1. Raw Material Preparation and High-Temperature Melting
Principle: Raw materials-including basalt, dolomite, and coke-are crushed, screened, and accurately metered according to a predefined formula before being fed into a melting furnace (typically a cupola or electric furnace).
Technical Highlights: The furnace temperature must be maintained above 1,400°C–1,500°C to ensure the raw materials are fully converted into a homogeneous molten melt with the optimal viscosity required for the subsequent fiberization stage.
2. Centrifugal Fiberization (Spinning)
Principle: The molten melt flows onto a high-speed centrifuge (usually a 4-roll or 6-roll spinner). The powerful centrifugal force flings the melt into micron-sized streams, which are then cooled and attenuated by high-speed airflow from a wind ring, forming mineral fibers with diameters of just 3–5μm.
Technical Highlights: During this stage, phenolic resin binders, water repellents, and dust-suppressing oils are simultaneously sprayed through nozzles. This ensures the fibers possess the necessary cohesive strength, hydrophobicity, and low-dust characteristics.
3. Collection, Pendulum Distribution, and Forming
Principle:
Fiber Collection: A negative-pressure suction box draws the fibers onto a high-speed mesh belt to form a primary wool felt.
Pendulum Distribution (Key Process): Modern lines utilize the Pendulum Method. An oscillating arm distributes the fibers in a multi-layer, cross-lapped, 3D pattern rather than simple horizontal sedimentation.
Technical Highlights: This 3D distribution significantly enhances the compressive and tensile strength of the rock wool board and eliminates the delamination issues common in traditional processes. The material is then pre-pressed and pleated to achieve the desired density.
4. Curing and Shaping
Principle: The pre-pressed wool felt enters a curing oven, where a gas-fired or electric hot-air circulation system maintains a constant high temperature (typically around 200°C).
Technical Highlights: The heat triggers the polymerization and curing of the binders on the fiber surfaces, "locking" the loose fibers into a stable board with specific strength, density, and thickness. A cooling section follows to stabilize the dimensions of the slab.
5. Precision Cutting and Post-Processing
Principle: The cured slab is processed by longitudinal and transverse cutting machines (flying saws) to specific dimensions. This stage also includes edge trimming, sanding, and profiling (chamfering or grooving).
Technical Highlights: Modern equipment utilizes high-precision servo control systems, keeping cutting tolerances within ±0.5mm. Advanced lines can integrate laminating machines for aluminum foil or fiberglass tissue. Additionally, integrated waste recycling systems crush trimmings for re-melting, while high-efficiency filtration systems ensure environmental compliance.
Summary: The technical trajectory of these production lines is moving toward fully continuous operation, high-capacity output (tens of thousands of tons annually), intelligent PLC-based automation, and low-emission manufacturing.