Tire Failure
San Antonio Tire Failure Lawyers – (210) 298-6666 - (800) 519-2800
Representing Victims of Accidents Caused by Tire Defects, Tire Blowouts, Tire Detread and SUV Rollovers
Modern steelbelted tires are the result of a complex design and manufacturing process that is intended to produce a product which can withstand the rigors of modern city and highway driving. When one of these products fails as a result of a design or manufacturing defect the results are often catastrophic. Thousands of people are killed or injured each year because of the sudden failure of defective tires. The mechanism of a tire failure is usually the detaching of the tread from the main carcass or inner plies of the tire. When this occurs the tread may take one or more of the tires' outer belts with it leaving the inner tire cords or remaining belts exposed. Although the concept of incorporating steel belts into radial tire construction has greatly improved impact and puncture resistance, it has also increased the incidence of tread belt separations in passenger and light truck tires. A basic understanding of the construction of a modern steel belted radial tire is instrumental in understanding this problem.
Tire Construction
Despite advancements in technology and manufacturing processes, tire building is still an extremely manually labor intensive process. A tire is not a single piece of rubber melted or molded into shape. It is instead a multi-component product consisting of at least 14 different parts or layers which are largely put together by hand. Tires are constructed in layers out of materials consisting of or combined with green uncured rubber. The initial layer consists of an air and waterproof innerliner over a cylindrical drum or barrel. On top of this are placed various plies which form the basic carcass of the tire. Next the beads are set in place and the plies are turned up around the beads. The bead is the part of the tire that sits on the rim. It is composed of high tensile strength steel wire formed into hoops which function as an anchor for the plies and holds the tire onto the rim. Once the plies have been turned around the bead, a bead filler is extruded into the gap of the area where the plies have been folded around the bead. Next steel belts which have previously been coated with a rubber skim stock compound are placed on the carcass. Finally the tread sidewall, rim cushion and base are added to the tire carcass. Each of the rubber components consist of a different compound mix designed to serve different purposes which must cure and form a chemical bond with all the adjoining components. The final stage is the loading of the green or uncured tire into an automatic tire press for vulcanization at high temperatures and pressures. It is during this process that a properly designed and manufactured tire will take on the aspects of a single body with molecular chemical bonds between all of the various components.
Manufacturing Defects
The main problem with steel belted radial tires is that the rubber compounds normally used in the construction of a tire will not cure or bond to a steel surface. For that reason the steel wires which make up the steel belts are coated with brass which does bond to the rubber used in tire making. The brass coated steel wires are run in parallel lines through a calendaring machine that applies a rubber skim coat to both the top and bottom of the wires which is pressed into the wire to achieve full coverage. Skim coat is uncured rubber and does not adhere to the wire chemically but merely because of its "tacky" or sticky surface texture. A critical ingredient in the curing process is the presence of sulfur in the uncured rubber. Sulfur is necessary for the chemical reaction which bonds all of the various components of the tire together. However, excessive sulfur can act as a contaminate and prevent a complete bond. Because of the nature of the skim coat formula, sulfur has a tendency to migrate or "bloom" from the interior of the rubber to the surface of the rubber skim coat. If curing does not take place prior to the sulfur migrating from the skim coat, the necessary chemical bond does not form and there will be a lack of adhesion either between the belts themselves or between the rubber and the wire which forms the belt. The results of the lack of chemical bond on a light truck or passenger tire at high speeds can be disastrous.
Because of cost concerns many manufacturers attempt to use the calendared steel belts even after they have become stale. Sometimes a chemical solvent is applied to calendared belts to remove sulfur blooms from the surface and return a "tacky" feel to the belt material. Although the chemical used will return the tacky feel to the calendared belts, the actual chemical formulation of the skim stock has now changed. The result is that the proper bond does not form during the curing process and the steel belts do not adequately adhere to the carcass or the tread of the tire.
In addition to the use of stale or outdated stock, any contamination of the green tire during the building process will interfere with the bond forming between all the components during the curing process. Because each step of the tire building process requires extensive handling by the tire builder, the opportunity for contamination is quite high. Even the internal atmospheric conditions of the tire plant can greatly affect the quality of the tire produced. If the plant is excessively humid or dusty the result could be an improper bond between the various tire components and ultimately, a potentially deadly tire tread separation accident.
Design Defects
In addition to manufacturing defects, many modern steel belted radial tires have inherently defective designs. The most critical area of the tire and the area subject to the most stress is the outer edge of the steel belts in the area known as the shoulder of the tire. When mounted, the portion of the tire in contact with the pavement is deflected from a round circumferential shape to a flat surface. Because of the inherent differences in the properties of Steel and rubber, this deformation puts tremendous stress on the belt edge of the tire. In order to alleviate this stress, some manufacturers install a wedge of rubber between the belts at their edges which is thicker than the rubber skim coat separating the belts. This is known as a belt edge wedge. It was this component that the National Highway Traffic Safety Administration (NHTSA) concluded was insufficient in the Firestone tires which were recalled. Although the Firestone tires were the most publicized, many manufacturers still use an insufficient wedge or no wedge at all. Other design defects may include insufficient skim coat thickness, poor rubber compound formulas, and insufficient or incorrect wire gauge and/or wire density in the manufacturing of the steel belts.
Call San Antonio Tire Defect Attorneys Cichowski & Gonzalez, P.C.
If you or a loved one has been injured or killed in an accident caused by a defective tire, you should contact the Texas tire defect attorneys at Cichowski & Gonzalez as soon as possible. Cichowski & Gonzalez will immediately begin to work on your behalf, securing evidence such as the tire, as well as the vehicle on which it was mounted. We will immediately begin an accident investigation and reconstruction while the evidence and witnesses are still available. You should never talk to an insurance company representative adjuster, or auto or tire manufacturers investigator, without first speaking with us.
Tire failure cases are highly technical cases, which require an experienced and knowledgeable law firm. In addition to being a Board Certified in Personal Injury Trial Law lawyer, Steve Cichowski was a registered professional engineer, licensed by the State of Texas prior to returning to school to earn his law degree. He has an excellent understanding of tire construction and the dynamic forces at work on a defectively designed or manufactured tire.
For additional information, check out our Tire Defect Information Center.