High-temperature silicone rubber sheet is widely used in automobiles, electronics, industrial equipment and other fields due to its high temperature resistance and aging resistance. However, in actual use, some users found that the surface of high-temperature silicone rubber sheet has "oiling". Is this normal? This article analyzes from the perspective of material properties and process.
Reasons for "oiling" of high-temperature silicone rubber sheet
High-temperature silicone rubber sheet is usually made of silicone as the base material, and is added with high-temperature resistant fillers (such as fumed silica) and vulcanizers. In a high temperature environment (such as above 200°C), if the vulcanization process is not perfect or a small amount of unreacted silicone oil or plasticizer remains in the formula, these substances may gradually precipitate to the surface, forming oily substances visible to the naked eye. This phenomenon is called "oil seepage" or "oiling".
Whether it is normal needs to be judged in combination with the scene
Minor oiling is a normal phenomenon: Some high-temperature silicone rubber sheets may have short-term oiling due to the migration of trace substances inside the material during the initial high-temperature use stage. It usually does not affect the sealing or insulation performance and can be restored after wiping.
Continuous oiling needs to be watched out: If the high-temperature silicone rubber sheet frequently produces oil during long-term use, and even becomes sticky and the hardness decreases, it may be caused by formula design defects or insufficient vulcanization. The material needs to be replaced in time to avoid safety hazards caused by performance degradation.
How to avoid abnormal oiling problems
Optimize the vulcanization process: Ensure that the high-temperature silicone rubber sheet is fully vulcanized during production to reduce low-molecular residues.
Select high-quality raw materials: Use high-purity silicone and stabilizing additives to reduce the risk of oiling from the source.
Strict testing and verification: Simulate working conditions through high-temperature aging tests (such as 200℃×72h) to detect material stability in advance.
Conclusion
The slight oiling of high-temperature silicone rubber sheets is within the normal range under certain conditions, but it needs to be evaluated in combination with actual conditions. Selecting high-temperature silicone rubber sheets that meet industry standards (such as UL certification or RoHS testing) and paying attention to production process details can effectively avoid abnormal oiling problems and ensure its reliability and service life in high-temperature environments.