The specific impacts are primarily manifested in three areas:
1. Raw material processing: Low temperatures increase the hardness of plastic pellets (such as PVC and PE) and slow their melting speed. This not only prolongs the injection molding cycle but can also cause defects such as missing material and bubbles due to uneven melting, requiring higher heating temperatures and increasing energy consumption.
2. Hydraulic system: Hydraulic oil viscosity increases significantly at low temperatures, making it difficult for the pump to draw oil and slowing pressure transmission. This, in turn, can cause slow response times in the injection molding machine's mold opening and closing, injection, and other actions, even leading to jamming and accelerated wear of hydraulic components.
3. Electrical and piping: Low temperatures can affect the sensitivity of electrical components such as sensors and solenoid valves, increasing the probability of failure. Furthermore, if water and gas pipes on the equipment's exterior are not properly insulated, they risk freezing and cracking in cold regions, disrupting production.
Winter Antifreeze Checklist for Vertical Injection Molding Machines
1. Raw Material Storage and Pretreatment: Store plastic pellets indoors at a temperature no lower than 10°C to prevent moisture absorption and clumping. Preheat the raw materials in a hopper dryer before starting the machine, ensuring the temperature reaches 20-30°C to improve melting efficiency.
2. Hydraulic System Maintenance: Replace the hydraulic oil with low-viscosity hydraulic oil specifically formulated for winter use (such as No. 46 anti-wear hydraulic oil) to reduce viscosity at low temperatures. Before starting the machine daily, run the hydraulic pump at no load for 10-15 minutes, allowing the oil temperature to rise above 25°C before resuming production.
3. Electrical Component Protection: Wrap the wiring terminals of key electrical components, such as sensors and solenoid valves, with insulation to prevent poor contact due to low temperatures. Check the electrical cabinet cooling fan daily to ensure it is functioning properly to prevent low temperatures from affecting component performance.
4. Antifreeze water and air lines: After shutdown, completely drain any accumulated water from the equipment's cooling water lines, or add antifreeze (at least 30% concentration) to the water. Install a drain valve at the end of the compressed air line to drain condensed water from the line before and after daily restart to prevent freezing and cracking.
5. Equipment shutdown management: During short-term shutdowns (1-2 days), keep the main power to the equipment on to allow the electrical components to dissipate heat and maintain the internal temperature. During long-term shutdowns (3 days or more), in addition to draining the water and air lines, apply anti-rust oil to the mold cavity, guide pins, and other areas to prevent low-temperature corrosion.
