Continuous rolling thin MDF production line

   The key features: (1)the utilization of new technology of fiber winnowing;(2)the specialized technology of  harrow roller forming machine,can effectively control and increase the precision of transversal and longitudinal forming;(3)density control system;(4)usage of steady mat transporting system;(5)big diameter heating roller with the running speed amounting to 40m/min;(6)usage of online precise saw cutting center or stand alone type precise saw cutting center.

(7)PLC programmable controller with man-machine interface display adopted for central management for the production line electric control system.

  The required raw material for production is wood materials including slash with diameter between 50-230mm,undersized log,lath from wood plant,the peeler core from plywood plant and so on.this section consists of chipping,chips storing,screening,chips transporting,water cleaning for chips etc to provide qualified chips for hot milling.

raw materials are sent in the drum chipper which will cut the raw materials into even chips so as to convey,store raw materials and do defiber through feeding belt conveyor.the chips will be sent in the bin for storage,then transported in the rectangular sieve for screening to sift out of scraps,big wood blocks etc.

the qualified chips via belt conveyor will be carried in bucket lifter that can elevate the chips to a high position on the belt conveyor where the powerful electric magnetic iron remover set to eliminate iron varias.after iron removing treatment,the chips are delivered in the water cleaning system aiming to eliminate sludge,sandstone and other varias.

according to the measurement result:the percentage of sediment of general wood chips is about 1%-3.5%,while the percentage of sediment of chips before entering into the hot mill should not be more than 0.04 % as per requirements.so the water cleaning process is essential to produce the thin board with high quality.

the chips after cleaning will be sent in the chip pre-heating bin via water filtration screw.

   This section includes hot milling,drying,glue blending and regulating,glue applying,fiber winnowing,fiber storage working process and so on for the supply of qualified fiber.chips are firstly preheated and softened under the action of steam in the pre-heating bin,then sent in the infeed screw hot mill via vibrating outfeed device,finally squeezed by change diameter screw to form the wood plug which will be delivered in vertical digester for digesting and softening treatment.

the new type of r-ray laser level of material control system aiming for accurately controlling the level of material for chipps and controlling the digesting time.the chipps after sofenting treatment will be sent in the milling chamber of hot mill for defiber,the fiber will be sent in the drying duct where it mixes with hot air.

then during the transportation it will be dryed at the state of suspension.after that the fiber and gas will be sepratated by cyclone separator.there is a fire-proofing discharge valve under the cyclone seperation rotary valve to send the dried fiber in the winnowing machine for seperation.if fire alarm goes off,the discharge valve will discharge the fiber in case the fiber with spark enters the forming machine.

the dry fiber has to be seperated by airflow with the aim of eliminating metal,rubber block,fiber agglomerates,thick fiber stalk etc for the continuous rolling production line giving priority to produce thin board to guarantee the protection for press in case of hard sundries entering into the press to damage steel band as well as to guarantee the quality of thin board.

then the fiber will be transported in the forming machine via pneumatic conveying.