The filler in non-metallic expansion joints, sometimes called thermal insulation or thermal insulation, is one of its key components to provide thermal, sound insulation, enhance structural integrity, and in some cases help with sealing. The filler is located inside the non-metallic skin and typically consists of multiple layers of material to accommodate the working conditions of the expansion joint in high temperatures, high pressures, or corrosive environments. Here are a few common filler materials:
Glass Fiber：
Glass fiber is a very high temperature resistant material that effectively insulates heat and is commonly used in high temperature applications such as boilers and hot air duct systems.
Ceramic fiber (Ceramic Fiber)：
Ceramic fibers have extremely high heat resistance and insulation properties, and are suitable for extremely high temperature environments, such as in high temperature flue gas pipelines in the steel industry and large power plants.
Aluminosilicate Fiber：
This material has excellent high temperature resistance and thermal insulation properties, while having good chemical stability, making it suitable for use in piping systems with high temperatures and corrosive media.
Calcium silicate (Calcium Silicate)：
Calcium silicate is a lightweight inorganic material with good heat insulation performance and fire resistance, which can be used in high temperature and fire protection requirements.
Rockwool：
Rock wool is a fibrous material made from the melting of basalt and other natural ores, which has good sound and heat insulation properties.
Magnesium silicate (Magnesium Silicate)：
Another high temperature resistant inorganic material used to improve the thermal insulation and fire resistance of expansion joints.
Installation of the filler is usually between the non-metallic skin and the metallic frame, by layering and combining it for optimal insulation and sealing. When maintaining and replacing non-metallic expansion joints, the filler also needs to be carefully handled to ensure its integrity and effectiveness. Proper installation and maintenance of the filler is essential for the long-term performance and safety of non-metallic expansion joints.