Brief Introduction to the Molding Process of Fiber Cement Board

This process employs a semi-dry molding technique used in the production of various fiber cement products—such as explosion‑proof boards, wood‑grain boards, and silicate fire‑resistant boards. It involves adding only enough water to meet the hydration needs of the cement, keeping the mixture as dry as possible while ensuring thorough binding of cement, additives, and reinforcing fibers. The resulting material is in a dry‑hard state, often described as “forming a ball when squeezed by hand, yet scattering when dropped.”

After spreading, the mixture is molded and locked within a frame. Under pressure, the cementitious materials consolidate and cure. Once the initial set is achieved, the frame is removed, and the board proceeds to curing and subsequent finishing stages.

Compared with the traditional wet molding process, the semi-dry molding method offers the following distinct characteristics:

Streamlined Operation: The process is simpler to operate, generates less waste, and requires significantly lower industrial water consumption.

Enhanced Material Structure: Fibers are distributed three-dimensionally within the cement matrix, resulting in a product with high uniformity.

Reduced Resource Use: The production line consumes minimal process water and does not require extensive wastewater recovery or treatment systems, leading to lower overall energy consumption.

Superior Product Performance: Press-molding within a locked frame produces boards with higher density and strength. The board breaks uniformly when fractured, indicating structural consistency and excellent long-term durability.

However, the semi-dry molding process also has certain limitations:

Longer Production Cycle: Due to the special mold‑frame locking and curing steps, the process requires extended cycle times. To achieve initial strength, products must be cured for 5–8 hours at 60–80 °C.

High Initial Investment & Space Requirements: The production line involves numerous auxiliary facilities, substantial initial capital outlay, and additional workshop space for handling, cleaning, and maintaining mold frames and pads.

Batch Processing & Dimensional Tolerance: Products are stacked and cured in batches, which can result in greater thickness variation. Subsequent sanding is often required to ensure dimensional consistency, making the method less suitable for manufacturing complex or intricately shaped products.

Despite these considerations, the semi-dry molding process remains widely adopted in countries such as the Netherlands, Germany, and Sweden for producing fiber‑cement products, owing to its stable equipment operation and reliable product quality. Over years of refinement—including improvements in paving and forming quality, as well as advances in mechatronics and precision programmable control—this method has achieved industrialized production of boards ranging from 8 mm to 40 mm in thickness.