With the rapid development of the coal industry, the demand for EP conveyor belts has greatly increased. EP conveyor belt has the characteristics of impact resistance, corrosion resistance, high strength, light belt body and long service life. Because EP conveyor belts often work in harsh environments such as coal mines, EP conveyor belts are prone to problems such as edge rubber falling off and even delamination. Once such problems occur, the entire conveyor belt will be seriously scrapped. In response to such problems, it is necessary to continuously strengthen the training of staff skills and strictly implement the regulations. At the same time, conveyor belt manufacturers also need to transform the edge rubber.
The shape of the edge rubber is approximately elliptical, with a maximum thickness of 15 mm and a maximum width of 35 mm.
(1) Since the middle skim layer of the belt carcass is on a plane, the adhesion between the edge rubber and the skim is small, and the edge rubber is easy to fall off, resulting in delamination.
(2) Because the width of the laminated edge rubber of the top layer and the bottom layer is too large (20 mm), easy to take the side exposed cloth-will cause delamination.
(3) Because the upper and lower top layers are in contact with the edge rubber in a curved shape, it is easy to form empty edges, resulting in edge rubber cracking and delamination.
(4) Due to the single size of the edge rubber, the conveyor belts of different thicknesses need to be pulled, which not only has a high labor intensity, but also has unstable quality, which is easy to cause uneven width of the belt blank. It is easy to delaminate with side exposed cloth and side sponge.
In summary, the single type of edge sealant and the unreasonable structure of the edge sealant are the main reasons for delamination.
The shape of the edge rubber is unchanged, the edge of the bottom layer of the skim is offset by 10 mm from the second layer, the remaining layers are offset by 2-3 mm from the upper layer of the middle layer, the upper part of the skim layer is offset by 2-3 mm, and the top edge is 10 mm The edge rubber is a ladder-shaped structure.
(1) Due to the adjustment of the width of the bottom layer and top layer of the belt carcass, the width of the blank holder has been changed from 20 mm to 10 mm, which fundamentally solves the problem of lateral exposure of the belt.
(2) The stepped structure is used to increase the contact area between the edge rubber and the belt skim, which greatly increases the adhesion between the belt skim and the edge rubber. The edge rubber is firmly fixed in the belt skim, which fundamentally solves the problem of the edge rubber. The problem of wear resistance and easy to fall off.
(3) Due to the new edge-sealing process, there is no empty edge between the edge-sealing rubber and the conveyor belt carcass, and the cracks and sponges in the edge-sealing rubber are eliminated.
(4) After repeated tests, we have newly developed two types of edge banding adhesives, which changed the unstable quality of the single edge adhesive in the past, which not only reduced the consumption of rubber, but also improved the quality of the conveyor belt.
3.1 Calendering process
The fabric is affected by moisture or oil stains, and the exposed rubber will affect the adhesion between the cover rubber and the skim and layer, causing delamination and blistering. Therefore, fabric drying should be strictly implemented. In order to do a good job of cleaning the fabric, the rubber should be fully smelted with a hot mixer to prevent the fabric from falling off.
3.2 Form a second sequence
(1) The uneven width of the belt carcass will cause difficulty in vulcanization, resulting in side rubber sponges and exposed cloth on the side. Therefore, the width of the conveyor belt skim should be measured frequently.
(2) The adhesive conveyor belt is stained with rubber, white stripes and bad cloth. Oil stains and debris can affect the adhesion between the rubber and the cloth layer, and between the cloth layer and the cloth layer, causing foaming. Before driving, the rubber and cloth layer must be removed with gasoline.
3.3 Vulcanization process
(1) Improper coordination of horns can easily cause scars, dew cloths and side sponges. Carefully check the width, thickness and appearance quality of the billet, and match it with suitable horns.
(2) During the vulcanization and stretching process, the strip should be straightened with four centers and one elasticity.
Tracked and compared the situation of three different specifications of EP conveyor belts before and after the side rubber transformation
in conclusion
The structural improvement of the edge rubber seems simple, but it has achieved remarkable results. Not only solves the problem of stratification of EP conveyor belts that has plagued for many years, but also greatly improves the appearance quality of EP conveyor belts, increasing the first-grade rate of EP conveyor belts from 85% to 99%, which not only reduces the labor intensity of workers And, the consumption of raw rubber and fabrics has been reduced, and good economic and social benefits have been achieved, which have been highly recognized by users. If an enterprise wants to develop, it must constantly innovate and produce high-quality products to meet customer needs.