds, air cleaner ducts), 31% fibers and filament (carpet backing, indoor-outdoor carpeting, rope), 30% resellers, distributors, and compounders, 23% film and sheet, 11% blow molding, 2% miscellaneous, 3%... 

Fitz felt his head turn with some resistance, like a stubborn steering wheel, and looked out through someone else s eyes there was a third mental presence in the bucket, squashed and largely unheard, like a man at the back of an overcrowded lift. 

The k factor varies from 115 to 70, depending on speed and whether any side forces are applied to the wheel. For example, at 10 kph the load wheel of a forklift has a k factor of 100. If the speed is increased to 16 kph, the factor drops to 85. The steering wheel has a lower factor of 70 at 10 kph. 

Integral skinned These integral skin urethanes are designed to have an outer layer that is not foamed, with a foamed inner section. This provides a firm feel without the dirt trapping of the cut cells. Typical examples of this style are steering wheels and motor car fascias. 

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