In industrial peanut processing, the peanut coating machine (also known as a sugar coating pan or nut enrobing drum) is indispensable for applying uniform layers of sugar, flour, chocolate, or seasoning powders. However, some producers may encounter the problem of high broken rate of finished products during use, which not only affects the appearance quality of products, but also may lead to economic losses. So, what is the reason for the high crushing rate of finished products? How to solve it?
1. Improper setting of equipment parameters
Parameters such as drum speed, inclination angle and temperature of peanut coating machine are very important to the coating effect. If the drum rotates too fast, the collision force between peanuts will increase, which will easily lead to crushing; If the inclination angle is not suitable, the fluidity of peanuts in the drum will be affected, which increases the possibility of damage.
Solution: Conduct a design of experiments using small-batch trials to determine the optimal parameters. First, set the baseline parameters: drum rotation speed of 18–22 RPM, tilt angle of 20°, and sugar coating inlet temperature of 45–50°C. Use a variable frequency drive (VFD) to dynamically fine-tune the rotational speed, and install an infrared thermometer to monitor product temperature in real time, ensuring it remains below 55°C to preserve the crunchy texture of the peanuts and prevent them from becoming brittle.
2. Quality of raw materials
The quality of raw peanuts itself may also be the reason for the high crushing rate of finished products. If the size of peanut particles is uneven, the inside is hollow or the shell is too fragile, it is more likely to be broken during processing.
Solution: Implement incoming material quality control using a sieve shaker to grade peanuts into uniform size fractions (e.g., 18/20, 20/24 mesh). Use a near-infrared (NIR) spectrometer to screen for moisture content and reject batches with aw outside 0.45–0.55. Incorporate a destoner and color sorter upstream to remove foreign objects and defective nuts before they enter the coating drum.
3. Coating materials and process problems
The adhesiveness and drying speed of coating materials have a direct impact on the quality of finished products. If the adhesion of the material is insufficient, it may need to be wrapped many times, which will increase the number of collisions between peanuts; If the drying time is not enough and the coating is not completely fixed, it will easily lead to damage.
Solution: Select suitable coating materials and optimize the coating process. For example, control the coating thickness, adjust the drying time and temperature to ensure uniform and firm coating.
4. The operation is not standardized
The experience and technical level of operators will also directly affect the production quality. If the operation is not skilled or the key steps are ignored, the crushing rate may increase.
Solution: Strengthen the training of operators, improve their skill level, and at the same time formulate detailed operating specifications and strictly implement them.
The high crushing rate of the finished products of peanut coating machine is usually the result of many factors, including equipment parameter setting, raw material quality, coating technology and operation specification. By optimizing these links, not only can the crushing rate be effectively reduced, but also the overall quality and market competitiveness of products can be improved.