the mold heating temperature is too high → reduce the heating temperature of the warmer, generally set: 280 ~ 285 ° Cį. the screw back pressure is too large → under the premise of quality will be back pressure, generally set: 400 ~ 600 PsiĮ. poor drying effect → check whether the dryer is normal, maintain the dryer, check the dry bead use time (usually 2 to 3 years replacement)ĭ. raw materials storage time is too long → raw materials to achieve first-in-first-out methodī. → Check the position of the suction plate and the lip of the plate (generally set to: 22mm)Ī. The position of the take-up plate is not correct. the lip ejection position / pressure is too large → adjust the ejection position / pressure to the appropriate stateĮ. remove the plate suction tube damaged → replace the damaged suction tube or repairĭ. mold damage → replace damaged parts or repairĬ. Surface scratches (embroid body / thread)Ī. the cooling time is too short → lengthen the cooling time (usually set to 3 ~ 4 S)Ĥ. the mold cooling water temperature is too high → check the cooling cycle water temperature (9 ~ 11 ° C ± 2 ° C)Į. the injection speed is too fast → appropriate to reduce the injection speed (usually 3.5 ~ 4 S when injected)ĭ. the screw back pressure is too large → adjust the screw back pressure to the appropriate pressureĬ. The screw temperature is too high → adjust the screw temperature appropriatelyī. Wall thickness change rate is too largeĪ. the raw material stays in the screw for too long → empty the raw material of the barrelģ. the mold temperature is too high → the temperature is reduced to the appropriate temperature (275 ~ 280 ° C)ĭ. the temperature of the barrel is too high → the temperature is lowered (generally, the preform does not produce a white fog temperature increase of 2 ~ 5 ° C) is the normal temperatureĬ. → The over-dried material is discharged, and the material is dried again.ī. The drying time is too long/the temperature is too high. the cycle time is too long → optimize the cycle time (to avoid the raw material staying in the screw for too long)Ī. the screw back pressure is too high → set the back pressure under the premise of quality (400 ~ 600Psi)Į. the barrel heating temperature is too high → under the premise of ensuring the quality, try to reduce the temperatureĭ. poor drying effect → check the operation of the dryer (such as: dew point, drying temperature / time)Ĭ. → The quality of raw materials is checked before entering the warehouse.ī. The quality of raw materials has quality problems.
Reasons and solutions for common quality defectsĪ.
(Optimization of the cycle to ensure that the average temperature of the mold is appropriate)ħ. Mold position setting that allows the robot to enter Injection speed and maximum pressure limit
PET PREFORM MOLD HOW TO
How to proceed to optimize the production cycleĪdjustment of the distance between the take-up plate and the ejector plate (essentially caused by oxidative degradation of PET) AA (Acetaldehyde) increase in acetaldehyde The ideal moisture content after drying is approximately: 10to40 ppm (/- 10 ppm), ie 0.001-0.004%
The most complete PET preform quality defect solution in history The moisture content of the raw material granules usually ranges from 0.1 to 0.3% (1000 to 3000 ppm). Third, the water absorption characteristics of PET Prepare for high temperature preparation for PET into the injection molding machine for shear plasticization. (essentially caused by hydrolytical degradation of PET)ī. It has an influence on the pressure resistance of the beverage bottle and is easily broken. – IV (Intrinsic Viscosity) viscosity drop. The odor of the beverage bottle causes the beverage to taste (but has little effect on the human body) – AA (Acetaldehyde) an increase in acetaldehyde. High levels of water are exacerbated in production: Second, why should the PET material be dried before the production of the preform?īecause PET has a certain water absorption, it absorbs a lot of water during transportation, storage and use. * The most complete PET preform quality defect solution in history * Excellent strength properties, and can be further improved by biaxial stretching. * No toxic gases will occur when burning. * Good hygiene, PDA – recognized by the largest chemical laboratory in the United States. * Excellent chemical resistance, with acid as the head is almost resistant to all organic drugs. * Excellent fragrance retention and good air tightness. * Excellent transparency of over 90%, excellent surface gloss and a glassy appearance. Is the abbreviation of English PolyethyleneTerephthalate PET （Polyethylene terephthalate） is one kind of polyester
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