Conveyor Belt Repairs: Their types and Ways of Fastening

Taking into consideration the meaning of conveyors for ensuring continuous production, quick repairs of conveyor belts becomes a competitive advantage. Three main methods of restoring the work of transporters: mechanical fastening, hot vulcanization and cold vulcanization, each type of repairs has its advantages and disadvantages. As rubber, rubber-fabric and rubber-cable belts are mostly used, we can compare their possibilities to restore conveyor functioning in case of damaging the belt.

Conveyor Belt Stitching after Being Torn

In case of a cautious attitude, conveyor belt can serve for many years, but real exploitation conditions may often lead to problems. In case of some emergency damage, a big part of the belt is substituted, sometimes completely, but for all other cases some local repairs are used:

• Longitudinal cut. A difficulty to restore this belt depends on its length, usually a patch or a mechanical patch is used
• Transversal cut. This cut is usually joined as a scarf or with an overlap, sometimes it is required to substitute some part of the belt
• Through break is repaired with a patch.

In all cases the applied material is the same as of the main belt with the purpose to preserve the resistance parameters throughout the belt. Taking into consideration the urgency of the repairs, it is better to have all conveyor belt fastener tools reserved or the downtimes can lead to serious losses. Remembering how important a conveyor is in production, especially in mines, careers or metallurgical plants, mechanical belt fastening systems should be adapted for repairs on the spot. The problem is not only in having a warehouse of spare parts and conveyor belt fastening tools.

On What does the Quality of a Conveyor Belt Fastener Installation Depend?

• First, from the corresponding tools and the width of the belt itself. It is impossible to restore all belts easily and quickly (even elastic rubber-cloth and rubber-cable belts have their elasticity limit). Usually a parameter of durability - elasticity depends on the character of the transported cargo (grain terminals have their loads and they are absolutely different from the parameters of a mining and a concentrating industry). In any case the width of the belt is a characteristic that influences the time of restoring the belt:
• A belt of a width of (10-20 mm) can be temporarily restored in a home-made way. For example, by sewing the butt ends until complete repairs are performed.
• If the width is 20 mm and more, the time and efforts, spare parts and materials are required.

In this process the damages that lead to the belt breaks, are not noticeable (especially at cement plants). If to ignore some modern service, belt cleaning, the increase of losses, because of the refusal of the equipment to work, is inevitable. The recommendation of the continuous conveyor functioning is simple: to determine beforehand, who will restore the work of the conveyor, while ensuring the reliability of the transportation of the goods.

Three Main Methods of Repairs of Conveyor Belts:

Raw rubber (caoutchouc) is the basis of the conveyor belts (that is armed by the fabric or cables) and as for now there is not any alternative. In 1905 such belts were repaired, applying a solid method of fastening. “Patches” were put on the damaged parts, heated until the temperature reached the peak of the raw rubber melting and they were the first methods of “repairing the conveyor”. The application was limited, because of the time losses, but the technology stayed. Many specialists still consider “welding of the rubber” to be an optimal decision for repairs. Let us explain the advantages of a mechanical conveyor belt fastener, compared to vulcanization.

Hot vulcanization is the first variant for repairing pneumatic tires

Till 1956 it was the main type of repairing rubber technic goods.

• Restoring of the damaged part is reached by means of heating, alloying of the repaired parts (including the cord, fabric or cables, that ensure homogeneity of the belt.
• While working in the conditions of the plant, the resistance of 90% from the parameters of the entire belt is guaranteed
• A big amount of material that is the same as the fabric of the main belt, a highly professional staff and stopping of the conveyor for 24-72 hours

Some special composition is applied for complete repairs, after the process it is required to perform some special tests for accessible cargoes.

Cold vulcanization is a process of gluing the damaged part

The word “vulcanization” does not have any relation to a temperature. Expensive alloys soften the rubber till the state of melting and a reliable fastening is formed due to this fact. Actually, it is “gluing” of the damaged part that does not require any serious preparation:

• A stable temperature, absence of dust and humidity at an accessible level are required in the working zone
• Fastening of the butt ends requires application of some substantial efforts for the period of “capturing” of the gluing compositions

If the technology is violated, stratification of the glueted part may happen, but this element can be enforced by a conveyor belt fastener installation. The general resistance of the restored part is approximately 75-85% compared to a primary state.

Mechanical Fastening of Conveyor Belts and its Pluses

It is possible to repair the belts in any conditions, using joining elements and fasteners, including some hardly reachable places and dismantling the belt is not necessary. Other advantages are

• High speed of restoring the conveyor and a low price
• Some special conveyor belt fastener tools and high professionalism of the repairing team are not required
• Fastening is not solid and in case of any errors in the process, it is easy to correct them
• The cost of sparing parts and materials is minimal

As for the present moment mechanical fastening of the conveyor belt becomes the main repairs method, hot or cold vulcanization are applied in the process of capital repairs or long stops.

Corrosion, low metal durability and formation of the sparks are considered to be the disadvantages of mechanical fasteners. PWS fasteners, patented by Odessa Coal Company, do not have these disadvantages. Some sparkless alloys, resistant to corrosion are used, and the construction is the same as the width of the restored belt. The service time is not definitely defined, we have delivered our fasteners to Ukraine and Kazakhstan since 2014 and as for now there are not any breakages, because of the waste. If you have a necessity to ensure some continuous work of the conveyor of any complexity and any cargoes, we are at your service.