During the vulcanization process of the conveyor belt, the control of vulcanization temperature and pressure is a key issue.
- If the temperature is too high, the rubber will heat up too quickly, the temperature difference between the inside and outside will be too large, the inner core rubber has not been fully vulcanized, and the outer rubber has begun to age;
- If the temperature is too low, the heat up of the rubber will be too slow, the vulcanization will be incomplete, and the joint strength will not meet the requirements.
- The reasonable curing temperature is generally 144℃～147℃.
The curing time should be determined according to the specifications provided by the conveyor belt manufacturer and the corresponding thickness of the conveyor belt.
The pressure should not be lower than 115MPa. If the pressure is low, the rubber inside the joint will not be tightly bonded with the steel rope and the rubber itself, air and other volatile substances will not be discharged, causing the inside of the joint to look like bread, which affects the quality of the joint.
Precautions for conveyor belt joint vulcanization:
- Things should be paid attention to in the vulcanization joint process of the old conveyor belt
As the old conveyor belt has been used for many years and has been bent many times, delamination has occurred between the steel rope and the rubber, and the galvanized layer of the steel rope has also been damaged due to the reaction with various elements in the rubber.
Therefore, during vulcanization, the bonding force per unit length of the steel cord and rubber will decrease. The only way to deal with this kind of conveyor belt is to increase the overlap length of the joint. The amount of increase depends on the degree of damage to the conveyor belt rope.
- Conveyor belt connect center requirements
When the conveyor belts are connected, the centerline must be consistent, otherwise it will not only cause the conveyor belt to run off, but also the uneven force of the steel cord on both sides.
The short side bears too much force when the force exceeds the bonding force between the steel cord and the conveyor belt, this cord will be drawn out, and the adjacent cords will be drawn out one after another. The joint will be taken out in a short time and damaged.
If the bonding force between the steel cord and the rubber exceeds the breaking strength of the steel cord, the cord with the greatest force will be pulled first, and then the other adjacent cords will be broken or pulled out respectively.
So the joint of the centerline of the conveyor belt is very important work when the conveyor belt is connected. Therefore, when the conveyor belt is stripped of the steel cord and ready to be jointed, first to fix the vulcanizer, and place a stable platform no shorter than 3m on both sides of the conveyor belt.
Place the two conveyor belts on the platforms on their respective sides, and find the centerlines of the two conveyor belts (when looking for the centerline, find 3 points on each side of the belt and the distance between the two points is not less than 1m), and then align it on a straight line and fix it on the platform.
Before you are ready to start the joint, check the centerline again, and adjust it in time if there is a problem, so that the centerline of the conveyor belt after connection can be consistent, the force of each steel cord is uniform, and the joint strength is guaranteed.
I appreciated it when you shared that it is great to control vulcanization temperature and pressure during the process. In this way, you can ensure that your conveyor belt can be used for a long period of time. I would like to think if a manufacturer wants to improve his conveyor belt, he should consider looking for a reliable service that can offer to do the vulcanization process.