Bai-Ott hot splicing joint material for ST7000N flame-retardant steel conveyor belts

A coal mine with a capacity of 10 million tons is using Bai-Ott-TianLihe hot-vulcanized jointing materials to vulcanize joints on ContiTech ST/S7000×12T+13.5+10 flame-retardant steel wire conveyor belts during a conveyor system renovation project.

This conveyor belt boasts a longitudinal tensile strength of 7000 N/mm. The steel cord core diameter is 13.5 mm, the upper cover is 12 mm thick, and the lower cover is 10 mm thick. The total conveyor belt length exceeds 2000 meters, and the roadway slope exceeds 25°, placing extremely high demands on the jointing materials and process.

The ST7000N flame-retardant steel wire conveyor belt used in this project boasts a longitudinal tensile strength of 7000 N/mm, a belt width of 1800 mm, a joint length of 9100 mm, and operates on a slope exceeding 25°. The construction team used Bai-Ott's hot-vulcanized joint material to achieve high-strength vulcanization of the entire steel conveyor belt directly. After testing by a recognized agency, the static joint tensile strength of the conveyor belt met the requirements of the latest MT/T668-2019 "Flame-Retardant Steel Wire Cord Conveyor Belts for Coal Mines."

High-strength materials drive process innovation, and Bai-Ott's hot-vulcanized joint material demonstrated significant advantages in this project. Its special formula achieves molecular-level bonding with the steel cord at a vulcanization temperature of 150°C, forming a continuous and stable bond. Material testing showed that after curing, peel strength increased by 15% and dynamic flexural resistance improved by 40%, effectively handling the alternating stresses generated by the conveyor belt during a 2,000-meter run.

Multiple machines collaborated for precise control. Ten vulcanizers were arranged in sections along the conveyor belt axis to accommodate the 9,100-mm-long joint area, with a pressure-equalizing system ensuring uniform pressure application of 1.8 MPa. During construction, the team monitored temperature fluctuations of the vulcanizing plates in real time, maintaining a temperature differential within ±3°C to ensure simultaneous vulcanization along the entire length. Mine technicians stated that the thickness error in the joint area after vulcanization was no more than 2mm, significantly improving equipment operational stability.

The project's effectiveness has been proven. To date, the modified conveyor system has operated for over 2,000 hours. Monitoring data indicates that vibration amplitude at the joints passing through the rollers has been reduced by 50%, power loss has been reduced by 12%, and no abnormal wear or delamination has been observed. A third-party test report confirms that the joints' dynamic fatigue life reaches 1 million cycles, meeting the mine's design service life requirements.