What are the injection molding conditions for PET cosmetic lotion bottles?
1、Barrel temperature. PET’s molding temperature range is narrow, and the temperature will directly affect the performance of the product. If the temperature is too low, the participation is not good, resulting in defects such as depression and lack of material in the plastic parts; conversely, if the temperature is too high, it will cause edge overflow, nozzle mouth flow, color darkening, mechanical strength reduction, and even degradation. The general barrel temperature is controlled at 240~280℃, and the barrel temperature of glass fiber reinforced PET is 250~290℃, not more than 300℃. Nozzle temperature is generally 10~20℃ lower than the barrel temperature.
2、Mold temperature. Mold temperature directly affects the cooling speed and crystallinity of the melt. Different crystals mean different performance of plastic parts. General mold temperature control at 100 ~ 140 ℃. When molding thin-walled plastic parts, it can be of a small value; when molding thick-walled plastic parts, it can be of large value.
3. Injection pressure. PET melt fluidity is good and easy to mold. Generally using medium pressure, the pressure is 80~140MPa. The injection pressure of glass fiber reinforced PET is 90~150MPa. The determination of injection pressure should consider the viscosity, type and quantity of PET.
