(1) Fabric. Fabric is the main flexible material of non-metallic expansion joints, it is compounded by excellent silicone rubber or high silica PTFE and alkali-free glass cotton, and it is a kind of high strength sealing composite material. It has function of absorbing swelling capacity, prevent air leakage and rainwater leakage. 

(2) Stainless steel wire mesh. Stainless steel wire mesh is the lining of nonmetallic expansion joints, it is used to prevent sundries into expansion joints and prevent thermal insulation material from lost.

(3) Heat preservation cotton. Used to ensure heat preservation and gas tightness properties, it is composed of glass fiber cloth, high silica cloth and all kinds of heat insulation cotton felt, its length and width are the same with outer fabric, has excellent extensibility and extension strength. 

(4) Thermal insulation packing layer. It’s the principle security of heat insulation, mainly composed of high temperature resisting material as multiple layers ceramic fiber, whose thickness can be confirmed by heat-transfer calculation.

(5) Frame. It’s the outline support to ensure enough strength and stiffness, frame material matches with medium temperature. Generally, below 400℃ use Q235-A, above 600℃ use stainless steel or heat-resisting steel.

(6) Baffle. Used for stream guidance and thermal-protective coating. Material matches with medium temperature, resistant to corrosion and abrasion. It won’t influence displacement of expansion joints.