polyurethane sealant for high-speed rail is a specialized sealing material designed for scenarios such as ballastless track jointing, vehicle body sealing, glass bonding, etc. The core requirements are high elasticity, high and low temperature resistance, aging resistance, vibration resistance, low VOC, flame retardancy, and must meet railway specific standards such as Q/CR 601-2017 and EN 45545.
1、 Core positioning and application scenarios
- Track system (primary purpose)
Jointing of ballastless track: Sealing of concrete joints such as track bed plates, bases, and protrusions to prevent water and debris intrusion, and to adapt to thermal expansion and contraction.
Rail board/sleeper anchoring: Enhance the connection between fasteners and foundations to improve track stability. - Vehicle body system
Body seam/skin sealing: Aluminum alloy/stainless steel body splicing, door/window frame, air conditioning port, pipe hole sealing.
Glass bonding: The windshield/side window glass is bonded to the window frame structure, combining sealing and structural strength.
Interior sealing: floor, ceiling, soundproof cotton, seats and other assembly seals. - Other
Tunnel/bridge joints, cable trays, equipment base sealing, etc.
2、 Product type and core performance - Mainstream type (by curing method)
table
Type solidification principle, advantages and disadvantages, typical applications
Single component moisture curing absorbs moisture from the air for easy construction, no need for proportioning, good thixotropy, no flow on the facade, slow curing, greatly affected by humidity, limited depth curing, vehicle body sealing, glass bonding, and small joint filling
Two component reaction curing A/B components are mixed in proportion, with fast reaction curing, high strength, good deep curing, stable performance requiring precise proportioning, high construction equipment requirements for ballastless track large joint filling, and structural bonding - Key Performance Indicators (Q/CR 601-2017 Core Requirements)
Displacement capability: ± 20% to ± 30% (adapted to track/vehicle thermal expansion and contraction)
Tensile strength: ≥ 2.5 MPa (track); ≥ 8.0 MPa (body structure)
Elongation at break: ≥ 350% (track); ≥ 400% (vehicle body)
Shore hardness: 20-30 A (orbital); 50-60 A (body structure)
Temperature resistance range: -40 ℃ to 90 ℃ (conventional); -50 ℃~150 ℃ (special)
Aging resistance: After 1000 hours of artificial climate aging, the tensile strength retention rate is ≥ 80%
Environmental protection/flame retardant: low VOC, solvent-free; Meets EN 45545-2 R22 (railway flame retardant)
Adhesive properties: Strong adhesion to substrates such as concrete, aluminum alloy, glass, stainless steel, etc., without detachment after cold and hot cycles
3、 Technical standards (must be met)
Domestic core: Q/CR 601-2017 “Railway ballastless track jointing materials” (special for track jointing)
Vehicle body/interior: EN 45545 (EU railway flame retardant), GB/T 13477 (universal sealant), HG/T 4363 (polyurethane sealant)
Construction specifications: TB/T 3541 (Construction of ballastless track), Q/CR 9655 (Assembly of high-speed rail body)