PET stretch blowing machine common problems solutions see as below:
| No. | Forming situation | Reason | Solution |
| 1 | Roll up or buildup at the bottom or neck of bottle | Delay minor blowing time too long | Shorten the delay minor blowing time |
| Temperature too low at the place where buildup | Raise the heating temperature at corresponding place in tube blank | ||
| 2 | Deformation at bottleneck | Blank head overheat | Check cooling water circulating |
| Temperature of 1st segment heating lamp too high | Reduce the voltage of 1st segment heating lamp | ||
| Air circulation not equal in heating case | Check the ventilator fan in heating case. | ||
| 3 | Bottom of the bottle too thick | Preheat of bottle bottom not finished | Raise temperature of heating case |
| Blowing too late | Blowing in advance | ||
| Advance blowing pressure too low | Increase advance blowing pressure | ||
| 4 | bottle bottom broken | Humidity not enough, permeation not enough | Increase humidity |
| Delay stretching time too long | Shorten delay stretching time | ||
| Extension ratio too large | Reduce extension ratio | ||
| Bottom of tube blank too thin | Improve bottom design of tube blank | ||
| 5 | Buckling in bottle bottom | Temperature of bottom too high (poor cooling in sprue) | Reduce the temperature of bottle bottom properly |
| Advance blowing too late | Advance blowing 0.1～0.2s ahead | ||
| Blowing time too short | Longer blowing time 0.1～0.2s for 1 to 3 times | ||
| Advance blowing pressure too low | Increase advance blowing pressure | ||
| 6 | Bottle bottom not full | Temperature of bottle bottom too low | Increase the temperature of bottom of heating area |
| No enough air release hole or not equal at the bottle bottom of mold | Add air release hole and make them distribute equally. | ||
| Design of stretching rod head not corresponding with the shape of bottom of tube blank | Replace stretching rod head | ||
| Blowing pressure not enough | Increase blowing pressure | ||
| rate of flow not enough at blowing valve | Wash blowing valve by gasoline | ||
| Blowing time too short | Increase blowing time | ||
| 7 | Decentration on bottle bottom | Related to bottle blank temperature, advance blowing, high pressure blowing etc. | Reduce temperature of bottle blank; faster stretching speed; check the gap between stretching head and bottom mold; delay advance blowing, and reduce advance blowing pressure; delay high pressure blowing; check whether bottle blank decentration |
| Stretching too short | Make sure the stretching rod leave bottle bottom for 0.1mm | ||
| Delay minor blowing time too short | Increase delay minor blowing time | ||
| 8 | Bottom become white | Temperature too high | Reduce temperature |
| Bottle blank too cold | Raise the temperature of bottle blank | ||
| The weight of bottle blank is too light | Add weight of tube blank | ||
| Stretching rod shifted from the centre line of bottle | Adjusting the position of stretching rod | ||
| Advance blowing too late, advance blowing pressure too low | Increase advance blowing pressure | ||
| Stretching rod didn’t reach the bottom | Adjusting the position of magnet ring switch | ||
| Temperature too high | Reduce temperature | ||
| Thickness of tube blank is not equal | Improve the quality of tube blank | ||
| Injection density is not equal | Improve the heating | ||
| Heating not equal | Check whether the rotation of tube blank has problem | ||
| 9 | Bottle bottom too thin | Blowing too earlier | Delay blowing time |
| Temperature of bottom is too high | Reduce temperature of bottom | ||
| Bottom of tube blank is too thin | Increase the thickness of bottom of tube blank | ||
| 10 | Bottle sticked on the base mold | The time of mold closing and base mold raising is not synchro | Faster the raising time for base mold |
| Plastic blowing time is too short | Longer the plastic blowing time | ||
| 11 | Buckling at the middle of bottle | Blowing time is too short | Longer blowing time 0.1～0.2s for 1 to 3 times |
| Temperature of middle of bottle is too low | Increase the temperature of middle of bottle properly | ||
| 12 | Crack at the middle of bottle just after blowing | Whole temperature of tube blank is too low | Increase the temperature of whole oven tunnel, increase properly the voltage of infrared lamp from 1st segment to 7th segment |
| Delay minor blowing time is too long | Shorten delay minor blowing time | ||
| Temperature difference of every part of bottle blank is too large | Heating equably | ||
| 13 | Bottle blank sticked on the stretching rod | No minor blowing or high pressure air source | Adjust minor blowing and high pressure air source |
| Blowing valve not working | Check whether blowing valve connected power, whether industry blowing valve opened | ||
| 14 | Bottle blank stretched longer, but not expanded | No high pressure air source | Open high pressure air source |
| Blowing time is too short | Longer blowing time | ||
| 15 | Upper part of bottle is too thick | Temperature of upper part is too low | Increase temperature at upper part |
| the position of air release hole of mold is far from upper part | Adjusting the position of air release hole | ||
| Extension ratio is too low | Increase extension ratio | ||
| Blowing ratio of upper part of bottle is too low | Change the shape of bottle | ||
| The speed of stretching rod is too slow | Adjusting the speed of stretching rod | ||
| 16 | Obvious mold closing line | The pressure for mold closing is not enough | Increase the mold closing pressure, adjust the angle of support rod for mold closing (<5̊) |
| Sealing is too earlier | Move backward the position of position switch of mold closing | ||
| 17 | Mold closing line with different size | Mold closing is too loosing | Lock tightly the mold base |
| 18 | Whole bottle turbid and not transparent | Whole temperature of bottle blank is not enough | Increase whole temperature |
| 19 | The transparent of bottle is not good | Heating temperature is too high | Reduce the temperature |
| Heating time is too long | Shorten the heating time | ||
| moisture in the compressed air | Removing moisture by dryer | ||
| The tube blank is not transparent itself | Improve the quality of tube blank, select to use material and improve the dryness of material | ||
| Tube blank design not proper | Improve the size design of tube blank | ||
| The blowing ratio is too small | Reduce the diameter of tube blank | ||
| 20 | pearly luster and whiten on the bottle | Heating temperature is too low | Raise temperature or slower the rotation speed |
| The thickness of tube blank is unequal | Improve the quality of tube blank | ||
| The thickness of tube blank is too thick, heating permeation not enough | Reduce the thickness of tube blank, or try to raise the cover of heating equipment, so as to increase the temperature distribution on the surface of tube blank | ||
| 21 | There is prints on the bottle | The quality of tube blank is not good | Check the quality of tube blank |
| Mold not clean | Cleaning the mold | ||
| 22 | Deformation just after leaving mold | Blowing time too short | Increase the blowing time |
| The temperature of cooling water is too high | Reduce the temperature of cooling water | ||
| 23 | Thickness distribution unequal at axial direction | Temperature of tube blank is unequal | Adjusting heating temperature |
| Advance blowing pressure too low or too high | Increase or reduce advance blowing pressure | ||
| Advance blowing too late or too earlier | Earlier or later advance blowing | ||
| 24 | Deformation after a longtime | Bottle blowing pressure too low | Increase bottle blowing pressure |
| Bottle blowing too short | Longer the bottle blowing time | ||
| 25 | Bending when heating bottle blank | Rotation wrongly when heating bottle blank | Make sure whether touch or hit aluminium baffle-board, etc. |
| Overheat at partial of bottle blank | Adjusting the output of heater | ||
| Pimple on the bottle blank | Check whether the bottle blank is qualified | ||
| 26 | Volume of produced bottle not enough | didn’t blowing to form shape | Check whether there is jam at the outlet |
| Air pressure not enough for plastic blowing | Check the air circuit and supply source for plastic blowing |
Are You Looking for PET Stretch Blowing Machine? Our Company Winiber Offers Whole PET Bottle Product Line. Contact With Us Now!
Comments are closed.