mdf production line

MDF/HDF(MDF hot press) is a kind of excellent substitute for natural wood panel with wide application. Materials such as wood and other plant fiber after being added suitable urea formaldehyde resin or other adhesives forms 450-880 kg/m3 panels on hot press. The panels are characterized with tight and smooth surface, uniform core layer and good wood working performance. 

  ^{The line consists of chip preparation, fiber preparation, glue mixing and applying, mat-forming and hot-pressing, cooling and sizing, sanding.}

^{1.Chip preparation
       Wood,  branches and  wood  residues are cut into chips of definite size. Chips from chips silo will be screened or airgraded to remove fines, soil and stones.}

^{2. Fiber preparation section
      Chips are  transported  to upper  bin  of  refiner,  and   positively  fed to digester by screw feeder for steaming. Steamed chips will be disintegrated to fiber under the force of heat and mechanism. Mix  drying medium and wet fiber which is in the state  of suspension  with the help of high  pressure air flow, and thus  exhaust moisture in fiber via drying medium to get dry fiber. Dry fiber falls on belt conveyor through cyclone discharge valve, and then be transported to dry fiber bin for storage.}

 ^{3. Glue mixing and applying section 
       Process  of  glue  applying   before  drying   is  adopted.  Feed  molten paraffin  and  water-proof additive to refiner.  Paraffin is mixed with  fiber uniformly under the force of refiner plates. Glue is transported to the blow line of fiber discharge valve.  This section can be controlled by PLC or computer.}

^{4.Fiber drying section
The fibers after mixing with glue is transported to drying ducts along with steam, and transported to cylcone separator by hot air. And thus the water in the fibers is drained out with hot air. The dried fibers and air is separated and then transported to silo.}

^{5. Mat-forming and hot-pressing section
   The fiber after drying is transported to the above of forming machine, and uniformly   spread on the  conveying  mesh  belt in the way of air-flow. Vacuum box equipped below the mesh belt provides  negative pressure and air will be removed via mesh belt,  fiber stays  on mesh  belt and  thereafter forms mats gradually.  Fluffy  mats will be    pressed by  pre-press. Pressed mats are cut into  definite length by longitudinal  and  transversal saw, then transported  to  loader  passing   through   accelerating  conveyor,    storage conveyor and extension conveyor. When finishing loading mats, carriage in the loader will feed conveying belt and mats into hot press, at the same time, shovel head at the front end of conveying belt pushes out pressed board.  When carriage  comes to terminal,  boards have been into unloader, and mats also arrives to due position. Carriage returns, conveying belt turns forward.  Mats are in the  relative still state and  stay on the  platen of press when  velocity  of  conveying  belt  is  the  same  as  the  returning speed of carriage.   Glue  in  the  mats cures, thanks to temperature  and pressure in  hot press,  and hence boards  with definite intensity and thickness form. Rough  boards will be put on support via unloader. Outfeeding conveyor  will  unload  boards  one after  another to next section when cage comes down.}

^{6. Cooling, sizing and sanding section 
   Rough  boards  after  air  cooling  are  turned into cut-to-size boards via  longitudinal  and transversal  saw.  And  then cut-to-size boards are sanded,    sorted,   stacked   and packed for storage.}