Whether it is high-density polyethylene bottles, polypropylene bottles, polyester bottles, injection molding of preforms and blow molding of bottles, the injection molding temperature high-density polyethylene is controlled at 160-220 degrees. The polypropylene is controlled at 170-230 degrees, and the polyester is controlled at 260-290 degrees. The actual control depends on the specific conditions of production, and the blank mold is cooled by cooling water. The cooling of the blank pipe thread should be more sufficient. The compressed air pressure used for blow molding is controlled at 0.5~0.8MPa, the temperature of the blown tube of polyester bottle should be controlled at about 90 degrees, and the pressure of compressed air should be controlled at 2~2.5MPa.
Pharmaceutical bottle production process condition
In the production of polyester medicinal plastic bottles, attention should be paid to the drying of raw materials. The moisture content of Weijiang dried polyester is generally about 0.4%. The presence of moisture will cause defects such as bubbles and silver whit, especially in forming. The high temperature will cause the viscosity to decrease, which affects the strength of the product. Therefore, it is necessary to dry the polyester before molding. Under normal conditions, it is dried for about 5 hours at a temperature of about 160 degrees to reduce the moisture content to 0.01%. In the following, the dried raw materials that have not been used in time should be sealed and stored in order to avoid re-absorption of water.