The most common type of passenger tires is radial tires. Besides the critical role that tires play in supporting the weight of your vehicle, the internal components and tread design are incredibly complex and have a direct impact on your safety.
Also, choosing the correct tire specification significantly improves tire life and reduces operational vehicle costs.
The internal construction of a tire is essential as it is what helps reinforced and strengthen the tire.
The inside of the tire is made up of plies of cord, this network of cords is called the tire’s carcass and typically is constructed of polyester, steel, and other types of textile materials, then reinforced with rubber.
For decades, there have been two types of tires: Bias and radial Tires.
Bias tires owned the road until the ’70s, when radial tires, game-changers in tire technology were introduced. Today, radial tires are the most popular by far.
Radial tires consist of one or two casing or sidewall plies comprised of either fabric or steel cords and aligned 90 degrees to the beads. Tread plies are then added for directional stability and puncture resistance. Each ply is made up of individual cords twisted like cables, laid side by side, and encased in rubber to form a uniform sheet of fabric or steel and rubber.
If you have ever wondered how tires are made, the following is a roadmap for the construction of radial tires:
Production conditions of radial tire:
- Requirements for temperature and humidity:
The room temperature of the production plant of the radial tire is kept constant and stable, the calendaring area and the shaping area must be strictly controlled at 22 degrees Celsius, and the humidity is usually kept below 50%. If higher, the steel cord will rust or cannot bond with rubber.
- Requirements for ultraviolet and ozone:
All radial tire semi-components should be isolated from UV and O3 to avoid the aging of rubber. Therefore the tire factory plant does not use daylight lighting.
Dust will hinder the bonding of rubber. The radial tire workshop should be strictly dust-free. Vehicles inside and outside should be separated. Besides, there ought to be control procedures against dust brought in by workers.
The following is a brief introduction to the production process of radial tires:
Process 1: Mixing and refining process:
The process is to mix the raw materials such as carbon black, natural rubber, synthetic rubber, silicon, additive, promoter, etc., then transport them into the mixing machine, finally come out of the rubber plate. Before entering the mixer, all raw materials must be tested then can be passed. The composition of the material recipe depends on the performance requirements of the tire. These requirements mainly come from traction, driving performance, road conditions, and tire requirements.
.Process 2: preparation process of adhesive parts:
All the semi-finished rubber components that make up the tire will be prepared in this process, some of which are initially assembled by the six procedures.
Section 1: Extrusion
The extrusion compound is fed into the extruder to extrude different semi-finished rubber parts： tread, sidewall, mouth, APEX, etc.
Section 2: Calendering
The raw material cord passes through the calendar, and a thin layer of rubber is pasted on both sides of the cord. The final product becomes a cord. The raw material cord is mainly nylon and polyester.
*Using Released Embossed Film
What are the Released Embossed Films, and how use they?
Released Embossed Film is frequently used as separation films, usually on sticky substrates, and prevents the rubber from sticking to itself, dust, and other foreign matters while calendaring and during storage to retain the properties of rubber before being taken for further processing. Released Embossed Film is widely used by rubber sheeting, tire, tread, and belt manufacturers. By its unique formulation and different patterns, it effectively reduces adhesion and eases the whole process. Read more…
Released Embossed Film
Section 3: tire ring forming:
The tires ring is made of a lot of steel wire after coating rubber. This compound rubber for tire rings has unique properties. When vulcanization is completed, the glue and wire can be tightly bonded together.
Section 4: fiber cord (coated rubber) cutting:
The fiber cord will be cut to the appropriate width and connected to the joint in this process. The variation of the width and angle of the fiber cord mainly depends on the specification of the tire and the requirements of the tire structure design.
Section 5: affixing triangular core strip （APEX)
In this process, the triangular core strip extruded by the extruder will be manually attached to the tire ring, which plays an essential role in the operating performance of the Radial tire.
Section 6: belt forming:
This procedure produces a belt layer. In the spindling room, many steel wires come out through the wire piercing board and then go through the mouth plate simultaneously as the rubber adhesive to the steel wire on both sides.
Process 3: tire shaping process:
The tires forming process is to assemble all the semi-finished products into raw tires on the molding machine. The raw tire here refers to the unvulcanized tire. The basic tire is checked and transported to the vulcanization process.
Process 4: Vulcanization process
The raw tire is loaded on a vulcanizing machine and is vulcanized into a finished tire after an appropriate time and suitable conditions in the mold. The vulcanized tire has the appearance of the finished tire pattern, font and tread pattern. Now the tires will be sent to the final inspection area.
Process 5: inspection process:
In this area, the tires are first examined by visual appearance. Then there is uniformity detection, which is completed by a uniformity test machine. The uniformity test machine mainly measures radial force, lateral force, cone force, and fluctuation. After the uniformity test is finished, the dynamic balance test should be done. The emotional balance test is completed on the dynamic balance test machine. Finally, the tires should be tested by X-ray and eventually shipped to the finished product warehouse for shipment.
Radial Tire Advantages
- The tread of radial tires does a better job gripping the road and provides improved durability and maneuverability.
- Because their plies run radially from bead to bead around the tire instead of diagonally, radial tires are more flexible – giving you a more comfortable ride.
- Radials have a thick shoulder that protects the interior from shocks and damage.
- These tires have less rolling resistance, so you use less fuel on radial tires.
- Radial tires provide more stability and less vibration.
- Radial tires last longer, in part because they generate less heat.
- Radial tires contain bead filler that allows the vehicle to handle better on the road.
Radial Tire Disadvantages
- Poor transport handling, since low lateral stiffness causes the tire sway to increase as the speed of the vehicle increases.
- Increased vulnerability to abuse when overloaded or under-inflated. The sidewall tends to bulge, which could cause damage and puncture.
- A ply layout causes the radial tire to follow a wheel track more consistently than a bias-ply tire.
- The radial tire is more expensive than a bias-ply tire which may be considered as a disadvantage.
The best way to determine the most appropriate tire for an application is to keep tire records.