8 common faults and troubleshooting methods of blow molding machines

8 common faults and troubleshooting methods of blow molding machines:

Fault 1: PET bottle transparency is not good

reason:

1. The heating temperature is too high

2. Heating time is too long

3. Compressed air contains water

4. The injection embryo tube itself is opaque

5. The embryo tube design is not suitable

6. The inflation ratio is too small

Method of exclusion:

1. Cool down

2. Shorten the heating time

3. Use a dryer to remove water

4. Improve the quality of embryo tube, select materials and increase the dryness of raw materials

5. Improve the design of embryo tube size

6. Reduce the diameter of embryo tube

Trouble 2: The PET bottle appears pearly luster and white

reason:

1. The heating temperature is too low

2. Uneven wall thickness of embryo tube

3. The embryo tube is too thick, and the heating and penetration are insufficient

Method of exclusion:

1. Heat up or slow down the revolution speed

2. Improve embryo tube quality

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

Fault 3: The position of the bottom nozzle of the PET bottle is offset

reason:

1. Start blowing too early

2. The stretch rod is not down to the end

3. Offset between the stretching rod and the center line of the bottle axis

4. The embryo tube wall thickness is uneven or the injection density is uneven

5. Uneven heating

Method of exclusion:

1. Delay the blowing time or increase the descending speed of the stretching rod

2. Adjust the position of the magnetic pole switch

3. Adjust the position of the stretch rod

4. Improve embryo tube quality

5. Improve the heating conditions, or check whether there is any problem with the rotation of the embryo tube

Fault 4: uneven wall thickness of PET bottles

reason:

1. The position of the stretching rod is not in the center of the embryo tube

2. The blowing holes are asymmetrical and the hole diameters are different

3. The stretching ratio is too low or the expansion ratio is too small

4. The embryo tube does not rotate in the heating furnace

5. Uneven embryonic tube wall thickness or uneven injection density

Method of exclusion:

1. Adjust the position of the stretch rod

2. Adjust the position and diameter of the blowing hole

3. Increase the stretching ratio or inflation ratio

4. Check the rotation device

5. Improve embryo tube quality

Fault 5: The upper part of the bottle is too thick

reason:

1. The upper temperature is too low

2. The position of the mold vent hole is too far from the upper part

3. The stretching ratio is too low

4. The inflation ratio of the upper part of the bottle is too low

5. The stretching rod speed is too slow

Method of exclusion:

1. The upper part is heated

2. Adjust the position of the vent

3. Increase the stretching ratio

4. Change the shape of the bottle

5. Adjust the speed of the stretching rod

Fault 6: The bottom of the bottle is too thin

reason:

1. Start blowing too early

2. The bottom temperature is too high

3. The bottom of the embryo tube is too thin

Method of exclusion:

1. Delay the start of blowing time

2. Lower the bottom temperature

3. Increase the thickness of the bottom of the embryo tube

Fault 7: The bottle clamping line is obvious

reason:

1. Insufficient clamping pressure

2. The sealing time is too early

3. Mold problem

4. The size of the germ tube tooth mouth does not match the mold

Method of exclusion:

1. Increase the clamping pressure and adjust the angle of the clamping support rod (<5 degrees) 2. Move back the position of the mold clamping stroke switch 3. Repair the mold or check the assembly position of the mold, such as whether the guide post is loose, or whether the mold is not tightly pressed 4. Repair the matching position of the mold teeth Fault 8: The bottom of the bottle or the bottleneck is rolled up, and the material accumulates reason: 1. The delayed blowing time is too long 2. One roll, one good 3. The temperature at the material accumulation is too low 4. The air pressure for the action is unstable, which affects the descending speed of the stretching rod Method of exclusion: 1. Shorten the delayed blowing time or reduce the descending speed of the stretching rod 2. Lower the gas volume on one side of the reel bottle 3. Increase the heating temperature of the embryo tube 4. Add a gas storage tank to the action gas source, or shorten the gas supply pipeline