A pneumatic tyre” is inflatable envelope with annular toroisal like shape made up of synthetic o natural rubber, or elastic material or blend thereof, protected with the fabric carcass textile cord ply (or steel for few radial ply tyre range) enclosing bead rings.
- Radial Ply Tyre- the Ply cords, in radial ply tyre are substantially laid at ninety degree to the tread centreline, carcass being stabilised through fundamentally inextensible circumferential belt.
- Bias Ply Tyre- the ply cords, in bias ply tyre (known as Diagonal ply), are laid at the substitute angle fundamentally less than ninety degrees to the tread centreline.
Functions and Definitions of Tyre parts Sidewall Rubber- The layer of rubber on the tyre sidewall and over carcass that might include fitting lines and protective ribs to help in the tyre centering on the rim. The tyre is protected by this from damages and scuffing. Sidewall- The tyre parts between the tread and the bead that flexes in service. Bead- the tyre part that is shaped so to hold the tyre and fit the rim on to it. Bead has cores formed of different strands of fundamentally inextensible steel-wire with the plies end wrapped around cores of anchorage. Carcass- Integral with bead, it is a tyre’s cord structure bonded with rubber that provides requisite strength. Ply- It is a rubber layer coated fabric cords. Cord- It is a non-textile or textile strands (threads) that is used several elements of tyre carcass, breaker, belts, plies, etc. Tread- It is part of tyre that comes in ground’s contact and by which the cornering, braking and driving forces are transmitted. Tread is made of a “special rubber compound” to provide the good wearing characteristics and in combination with pattern of tread it transmit these forces. Classification of Tyre Pattern
Semi-lug tyre- it is designed for the drive wheel application. It could be used as the steering wheels. Lug tyre- it is designed for the drive wheel positions. It provides the greater traction. Rib Tyre-it is also called steering wheel tyre and it can be used in all the application of wheel position highway. Storage and Care of Flaps and Tubes Tubes
The flap and the tube should be of correct size for tyre. If unsure, ascertain from manufacturer of tyre the suitability of tube for the use with “radial ply tyre”. In new tyre the fitment of new flap or tube is recommended strongly without exception. Failure of tube in service might cause tyre to fail with that. If too large, the tubes or used tubes that have grown excessively in the services might crack or crease inside the tyre with the severe hazard of loss of automobile control and tyre deflation. Small tubes would stretch too much and it would result in faster loss in its “physical properties”. Weak, cracked and creased tubes are not suitable for the services and it must be exchanged with new tubes. The new tubes must be left in original package and also it is only taken out when needed for fitment. The tube, in event of tube or tyre repair, removed from the tyre is reused and segregated in eth similar tyre after repair is executed. With or without the tyres, where tubes are seen fitted inside the tyres, in tyres the inflation pressure must be maintained at minimum required in order to let a tube stay in its shape inside tyre. Used Tubes
The used tubes must be deflated first, by removing core of valve, then repaired and examined, before storage if necessary. Any of following storage techniques must be observed: place the tube in a tyre, rub over with the dusting chalk, and slightly inflate. Flaps
Whenever flap use is indicated by tyre manufacturer or tyre industry, ensure that correct code or size suggested for rim or tyre size combination is utilised without exceptions. Damaged or old flaps should not be used again. Used Flaps
The used flaps must be rubbed over lightly with the dusting chalk and it must be used without any distortion in similar type, if possible. Suppliers and market Trends
Japan, India, China and Africa are the main suppliers of tyre, tubes and flaps. In china, the famous company that supply tyres is “Ningbo Haishu Yuanxing Tire Valve Co., Ltd”. There top three markets are South America 12 percent, Domestic market 12 percent and Southeast Asia 39 percent. Companies like, Dunlop have been engaged in industry as the key player that made tyres and tubes used in “military aircrafts” from famous Spitfire and Vulcan to the new “F-35 joint strike fighter”, the heavy aircrafts of military like C-130, the Hawk, the Tornado, and new A400M. Figure 1: world's largest tire producers in 2016, based on tire-related sales Key Market Players
Bridgestone was a top Japanese tire manufacturer and also a manufacturer of various industrial rubber products, sporting goods, and bicycles, when this company decided to combine its “Bridgestone U.S.A functions with Firestone Tire and Rubber Company” in year 1990. Furthermore a “Compagnie Generale des Etablissements Michelin” is also a key market player. Its headquarter is in France. Michelin was among the earliest manufacturer of carriages and bicycle’s tires and also it has become the second place inner tube and tire’s manufacturers in world with around 14.4 billion dollar revenues and 127,467 employees in year 2001. Future Prospects
A future prospect based on the tire development with low “rolling resistance” for the use with vehicles running on the efficiency-depended alternative fuels. Bridgestone and Goodyear have manufactured a wire, which could safely run for two hundred miles after the flat, reducing the dangers and inconvenience of changing tire on side of road. Though in 2000s, run-flats were in increased demand, manufacturers faced the challenge of how to offer post-damage prolonged durability without even sacrificing smooth ride throughout the regular performance of tire. Also Goodyear has been operating on “microprocessors” to observe the wear, temperature and air pressure of tire that may extend a life of tire by fifteen percent. In the meantime, Bridgestone has established a tire that is able to heal itself upon being “punctured’. Impact of Political Factor The political factor that affects the tyre industry is the government policy influence on export and import of natural rubber, more significant is that major emergencies and events would happen and has happened worldwide such as possible war factors, and catastrophic events occurrence etc.