How Does MGO Board Achieves the Service Strength Required for Wall Panels？

The service strength of magnesium oxide (MGO) board as a wall panel is fundamentally dependent on the hydration and hardening reaction of the magnesium cementitious system to form a dense and stable crystalline structure. It is further enhanced through the multi-dimensional coordination of scientific raw material proportioning, standardized production processes, scenario-based structural optimization and standardized post-curing. Ultimately, this achieves the compressive strength, flexural strength, impact resistance and overall structural stability required for wall panels. Its strength indicators must comply with the requirements of Magnesium Oxide Flat Plates (GB/T 23266-2009) and relevant specifications for wall applications.

I. Core Foundation: Precise Proportioning of the Magnesium Cementitious System

This is the fundamental source of MGO board's strength. By regulating the reaction ratio of cementitious materials, stable and high-strength hydration products (mainly 5·1·8 phase hydrated magnesium oxychloride cement) are generated. Meanwhile, fillers and reinforcing fibers are combined to optimize the matrix structure:

Molar ratio control of main cementitious materials: The molar ratio of magnesium oxide (MgO) to magnesium chloride (MgCl₂, or magnesium sulfate MgSO₄) is precisely controlled at 5~7:1 to ensure sufficient hydration reaction without excess free ions. This prevents efflorescence and deliquescence that cause matrix looseness, and ensures the dense interweaving of hydration crystals.

Gradation optimization of fillers: Inorganic fillers such as quartz sand and talcum powder are added in accordance with the gradation of coarse and fine particle sizes to fill the pores of the cementitious system, improve the compactness of the board, reduce the shrinkage rate, and minimize strength loss caused by shrinkage cracking.

Compound matching of reinforcing fibers: Fiberglass cloth (double-sided/multi-layer covered), wood fiber or bamboo fiber are incorporated, forming a "network skeleton" in the matrix. This disperses the stress on the board under external force and significantly improves its flexural strength and impact resistance (the key to the flexural and crack resistance of MGO board as a wall panel).

Addition of modifiers: Retarders, tougheners, water repellents and other additives are added to adjust the hydration reaction rate, improve the toughness of the cementitious matrix, prevent brittle cracking of the board, enhance water resistance, and avoid strength reduction due to water absorption.

II. Production Guarantee: Standardized Molding and Pressing Processes

The compactness and structural uniformity of the board are improved through process control, avoiding strength weaknesses caused by molding defects. The core process requirements are as follows:

Homogeneous mixing of slurry: Cementitious materials, fillers, fibers, modifiers and water are fully mixed without caking or segregation, ensuring the uniform distribution of all components in the slurry and laying a foundation for the uniformity of hydration reaction and strength.

Pressure control in press forming: Adopt the roller pressing/mold pressing forming process with the pressing pressure controlled within a reasonable range, so that the compacted density of the board is ≥1.8g/cm³, further reducing internal pores and improving compressive and flexural strength.

Layered composite reinforcement: For the usage requirements of wall panels, a layered structure of "double-sided fiberglass cloth + core cementitious filler" is adopted. The fiberglass cloth serves as the load-bearing layer and the core ensures compactness, balancing the surface strength and overall flexural performance of the board.

Fixed-thickness precision cutting: Fixed-thickness cutting is carried out in a timely manner after forming to ensure regular board dimensions, avoid edge chipping and uneven thickness, and prevent local damage due to stress concentration after installation.

III. Scenario Adaptation: Optimized Structural Design for Wall Panel Applications

The basic strength of a single MGO board needs to be combined with installation structural design to be converted into the overall service strength of the wall, adapting to the scenario requirements of different partition/enclosure wall panels:

Composite with light steel keel frame: When thin MGO boards (9~12mm) are used for non-load-bearing partition walls, they are installed in cooperation with a light steel keel frame and fixed to the keel with self-tapping screws at a spacing of ≤300mm. Under external force, the load of the board is shared by the keel, forming a "board-frame" cooperative load-bearing system and improving the overall stability of the wall.

Reinforcement of thick boards with stiffeners: When thick MGO boards (15~18mm) are used for solid partition/enclosure walls, light steel stiffeners/keel supports can be added inside or on the installation surface of the board. Local thickening/reinforcement is applied to stress-concentrated parts such as door and window openings to avoid local damage.

Crack resistance reinforcement at splicing joints: The splicing joints of wall panels are treated with "joint sealant + fiberglass mesh tape" to eliminate the strength weakness at the splicing gaps, ensure the overall deformation resistance of the wall, and prevent the wall strength from being affected by splicing cracking.

Cooperative design of composite layers: For sandwich MGO wall panels (composite with rock wool, calcium silicate, etc.), the core material is bonded to the MGO board with special adhesive, ensuring the interlayer bonding strength ≥0.3MPa to avoid interlayer peeling and ensure the overall load-bearing capacity of the composite wall panel.

IV. Key Finishing Step: Standardized Post-Curing Process

The hydration reaction of the magnesium cementitious system is a slow reaction, and the curing conditions directly determine the growth quality of hydration crystals and the final strength. The core curing requirements are:

Temperature and humidity control: The curing environment is maintained at a temperature of 20~30℃ and relative humidity of 60%~80%, avoiding high-temperature exposure, low-temperature freeze-thaw or rain to prevent the interruption of hydration reaction and abnormal crystal growth that lead to matrix looseness.

Guarantee of curing period: The basic curing period is ≥7 days (the critical period of hydration reaction), and the complete solidification curing period is ≥28 days to ensure the sufficient formation and stable structure of 5·1·8 phase hydration products.

Moisture content regulation: Gradient drying treatment is carried out in the later stage of curing to control the final moisture content of the board at ≤10%, which not only ensures the complete hydration reaction, but also avoids deformation and cracking of the wall panel due to moisture content changes after installation, thus ensuring long-term strength.

Finished product stacking: Cured MGO boards are stacked flat at a moderate height to avoid local deformation under pressure and hidden internal stress in the boards.

V. Core Strength Indicators of MGO Board for Wall Panels

Qualified MGO wall panels must meet the following basic strength requirements to adapt to the usage needs of non-load-bearing walls:

Compressive strength ≥30MPa;

Flexural strength ≥12MPa;

Surface density in line with partition wall specifications (approx. 20~25kg/㎡ for 9mm boards);

Interlayer bonding strength (composite boards) ≥0.3MPa (no peeling or delamination).