Production Process Essentials of Magnesium Oxide Board

Magnesium oxide board (MgO board), also known as magnesium cement board, is a high-performance environmentally friendly building material with excellent fire resistance, moisture resistance, corrosion resistance and high strength. Its complete production process includes raw material preparation, slurry mixing, molding, curing, post-treatment and finished product inspection, with strict technical standards for each link.

1. Raw Material Preparation

The core raw materials of magnesium oxide board consist of basic inorganic materials and functional auxiliary materials. The main inorganic raw materials are light-burned magnesium oxide (MgO) and magnesium chloride solution (MgCl₂), which form the basic gelling system through chemical reaction. Auxiliary materials include glass fiber mesh cloth, wood flour, rice husk powder, talc powder and waterproof agents. Glass fiber acts as a reinforcing skeleton to improve the board's tensile and impact resistance, while plant powder and inorganic fillers optimize the board's flatness, toughness and dimensional stability. All raw materials need to be screened and inspected in advance to ensure uniform particle size and qualified purity, avoiding impurities affecting product quality.

2. Automatic Slurry Mixing

This is the key link to determine the uniformity of the board substrate. According to the fixed production formula, magnesium oxide powder, magnesium chloride solution, fillers and functional additives are accurately proportioned and put into a professional high-speed mixer. The mixing process strictly controls the stirring speed and time to ensure full fusion of raw materials and form a homogeneous, fine and stable inorganic slurry. Reasonable proportioning is critical: the scientific molar ratio of magnesium oxide to magnesium chloride can effectively prevent the finished board from returning to halogen, absorbing moisture and warping, and ensure the compactness and strength of the substrate.

3. Continuous Molding and Laminating

The well-mixed slurry is transported to the automatic molding machine for continuous plate making. The production adopts a multi-layer composite process: a layer of glass fiber mesh cloth is laid as the base layer first, then the slurry is evenly coated, and multi-layer mesh cloth and slurry are superimposed according to the required board thickness to form a composite structure. During the molding process, the automatic leveling and rolling device is used to control the board thickness uniformly, eliminate internal bubbles, and make the slurry and fiber mesh closely bonded. This continuous molding process ensures the consistency of board size, flatness and structural strength, and realizes efficient mass production.

4. Initial Setting and Curing Reaction

After molding, the wet board is sent to the constant temperature and humidity curing workshop for initial setting and chemical curing. The gelling system of magnesium oxide and magnesium chloride undergoes a hydration reaction at a specific temperature and humidity, gradually forming a stable crystalline phase structure, which makes the board preliminarily shaped and gain basic strength. The curing environment is strictly controlled with temperature maintained at 20-28℃ and humidity above 60% to avoid rapid water loss or insufficient reaction caused by dry and high-temperature environment, which leads to board cracking and insufficient hardness.

5. Natural Aging and Deep Curing

After initial setting, the semi-finished boards are stacked and placed in a ventilated dry workshop for natural aging and deep curing for 7-15 days. During this period, the internal chemical reaction is completely completed, the internal stress of the board is fully released, and the structural density, hardness and dimensional stability are further improved. Sufficient aging treatment can fundamentally solve the common quality problems of magnesium oxide boards such as halogen return, moisture deformation and surface efflorescence, and greatly improve the durability of finished products.

6. Post-Processing and Finishing

After reaching the qualified curing standard, the boards enter the finishing process, including fixed-size cutting, edge trimming, surface polishing and dust removal. According to customer demand, secondary processing such as surface waterproof coating, color spraying and veneer pasting can be carried out. Precision cutting ensures that the length, width and diagonal error of each board meet the industry standard, and edge trimming avoids burrs and cracks, improving the appearance quality and installation adaptability of the product.

7. Finished Product Inspection and Packaging

All finished boards need to pass strict quality inspection before leaving the factory. The inspection items include appearance quality (flatness, surface defect, edge integrity), dimensional accuracy, physical properties (bending strength, impact resistance, water absorption rate) and fire resistance grade. Qualified products are stacked neatly, packaged with waterproof and dustproof materials, and marked with product specifications, production date and quality certification. Unqualified products are reprocessed or scrapped to ensure factory product qualification rate.

Core Production Key Points

The quality of magnesium oxide board mainly depends on three core factors: accurate raw material proportioning, sufficient curing reaction and standardized production operation. Reasonable formula design avoids halogen return and moisture absorption problems; strict temperature and humidity curing conditions ensure stable internal crystal structure; standardized molding and processing ensure consistent product performance, making the final product meet the requirements of fireproof, waterproof, environmental protection and high-strength building materials.