1. Raw Material Pretreatment  

   Retardant-Resin Mixing: Liquid flame retardant (e.g., ammonium polyphosphate) is precisely blended with resin at 12~18% of board weight, then uniformly coated on wood fibers via high-pressure spraying.  

   Fiber Drying: The mixture is rapidly dried at 120~150℃, controlling moisture content to 8±0.5% to prevent steam explosion during pressing.  

glue mixer

fiber drying machine

2. Mat Forming & Pre-pressing  

   Fibers are air-laid into a mat and pre-compressed at 5~8 MPa to evacuate air, forming a preliminary slab.  

mat forming machine

pre press

3. Continuous Hot-Pressing Core Stage  

    High-Temp Activation Zone (Entry Section):  

     The slab enters the initial press section with upper/lower steel belts moving at 600~1000 mm/s.  

     Platens heat to 250~280℃ within 30 seconds, triggering retardant decomposition.  

    High-Pressure Curing Zone (Core Section):  

     Pressure rises to 12~18 MPa with dwell time >120 seconds, forcing molten retardant into fiber pores.  

     Negative-Pressure Detoxification (-0.05 MPa) simultaneously extracts toxic gases (e.g., PH₃, HCN).  

    Gradient Cooling Zone (Exit Section):  

     Three-stage cooling: 200℃ → 120℃ → 80℃ at a rate ≤15℃/min to prevent surface cracking.  

4. Post-Curing Treatment  

   Boards enter a 120~150℃ curing oven for 20~30 minutes to complete retardant crosslinking, forming a stable carbonized fireproof layer.  

5. Quality Reinforcement  

   Online infrared scanners detect and mark areas with density deviation >±3% or temperature anomalies for rework.  

   Flame resistance sampling: EN13501-1 vertical burn tests conducted every 30 minutes.  

Core Mechanism:  

The synergy of retardant activation at 280℃, deep penetration under 18 MPa, and gradient cooling enables ≥1.5mm fireproof layer depth and V-0 self-extinguishing performance—unachievable by standard presses—while negative-pressure detoxification ensures operational safety.

The machines we can offer includes: Wood chipper, Ring flaker, Strander, Wet silo,  Drum dryer, Dry silo, Glue dosing and applying system /Glue blender, Mat forming, Continuous Multi-rolls pre-press, Multi opening hot press and Continuous press, Auto edge cutting machine line, Sanding machine line, kinds of related belt conveyor and so on.