During the preparation and inspection stage of the plastic recycling mill, detailed control should be carried out from five aspects: equipment integrity, environmental adaptability, electrical safety, raw material adaptability, and operator qualifications. Specific precautions are as follows:
1、 Equipment integrity check
Verification of core component functionality
Grinding discs and cutting tools: Check the degree of wear of the grinding discs (fixed and moving knives). If the blade becomes dull, chipped, or cracked, it should be replaced or repaired in a timely manner to avoid affecting the crushing efficiency and particle uniformity. For example, when PET bottle flakes are crushed, blunting the blade can cause the flakes to adhere or produce excessive fine powder.
Sieve: Confirm that the sieve aperture matches the target particle size (such as 20 mesh, 40 mesh), and check if the sieve is damaged or blocked. If the sieve is clogged, it needs to be cleaned with compressed air or special tools to prevent material accumulation from affecting discharge.
Transmission system: Check the tension of belts and chains to avoid slipping caused by looseness or increased wear caused by tightness. For example, belt looseness may cause equipment vibration and accelerate bearing damage.
Cooling system: If the equipment is equipped with water or air cooling devices, it is necessary to check whether the water pipes/air ducts are unobstructed, whether the cooling water flow or air volume meets the standards, to prevent equipment shutdown or material deformation caused by overheating.
Confirmation of auxiliary component status
Inlet and outlet: Clean the residual materials at the inlet to prevent the mixing of hard debris (such as metal and stones); Check if the discharge port is unobstructed to avoid blockages that may affect continuous production.
Dust removal device: Check whether the dust removal bag or filter element is intact to ensure dust collection efficiency. If dust removal fails, it may lead to excessive dust in the workshop, causing safety risks.
Safety protection devices: Confirm that safety devices such as protective covers, emergency stop buttons, and limit switches are intact to prevent personnel from coming into contact with rotating parts or equipment abnormalities that prevent timely shutdown.
2、 Environmental adaptability check
site conditions
Space layout: Ensure sufficient operating space (recommended ≥ 1.5 meters) around the equipment for maintenance, inspection, and material handling.
Ground flatness: Check whether the ground is flat to prevent equipment vibration from causing tilting or displacement. If the ground is uneven, use a shim to adjust the level.
Ventilation conditions: Keep the workshop well ventilated to avoid dust accumulation. If the dust concentration is too high, it is necessary to install local exhaust devices or strengthen overall ventilation.
Ambient temperature and humidity
Temperature control: The operating environment temperature of the equipment should be between 5-40 ℃ to avoid high temperature causing aging of electrical components or low temperature affecting the fluidity of lubricating oil.
Humidity management: The relative humidity should be ≤ 85% to prevent metal parts from rusting or electrical system short circuits. If the environment is humid, regular rust prevention treatment should be carried out on the equipment.
3、 Electrical system safety inspection
Power supply and wiring
Voltage matching: Confirm that the power supply voltage is consistent with the rated voltage of the equipment (such as 380V or 220V) to avoid voltage fluctuations that may damage the motor or control components.
Line insulation: Check whether the cable is damaged or aged, whether the grounding wire is reliably connected, and prevent leakage or electric shock accidents.
Overload protection: Test the sensitivity of overload protection devices such as circuit breakers and thermal relays to ensure that the equipment can automatically power off when overloaded.
Control cabinet inspection
Instrument calibration: Check whether the temperature gauge, pressure gauge, ammeter and other instruments display accurately, with an error of ≤± 5%, to avoid misjudging the equipment status.
Button and indicator light: Confirm that the operation button, emergency stop button, and indicator light are functioning properly without any jamming or malfunction.
Cooling fan: Check if the cooling fan inside the control cabinet is running properly to prevent component damage caused by high temperature inside the cabinet.
4、 Raw material compatibility inspection
Raw material pretreatment
Cleanliness: Remove hard impurities such as metal, sand, glass, etc. from raw materials to prevent damage to the grinding disc or sieve. For example, recycled plastic film needs to be first treated with a magnetic separator to remove iron filings.
Moisture content: Control the moisture content of the raw materials to ≤ 5% to avoid moisture causing material adhesion or clogging of the sieve mesh. If the moisture content is too high, drying treatment (such as hot air drying or centrifugal dehydration) is required.
Size control: Pre crush large raw materials (such as plastic drums and trays) into blocks of ≤ 50mm to reduce the load on the grinding machine and improve crushing efficiency.
Material Classification
Material differentiation: Classify and recycle according to plastic types (such as PE, PP, PVC, ABS) to avoid mixing different materials that may result in differences in crushing effects or decreased material properties.
Color classification: If specific color products need to be produced, raw materials need to be classified by color to reduce subsequent color matching costs.