PROJECT PROFILE

The Indian biomass sawdust drying and palleting production line has been officially put into production. The production line is composed of heat source, feeding machine, rotary dryer, pallet machine, etc., it can keep the strength and stiffness constant and removes the wood's own natural defect during the moulding process, and intensity strength are more than traditional board assembly products. The pallets are environmentally friendly, which can realize the recycle, recycle and reuse, low pollution, recovery rate can reach 100%.

PROJECT PROCESS

Detailed introduction to the working process of wooden pallet hydraulic press

I. Raw material pretreatment stage

‌--Raw material crushing and grading‌

The logs/wood blocks are crushed to 10-30mm particle size by a double-shaft crusher, and the magnetic separation device removes metal impurities (iron removal efficiency ≥99%). The vibrating screen separates coarse materials (≥5mm) and qualified materials (≤5mm), and the coarse materials return to the crushing process for cyclic processing. 

--Drying and mixing the glue‌

The dryer adjusts the moisture content to 8%-15% (wood-plastic mixture needs ≤3%). Add adhesive (such as PE recycled material + coupling agent) and stir it through a high-speed mixer for 20 minutes (temperature 70℃).

II. Compression molding stage

-‌-Mold preheating and loading‌

The hydraulic press mold is heated to 50℃ in advance (the wood-plastic process requires 190℃ storage bin insulation). The automatic feeding system evenly spreads the mixture into the mold, and the filling density deviation is ≤2%.

-‌-Pressure molding‌

Four-column/frame hydraulic press (tonnage 800-2000 tons) performs multi-stage pressurization:

1)Fast down pressure‌: pressurize to the set pressure within 35 seconds (pine 22MPa, miscellaneous wood 25MPa)

‌2)Pressure holding and curing‌: hold pressure for 6-10 minutes, pressure fluctuation ≤1MPa, ensure pallet density ≥0.8g/cm³

‌--Temperature control‌

WPC process mold temperature is maintained at 150-200℃, pure wood process uses steam heating (120-150℃)

III. Post-processing stage

--Cooling and demoulding

Natural cooling or forced air cooling to below 40℃ after pressing to avoid thermal deformation. Hydraulic press automatic ejection device completes demoulding (demolding force ≤ total pressure 10%).

-‌-Finishing and quality inspection

Remove burrs, test pallet size tolerance (±1.5mm) and load strength (static load ≥1.5 tons). Waste is recycled and reused through the crushing system, and the raw material utilization rate is ≥95%.

IV. Core equipment parameters

‌--Process ‌Technical indicators‌

Pressing speed: Single molding time 7-10 minutes, daily output 150-240 pieces

Energy consumption control: Steam heating system comprehensive energy consumption ≤120kW·h/ton

Automation level: PLC control positioning accuracy ±0.5mm, failure rate ≤0.3%