Abstract: The rubber belt conveyor process important status in bulk cargo transportation equipment.

Rubber conveyor belt plays an important role in bulk material transfer equipment. Therefore, how to repair the damage of conveyor belt as soon as possible to ensure the normal material transport is an important issue for maintenance personnel. This paper analyzes the common damage types and causes of conveyor belt, compares and discusses the effects of various repair methods, puts forward a set of feasible cold adhesive repair technology, and puts forward measures to improve the cold adhesive quality, which is of practical significance to guide the maintenance of conveyor belt.

1.1 local wear (skin damage)

Fabric core conveyor belt, steel core conveyor belt are very easy to appear this kind of damage. The main reason is that the transfer place, the material guide groove, the invalid roller and other parts are easy to get stuck in a large material block, once the conveyor belt running, will inevitably cause local excessive wear conveyor belt. In the rizhao port coal loading and unloading system, cantilever belts such as stokers and reloaders have happened that the conveyor belt was locally ground to 5 layers of canvas while other parts were covered with glue. In the loading system, a belt was directly stuck on the belt due to the lower apron of the material guide groove, the result is that the skirt plate on both sides of this belt is all worn out with steel wire.

1.2 Part crushing (through wound)

Fabric core conveyor belt, steel core conveyor belt have this kind of damage. When conveying materials on the conveyor belt, there are often large stones and sharp material blocks in it. These material blocks are not sufficiently buffered at the transfer point, so they break the conveyor belt with large impact force and form a hole. If materials are mixed with sharp objects, such as iron crowbars, it is easy to cut the conveyor belt, resulting in a large area of conveyor belt tearing.

1.3 damage of adhesive joint

The adhesive joint of conveyor belt is formed by relap vulcanization when the belt is installed. If the joint part is not handled well, it is easy to cause premature wear and peeling of the joint part.If not treated in time, the joint part damage deterioration speed is fast, easy to break the belt accident.

1.4 longitudinal crack of steel wire core conveyor belt

Part of steel wire conveyor belt often appear longitudinal penetrating scratch, as long as dozens of meters or even hundreds of meters, this kind of damage is generally called longitudinal crack.Most of the causes are sharp tools stuck in some places, such as the scraper sweeper, the operator did not remove them in time, resulting in a long distance scratch and tear of the conveyor belt after the belt operation.

2. Conveyor belt damage repair method and cold adhesive repair process

2.1 comparison of different repair methods

Since 2000, We maintenance personnel of hot vulcanization, mechanical CARDS, tiles, cement and other repair way, compares the repair effect of several kinds of repair technology, through the comparison of the repair time and repair quality (as shown in table 1 and table 2), it is not hard to find, replace the cold sticking method need to simple, less auxiliary work, require less downtime.This in the loading, unloading pressure is greater, the cold adhesive method showed great advantages.

Table 1 comparison of time required by different vulcanization methods

(taking 1m longitudinal opening as an example)

Table 1 comparison of time required for different curing methods

Take, for example, the 1M Longitudinal slit

Table 2 comparison of repair quality by different vulcanization methods

Take, for example, the 1M Longitudinal slit

Cold bonding technology

The cold bonding repair process is similar to the hot vulcanization process, The repair process is as follows: take steel core conveyor belt as an example:

Belt positioning. Use the clamp to clamp the belt to be repaired to a balanced

state.

Treatment of repair site. According to the shape and degree of repair parts for trimming, polishing, as far as possible to make repair parts to form a smooth transition concave surface, do not have the emergence of warping. The purpose of grinding is to remove impurities and loose layer, increase the surface roughness of rubber, improve the bonding effect. General Use of grinding machine with gauze wheel or tungsten steel disc grinding, attention to grinding time, to avoid high-temperature carbonized rubber layer surface.

Fig. 1 section of cold bonding and sewing repair structure for Steel Cord Conveyor Belt 1 fine iron wire hole 2 steel wire rope 3 fine iron wire 4 original belt V 5V groove filling cold glue 6 fine iron wire knot 7 Conveyor belt

Fig. 2 cold bonding repair structure of steel rope core conveyor belt looking down 1 through wire eyelet 2 steel rope 3 through thin wire groove 4 original belt V groove side 5V groove fill cold bonding 6

Reinforced structure with steel core conveyor belt. If the opening is long, then  use the thin steel wire to sew the crack, the interval is 30mm ~ 40mm, the position is  in the middle section of the groove, as shown in figure 1, figure 2, the thin steel wire according to the horizontal “8” shape through the small hole, see figure 1. This procedure is not required for non-penetrating injuries.

Clean and Polish the area. In order not to affect the adhesive force, the repair parts with Compressed air or hot air guns, blowers, brushes and other side of the brush blowing, to ensure that the surface clean dust-free, oil, chemical cleaning agents. Do not use chemical cleaning agent cleaning, cleaning agent easy to penetrate into the conveyor belt canvas layer, short time can not fully play, easy to cause repair layer bulge defects, special attention can not be washed with water.

Drying and grinding parts. Glue layer in the infiltration of water, humid environment And cleaning the residual solvent will affect the effectiveness of repair. Use Iodine Tungsten lamp or hot air gun to dry repair surface to gray white, ensure complete drying. Bake for a period of time, observe whether the surface becomes moist, dark color, if the color changes continue to bake.

The iodine tungsten lamp should keep a

with the above-mentioned repair process except

certain distance from the polished surface

for direct repair can be. For the large area

when used. of through injury, usually due to local severe

wear, it is not suitable to use cold bonding

treatment.

Dispensing Glue. According to the size of

Construction measures under special working

the repair surface to determine the amount of glue, and according to the ratio given in the manual, accurately weighing each cold viscose composition for deployment. After the adhesive is prepared, it must be used up within 3 ~ 5 minutes at a time.

With the principle is to use with with, do

conditions

The best  construction  temperature  is  15 °C ~ 30 °c, the humidity is lower than 85, if the temperature is too low or the humidity is too high, the dust is too much, then the necessary measures need to be taken.

not leave glue.

When the ambient temperature is lower than

10 °C, heat is recommended

GLUING and protection. Before applying glue, Air Gun or iodine tungsten lamp heating.

paste temporary tape paper on the back of

the repair surface to prevent glue leakage; then brush a small amount of base glue on the repair surface and let it stand for a period of time, then pour glue on it and scrape the surface flat.

Curing. After repair, cold glue also need

Heating lamp can not be too close to repair

surface to prevent damage repair surface. Moderate heating can speed up the curing time, shorten the maintenance time, is conducive to the production as soon as possible, but also conducive to bonding strength.

some time to cure reaction, curing due to

It is not suitable to construct in rainy

repair agent type of different time

and windy environment. If it is to be

slightly different. In addition, proper

heating and drying at 50 °C ~ 70 °C can

constructed, the necessary measures must be

speed up the time of putting into use.

taken, such as shielding, sealing, dust

For the fabric core conveyor belt, the removal, heating and baking, hot air

smaller through-and-through injury dehumidification and so on.

generally  does  not  need  to  do  the If repair time is inconsistent with

reinforcement structure, in accordance

production or construction time is not

Yes, we can take a piecemeal approach to

repair. The time and load after the piecewise repair can be controlled by the force and repair condition of the repair position. The proper heating of 50 °C ~  70 °C can speed up the time of putting into use.

Main measures to improve the quality of cold bonding repair of conveyor belt

To improve the quality of cold bonding repair, scientific management must be carried out. The quality management  of cold bonding repair mainly includes cold bonding material, operators, cold bonding working environment, cold bonding process and so on.

Cold-bonding material

Cold adhesive material storage has certain temperature requirements, general requirements of room temperature, light preservation, if not properly handled, it is difficult to ensure the quality of cold adhesive repair. Therefore, for cold adhesive materials to be strictly managed, left

The rest of the material must be sealed, with plastic to consider the amount, to avoid waste. Over the use  of the cold adhesive material had better not, to avoid repair hidden dangers.

Operator

Cold adhesive repair operators  must be technical training, cold adhesive technology has a minimum understanding, can not think that cold adhesive repair operation is simple, just gelatinize can be finished, do  not care. Must have a scientific attitude, in accordance with the cold bonding repair process.

Cold bonding working environment

Cold bonding repair of the working environment, must be conducive to ensuring bonding quality. Environmental factors such as humidity, temperature and cleanliness have an important influence on the quality of cold bonding repair.

If the ambient air humidity is large, the surface of the belt after grinding easily absorb moisture, affect the  wet cold adhesive, easy to damage  the interface after bonding. In order to  ensure the cold sticky quality, ambient  air humidity should not be more than 85.

If the cold glue environment temperature is low, cold glue fluidity is poor, conveyor belt surface temperature is also low, this brings the cold glue wet by sticky surface difficult. Therefore, the temperature should not be less than 15 °C, of course, too high is not good, not easy  to control,  it  is  best  not  to  exceed 25 °C

Cold adhesion work site also to avoid flying dust, because to the adhesion surface long time open, if the air dust is larger, it will make plastic surface pollution, affect the quality of cold repair.

Cold bonding process

Each kind of cold adhesive material  has its specific process conditions, must be in accordance with the provisions of  the product description, can not be arbitrary, eager to achieve, only for progress, ignoring quality. Strictly in accordance with the cold bonding process requirements of construction is to improve the bonding quality of a favorable guarantee.

In short, in order to ensure the quality of cold bonding repair, must be from the cold bonding repair process of  the entire construction process to ensure that the bonding quality meets the requirements.

Conclusion

Compared with other patching methods, the cold bonding patching method is simple, easy to master and operate, and is very suitable for patching the local damage of conveyor belt. As long as the measures are properly controlled, there is no great difference between the repair effect and the hot vulcanization method. Therefore, the cold bonding repair  method has very good  practical  value and popularization prospect.