Plasticisers are needed to ensure that the tyre gives you a positive and safe feeling while driving, even in snow and rain. These oils and resins make the tyre flexible and improve the grip of the material.
For you, the driver, this means that plasticisers improve rolling resistance. Oils also add to the slip resistance of the tyre. That's why more oils are used in winter tyres than in summer tyres; plasticisers prevent the rubber from hardening at low temperatures.
In addition to the main components of rubber, fillers and plasticisers, chemicals, such as sulphur as mentioned above, and antioxidants are also used in tyres. These also affect driving behaviour. The development of a new rubber compound involves constantly balancing the materials. A complex process that varies from tyre to tyre and the material used.
With seasonal tyres, it quickly becomes clear how important rubber compounds are. We explain the differences between summer and winter tyres. Car tyres and the material used: What constitutes a tyre? We use different tyres depending on the season and environment.
These differences might be obvious, for example in the tread depth. However, they might be harder to spot or even go unnoticed in other areas.
State of Goodyear Tire Company in dramatically increased workers' productivity. The history of tires provides an excellent example of how innovations in one industry can cause massive changes in another.
Simply put, the "take-off" of the automobile industry transformed the rubber industry in the United States during the early years of the twentieth century. The late-nineteenth century rubber industry concentrated on producing footwear and bicycle and carriage tires. By World War I, rubber and automobile tires were virtually synonymous in the public mind. Seven thousand new car sales in were accompanied by sales of 28, tires as original equipment OE and an additional 68, replacement tires.
By , with tires forming about fifty percent of rubber sales, OE tire sales exceeded four million for the one million new cars produced and total tire production reached This vast increase in production was accompanied by the emergence of now well-known firms like Goodyear, Goodrich, and Firestone, and the formation of the industry's center in Akron, Ohio. And while employment soared, production increases were possible only with the aid of technology.
The fundamental innovation was the mechanization of core building. Before , tires were built up by workers stretching, cementing, and stitching each ply and the beads around an iron core. In , W. State of the Goodyear company patented a machine that carried the plys, beads, and tread on rollers carried on a central turret. The worker pulled the appropriate material over the core while the machine's electric motor held the proper tension so the worker could finish cementing and stitching.
Skill and dexterity remained important, but the core-building machine simplified and sped-up production from six to eight tires per day per worker to twenty to forty a day, depending upon the type.
A passenger car tire is manufactured by wrapping multiple layers of specially formulated rubber around a metal drum in a tire-forming machine. The different components of the tire are carried to the forming machine, where a skilled assembler cuts and positions the strips to form the different parts of the The first step in the tire manufacturing process is the mixing of raw materials—rubber, carbon black, sulfur, and other materials—to form the rubber compound. After the rubber is prepared, it is sent to a tire-building machine, where a worker builds up the rubber layers to form the tire.
At this point, the tire is called a "green tire. When a green tire is finished, the metal drum collapses, allowing the tire assembler to remove the tire. The green tire is then taken to a mold for curing. Quality control begins with the suppliers of the raw materials. Today, a tire manufacturer seeks suppliers who test the raw materials before they are delivered to the tire plant. A manufacturer will often enter into special purchasing agreements with a few suppliers who provide detailed certification of the properties and composition of the raw materials.
To insure the certification of suppliers, tire company chemists make random tests of the raw materials as they are delivered. Throughout the batch mixing process, samples of the rubber are drawn and tested to confirm different properties such as tensile strength and density.
Each tire assembler is responsible for the tire components used. Code numbers and a comprehensive computer record-keeping system allow plant managers to trace batches of rubber and specific tire components. When a new tire design is being manufactured for the first time, hundreds of tires are taken from the end of the assembly line for destructive testing. Some of the tires, for example, are sliced open to check for air pockets between body plies, while others are pressed down on metal studs to determine puncture resistance.
Still other tires are spun rapidly and forced down onto metal drums to test mileage and other performance characteristics. A variety of nondestructive evaluation techniques are also used in tire quality control.
X-ray videography provides a quick and revealing view through a tire. In an X-ray tire test, a tire is selected at random and taken to a radiation booth where it is bombarded with X-rays. A test technician views the X-ray image on a video screen, where tire defects are easily spotted.
If a defect shows up, manufacturing engineers review the specific steps of tire component assembly to determine how the flaw was formed. In addition to internal testing, feedback from consumers and tire dealers is also correlated with the manufacturing process to identify process improvements.
Constant improvements in rubber chemistry and tire design are creating exciting new tires that offer greater mileage and improved performance in extreme weather conditions. These allow your tyre to be flexible. A layer called the carcass ply is placed directly above the inner liner of the tyre and is what gives your tyre strength. Sidewall This is the area of extra-thick rubber that runs from the bead to the tread and gives your tyre its lateral stability. Sipe and Groove The tread blocks are separated by the deep grooves that allow your tyre to disperse water, snow and mud.
Sipes are the smaller grooves or cuts made in the tread blocks themselves that give extra grip, which is especially important in a tyre made for snow and ice. Shoulder Your tyre has a small bevelled edge where the tread meets the sidewall. Its design and construction plays an important role in how your tyre helps you take corners. Tread This is the area of your tyre where the rubber meets the road.
The ingredient proportions will depend on what the performance goals of the tyre will be.
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