1. Raw Material Preparation Section

This is the starting point of the production line, aiming to process logs or processing residues into qualified wood chips.

  Main Equipment: Chipper, chip screen, re-chipper, chip washer, belt conveyor, chip silo, etc. .

  Process Description: Logs are debarked and chipped into qualified chips by the chipper. The chips then pass through a screening system to remove oversized or undersized fragments and impurities. Some lines also include a washing system to remove sand, stones, and metals, protecting the refiner plates in subsequent steps .Qualified chips are stored in a chip silo to buffer production .

2. Fiber Preparation Section

This is the core technological step in MDF production, where the task is to separate wood chips into individual fibers .

  Core Equipment: Refiner (including feeding screw, preheater, refining unit), wax application system .

  Process Description: Chips first enter a preheating bin and are then compressed by the feeding screw into a dense plug, fed into the preheater for softening with high-temperature steam . The softened chips enter the refiner's refining unit, where they are separated into fibers by the action of rotating at high speed refiner plates . During this process, molten wax (a water repellent) is evenly sprayed onto the fibers . Today, advanced refiner plates can reach diameters of up to 60 inches, with a single unit capacity of up to 40 tons per hour .

3. Resin Blending & Drying Section

  Main Equipment: Resin mixing system, metering pumps, drying pipeline, air heater, cyclone separator .

  Process Description: Wet fibers from the refiner's blowline are thoroughly mixed with the applied adhesive (mainly Urea-Formaldehyde resin) in a high-speed air stream . The blended fibers immediately enter the drying pipeline, coming into brief contact with high-temperature air. Within seconds, the fiber moisture content is evaporated to the required 8%-12% . Dried fibers are separated from the air by a cyclone and sent to a dry fiber bin. Advanced blending technology  can save up to 25% in glue compared to traditional methods .

4. Mat Forming Section

This process is critical for determining the density uniformity of the board .

  Core Equipment: Former (mechanical or air-flow type), pre-press, flying cut-off saw, metal detector, mat reject system .

  Process Description: Dry fibers from the bin are output and evenly spread by the former onto a continuously moving forming wire, creating a fluffy mat with uniform thickness, width, and density . The mat then passes through a pre-press, where pressure expels some air, increasing its density and strength for subsequent conveying and hot pressing. The pre-pressed mat is trimmed to size by edge trimmers and a cut-off saw and checked by a metal detector. Rejected mats are broken up by the recycle system and returned to the dry fiber bin . For thin board production, special forming technology (e.g., Starformer) is required to ensure forming accuracy .

5. Hot Pressing Section

Hot pressing is the core process where the mat is cured and formed. Heat and pressure cure the adhesive and create bonds between the fibers .

  Core Equipment: Hot Press (continuous press or multi-opening press), loader, unloader, simultaneous closing mechanism, thickness stops .

  Process Description:

      Multi-opening Press: Mats are loaded into the press openings (e.g., 15 layers), pressed and heated simultaneously for curing, then unloaded .

      Continuous Press : The mat is continuously conveyed through the press by steel belts, gradually solidifying into a continuous ribbon of raw board under high temperature and pressure . Continuous presses offer advantages like extremely high efficiency, tight thickness tolerances, uniform board quality, and less sanding allowance .

  Key Process Parameters: Control of pressing temperature, pressure, and time is critical. Temperature depends on the adhesive type and board thickness; pressure varies during the cycle, typically high for closing, then reduced (0.6-1.3 MPa) for curing; mat moisture content is generally controlled around 10%—too high can cause blistering and delamination, too low can result in a soft surface and low strength . In thin board production (<3mm), press speed and infeed compaction curve control are especially crucial .

6. Post-Treatment & Sanding Section

  Main Equipment: Turner cooler, intermediate storage, sander, dimension saws, stacker .

  Process Description: Hot raw boards exiting the press must be cooled forcibly by a turner cooler. Cooled boards are stacked and conditioned (stored) for a period to relieve internal stresses and allow the adhesive to cure fully . Conditioned boards enter the sanding line, where multiple sanding heads remove the pre-cured surface layer, resulting in a smooth surface and precise thickness . Finally, boards are dimensionally cut to final sizes (e.g., 4'x8'), inspected, graded, and stacked for storage .

sander

cross-cut saw