Bonding strength of polyurethane rigid foam insulation decorative integrated board and core material

There are clear technical indicators and control requirements in the current public industry standards and engineering specifications regarding the bonding strength requirements between the polyurethane rigid foam insulation decorative integrated board and the core material.

1. Bonding strength indicators specified in core standards

‌Exterior wall insulation scenario‌: According to relevant industry standards, the ‌tensile strength of the polyurethane rigid foam insulation and decorative integrated board system is ≥0.10MPa‌. This indicator requires that the damaged part must not be located at the interface of each layer to ensure the connection stability between the board and the core material.

‌Internal insulation scenario‌: In the spray rigid foam polyurethane internal insulation system, the tensile bonding strength between the insulation layer and the base wall shall not be less than 0.10MPa, the tensile bonding strength between the plaster layer and the insulation layer shall not be less than 0.20MPa, and the damaged part shall not be located at the interface of each layer.

‌Additional requirements for weather resistance‌: After the weather resistance test, the bonding part between the plate and the core material shall not crack, hollow or fall off, and the bonding strength must remain stable under long-term use.

2. Key Characteristics Affecting Bonding Strength

‌Self-adhesive performance‌: The molecular structure of polyurethane is highly polar. During the foaming molding process, it can directly bond with core materials of the same strong polarity (such as metal panels, calcium silicon boards, etc.) without the need for secondary bonding. The basic strength of the bond is guaranteed from the material itself.

‌Full substrate adhesion ability‌: During the physical foaming process, polyurethane rigid foam can closely adhere to different types of core material base surfaces, without the need for additional firmware to assist in fixation, and avoid the risk of interface delamination.

3. Testing and acceptance requirements

The test needs to use a tensile testing machine or a portable bonding strength detector, apply a tensile force perpendicular to the interface at a constant rate, record the maximum damage load, and then calculate the bonding strength value.

The detection process needs to observe the damage mode simultaneously. The damage of qualified products should occur inside the foam core material, not the bonding interface between the board and the core material.