What are the tire production processes?

Fully automatic production has always been the goal pursued by the tire manufacturing industry and the development trend of the global tire industry. In recent years, tire production process automation has developed in two directions: continuous improvement of existing traditional processes and development and application of new concept technologies.

Broadly speaking, brand-new conceptual technology is an anti-traditional and revolutionary technology. At present, Michelin C3M technology, mainland MMP technology, Goodyear impact technology, Sanhai CCC technology, Bridgestone ACTAS technology and Pirelli MIRS technology have emerged in this field.

The six new concepts of tire manufacturing technology mentioned above have brought threats and challenges to the position of traditional manufacturing technology. In this regard, although it is widely reported by overseas industry media, the key technologies are rarely disclosed. The author will sort out and screen the collected data, and roughly outline four new concept technologies.

I. Basic information

As we all know, the tire industry has developed for more than one hundred years. After hundreds of years, the traditional tire production technology has been improved day by day, from rubber mixing, component preparation (calendering, extrusion), molding, vulcanization to finished product quality inspection, each stage has a high degree of automation. After everything has reached a certain historical height, it will be very difficult to continue to move towards higher goals. At this time, if we can think and break through from another angle or in another way, we will often have better results and greater gains. In this context, a new concept of tire manufacturing technology is developed according to this idea.

Compared with the traditional tire manufacturing technology, the above-mentioned new concept technology generally has the advantages of saving investment, occupying less equipment, high production efficiency and reducing costs. See table 1 for details.

Table 1 Technical and Economic Indicators of New Concept Tire Manufacturing Process

Second, Michelin C3M technology

C3M full name: command+control+communication &; Manufacturing; Command, control, communication and manufacturing integrated system.

C3M has the following five technical points: ① Continuous low-temperature mixing; (2) directly pressing out the rubber piece; (3) weaving/winding the skeleton layer on the forming drum; ④ Pre-vulcanized annular tread; ⑤ Electrothermal vulcanization of tires.

The key equipment of C3M is special knitting machine and extruder. With the forming drum as the core, C3M technology can be realized by properly configuring special weaving unit and extrusion unit. Special knitting machine weaves seamless annular carcass ply and belt around the forming drum, and winds steel wire around the forming drum to obtain traveler. The extrusion unit continuously mixes rubber at low temperature (below 90℃) and extrudes rubber parts such as sidewall and triangular rubber strip.

The technological feature of C3M is that the parts do not need to be cooled/parked, nor need to be re-processed or pre-assembled, and they are directly sent to the building drum to complete the tire building at one time. During the forming process, the forming drum is always in a heated state, and the blank is presulfurized at the same time of forming to achieve the setting.

Michelin 1982 began to study C3M technology, and 1992 announced the success of the research. The first C3M factory was built in clermont-ferrand, where Michelin is headquartered, the following year. By the end of 1998, it had grown to 7 factories, as shown in Table 2.

Table 2: List of Michelin C3M factories

Third, mainland MMP technology.

The full name of MMP is: modular manufacturing process; ; Building block molding method.

As we all know, the traditional tire production process consists of four major processes: ① shaping/mixing; (2) calendering and extrusion; ③ molding; ④ Vulcanization. Most existing tire factories have the above four procedures except the first procedure for purchasing finished rubber.

MMP broke the complete model of the four major processes in traditional tire factory, and divided the four major processes into two parts for operation. The first block includes the first step (molding/mixing), the second step (calendering and extrusion) and the first half of the third step (carcass molding), and the second block includes the second half of the third step (belt bonding and tread bonding) and the fourth step (vulcanization). The factory that performs the first production task is called "platform", and the factory that performs the second production task is called "satellite factory". The platform is responsible for the production and pre-assembly of tire basic components, and the satellite factory is responsible for the overall assembly and final vulcanization of tire manufacturing process. Usually, a platform can be configured with multiple satellite factories to form a radiation network.

In other words, the biggest feature of MMP technology is the new mode of "basic component factory+assembly factory". The platform (basic parts factory) is located in an area with low labor cost to reduce production costs; Satellite factories (assembly plants) are located in technologically developed areas or areas with strategic market position to ensure product quality and achieve the purpose of supplying finished products locally.

Platform products (basic components of tires) are standardized, that is to say, tires of the same specification, different brands and different series have the same basic components except tread and belt. The bodies on the platform have been presulfurized. According to the technical requirements of products, belts can also be installed on the platform.

The original idea of MMP was put forward by Bernadatte Hausmanr, manager of purchasing and strategic resources department of continental company. 1The project was approved at the end of 1993.1In June 1996, the first full-scale MMP demonstration factory was put into production in Germany. At the beginning of 1997, MMP technology passed the review of the board of directors of mainland companies, which opened the curtain of global application.