1. Before injection molding, the material must be dried for three to four hours to prevent excessive moisture content from significantly compromising the quality of the finished preforms.
2. Thermal insulation plates should be installed between the injection molding machine platens and the preform mold; adequate venting must be ensured during the injection process to prevent cracking.
3. The melt temperature should be controlled between 270°C and 295°C; this can be verified using the "air shot" method during the process.
4. The injection phase should be rapid, with the injection time kept within four seconds.
5. Back pressure should be maintained below approximately 100 bar to prevent wear issues during the molding process.
6. Residence time for the material should not be excessive; for downtime of 15 minutes or less, a simple air shot suffices, whereas for longer periods, a high-viscosity PE (polyethylene) purge material should be used to clear the barrel.