There are several techniques for repairing conveyor belts, and the most appropriate technique depends on the type and extent of the damage. Here are some common techniques for repairing conveyor belts:

1. Patching: This is a common repair technique for minor tears or punctures in the conveyor belt. A rubber patch is applied to the damaged area using an adhesive compound, and then cured according to the manufacturer’s instructions.
2. Splicing: Splicing is a method of joining two ends of a conveyor belt together. It is used when the belt is too damaged to be repaired with patching. There are several splicing techniques, including mechanical splicing, vulcanized splicing, and cold bonding. Mechanical splicing uses metal fasteners to join the two ends of the belt, while vulcanized splicing involves heating the belt ends and fusing them together. Cold bonding uses an adhesive compound to bond the belt ends together without heat.
3. Belt Clipping: This is a temporary repair technique that involves clipping a metal fastener over the damaged area of the belt to hold it together until a permanent repair can be made. Belt clipping is not recommended for long-term use as it can cause additional damage to the belt.
4. Belt Replacement: If the damage to the conveyor belt is extensive, or if the belt is old and worn out, it may be more cost-effective to replace the entire belt rather than attempting to repair it.

It is important to note that repairing conveyor belts can be a hazardous task, and should only be performed by trained professionals using proper safety equipment. Proper maintenance and regular inspections can help prevent damage to the conveyor belt, reducing the need for repairs and extending the life of the belt.