Automobile tire

Polypropylene fibers for use in car pets and automobile tires consum er Items (luggage appliances etc) packaging material... 

The elastomer produced in greatest amount is styrene-butadiene rubber (SBR) Annually just under 10 lb of SBR IS produced in the United States and al most all of it IS used in automobile tires As its name suggests SBR is prepared from styrene and 1 3 buta diene It is an example of a copolymer a polymer as sembled from two or more different monomers Free radical polymerization of a mixture of styrene and 1 3 butadiene gives SBR... 

Figure 4 shows a fault tree for a flat tire on an automobile. The top event, the flat tire, is broken down into two immediate contributing events, road debris and tire failure. The contributing event, road debris, is a basic event. This event, which caimot be broken down into other events unless additional information is provided, is enclosed in a circle to denote it as a basic event. The other event, tire failure, is enclosed in a rectangle to denote it as an intermediate event. 

Consider again, for example, the case of the flat tire on an automobile. The initiating event in this case is the flat tire. There are two safety functions which can be defined a spare tire and an emergency road patrol. Other safety functions might be included depending on the particular situation. 

Elastomers. Elastomers are polymers or copolymers of hydrocarbons (see Elastomers, synthetic Rubber, natural). Natural mbber is essentially polyisoprene, whereas the most common synthetic mbber is a styrene—butadiene copolymer. Moreover, nearly all synthetic mbber is reinforced with carbon black, itself produced by partial oxidation of heavy hydrocarbons. Table 10 gives U.S. elastomer production for 1991. The two most important elastomers, styrene—butadiene mbber (qv) and polybutadiene mbber, are used primarily in automobile tires. 

A further apphcation of the concept may be found in the patterning of automobile tires to channel residue incident to contact with the road surface away from the automobile tire. Any of these apphcations of the central idea of providing a solution to increase road traction also may be patentable. 

The initial research effort may prove to be a broad spectmm of apphcations or solutions to the original problem that in turn provide any number of inventions. When efforts move toward reducing the invention to practice and refining the invention so that it proves to be commercially marketable, certain apphcations may prove to be unfeasible or commercially impractical. As a result, only one apphcation, eg, the creation of a given pattern on the surface of the automobile tire, may ultimately prove commercially marketable. However, ah the solutions which are developed and considered over the research and development process may comprise inventions that are worthy of disclosure and claiming in a patent. An apphcation which is not commercially viable today may become viable within the seventeen-year lifetime of a patent. 

In the category of industrial appHcations, nylon is the predominant fiber used in the carcass of bias tmck, racing car, and airplane tires because of its exceUent strength, adhesion to mbber, and fatigue resistance. Nylon is used less in the carcass of radial tires for automobiles and in replacement bias and bias-belted tires because of the development of temporary flat spots. For this reason, nylon has lost most of this market to polyester. 

These new synthetic mbbers were accessible from potentially low cost raw materials and generated considerable woddwide interest. For a time, it was hoped that the polysulftde mbbers could substitute for natural mbber in automobile tires. Unfortunately, these original polymers were difficult to process, evolved irritating fumes during compounding, and properties such as compression set, extension, and abrasion characteristics were not suitable for this apphcation. 

Another important apphcation for 4-/ f2 -octylphenol is ia the production of phenoHc resias. Novolak resias based oa 4-/ f2 -octylpheaol are widely used ia the tire iadustry as tackifiers. The tackiaess of these resias biads the many parts of an automobile tire prior to final vulcanization. A specialty use for novolak resias based oa 4-/ f2 -octylpheaol is the productioa of a ziacated resia, which is formulated as a dispersioa ia water and coated onto paper ia combination with eacapsulated leuco dyes to yield carbonless copy paper (see Microencapsulation). Pressure from writing bursts the encapsulated leuco dye, which is converted from its colorless form to its colored form by the ncated resin (53). Novolak resias based oa 4-/ f2 -octylpheaol are also used ia the productioa of specialty printing inks. 

Some amino resins are used as additives to modify the properties of other materials. For example, a small amount of amino resin added to textile fabric imparts the familiar wash-and-wear quaUties to shirts and dresses. Automobile tires are strengthened by amino resins which improve the adhesion of mbber to tire cord (qv). A racing sailboat may have a better chance to win because the sails of Dacron polyester have been treated with an amino resin (1). Amino resins can improve the strength of paper even when it is wet. Molding compounds based on amino resins are used for parts of electrical devices, botde and jar caps, molded plastic dinnerware, and buttons. 

Vinylpyridine (23) came into prominence around 1950 as a component of latex. Butadiene and styrene monomers were used with (23) to make a terpolymer that bonded fabric cords to the mbber matrix of automobile tires (25). More recendy, the abiUty of (23) to act as a Michael acceptor has been exploited in a synthesis of 4-dimethylaminopyridine (DMAP) (24) (26). The sequence consists of a Michael addition of (23) to 4-cyanopyridine (15), replacement of the 4-cyano substituent by dimethylamine (taking advantage of the activation of the cyano group by quatemization of the pyridine ring), and base-cataly2ed dequatemization (retro Michael addition). 4-r)imethyl aminopyri dine is one of the most effective acylation catalysts known (27). 

In 1995, about 28-30 x 10 tires were retreaded (54). Retreading has been the most cost-effective alternative to recycling mbber. However, worn retreaded tires usually are discarded in a landfill. Approximately 10% of discarded automobile tires and 55—70% of tmck and bus tires are retreaded (55). 

Economics and price of the final article often dictate a specific type of mbber that can be used. The expected usable life for the product is controlled by many factors including end customer awareness, competitive situation in the marketplace, safety, reUabiUty, and other factors. Rubber is almost always used as a functional part of another system. For example tires, hoses, belts, O-rings, and numerous mbber components are used in manufacturing automobiles and tmcks. The overall life of the vehicle as well as its performance level often control or direcdy relate to the service life or quaUty level of the mbber parts. 

A well-known example of blocking arises in the comparison of wear for different types of automobile tires. Tire wear may vary from one automobile to the next, irrespective of the tire type, because of differences among automobiles, variabiUty among drivers, and so forth. Assume, for example, that for the comparison of four tire types (A, B, C, and D), four automobiles (1, 2, 3, and 4) are available. A poor procedure would be to use the same type of tire on each of the four wheels of an automobile and vary the tire type among automobiles, as in the following tabulation ... 

Such an assignment is undesirable because the differences between tires caimot be separated from the differences between automobiles in the subsequent analysis. Separation of these effects can be obtained by treating automobiles as experimental blocks and randomly assigning tires of each of the four types to each automobile as follows ... 

The symmetry of the preceding example is not always found in practice. For example, there may be six tire types under comparison and fifteen available automobiles. Tires are then assigned to automobiles to obtain the most precise comparison among tire types, using a so-called incomplete block design. Similar concepts apply if there are two or more primary variables, rather than tire type alone. 

Background variables could also be introduced into the experiment by randomization, rather than by blocking techniques. Thus in the previous example, the four tires of each type could have been assigned to automobiles and wheel positions completely randomly, instead of treating automobiles and wheel positions as experimental blocks. This could have resulted in an assignment such as the following ... 

The first use for butyl mbber was ia inner tubes, the air-retention characteristics of which contributed significantly to the safety and convenience of tires. Good weathefing, ozone resistance, and oxidative stabiUty have led to appHcations ia mechanical goods and elastomeric sheeting. Automobile tires were manufactured for a brief period from butyl mbber, but poor abrasion resistance restricted this development at the time. 

Because of increased production and the lower cost of raw material, thermoplastic elastomeric materials are a significant and growing part of the total polymers market. World consumption in 1995 is estimated to approach 1,000,000 metric tons (3). However, because the melt to soHd transition is reversible, some properties of thermoplastic elastomers, eg, compression set, solvent resistance, and resistance to deformation at high temperatures, are usually not as good as those of the conventional vulcanized mbbers. AppHcations of thermoplastic elastomers are, therefore, in areas where these properties are less important, eg, footwear, wine insulation, adhesives, polymer blending, and not in areas such as automobile tires. 

In the United States, regulation of emissions from new automotive vehicles has followed the prototype-replicate route. The argument for routine annual automobile inspection is that cars should be regularly inspected for safety (brakes, lights, steering, and tires) and that the additional time and cost required to check the car s emission control system during the same inspection will be minimal. Such an inspection certainly pinpoints cars whose emission control system has been removed, altered, damaged, or deteriorated and force such defects to be remedied. The question is whether... 

Polypropylene fibers for use in carpets and automobile tires consumer items (luggage, appliances, etc.) packaging material. 

Besides all the gaseous and liquid wastes of transportation that result from energy use, and the loss of natural environment to roadv ays, there is also the solid-waste problem of disposal— vehicles and components such as tires and batteries. Responding to the growing disposal problem, many manufacturers are building automobiles that contain far more recyclable parts. 

Surface friction is a source of rail s advantages in transport energy efficiency. Under similar conditions, steel wheels on steel rail generate only abont 20 to 30 percent of the rolling friction that rubber wheels on pavement generate, both because rails are much smoother than paT. cnicnt and because steel wheels arc much more rigid than rubber tires, so steel wheels deform much less at the point of contact with the gi ound. Each rail wheel has only about 0.3 sq in of surface in contact with the rail, whereas an automobile... 

The first commercially successful pneumatic tire was developed in 1888 in Belfast by the Scottish veterinarian John Boyd Dunlop primarily to improve the riding comfort of bicycles. Dunlop also showed, albeit qualitatively, that his air-inflated pneumatic took less effort to rotate than did the solid rubber tires in use at that time. His qualitative tests were the first known rolling resistance experiments on pneumatic tires. Due to this significant reduction in rolling loss, many professional cyclists in Britain and Ireland adopted air-inflated tires for their bicycles by the early 1890s. Pneumatics for the nascent automobile industry soon followed. 

The energy required to produce a tire is only about 10 percent of that consumed while in use on an automobile overcoming rolling resistance during 40,000 miles of seiwice. The majority of the manufacturing energy expended, 60 to 70 percent, is for the mold during the vulcanization process. 

Schuring, D. J. (1980). The Rolling Loss of Pneumatic Tires. Ruhher Clhcmistiy and Technology. 83 600-727. Tabor, D. (1994). The Rolling and Skidding of Automobile Tyres. Physics Education 29 301-306. 

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