1. Forming a self-supporting ceramic body in a flame

When a rubber material containing an inorganic filler is exposed to a flame, the rubber degrades or burns, and the degradation or combustion products volatilize, leaving less strong inorganic residues or ash. These residues are usually non-agglomerated or non-self-supporting, and even broken into particles or powders, so they have no fire protection effect. When the specially designed and formulated ceramic rubber is exposed to flames, it can be adjusted according to the type of rubber and the formula, which can be adjusted at 350 Ceramicization occurs in the range of ~800 °C or above, and sintered into a porous self-supporting ceramic body, which can maintain the structural integrity for a certain period of time (0.5 ~ 2h) in a high temperature flame of 650 ~ 1000 °C, and can be very good. Give full play to the effect of "passive fire prevention" and gain valuable time for fire safety.

2. Has a certain strength, good thermal shock resistance

The sintered body after ceramization is relatively hard, has a ceramic sound when knocked, and has a certain flexural strength and piercing strength. The flexural strength of the ceramized silicone rubber specimen is much greater than that of ordinary silicone rubber, and it increases significantly with the increase of temperature. The sintered body of ceramized silicone rubber does not burst and shows good thermal shock resistance by spraying water on the specimen ablated at high temperature by simulating the firefighting process.

3. Halogen-free, low smoke, low toxicity, self-extinguishing, environmental protection

Ceramicized silicone rubber can achieve flame retardant self-extinguishing effect without adding halogen flame retardant, flame retardant UL94V-0, oxygen index can be as high as 38. Under the ablation of the flame, the smoke will be completely cut off after being burned for a few minutes, and in the following ablation process, no more smoke will be produced. The combustion of ceramic silicon rubber produces carbon dioxide, water and silicon dioxide, all of which are non-toxic substances. It can be seen that ceramic silicon rubber is an environmentally friendly material.

4. Good electrical performance

The electrical properties of the optimized ceramized silicone rubber—the volume resistivity before sintering is not less than 1015Ω·cm, and the volume resistivity decreases with the increase of the sintering temperature, and the volume resistivity decreases after burning at 1000℃ for 30min is 107Ω·cm. The volume resistivity of ordinary silicone rubber before and after sintering is not less than 1015 and 107Ω·cm, respectively.

5. Easy to process

The compound preparation and product production process is similar to that of ordinary silicone rubber, which can be produced using conventional rubber processing equipment (extruder, flat vulcanizer, injection machine, etc.). The production process of the fire-resistant cable is simplified and the cost is reduced.