Silicone rubber possesses unique characteristics such as slow combustion, no dripping, and the release of non-toxic gases, making it widely used in the field of fire and flame retardant materials. Ceramicized silicone rubber, a novel fire-resistant material, retains the properties of ordinary rubber at room temperature but forms a dense and hard ceramic body at high temperatures, effectively preventing flame propagation. In recent years, ceramicized silicone rubber has found extensive application in the thermal insulation and sealing of batteries in new energy vehicles (NEVs), providing cushioning and energy absorption between battery cell modules, end plates, and modules while ensuring high-voltage ignition prevention and thermal insulation.
Characteristics of Ceramicized Silicone Rubber:
1. Formation of Self-Supporting Ceramic Body in Flames:
When rubber materials containing inorganic fillers are exposed to flames, the rubber degrades or burns, leaving behind weak inorganic residues or ash with no self-supporting properties. These residues are typically non-cohesive, even breaking into particles or powder, offering no fire protection. However, specially formulated ceramicized rubber can undergo ceramicization in the range of 350 to 800°C or higher, depending on the rubber type and formulation. The resulting sintered, porous ceramic body maintains its structural integrity in high-temperature flames (650 to 1000°C) for a certain period (0.5 to 2 hours), effectively providing passive fire protection and buying valuable time for fire safety.
2. Good Strength and Resistance to Thermal Shock:
Ceramicized sintered bodies are relatively hard and produce a ceramic sound when tapped, exhibiting a certain flexural strength and puncture resistance. According to information obtained from coating experts, the bending strength of ceramicized silicone rubber specimens is significantly higher than that of ordinary silicone rubber, and it increases noticeably with temperature. Simulating the firefighting process by spraying water on specimens subjected to high-temperature erosion, ceramicized silicone rubber sintered bodies do not crack, demonstrating excellent resistance to thermal shock.
3. Halogen-Free, Low Smoke, Low Toxicity, Self-Extinguishing, and Environmentally Friendly:
Ceramicized silicone rubber achieves flame retardancy and self-extinguishing effects without the need for halogen-based flame retardants. It meets the UL94V-0 flame retardancy rating and has an oxygen index of up to 38. When exposed to flames, it produces minimal smoke after a few minutes of burning. Furthermore, during subsequent burning, it does not generate smoke. The combustion of ceramicized silicone rubber produces non-toxic substances such as carbon dioxide, water, and silicon dioxide.
4. Excellent Electrical Properties:
Optimized formulations of ceramicized silicone rubber exhibit good electrical performance. The volume resistivity of the pre-sintered rubber is not less than 10^15 Ω•cm, and it decreases as the sintering temperature increases. After burning for 30 minutes at 1000°C, the volume resistivity decreases to 10^7 Ω•cm. Comparatively, ordinary silicone rubber maintains volume resistivities of not less than 10^15 and 10^7 Ω•cm before and after sintering, respectively.
Application in New Energy Vehicle Battery Sealing:
The primary application of ceramicized silicone rubber lies in the thermal insulation and sealing of batteries in new energy vehicles. It ensures electrical safety during fire incidents and provides maximum safety time for passengers. Thus, the urgent development and application of ceramicized silicone rubber, a new type of fire-resistant and insulating material, in the new energy vehicle industry is understandable. The production equipment for ceramicized silicone rubber compound mixing is the same as that for ordinary silicone rubber. The compound exhibits excellent extrusion and compression molding properties, allowing for direct extrusion and vulcanization into wires and cables using silicone rubber wire and cable equipment, without the need for additional equipment, thereby significantly reducing production costs. Ceramicized silicone rubber maintains rubber elasticity at room temperature and does not become brittle or fall off like mica tape when exposed to fire, passing spray and vibration tests.
If you are interested in our ceramicized silicone rubber, please contact FuQiang (FQ), where our dedicated team will address your requirements.
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