Process control of PET plastic bottle:
(1) drying and preheating of PET raw materials: the drying temperature is about 170 ℃, and the drying time is 4h-5h, otherwise the mechanical properties and transparency will be affected.
(2) injection molding (barrel temperature and injection pressure) - the barrel temperature is about 280 ℃, which is not easy to exceed 285 ℃. Otherwise, acetaldehyde is easy to be produced, and the pressure is kept at 0.4-0.5mpa. If the pressure is kept too high, the transparency will be reduced; the cooling of the bottle will be fast, or the transparency will be affected.
(3) bottle temperature adjustment: the temperature is required to be 95 ℃, the orientation temperature is too low, the bottle stress is white, and the bottle with too high temperature appears crystal fog.
(4) stretch blow molding: suitable mold, control the stretch ratio, control the air blowing rate, pressure holding time and exhaust before opening.