Introduction of blow molding machine and answers to common questions about blow molding

Bottle blowing machine introduction

1. The type of blow molding machine. At present, the two-step PET blow molding machine includes a rotary automatic blow molding machine, a linear automatic blow molding machine, and a manual semi-automatic blow molding machine.

2. The structural part of the bottle blowing machine is replaced by a preform lifting system, a preform management system, a blank separation system, a transmission system, a heating system, a bottle blowing system, and a bottle taking system (such as mold base, stretching, and blowing).

3. Associated equipment, the blow molding machine action is changed from the low pressure air compressor system (air compressor host, air storage cylinder, filter system, refrigeration and dryer) supply and electric mode (servo motor) supply, blowing bottle supply mainly uses high pressure air Compressor system (main unit of high-pressure air compressor, storage cylinder, filtration system, refrigerating and drying machine) is also equipped with a chiller (because the blown bottle needs to be shaped quickly
Blowing principle

When the processed PET tube billet reaches a certain temperature after heating, it is stretched and extended again, with two blowing air blowing, two blowing air to maintain pressure, and then exhausting.
Bottle blowing process problems and solutions

Fault 1: PET bottle transparency is absolutely not good Reason: 1. The heating temperature is so high 2. The heating time is too long 3. The compressed air contains water 4. The injection embryo tube itself is absolutely opaque 5. The embryo tube design is absolutely unsuitable 6. The inflation ratio Very small

Elimination methods: 1. Cool down 2. Reduce heating time 3. Use dryer to remove water 4. Improve embryo tube quality, select materials and increase raw material dryness 5. Improve embryo tube size design 6. Reduce embryo tube diameter

Fault 2: The PET bottle appears pearly luster and whitening. Reasons: 1. The heating temperature is too low 2. The wall thickness of the embryo tube is never uniform 3. The thickness of the embryo tube is very thick, and the heating and penetration are insufficient

Remedy: 1. Increase the temperature or slow down the revolution speed 2. Improve the quality of the embryo tube 3. Reduce the thickness of the embryo tube, or try to increase the outer cover of the heating device to increase the surface temperature of the embryo tube

Trouble 3: The position of the nozzle at the bottom of the PET bottle moved westward. Reasons: 1. The blowing time was too early 2. The stretch rod did not go down to the bottom 3. The stretch rod and the center line of the bottle axis moved westward 4. The wall thickness of the embryo tube was never Uniformity or injection density is never uniform5, heating is never uniform

Remedy: 1. Delay the blowing time or increase the descending speed of the stretch rod. 2. Adjust the position of the magnetic pole switch. 3. Adjust the position of the stretch rod. 4. Improve the quality of the embryo tube. 5. Improve the heating conditions. No question

Fault 4: PET bottle wall thickness is not always the reason: 1. The position of the stretch rod is never in the center of the embryo tube 2. The blow hole is absolutely asymmetrical, and the pore diameter is never the same. 3. The stretch magnification is so low or the inflation ratio is very small 4. The embryo tube never rotates in the heating furnace. 5. The wall thickness of the embryo tube or the injection density is never uniform.

Elimination methods: 1. Adjust the position of the stretch rod 2. Adjust the position of the blowing hole and the aperture 3. Increase the stretching ratio or inflation ratio 4. Check the rotation device 5. Improve the quality of the embryo tube

Fault 5: The lower part of the bottle is very thick. Reasons: 1. The temperature of the upper part is too low 2. The position of the mold vent hole is far away from the lower part. 3. The stretching ratio is too low. 4. The inflation ratio of the upper part of the bottle is too low.

Remedy: 1. Heat the upper part 2. Adjust the position of the exhaust hole 3. Increase the stretching ratio 4. Change the shape of the bottle 5. Adjust the speed of the stretch rod. Fault 6: The bottom of the bottle is very thin. Reasons: 1. The blowing time is too early. 2. The temperature at the top is so high. 3. The top of the embryo tube is very thin.

Remedy: 1. Delay the start of blowing time 2. Reduce the top temperature 3. Increase the thickness of the top of the embryo tube

Fault 7: The bottle clamping line is obvious. Reasons: 1. The clamping pressure is never enough. 2. The sealing time is too early. 3. The mold problem. 4. The size of the germ tube and the mold match.

Remedy: 1. Increase the mold clamping pressure, adjust the angle of the mold clamping support rod (<5 degrees) 2. Then move the mold clamping stroke switch position 3. Repair the mold or check the mold assembly position, if the guide post is loose, Or whether the mold has not been pressed tightly Fault 8: The top of the bottle or the bottleneck is rolled up, and the cause of the material accumulation: 1. The delayed blowing time is very long. 2. One roll is good. 3. The temperature at the accumulation place is very low. Extension rod descending speed Remedy: 1. Shorten the delayed blowing time or reduce the descending speed of the stretching rod. 2. Reduce the air volume on the side of the coil. 3. Increase the heating temperature of the embryo tube. 4. Add an air storage tank to the action air source or Is to shorten the air supply line Trouble 9: The bottom of the bottle is stretched and perforated. Reasons: 1. The temperature is not enough and has not penetrated. 2. The extended stretch time is very long. 3. The stretch is higher than that. 4. The top of the embryo tube is very thin. 5. The stretched rod head is very sharp. Elimination methods: 1. Warm up 2. Shorten the delay stretch time 3. Reduce the stretch ratio 4. Improve the design of the top of the embryo tube 5. Round the stretch head Fault 10: Blasting at the bottom of the bottle Cause: 1. The delayed blowing time is very short 2. The delayed mold opening time is very short 3. The temperature is very high 4. The exhaust valve never works Remedy: 1. Lengthen the delay blowing time or increase the descending speed of the stretch rod 2. Lengthen the delay opening time 3. Cool down 4. Use gasoline to clean the exhaust valve Fault 11: The bottom of the bottle is never full. Reasons: 1. The temperature of the bottom of the bottle is very high. 2. The vent hole at the bottom of the mold is insufficient or not uniform. 3. The stretch rod has not reached the top 4. The stretch rod head design is never It conforms to the shape of the top of the embryo tube 5. The blowing pressure is not enough 6. The flow of the blowing valve is not enough 7. The bottom curve design of the bottle is by no means good Remedy: 1. Reduce the temperature at the top of the heating zone or use a damp cloth to lower the temperature at the top of the embryo tube 2. Increase the number of vent holes and make them evenly distributed 3. Adjust the stretch rod to the bottom of the bottle 4. Replace the stretch rod head 5. Increase the blowing pressure 6, use gasoline to clean the blowing valve 7, increase the bottom curve and streamline design of the bottle Fault 12: 1. If the tooth part of the embryo tube is in a specific position, it is also the cause of the uneven thickness of the embryo tube. 2. If the mold clamping line is in a specific position, it is also a mold exhaust problem. 3. The embryo tube is heated. Uneven 4. The design of the top of the mold is definitely not good Elimination methods: 1. Improve the thickness design of the embryo tube 2. Improve the vent on the top of the mold 3. Improve the heating conditions 4. Improve the top design https://www.ruiyingmachine.com/