When regenerating by drying, it is important to gradually increase the temperature to avoid abrupt drying that may cause particle explosion, reducing the recovery rate.
During the regeneration of silicone by calcination, excessively high temperatures can alter the pore structure of the silicone, significantly reducing its adsorption efficiency and affecting its usability. For blue dye indicators or color-changing silicone, the regeneration temperature should not exceed 120°C, as the colorant may gradually oxidize and lose its coloring function.
Silicone typically undergoes screening to remove fine particles after regeneration, ensuring uniformity of the granules.
Aging activates oxidative cracking reactions through mechanical forces: As silicone sealing rings repeatedly deform during the sealing process, their mechanical stress weakens the atomic valence forces in the rubber molecular chains, thereby reducing the activation energy for oxidation reactions. The reduction in oxidation activation energy makes the oxidation cracking reaction of rubber molecular chains easier and faster.
Silicone O-Ring Internal Heating Accelerates Oxidation Reaction: As silicone O-rings are repeatedly deformed, hysteresis occurs, generating internal friction, which leads to internal heating of the rubber. This further accelerates the oxidation chain reaction of the rubber, contributing to its aging.
Ozone Cracking in Silicone Seals: An ozone cracking phenomenon occurs during the cyclic deformation process of silicone seals. This is more pronounced under high-temperature conditions.
Silica gel absorbs moisture, which can then be removed through thermal desorption. There are various methods of heating, such as electric furnaces, flue gas waste heat, and hot air drying. The desorption heating temperature should be controlled between 120-180°C, while for blue indicator gel, colored silica gel, and blue silica gel, it is advisable to maintain a temperature of 100-120°C.
The lifespan of silicone seals is typically influenced by three factors: mechanical force, oxidation, and ozonation. Generally, silicone seals become brittle, with fatigue cracks spreading more rapidly. Reducing the critical fracture energy can decrease their lifespan. The main factors affecting the specific lifespan of silicone seals include the following aspects:
Aging can cause mechanical cracking reactions due to the mechanical force: because of the viscosity of high polymers, the relaxation process of rubber during deformation cycles does not complete in time and then enters the next deformation cycle, causing the internal deformation and residual stress of the silicone rubber seals to continuously increase. When the stress gradient is large, it can lead to the direct breaking of rubber molecular chains, producing free radicals, which then cause the free radical oxidation chain reaction aging of the rubber in the presence of oxygen.
