Blow Molding Machine Operation Procedures, Common Problems, and Solutions

Blow Molding Machine Operation Procedures, Common Problems, and Solutions

Poor Bottle Transparency - Causes: 1. Excessively high heating temperature or prolonged heating time; 2. Moisture in compressed air; 3. Opaque injection preform tube itself; 4. Inappropriate preform tube design; 5. Insufficient blow-up ratio. Solutions: 1. Lower the temperature and shorten the heating time; 2. Remove moisture using a dryer; 3. Improve preform tube quality by selecting appropriate materials and increasing raw material dryness; 4. Adjust the preform tube size design; 5. Reduce the preform tube diameter.

Uneven Bottle Wall Thickness - Causes: 1. The stretching rod is not centered on the preform tube; 2. Asymmetrical air holes with inconsistent diameters; 3. Insufficient stretching ratio or insufficient blow-up ratio; 4. The preform tube does not rotate in the heating furnace; 5. Uneven preform tube wall thickness or uneven injection density. Solutions: 1. Adjust the position of the stretching rod, and adjust the position and diameter of the air holes; 2. Increase the stretching ratio or blow-up ratio; 3. Check the rotation device and improve preform tube quality.

Bottle bottom too thin -

Causes: 1. Initiating air blowing too early; 2. Bottom temperature too high; 3. Preform tube bottom too thin. Solutions: 1. Delay initiating air blowing; 2. Lower bottom temperature; 3. Increase preform tube bottom thickness.

Bottle parting line obvious -

Causes: 1. Insufficient parting pressure; 2. Sealing too early; 3. Mold problem, preform tube thread size does not match mold fit. Solutions: 1. Increase parting pressure, adjust parting strut angle (<5 degrees); 2. Move parting limit switch position backward; 3. Repair mold or check mold assembly position, such as whether guide pillars are loose, or whether mold is not tightened; 4. Repair mold thread fit.

Bottle bottom curled up, material accumulation -

Causes: 1. Initiating air blowing time too long; 2. One curled, the other good; 3. Temperature too low at the accumulation point; 4. Unstable operating air pressure, affecting the lowering speed of the tension rod. Troubleshooting Methods:

1. Shorten the blowing time or reduce the descent speed of the stretching rod;

2. Reduce the air volume on one side of the bottle winding;

3. Increase the heating temperature of the preform tube at that point;

4. Add an air tank to the operating air source or shorten the air supply line.

Bottom Misalignment -

Causes:

1. The stretching rod speed is too slow;

2. Insufficient blowing time;

3. Severe preform eccentricity.

Solutions:

1. Adjust the throttle valve on the stretching cylinder to its maximum;

2. Increase the blowing time;

3. Measure the preform tube eccentricity (a large eccentricity will cause the preform tube to bend when heated to a higher temperature);

4. Include a temperature protection function.

1. Before familiarizing yourself with the machine's performance and operating sequence, you must first read the instruction manual to understand the machine's performance and operating procedures. Only operate the machine after you are familiar with it.

2. Before starting the machine, check if the hydraulic oil level is above 2/3 of the gauge reading. If not, add the same type of hydraulic oil.

3. Before starting the machine, check if the manual oil pump is empty. If it is, add the same type of lubricating oil to the mark. Manually press the oil pump handle until oil seeps from each lubrication point.

4. Do not start the machine if the protective cover is not in place or if the equipment is malfunctioning.

5. Do not start the machine if the door is not closed.

6. Do not start the machine before removing any debris, especially from moving parts.

7. Check if the water pressure in the cooling system is between 2 and 6 kgf/cm².

8. Check the electrical components for short circuits or leaks, check for any openings in the oil lines, and check if anyone is working on the machine frame. If so, remove the affected areas before operating the machine.

9. Before each start-up, preheat the barrel head until it reaches the set temperature and maintain this temperature for at least 5 minutes before starting the machine.

10. Before starting the machine, turn on the air pump and ensure the air pressure reaches 5 to 8 kgf/cm².

11. When starting the machine, except when installing molds, no two people should operate the machine simultaneously to avoid accidental operation. Before starting, ensure there are no personnel in the danger zone. During trial operation, press the start button and remove your fingers only after observing normal operation.

12. Set the corresponding product operating parameters according to the "Process Card". Check important processes every two hours and record the results on the production process monitoring card.

13. During startup, if a malfunction or other problem occurs, stop the machine immediately and notify the equipment maintenance personnel for inspection.

14. While the machine is running, no personnel are allowed to enter the danger zone inside the doors or protective railings or to troubleshoot.

15. After starting the machine, check the pressure. The system pressure must not exceed 140 kgf/cm², and the normal operating pressure must not exceed 100 kgf/cm². The accumulator adjustment pressure must not exceed its value. Check if the heating system temperature is within the set range; the deviation should generally not exceed ±10℃.

16. When shutting down, put the machine in manual mode and return it to the starting position. Turn off the oil pump and heating switch, and then turn off the main power.