Because PET macromolecule contains lipid group, it has certain hydrophilicity. Particles are sensitive to water at high temperature. When the moisture content exceeds the limit, the molecular weight of PET decreases and the finished product becomes colored and brittle. Therefore, it is necessary to dry the material before processing. The drying temperature is 150 C, more than 4 hours, generally 170 C, 3 - 4 hours. Air-firing can be used to check whether the data is completely boring. Generally, the share of recycled materials should not exceed 25%, and the recycled materials should be completely dull.
Because PET has a short stable time after melting point and a high melting point, it is necessary to choose an injection system with more temperature control sections and fewer self-conflict heat during plasticization, and the practical component of the finished product (water-containing mouth material) of the cosmetic packaging bottle manufacturer should not be less than 2/3 of the injection volume of the machine.
PET bottle embryo is usually formed by warm runner mould. There must be a heat insulation plate between the mould and the injection machine template. Its thickness is about 12 mm, and the heat insulation plate must be able to accept high pressure. Exhaust must be sufficient to prevent partial overheating or fragmentation, but the exhaust outlet depth should not exceed 0.03 mm, otherwise the flash will occur simply.
The injection rate should be fast to prevent premature solidification during injection. However, too fast and high shear rates make the material vulnerable, usually within four seconds.
We can finish all the processes inside our own facility from mold design, tooling making, injection, bottle blowing, spraying, silk screen, hot stamping, vacuum metallization , digital printing, laser etching, ultrasonic welding to final assembling.