During the processing of rubber conveyor belts, the variety, dosage and dispersion of the filling and reinforcing agent have a great influence on the wear resistance of the rubber. The wear resistance is directly related to the content of the rubber. Anything that can increase the combined rubber Factors are all beneficial to the wear resistance, so as the surface area of carbon black increases, the structure improves and the degree of dispersion increases, the wear resistance will also increase. The dispersibility of carbon black affects the abrasion resistance of the rubber; under harsh conditions The structural effect of the lower carbon black is significant. Generally speaking, the wear resistance of the rubber compound is affected by the dispersion of the carbon black. The abrasion resistance ratio of the rubber compound filled with high abrasion carbon black is about 10% higher than that of the medium The grinding carbon black is 20% lower, and the abrasion resistance of the rubber belt manufacturer's medium abrasion-resistant carbon black is particularly outstanding in the test of high ambient temperature and harsh conditions;
The research results show that in natural rubber or styrene butadiene rubber, 50-60phr carbon black is generally used, and 5-7phr oil is appropriate. If the amount is too high, the abrasion resistance will decrease. The amount of carbon black in butadiene rubber is changed from 45phr is increased from 60 to 70phr. When the oil is increased from Sphr to 15-20phr, the abrasion resistance of the rubber compound is improved. The rubber compound mainly made of butadiene rubber has better abrasion resistance than the rubber wide belt manufacturer's high-filled compound. Low filling rubber; other methods to improve rubber abrasion resistance: surface treatment method uses liquid or gaseous antimony pentafluoride or hydrochloric acid or chlorine to treat the surface of nitrile rubber to reduce the friction coefficient of rubber products and improve the wear resistance of products For example, when the rubber is subjected to repeated alternating stress (or strain) on the heavy-duty conveyor belt of a cement plant, the phenomenon that the structure or performance of the material changes is called fatigue. As the fatigue process progresses, the phenomenon that leads to material damage is called fatigue failure. , The two cannot be equal.
With the development of the fatigue process, the tensile strength increases first, and then tends to decrease after the extreme two, while the tear strength, dynamic modulus and loss tangent decrease first, and then increase after the minimum value. Various properties Changes have taken place during the fatigue process. The reason for the changes in physical properties is the changes in the fatigue-induced structure. The structure of rubber changes during multiple tensile fatigue processes. Although these structural changes are very important for some products, The measurement is cumbersome and difficult. For most products, the fatigue damage shown by cracks and complete rupture is the main aspect. Therefore, we will discuss the related formulation design issues with fatigue damage. The damage mechanism may include thermal degradation, Oxidation, ozone erosion and damage through crack propagation are strictly a comprehensive process of mechanics and chemistry. Under the reciprocating deformation of rubber, the relaxation process generated in the material is too late to complete within the deformation cycle, resulting in internal production. The stress cannot be evenly distributed, it is possible:
In some defects (such as cracks, weak bonds, etc.), causing fracture damage, in addition, because rubber is a viscous polymer: its deformation includes reversible deformation and irreversible deformation, in the periodic deformation irreversible deformation produces stagnation This part of the energy is converted into thermal energy of the thermal insulation conveyor belt, which increases the internal temperature of the material, and the strength of the polymer material generally decreases with the increase in temperature, which leads to the shortening of the fatigue life of the rubber. In short, the fatigue failure of the rubber is not purely mechanical Fatigue is often accompanied by thermal fatigue damage;
In the analysis of the fatigue failure of rubber, it can be considered that the energy applied by multiple stretches will cause the initial dissipator to break slightly:
The relaxation of the concentrated stress at its periphery will be consumed by the expansion of the micro-fracture starting from the failure center after a certain period of time to reach fatigue failure. If the energy consumed by the former form is EA and the energy consumed by the latter form is EB Then the total energy E required for the glue to reach fatigue failure is: E=EA+EB, and the sizes of EA and EB vary with the conditions of fatigue failure.
