The core factors affecting the mixing performance of an organic fertilizer double axis mixer are divided into three categories: raw material characteristics, fertilizer production machine parameters, and operating process.  Specifically:

1. Raw Material Characteristics

◦ Raw material particle size and ratio: If the particle size difference between coarse and fine raw materials is too large (e.g., uncrushed straw mixed with finely decomposed manure), stratification and segregation will occur, significantly reducing mixing uniformity; when the ratio of organic raw materials to inorganic additives and microbial agents is significantly different, a longer mixing time is required to achieve uniform mixing.

◦ Moisture content: High moisture content (exceeding 35%) easily causes clumping, making it difficult for the mixer blades to break up the clumps; low moisture content (below 20%) results in loose material, leading to "empty mixing" and preventing the formation of a uniform mixture.

◦ Material stickiness: Highly sticky raw materials (such as humic acid and viscous sludge) easily adhere to the blades and machine wall, forming "wall-hanging material," leading to insufficient local mixing.

2. Equipment Parameters

◦ Blade structure and rotation speed: Unreasonable blade angle (usually needs to be adjusted to 45°–60°) and severe wear will reduce the material pushing and turning ability; too fast a rotation speed can cause centrifugal stratification of the material, while too slow a rotation speed results in insufficient mixing intensity.  A speed of 20–40 r/min is generally recommended.

◦ Twin-shaft synchronicity: When the rotation speeds of the two mixing shafts are not synchronized, it will cause inconsistent material pushing speeds, resulting in local mixing dead zones.

3. Operating Process

◦ Feeding order: Adding lightweight, large-particle raw materials first, followed by heavy, fine-powder additives (such as microbial agents and binders), can improve the mixing effect; conversely, it is easy to cause stratification problems with fine materials settling at the bottom and coarse materials floating on top.

◦ Mixing duration: Too short a duration will result in insufficient mixing, while too long a duration will increase energy consumption and may damage the activity of microbial agents. A mixing time of 3–8 minutes should be set according to the material characteristics.