BIAS TIRE AND RADIAL TIRE


Project Description

BIAS TIRE AND RADIAL TIRE

Tire classification according to the structure, to the current widespread use of points, can be divided into bias tire and radial tire two categories.  

 

The structure of bias tire  :

The bias tire is made of multiple layers of skew fabric. bias tire because of different tire body cord material can be divided into cotton cord tire, rayon cord tire, nylon cord tire, polyester cord tire and steel cord tire five categories.

BIAS TIRE AND RADIAL TIRE

 

Their characteristics are as follows:

1.Cotton cord tires. The tire body of cotton cord tire is made of cotton fabric as the tire body. Cotton thread is the earliest used as the body material, but because of its low original strength, the body needs more curtain layer. Cotton cord tire body high heat, slow heat dissipation, low number of refurbishment, and easy to absorb water, therefore, is no longer used. But although no longer use cotton cord as the fetal body, but no matter what material as the fetal body, its fetal body strength is based on cotton cord as the benchmark, this has become a world practice, but also enough to make the cotton line immortal.

2.Rayon cord tires. After cotton cord is widely used by tire manufacturers is rayon cord. Rayon was a new kind of fiber introduced at the Paris Exposition in 1889. Although it was not silk, it had the same luster and touch as silk. It was invented by a French physiologist, Irelou do Charudonis. The advent of rayon, because of its strong toughness, better than cotton strength, and heat and fatigue resistance, therefore, very quickly become the main material of tire cord. The tire that makes with rayon cord, its comprehensive performance is much stronger than the tire that cotton cord is the tire body, because this makes the tire again forward crossed a big step. But rayon is also easy to absorb moisture, in the wet state of the strong reduction.

3.Nylon cord tires. Nylon once again caused a world sensation when it was praised as “stronger than steel, thinner than spider silk, made of coal, air and water, with excellent elasticity and luster, and a fibrous protein like protein.”

Nylon is used as the tire body, so that the strength of the tire is stronger, impact resistance, elastic, low density, tire temperature rise slowly, and can be repeated refurbishing, and not easy to absorb water. But it has the disadvantage of heat expansion and cold contraction, the body is easy to deform. In winter, when the vehicle is parked outside for a little longer, the tyre will appear “flat spot”, which is the reason.

5.Polyurethane cord tires. Its strength is similar to nylon, and its expansion and thermal dependence are better than nylon. Therefore, it is widely used as the skeleton of passenger car tires abroad.

6..Steel cord tires. Steel cord tire was invented by Michelin Tire Company in France in 1946. This kind of tire has strong tire body strength, small rolling loss, impact resistance, good wear resistance, safe driving and high refurbishing rate. But its body rigidity is strong, the buffer performance is poor.

 

 Structure of radial tire:

 The cord in the radial tire cord layer is arranged radially at the center point of the tire, and then the cord is hooped with a steel belt of 10°-20°(the Angle of the steel line in the steel belt) above the cord.

The tire body of a radial tire is made of nylon and rayon, while the tire body of a truck and other heavy trucks is made of steel wire.  In addition, radial tire because of the force and function of each part of the different, therefore, the selection of rubber is also different.

The following is a selection of compound for each part of a radial tire according to its different functions.

1.Tread adhesive.  Because the tread of the tire should be in direct contact with the road, therefore, it has good wear resistance, small rolling resistance and noise, and also has excellent heat resistance and thorn resistance.  In addition, the radial tire buffer elongation is small, so that the tread load increases, especially on the poor road surface is more obvious, therefore, tread rubber also has good elasticity, fatigue resistance and high aging resistance.  Therefore, the use of tread glue is very particular.

2.side glue.  The bending deformation of the radial tire side is much larger than that of the bias tire. Therefore, the rubber resistant to bending deformation must be selected.  In addition, the side of the tire is easy to crack under the action of ozone, at the same time, the side of the tire also bears a large mechanical deformation, so the side of the tire adhesive should also have a lower constant extension strength, excellent fatigue resistance and ozone resistance.

3.belt layer glue. The belt layer of radial tire is subjected to higher shear stress than the bias tire buffer layer. At the same time, the smooth transition of hard buffer layer should be realized and the clearance of the tire shoulder position should be avoided. Therefore, the tape layer adhesive should have high strength, fatigue resistance, heat resistance and adhesion.

4.tire body cord adhesive. The circumferential elongation deformation and shear deformation along the cord of radial tire body are larger than that of skew-cross tire, so the cord adhesive should have higher strength, fatigue resistance, heat resistance and adhesion. At the same time, the cord adhesive should also have a high degree of cohesion.

5.shoulder pad glue. The tire shoulder pad is used to separate the curtain layer from the end of the buffer layer to make the hard tread smoothly transition to the soft side of the tire, and transfer and absorb the stress concentrated on the tire shoulder under dynamic conditions to reduce the risk of the tire shoulder void. Because the shoulder pad is located in the high stress zone, it should have excellent fatigue resistance and good adhesion performance.

6.bead trigonometry. In order to strengthen the bead part, so that the bead can be formed steadily, and form the rigid transition of the bead to the bead example, generally by a larger hardness or two kinds of different hardness of the triangle tape to fill the steel ring and strengthen the bead part of the side, to ensure the radial bead wire to soft bead side gentle transition. In addition, this kind of glue also has good adhesion performance.

BIAS TIRE AND RADIAL TIRE

 

From the above production of radial tires needed to see the different rubber, the manufacture of radial tires is very complex and not easy.

In addition, radial tire production technology requirements are very strict, must have advanced equipment, fine raw materials, strict process management and reliable testing means.  It can be said that the radial tire is the crystallization of human wisdom.

Radial tire according to the belt layer and the body with different types of cord, radial tire can be divided into three categories: full wire radial wheel, wire belt fiber tire body radial tire (semimennis radial tire) and all fiber radial tire.

Most of the radial tires for heavy trucks are full steel wire radial tires or half steel wire radial tires;  Radial tyres for light trucks are usually half-wire radial tyres;  The radial tyres used in cars range from half steel to all fibre

Below is a representation of the wire, nylon and fiber, which are inscribed on the wall of the tire

STEEL

NYLON

POLYESTER

 

Remarkable features of radial tires:

1.It can drive at high speed

“Velocity – standing wave – heating – degumming – bursting” is a line connected together. Radial tires, on the other hand, are less prone to “standing wave” phenomena, even when turning at high speeds, because they have a strong steel band around the fabric. So radial tires can run at high speeds, but bias tires can’t. However, everything has its limits, especially the tires, because it plays an integrated role, so in the design of wheel tire production, has set its critical speed (of course this kind of structure of tire speed than the tire is much higher), if the speed more than the critical speed of the tire, also the above situation will happen. Therefore, each driver should know the speed level of the tires used in his car, and drive in strict accordance with the prescribed level, as far as possible to avoid the occurrence of tire blowout and rollover accidents.

2.Not easily punctured

The crown of radial tires is less likely to be punctured by sharp objects such as nails (relatively speaking) because of the steel strip layer. Experimental results show that to drive a 2mm diameter nail from the tread, only 196N force is needed to penetrate the bias tread, while 980N force is needed to penetrate the radial wire tread. That is to say, steel wire radial tire and skewline layer tire comparison, both into the same nail, into the tread force, steel wire radial tire is 5 times skewline layer tire

3.Long service life

Because the steel belt of the crown of radial tire is very strong, so the crown of tire can be used more hard rubber, so as to improve the wear resistance of tire and prolong the service life of tire.

4.Strong safety performance

The tread of radial tire is generally wide, so it has strong grip, good braking performance and good handling stability. In addition, we have introduced before the temperature is a major cause of tire problems, and the radial tire because of its tire side thin, so in the driving temperature is low, fast heat dissipation. In general, the radial tire at the speed of 110km/h continuous driving, its temperature is 100℃, and bias tire, when the speed reaches 69km/h continuous driving, its temperature is as high as 120℃. Therefore, radial tires can be safely and at high speed on the highway. In addition, radial tire also has soft tire wall, good shock absorption, ride comfortable, low noise characteristics.

The experimental results show that, compared with the bias tire, the radial tire can improve its wear resistance by 50% ~ 100%, rolling resistance by 30%, fuel saving by 8% ~ 10%, traction capacity by 10% ~ 20%, side force by 50% ~ 70%, and puncture resistance by 5 times as much as that of the bias tire.