2026/04/20
Loose and brittle granules produced by double roller press granualtor are mainly caused by issues such as material ratio, moisture content, equipment pressure, and roller wear. These problems can be addressed by gradually adjusting the raw materials, equipment, and process.
First, optimize the basic conditions of the raw materials. Controlling the moisture content is crucial. For compound fertilizers and inorganic powders, the suitable moisture content is 3%-8%, while for organic fertilizers it is 8%-12%. Too low a moisture content results in poor adhesion, while too high a moisture content leads to soft molding. This can be adjusted by spraying humidifiers or adding dry materials. Insufficient fine powder content prevents the material from densely filling the roller die. It is necessary to ensure that the proportion of fine powder (below 1mm) is not less than 40%, and a reasonable mix of coarse and fine powders is essential. For raw materials with poor adhesion, appropriate amounts of binders such as bentonite, attapulgite, and humic acid can be added, with the addition amount controlled at 1%-5%, to improve the granule bonding strength.
Next, adjust the core parameters of the fertilizer production machine. Appropriately increase the hydraulic system pressure to ensure the linear pressure reaches 15-30MPa, allowing the material to be fully extruded and compacted. Simultaneously reduce the spindle speed. Excessive speed will shorten the material's residence time, preventing proper compaction. Appropriate speed reduction can improve particle density. Check the gap between the two rollers, ensuring it is uniform and well-fitting, with consistent parallelism at both ends. Excessive gap will directly lead to pressure loss. If the roller skin grooves are severely worn, shallow forming and poor cohesion will occur, requiring timely welding repair or replacement with new roller skins.
Finally, standardize the production process to ensure uniform and stable feeding, avoiding pressure fluctuations caused by inconsistent feeding. Use a forced feeder to ensure sufficient material intake. After forming, the particles can be sized using a rounding machine to enhance density and roundness. Low-temperature, slow drying should be used to prevent internal cracking. Following this sequence of adjustments can effectively solve the problem of loose particles and improve the finished product qualification rate.
