Drum vulcanizer is the key equipment in the production of rubber sheets, conveyor belts, rubber floors, etc. The product is vulcanized and molded by high temperature and high pressure. Its core components include the main vulcanizing drum, pressure steel belt, drive roller, tension roller, etc. The steel belt plays the role in transferring pressure and heat in the vulcanization process, and is an important component to ensure product quality.
Precipitation hardened stainless steel belts that are widely used in drum vulcanizers have excellent performance: the most representative is Mingke MT1650, where 1650 indicates that the tensile strength of the steel is 1650N/mm² martensitic stainless steel. Based on the cross-sectional area of the steel belt, we can calculate the ultimate tensile force of the steel belt. The tensile strength of the steel strip is only a reference value, and the tensile force it bears is directly related to the service life. In addition, the actual running time of the steel belt, the types of products produced, and the daily maintenance of the steel belt are all factors that affect the service life of the steel belt.
With the development of technology, MT1650 martensitic stainless steel from Mingke has been maturely used in drum vulcanizers, which not only reaches the manufacturing level in Europe, but also has more advantages in economy. Mingke MT1650 precipitation hardening stainless steel is a low-carbon precipitation hardening martensitic stainless steel based on chromium,nickel,copper. It mainly uses its high-strength characteristics, good corrosion resistance, and is not easy to deform under heat treatment, and maintains high strength until the temperature is about 600 °F (316 °C). At the same time, steel belt has good repairability.Detailed performance is as follows:
Compared to domestic steel wire adhesive mesh belt, the selection of steel belt has the following obvious advantages:
1) The steel belt has a long service life, high temperature resistance, is not easy to elongate, and the maintenance is simple and convenient, while the steel wire adhesive mesh belt needs to be re-glued in the short term, and the mesh belt is easy to elongate;
2) The surface quality of the products produced by the steel strip is good, and the flatness and smoothness can reach the high processing accuracy requirements;
3) There is no glue process in the steel belt, and the equipment can basically maintain 24 hours of continuous operation, with high production efficiency;
4) The surface of the steel strip can reach high processing accuracy to meet the needs of high-quality products;
5) The steel belt is easy to maintain, and the part can be removed by digging and repairing, and replacing it with a new patch. Large areas can be cut off in the length direction and re-welded into a new section of steel belt.
6) The small bulges of the steel belt adopts the method of heat shrinkage, which can greatly improve the flatness.
7) If the steel belt has longitudinal deformation along the entire steel belt, there is no good maintenance method. Unless the longitudinal splicing technology with complex process is adopted, but the cost of complex process is high.
How to use steel belt better?
Steel belt users are very concerned about the service life of steel belts, we have summarized the following points related to the service life of steel belts, hoping to help you better understand our steel belts.
Firstly, the steel belt will bear too much stress will affect the service life.
What is the best stress for the steel belt? Of course, the less stress the steel belt bears, the longer the life, which should be combined with the needs of users to produce rubber products. Generally speaking, taking MT1650 steel belt application in DLG-700X1400 equipment of Shanghai Rubber Machinery No. 1 Factory as an example, most production users adjust the value of the hydraulic gauge at about 15~20Mpa. In addition, due to the different diameters of the hydraulic cylinders used by the drum vulcanizer to support the extension rollers, the specific values will also be different. Please consult the equipment manufacturer for the specific values indicated by the hydraulic table of the drum vulcanizer.
Secondly, many users think that the thicker the steel belt, the longer its lifespan before buying it, which is actually a misunderstanding. Although the thick steel belt can withstand the impact of hard objects in the material and is not easy to produce large pits, the thick steel belt has a large bending curvature radius, which is more sensitive to fatigue damage caused by repeated bending, and the bending stress is larger, so the thicker steel belt may not have a longer service life.
In addition, after the installation of the steel belt, it is not advisable to immediately adjust the pressure to the value required for production, and the pressure should be gradually increased until normal operation. The temperature of the steel belt should also be gradually increased to reduce the internal stress deformation caused by thermal expansion and contraction, and the heating device should not be started when the vulcanizer stops running.
Finally, if the following conditions are not paid attention to during use, the steel belt is also prone to damage:
1) Serious damage to the steel belt caused by improper operation. If the rubber material is partially overlapped, foreign objects similar to maintenance tools will enter the drum vulcanizer, resulting in local deformation of the steel strip and leaving traces on the surface of the product.
2) The maintenance interval is too long, and the surface of the steel belt should be cleaned every week.
3) Poor quality of vulcanized raw materials. This is mainly due to excessive local stress caused by hard foreign matter in the raw material
4) The equipment is not operating properly. For example, the steel belt deviation caused by various reasons leads to the steel belt ruffles.
5) The edge of the steel strip forms an sharp angle, which causes the stress concentration and cracks
6) The steel belt is poorly cleaned, with foreign objects sticking to the inner surface of the steel belt
7) The rubber product is narrower than the width of the steel belt, and the edge of the vulcanized rubber product exerts force on the same position of the steel belt for a long time
8) The amplitude of the manual adjustment roller is too large, or the drum vulcanizer is frequently adjusted
Some relevant calculations about drum vulcanizers
1. Drum diameter and length
The drum vulcanizer completes the heating, pressurization and vulcanization of the product on the vulcanizing drum. Therefore, the diameter and length of the vulcanizing drum are one of the most representative parameters.
- The common specifications of the main drum diameter are 350, 700, 1000, 1500 and 2000mm. The diameter ratio of the main drum to the slave drum is: D0 = 2/3D, and the slave drum D0 should not be too small, otherwise it will affect the bending fatigue life of the pressure band. D0 is too large, the machine is bulky, inconvenient to operate, based on the above analysis, the diameter of the main drum D for the steel wire hanging glue pressure belt, D=700~1000mm is appropriate;
- For thin steel strips, D=1500~2000mm is appropriate. the length of the main drum,
- Based on the width of the vulcanized product, at the same time, the problem of stiffness should also be taken into account, therefore, its length-diameter ratio should not be too large, generally L/D=1~3 is appropriate.
Second, the length and thickness of the pressure belt
- The pressure belt is the main component to ensure the vulcanization pressure of the product, and its width is determined by the maximum width of the vulcanized product.
-The length of the pressure belt is calculated according to the structure of the vulcanizer, and as the length L decreases, the life of the pressure belt decreases proportionally.
- The thickness of the pressure belt also directly affects the tensile strength, bending strength and fatigue life of the steel belt. Therefore, whether it is suitable or not will directly affect the performance of the drum vulcanizer.
- The calculated optimal value for δ is:
δ ＝(PDD0 /2E)1/2
δ – the thickness of the pressure belt cm
P-Vulcanization pressure kg/㎠
D-Vulcanizing drum diameter cm
E-The elastic modulus of steel belt kg/㎠
D0 – The minimum roll diameter through which the pressure belt passes, usually cm in diameter of the upper and lower adjustment rollers or tension rollers
3. Calculation of the tension of the steel belt
E: Elasticity coefficient (kgf/mm2)
P: Steel belt tension (kg)
D: Pulley diameter (mm)
B: Steel belt width (mm)
T: Steel belt thickness (mm)
For example, Shanghai Rubber No. 1 Factory standard small drum sulfur, small drum diameter of 400mm, large drum diameter of 700mm, cylinder diameter of 100mm. Hit 20MPa pressure. The size of the steel strip is: 7650*1.2*1380mm, then the calculation is: picture 
= 783.61 (less than the yield strength of 1100MPa at the weld)
σ should be lower than the strength of the welded position of the steel strip
If you have any questions or need further information, please feel free to contact us~
Post time: Mar-11-2025