The vermicelli cutting machine is a key equipment in the vermicelli production line, used to accurately cut the continuously extruded vermicelli according to the set length. Due to the high moisture content (usually 30%~40%) and sticky texture of vermicelli, as well as the need for long-term high-speed operation of the equipment (up to hundreds of cuts per minute), it is prone to malfunctions caused by mechanical wear, material blockage, or improper operation. The following are common faults, cause analysis, and solutions for noodle cutting machines, covering four major modules: transmission system, cutting components, electrical control, and material handling:
1、 Transmission system malfunction
1. Unstable cutting blade speed
Phenomenon: The blade rotates quickly and slowly, resulting in a deviation of more than 5mm in the cutting length of the powder strip (the standard should be ≤ 2mm).
Reason:
Belt pulley wear or belt slippage (contact area between belt and groove<70%);
Motor speed fluctuation (voltage instability or motor carbon brush wear);
Wear of gearbox gears (tooth clearance>0.5mm).
solution
Replace the worn pulley or adjust the belt tension (deflection of 10-15mm when applying a force of 50N at the center point);
Check the power supply voltage (stable within the range of 380V ± 5%), replace the motor carbon brush (contact surface wear>1/3 needs to be replaced);
Disassemble the gearbox, replace worn gears or adjust the tooth clearance (by adding or removing shims).
2. The conveyor belt slips or deviates
Phenomenon: Uneven conveying speed of noodles leads to misalignment of cutting positions (such as normal cutting at the front end and offset at the rear end).
Reason:
Insufficient tension of the conveyor belt (loose adjustment bolt of the tensioning device);
Powder residue adheres to the surface of the roller (friction coefficient decreases);
The conveyor belt joint is aging and cracking (causing local relaxation).
solution
Rotate the tensioning device bolt to ensure that the conveyor belt does not slip or sag significantly on the roller (sagging amount ≤ 20mm);
Rinse the surface of the roller with a high-pressure water gun (pressure ≤ 0.3MPa), or apply a food grade anti sticking coating (such as polytetrafluoroethylene);
Re sulfurize or mechanically connect the conveyor belt joints (ensuring that the joint strength is ≥ 80% of the strength of the conveyor belt body).
2、 Cutting component malfunction
1. The blade wears out quickly or breaks
Phenomenon: After 1-2 days of use, the blade may become blunt or suddenly break during operation (with a brittle fracture surface).
Reason:
The blade material does not match (65Mn spring steel or 9CrSi alloy steel with a hardness of HRC52~56 should be selected);
When cutting, the powder strip has a high sand content (due to insufficient cleaning of the raw materials, sand hardness>blade hardness);
The blade is installed too tightly (causing stress concentration) or too loosely (vibrating during cutting).
solution
Replace blades that meet the standards (such as 65Mn steel that requires quenching and tempering treatment);
Strictly control the raw material cleaning process (sand content ≤ 0.5%) and increase the number of filter screens (mesh size ≥ 100);
Adjust the torque of the blade fixing bolt (using a torque wrench, the standard value is usually 15~20N · m).
2. Uneven cutting surface
Phenomenon: Burrs, adhesion, or flattening appear on the cut surface of the vermicelli (affecting the appearance and taste of the product).
Reason:
Blade angle deviation (standard angle is 30 °~45 °, deviation>5 ° will cause uneven distribution of cutting force);
The gap between the blade and the conveyor belt is too large (the gap should be ≤ 0.5mm, otherwise the powder strip will be squeezed and deformed);
When the moisture content of the noodles is too high (>45%, the viscosity increases and the blades are prone to sticking).
solution
Use an angle ruler to correct the installation angle of the blade, with a deviation of ≤± 2 °;
Adjust the blade height adjustment bolt to ensure that the gap meets the standard;
Control the ripening degree of vermicelli (starch gelatinization degree ≥ 85%) and reduce the moisture content to 38%~42%.
3、 Electrical control malfunction
1. Large cutting length error
Phenomenon: Setting the cutting length to 20cm, the actual length fluctuates between 18-22cm.
Reason:
Encoder malfunction (loss or interference of pulse signal);
PLC program logic error (such as improper counter parameter settings);
Sensor position offset (distance between photoelectric sensor and powder strip>5mm, resulting in detection delay).
solution
Check the encoder connection wire (shielding layer grounding), replace the damaged encoder (resolution ≥ 1000 pulses/rev);
Re debug the PLC program (ensure that the cut-off signal is synchronized with the blade rotation cycle);
Adjust the sensor position (2-3mm away from the edge of the powder strip, adjust the sensitivity to the mid-range).
2. Frequent shutdown of equipment
Phenomenon: Suddenly stopping during operation, the control panel displays "overload protection" or "emergency stop triggered".
Reason:
Motor overload (cutting resistance>120% of motor rated torque);
Aging of electrical components (such as contact erosion of contactors and misoperation of thermal relays);
The operator accidentally touches the emergency stop button (the button is stuck or the circuit is short circuited).
solution
Reduce cutting speed (through variable frequency drive) or check if the blade is passivated;
Replace the contactor (contact capacity ≥ 1.5 times the rated current of the motor) and thermal relay (action current setting value=rated current of the motor × 1.1);
Check the emergency stop button circuit (use a multimeter to measure continuity and repair the short circuit point).
4、 Material handling malfunction
1. Powder strips block the cutting edge
Phenomenon: Powder sticks accumulate under the blade, causing the equipment to jam (requiring manual cleaning before restarting).
Reason:
Uneven maturation of vermicelli (local hard core or soft block);
Cutting speed too fast (blade rotation frequency>1.2 times the extrusion speed of the powder strip);
Insufficient cooling (viscosity increases when the temperature of the vermicelli exceeds 40 ℃).
solution
Adjust the cooking process (steam pressure 0.2~0.3MPa, time 3-5 minutes);
Reduce the blade speed through a frequency converter (matching the extrusion speed);
Increase the cooling air volume (wind speed ≥ 3m/s) or extend the length of the cooling conveyor belt (≥ 5m).
2. Too much shredded vermicelli
Phenomenon: After cutting, a large amount of debris is generated (debris rate>5%, affecting the yield).
Reason:
Blade passivation (tearing the powder strip during cutting instead of shearing);
The conveyor belt speed is too fast (the noodles break after being stretched);
Unreasonable cutting edge design (such as excessive gap between blade and pallet).
solution
Regular sharpening blades (use an oilstone to polish the edges after each shift to maintain sharpness);
Reduce the speed of the conveyor belt (synchronized with the rotation cycle of the blade);
Optimize the cutting edge structure (using a combination of "blade+pallet", with the pallet material being food grade stainless steel).
5、 Fault prevention and maintenance suggestions
Daily inspection:
Check the blade fastening bolts, belt tension, and sensor positions before each shift;
Record the cutting length, motor temperature (≤ 70 ℃), and noise (≤ 75dB) every 2 hours during operation.
Regular maintenance:
Replace the gearbox lubricating oil every 200 hours (recommended to use 320 industrial gear oil);
Clean the electrical cabinet every 500 hours (use compressed air to blow away dust and check the tightness of the wiring terminals).
Spare parts management:
Reserve key spare parts (such as blades, belts, encoders) to ensure that production can be restored within 2 hours after a malfunction;
Establish a spare parts life file (such as an average blade life of 800 hours and prepare for replacement 100 hours in advance).