High elasticity polyurethane sealant, with a fracture elongation rate of 300% -800%, displacement capacity of ± 25% – ± 50%, and elastic recovery rate of ≥ 70%, achieves “high elasticity+high strength+weather resistance” through the separation of soft and hard segments. It is the preferred elastic sealing material for building expansion joints, automobiles, road surfaces, and curtain walls.
1、 Core elasticity index (high elasticity definition)
Tensile elongation at break: 300% -800% (GB/T 13477.8), can be repeatedly stretched without cracking.
Displacement capability: ± 25% (level 25)/± 50% (level 50), suitable for joint thermal expansion and contraction.
Elastic recovery rate: ≥ 70%, good rebound after stretching, without permanent deformation.
Shore A hardness: 20-60 (soft elasticity), 60-80 (medium high elasticity).
Temperature resistance: -40 ℃~+120 ℃, not brittle at low temperatures and not flowing at high temperatures.
2、 High elasticity principle (soft and hard segment design)
Soft segment: Polyether/polyester polyol, providing high elongation and low-temperature flexibility.
Hard segment: isocyanate+chain extender, providing strength, resilience, and weather resistance.
Microphase separation: Soft and hard segments self assemble into an “elastic network” that balances high elasticity and strength.
3、 Mainstream types and characteristics
- One component wet curing (most commonly used)
Principle: When exposed to moisture in the air, it solidifies without the need for mixing.
Advantages: Convenient construction, good thixotropy, can be used for facade construction, solvent-free.
Representative: 3M 560, Loctite PU9100, Hengyue HS-601. - Two component (high-strength/fast curing)
Principle: Mix A (prepolymer) and B (curing agent) in proportion for curing.
Advantages: Fast curing, higher strength, suitable for large engineering/industrial batches. - Classify by elasticity
Ultra high elasticity: elongation ≥ 600%, displacement ± 50%, suitable for large deformation joints.
High elasticity: elongation rate of 400% -600%, displacement of ± 35%, universal type.
Medium to high elasticity: elongation rate of 300% -400%, displacement of ± 25%, strength priority.
4、 Typical application scenarios
Architecture: Expansion joints, settlement joints, curtain wall joints, door and window sealing, concrete crack repair.
Automobile: windshield bonding, body welding seams, cabin sealing, interior decoration fixing.
Transportation: Highway/airport runway joint filling, bridge expansion joints, tunnel waterproofing.
Industry: Container, refrigerated truck, ship, equipment shell sealing, metal/plastic bonding.