The history of tire and its Mission
The history of tire and its Mission
The History of Tire
The first step of wheel tire has been founded with the simple tire model for J.B. Dunlop’s suns three wheel bicycle by attaching a tent fabric with nails and where it obtained through blowing it with air on top of a wooden wheel with plastic solution injected.
The development of the tire in the meaning of today has started in the beginning of 1900s. Rubber the widely used main raw material in the tire today was obtained from rubber tree raised initially only in South America, afterwards in Malaysia, Indonesia, Sri Lanka and other Southeast Asian countries. Rubber initially has been used for other purposes, but its use in the tire sector is realized with Goodyear’s cooking of rubber with sulfur (vulcanization) to shape it. Thereafter, a fast development has started in tire technology by Dunlop placing steel wires at heels and by developing inner tire and when 1920s arrived, cord fabric made of cotton were included in the main material of pneumatic wheel tire.
Today with the development of more resistant cord threads than cotton, instead of cord fabric and steel cords synthetic layer fabrics such as rayon, polyester and nylon are widely used. The classification and standardization of tires has started in the 1940s by the development of tire sizing system based on number-alphabet group which consisted of tire cut width and rim sizes.
Structure of Tire
I- Elements of Tire:
The elements that make up tire; based on their function; can be divided into two as basic and optional elements.
A- Basic Elements:
1- Basic Elements of Cross Tire
• Summer / Winter Structure
• Ridge
• Cheek
• Heel
2- Basic Elements of Radial Tire
• Chasing Structure
• Ridge
• Cheek
• Heel
• Binder/Tie (steel or textile)
B- Optional Elements
1- Optional Elements of Cross Tire
• Impact layer
• Chafer
• Strips
• Fillings
2- Optional Elements of Radial Tire
• Restriction or reinforcement layers
• Strips
• Fillings
• Chafer
Basic Elements of a Tire
Casing:
The element carrying the load on the tire is pressured air. To the contrary of common belief, chasing is not the element carrying load. However, the carcass structure assumes the duty of pressured air carrying load to be kept within the structure. Charka is obtained by textile or steel cord to be placed in layer form into the mixture matrix. The cords that make up charka are bundled around the heel cord and enables for structure to be clenched with the heel. It is structure that determines tires conduct, capacity and endurance under load.
Torso (back):
Enables tires contact with the road. Through transferring engine power to the road, it provides acceleration and tow and through transferring break power, it provides slowing down and stopping. It protects the casing structure against negative impacts coming from the road such as heating, abrasion, splitting – up, cutting. The design on the back and the type of chemical mix forming the back determines tires holding the road, its tow, its conduct on wet ground, movement and breaking capability.
Cheek:
It protects the tire through mixture covering against outside impacts that chasing may receive. It helps for the cooling of the tire.
Heel:
It is the significant part which assumes the function for chasing structure ends to be locked hyper statically from both sides. It is made up of steel cords, it is covered with mixture material and it has a circular structure. Another duty of the heel is the mounting of the rim to the tire.
Tie:
A peculiar structure which has radial structure. It is a steel or textile cord structure, which is placed top of body layers on extending 90 degrees angle from heel to heel and a 20 degree angled only to be found on the back region. This structure impacts in a way to increase tires speed performance. It enables for tires turning resistance to decrease.
Optional Elements of Tire
Impact Layer:
It is an intermediary structure located on top of tires chasing structure and below back region, which is produced from nylon origin cord material covered with special rubber mixture, consisting of single or multiple layers.
This layer increases tires back regions endurance and stability against impacts created by increasing speeds and under load. In addition, this structure helps for protection of chasing structure, for the back resistance to increase against back puncturing and cuts.
BODY(CARCASS)
The body is made up of several layers of different fabrics, called plies. These ply fabrics can be made of nylon, polyester, or steel cord.
The cords in a radial tire run perpendicular to the tread center line.
In Diagonal bias tires, casing is constructed of alternate layers of rubber coated ply cords which extend around the beads and are at alternate angles substantially less than 90° to the center line of the tread.
The plies are coated with rubber to help them bond with the other components and to seal in the air.Carcass provides tire pressured air retention which is the virtual element for load carrying.
The ply transmit all loads, breaking and steering forces between the wheel and the road and withstands the burst loads of the tire under operating pressure.
Chafer:
The component covering the top of the heel structure with the casing structure converging in the heel region of the tire and protecting the casing against damage that can be caused during mounting and demounting of the tire to the rim and which provides leak proofing in tubeless tires and that provides decreasing of the thermo impacts and corrosion that are caused by rubbing between rim and tire heels.
Strips:
It is a mixture of structure that prevents opening and spreading of layer ends during tire production which are placed at ends of layers that make up the tire.
Fillings (Apex):
It is a mixture of structure placed to fill the space that may be formed at the heel region of the tire and layer turns and which provides for the region where the tire sits on the rim to be more rigid.
Reinforcement Layers:
Found in some tires in the back region, it is a supplemental structure which increases endurance. It impacts especially in increasing speed performance in radial carriage tires.
Inner Liner:
In addition to optional elements, in tubeless tires, it is a structure produced from special chemical mixture that prevents the gas (Nitrogen, dry air etc.) and humidity used in pressurization of the tire on the inner surface of the tire extending from heel to heel to leak into the casing structure. This structure substitutes the place of inner tires for the tire to hold pressure.
Classification of Tires
A. BY CONSTRUCTION
There are two basic types of tire construction that must be considered when choosing either a replacement tire for certain applications or when spec’ing new tires on an original equipment vehicle:
1. CROSS PLY TIRES
Also indicated as CONVENTIONAL or BIAS TIRE. Bias ply tires are constructed of overlapping crossed layers of cord material and are typically made with nylon, polyester, or other materials.The crossed plies run on a diagonal from tire bead to tire bead and comprise a generally stiff sidewall area. Sometimes, extra crossed plies or breakers are used under the tread area to further stiffen the crown area and provide better wear resistance or other performance parameters (such as puncture resistance, etc.).
Bias ply tires have been designed over the years to perform in many different types of applications from all-highway to on-off road, to all off-road service conditions.
Bias tires can be in the with and without belt.
2. RADIAL TIRES
Radial ply tires are made with the cord material running in a radial or direct line from bead (at 90 degrees to the centerline of the tire), and are typically made with one steel body ply or multiple body plies of other materials. Under the tread area, the radial tires usually have two or more crossed plies or belts made of steel cord to stabilize the crown area and offer better puncture resistance.
The radial tires’sidewall area is generally less stiff than the bias ply sidewall, though the tread area is normally much stiffer.
Radial tires typically are used in applications where heat build-up with bias ply tires is a problem. With the many improvements to radial tire construction made in recent years, the radial tire is now used in virtually all types of service conditions.
Radial tires can also be splitted into subgroups such as :
a. Fabric ply&fabric belted .
b. Fabric ply&steel belted .
c. Steel ply&steel belted (All steel)
Bias Ply Tire Considerations
• Stiffer sidewalls give better driver handling/feel
• Lower susceptibility to sidewall snags/hazards/rusting
• Lower initial tire purchase price
Radial Tire Considerations
• Better treadwear performance
• Higher potential for retreading
• More fuel efficient
• Lower susceptibility to tread punctures
• Better traction characteristics
A. BY SERVICE
1. Passenger(car) tires.
2. Ultra light &light truck tires.
3. Truck (including bus) tires.
4. Off-the-road tires.
5. Industrial tires.
6. Tractor tires.
7. Field/garden tires (for small type of vehicles).
C. BY TYPE OF AIR RETENTION
- Tube type
- Tubeless tires
The tubeless tire is similar in construction to a tube-type tire, except that a thin layer of air and moistureresistant rubber is used on the inside of the tubeless tire from bead to bead to obtain an internal seal of the casing.
This eliminates the need for a tube and flap.The two types of tires require different rim configurations:
The tubeless tire uses a single-piece wheel; and the tube-type tire requires a multi-piece wheel assembly.
Both tires, in equivalent sizes,can carry the same load at the same inflation pressure. However, tubeless tires generally offer more benefits :
• Less complicated mounting process due to use of a single-piece wheel
• Decreased weight with lighter tire/wheel assembly
• Less maintenance of parts and reduced parts inventory
• Improved bead durability potential from less brake drum heat resulting from higher wheel clearance
• Improved crown and sidewall durability potential from cooler running
tubeless casing
• Better lateral stability from lower section height
• Reduced downtime from punctures |
