1、 Preparation before operation

1. Equipment inspection
   • mechanical partCheck for wear or looseness of components such as screws, barrels, cutters, and molds to ensure proper lubrication of the transmission system (such as motors and reducers).
   • Electrical systemConfirm that the wiring of electrical components such as heating coils, temperature controllers, and sensors is secure to avoid short circuits or electrical leakage; Check if the emergency stop button is sensitive.
   • safety deviceVerify whether the safety door, protective cover, and interlocking device are intact to ensure that the equipment can automatically shut down in case of abnormalities.
2. Preparation of raw materials
   • Classification cleaningClassify and recycle according to the type of plastic (such as PE, PP, PVC), remove impurities such as metal and sand, and avoid clogging screws or molds.
   • preprocessingCrush and dry large or thick walled waste before granulation (if the moisture content is greater than 0.5%, it needs to be dried) to prevent water vaporization from causing bubbles or degradation.
   • Additive ratioAdd toughening agents, lubricants, color masterbatch, etc. based on the properties of the raw materials to ensure uniform mixing of the formula.
3. environmental control
   • well-ventilatedThe equipment operation area needs to be equipped with an exhaust system to avoid the accumulation of harmful gases (such as vinyl chloride) evaporated from high-temperature melts.
   • Fire and explosion preventionKeep away from flammable materials, equip with fire extinguishers or automatic fire extinguishing devices, and prohibit smoking or working with open flames near equipment.

2、 Operation monitoring

1. temperature control
   • Segmented heatingSet the temperature in each zone according to the process requirements (such as 120-150 ℃ in the feeding section, 160-180 ℃ in the compression section, and 180-220 ℃ in the metering section), to avoid material decomposition caused by high temperature or affecting fluidity caused by low temperature.
   • temperature fluctuationReal time monitoring of temperature controller display value. If the temperature suddenly rises or drops, immediately stop the machine and check the heating coil or sensor.
2. Screw speed and pressure
   • Speed matchingAdjust the screw speed (usually 50-150rpm) according to the plasticization of the raw materials to avoid excessive speed causing shear overheating or too low speed causing melt accumulation.
   • pressure monitoringObserving the melt pressure gauge, if the pressure rises abnormally (such as exceeding the rated value by 20%), it may be due to blockage of the mold head, and the filter screen needs to be cleaned or replaced.
3. Particle cutting system
   • Blade sharpnessRegularly check the wear of the cutting blade. Passivation of the blade can cause irregular or continuous particles, which need to be replaced or sharpened in a timely manner.
   • Particle cutting speedAdjust the speed of the granulator to synchronize with the extrusion speed to ensure uniform particle length (usually 2-5mm).
4. Cooling and drying
   • cooling water flowKeep the cooling water circulation smooth, control the water temperature at 20-40 ℃, and avoid particle adhesion or deformation.
   • Drying treatmentUse a vibrating screen or centrifugal dryer to remove surface moisture from particles and prevent mold or clumping during storage.

3、 Security protection

1. personal protection
   • wear equipmentOperators are required to wear protective goggles, heat-resistant gloves, dust masks, and anti smashing safety shoes to avoid splashing molten metal or mechanical injuries.
   • Do not touchIt is strictly prohibited to touch high-temperature components such as screws, molds, or cutting knives with hands during equipment operation.
2. emergency response
   • earth leakage protectionEnsure good grounding of the equipment, install residual current circuit breakers, and automatically cut off the power supply in case of leakage.
   • Fire responseIf a fire is caused by the decomposition of raw materials, immediately press the emergency stop button, turn off the heating power, and use a dry powder fire extinguisher to extinguish the fire.
   • Personnel trappedIf the operator's clothing is caught in the screw, do not forcefully pull it. Stop the machine immediately and cut off the power before rescue.
3. Operating Specifications
   • No idling allowedBefore starting the equipment, it is necessary to confirm that the mold head has been installed and that there is raw material at the feeding port to avoid wear caused by screw idling.
   • gradually warming upDuring cold start, it is necessary to increase the temperature in sections (with an interval of 10-15 minutes between each section) to prevent the screw from deforming due to thermal expansion and contraction.
   • Shutdown sequenceStop feeding first, wait for the material inside the screw to be emptied, then turn off the heating and main power, and finally clean the residue of the mold head.

4、 Maintenance and upkeep

1. Daily cleaning
   • Clean the mold headAfter daily shutdown, use a copper shovel or specialized tool to clean the residual melt in the die hole to avoid blockage and affect the next production.
   • Clear accumulated materialCheck whether there is material accumulation at the root of the screw and the inner wall of the barrel, and clean it in a timely manner to prevent degradation and black spots.
2. regular maintenance
   • Lubrication and maintenanceReplace the lubricating oil of the gearbox every 500 hours and check the lubrication condition of bearings, chains, and other parts.
   • Replacement of vulnerable partsCheck the wear of the screw and barrel every 2000 hours. If the gap exceeds 0.5mm, repair or replace it; Replace the pellet cutter every 1000 hours.
3. Long term shutdown
   • rust prevention treatmentIf the shutdown exceeds 3 days, clean the surface oil stains of the equipment, apply rust proof oil, and cover it with a dust cover.
   • Empty materialsAfter turning off the heating power, manually rotate the screw to empty the residual material in the barrel to prevent solidification and blockage.

5、 Common Problems and Solutions

6、 Expansion suggestions

1. Train operatorsRegularly organize safety operation training, familiarize oneself with equipment structure, process parameters, and emergency procedures.
2. Record production dataEstablish equipment operation logs to record parameters such as temperature, pressure, and output for easy traceability of issues.
3. Select high-quality raw materialsAvoid using waste materials with excessive or heavily polluted recycled components to reduce equipment failure rates.

By strictly following the above precautions, the operational stability, product quality, and safety of the recycling granulator can be significantly improved, the service life of the equipment can be extended, and production costs and environmental risks can be reduced.