Analysis of Common Problems of Pet Blow Molding Machine

Publish Time:
Xinsen Machinery
Question 1 PET bottle transparency is not good.Question 2 The PET bottle appears pearly luster and white.Question 3 The position of the nozzle at the bottom of the PET bottle is offset.Question 4 Uneven wall thickness of PET bottles.

Question 1 PET bottle transparency is not good 

reason:

1. The heating temperature is too high. 2. The heating time is too long. 3. The compressed air contains water. 4. The  preform itself is opaque. 5. The design of the preform is not suitable. 6. The expansion ratio is too small.

Elimination method :

1. Cool down 2. Shorten the heating time 3. Use a dryer to remove water 4. Improve the quality of the preform, select materials and increase the dryness of the raw material 5. Improve the design of the preform size 6. Reduce the diameter of the preform

water bottle

Question 2 The PET bottle appears pearly luster and white

reason:

1. The heating temperature is too low 2. The wall thickness of the embryo tube is uneven 3. The thickness of the preform is too thick, and the heating and penetration are insufficient

Elimination method :

1. Heat up or slow down the revolution speed 2. Improve the quality of the preform 3. Reduce the thickness of the preform, or try to increase the outer cover of the heating device to increase the surface temperature of the preform

product line of water bottle

Question 3 The position of the nozzle at the bottom of the PET bottle is offset

reason:

1. The blowing time is too early 2. The stretching rod is not down to the end 3. The stretching rod is offset from the center line of the bottle axis 4. The preform wall thickness is uneven or the injection density is uneven 5. The heating is uneven

Elimination method :

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 preform. 5. Improve the heating conditions.

water bottle machine

Question 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 pore diameters are not uniform. 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. The wall thickness of the embryo tube is not Uniform or uneven injection density

Elimination method :

1. Adjust the position of the stretching rod 2. Adjust the position and aperture of the blowing hole 3. Increase the stretching ratio or inflation ratio 4. Check the rotation device 5. Improve the quality of the preform